Machine Shop (Geezer-X)
Moderator: Eric Wallgren
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- Claude Regnier
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Modified Trucks
Eric, could you e-mail me at cerslalom@msn DOT com regarding the trucks from the Farm race.
We could make arrangements for North Carolina.
We could make arrangements for North Carolina.
Many Happy Pumps!
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- Adam Daniels
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Mr. Wallgreen,
How much would it cost (about) to take a 110mm rtx and trim it down to 90mm but have an axle that can still be spaced to 110mm?
thanks
i ask this because i have a split fire ds90 in the rear and wanted to know if a trimmed rtx would work in the front. is it ok to mix brands or would another ds 90 in the front be better?
How much would it cost (about) to take a 110mm rtx and trim it down to 90mm but have an axle that can still be spaced to 110mm?
thanks
i ask this because i have a split fire ds90 in the rear and wanted to know if a trimmed rtx would work in the front. is it ok to mix brands or would another ds 90 in the front be better?
No vestido para mi


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- Old LaCosta Boy
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Kuhl!!!!
Mig,
Thanks for the pics, they gave my wife quite a laugh. And let it be known that Geezer bailed on the Hester model when the going got tough. But since he beat me on the other board I wish he would have stuck with the Hester!!!!!
Thanks for the pics, they gave my wife quite a laugh. And let it be known that Geezer bailed on the Hester model when the going got tough. But since he beat me on the other board I wish he would have stuck with the Hester!!!!!
La Costa Boy For Life
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- Fatboy
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- Old LaCosta Boy
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Hey Geezer,
Just thought I'd drop you a line to tell you that I really enjoyed meeting you and racing you in the vintage at the Farm. Not a day goes by, especially when I am in the suit & tie at work, that I don't think back to the Farm.
We/I need to find anyone that has a pic of you in the blue and me in the red sweatsuits in 90 degree heat racing for the pure fun of it. It makes me smile just thinking about it.
Hey BTW, You coming down to Marion's race in November?
BTW X 2, I don't know what the rest of you guys did, but I had my number framed and it now graces the wall of my office. A true Tway's mom memorial.........
C-ya at the next one.
Just thought I'd drop you a line to tell you that I really enjoyed meeting you and racing you in the vintage at the Farm. Not a day goes by, especially when I am in the suit & tie at work, that I don't think back to the Farm.
We/I need to find anyone that has a pic of you in the blue and me in the red sweatsuits in 90 degree heat racing for the pure fun of it. It makes me smile just thinking about it.
Hey BTW, You coming down to Marion's race in November?
BTW X 2, I don't know what the rest of you guys did, but I had my number framed and it now graces the wall of my office. A true Tway's mom memorial.........
C-ya at the next one.
La Costa Boy For Life
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- Venezuelan Racer
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- Location: Stamford, CT and Venezuela in the heart
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Geezer are you still making this modification? 8mm straight axles on TTCs?
Last edited by Leonardo Ojeda on Fri Sep 02, 2005 6:46 am, edited 1 time in total.
"I`ll see you at the end of the hill"
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- Pat C.
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"Geezerized" Metal Seismics with 8mm axles?
How do I get some of these?
-- Pat
-- Pat
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- Pat C.
- Posts: 1400
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Just finished my 8mm axle upgrades.
I just finished up some 8mm axle upgrades to 4 trucks today in the machine shop at work.
I faced the hangers square to the axles, turned some 8mm axles, pressed them into the hangers.
3 of 4 are true as can be. The 4th one has a slight bend to the axle when it is pressed into the hanger, but not when the axle is free by itself. I guess the hanger has an untrue hole in it.
Can't wait to try them out.
-- Pat
I faced the hangers square to the axles, turned some 8mm axles, pressed them into the hangers.
3 of 4 are true as can be. The 4th one has a slight bend to the axle when it is pressed into the hanger, but not when the axle is free by itself. I guess the hanger has an untrue hole in it.
Can't wait to try them out.
-- Pat
Modifications
Geez, please call me. 703-930-1044. Modifications needed.
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Phony Grade 8 Kingpins?????
Hey! Speaking of foreign made flim-flam, I recently bought some 3/8" bolts grade 8 to replace king-pins(you know, for the 2 1/4" length), I had to buy 2 1/2" long bolts and cut them, when I did with a USED hacksaw, they did'nt seem any harder than my memory of cutting grade 5 bolts of the same size. The box in the tray said "may contain items from India, Indonesia, China,......". I thought they'd be harder to cut than they were and it made me wonder if there was some metalurgical shenanigan afoot. They were gold/brass sorta colored and stamped with the same markings as the 2" kingpins in the baseplates from stock Trackers. Anyone have any thought s on the matter? Am I at much risk cranking cones at 165+/- lbs? I already put replacement Grade 5's in and repounded them out (with a hammer on a wood stump) to put these Grade 8's in so I'm wondering if I'm causing a risk to the baseplates (Tracker RT baseplates) by putting in a new set of "true" USA made Grade 8's (which would be the 3rd set of kingpins for some of these hangers). Thanks - Paul H.
I just dig slalom!
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- Geezer-X
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remodification
Geez, I need to talk to you about a remodification on my already re-axled Tracker s's and x's. I need one set turned into a halftrack width and one turned into a mid track width. Can ya do it?
PA Dan get some real trucks.
PA Dan get some real trucks.
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.....and now for something completely different.......
Hey Eric,
Have you been successful putting straight 8mm axles in the metal Seismics?
If so, I can keep you busy for a while
Dan
Have you been successful putting straight 8mm axles in the metal Seismics?
If so, I can keep you busy for a while

Dan
Dan Mitchell, aka PA Dan
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- Geezer-X
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I made the assumption (Samuel Jackson in Pulp Fiction.. "When you assume, you make ass out of You, and Umption") That we were discussing skateboard wheels. Typically, the space between the bearing seats is about .390" give or take, and most bearing spacers are about .400". Assuming (again) that a 608 bearing is 7mm wide, both the inner and outer races, that means that the bearing, in a static condition, has ZERO preload. No matter how loose or tight the axle nuts are. I design and fabricate automated laboratory instrumentation, some of which needs to be really, really precise and repeatable, and I have yet to resort to preloading ball bearings to mitigate runout. Now, if we were to discuss the wheel bearings on my Austin Healey, the spindle bearings on my ancient lathe, or the headset, bottom bracket, and hub bearings of my many old and interesting bicycles, we could add preload to the list of topics. If you were clever, you'd lock your bearings in to you wheel hubs, so that while turning, you divided the lateral load equally between the inner and outer bearings, rather than just loading the bearings on the inside of the turn, the way our lame, underdeveloped skateboards work today. The other advantage of Biltins, is that the "spacer", being integrated with the bearing's inner race, assures nice coplaner alignment between the axis of the races when you honk down on the nuts real good.
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I'll check to see if he has tested Oust. So far all I've heard is that he looked at them (the photos?) and said the design is the right idea but he feels they are way overpriced and most likely are from China (since if they weren't Oust would surely trumpet that fact).
BTW, he's not an NMB employee. He used to work for a bearing company that supplied many of the skate bearings you see on the market. He tells stories of big shipments of Chinese bearings coming to that company for like $0.15 per. They'd put the shields on for the different "cool" brands (Speed Demon, Pig Abec 5, Black Beauties, etc.). The skate bearing "companies" would buy them for $.35 a bearing. Kids would then be tricked into buying them as something they were not in skateshops for like $20 a set.
Anyway, these days he doesn't participate in those shinanigans and has his own company called California Bearing (http://www.californiabearing.com/). It is not a skateboard bearing company and I'm sure he sells more bearings in an hour to the government than he sells to skateboarders in a year. He simply chose NMB to produce bearings for skateboarding to his specs. He then washes them all in his certified clean room and relubes with his own lube. He says good things about Bones Swiss, (which are apparently still made by WIB in switzerland even though the company was sold to NSK and then to the Canadian company Roto Precision), and Ninja bearings that are made by a quality bearing manufacturer in Japan. So I don't doubt he will praise Oust if they perform well in the measurements and tests he performs
FWIW, recent measurement of Biltin showed that the Abec 7 model measure out to the same as the Abec 3 Biltins. Similarly, the Pleasure Tools Abec 7 has tolerances in the 3 range as well. He says this is common with the Chinese bearings and that Chris and Ed may not even know that their suppliers are burning them. But that's what they get for dealing with the Chinese industry I guess.
-Rich
BTW, he's not an NMB employee. He used to work for a bearing company that supplied many of the skate bearings you see on the market. He tells stories of big shipments of Chinese bearings coming to that company for like $0.15 per. They'd put the shields on for the different "cool" brands (Speed Demon, Pig Abec 5, Black Beauties, etc.). The skate bearing "companies" would buy them for $.35 a bearing. Kids would then be tricked into buying them as something they were not in skateshops for like $20 a set.
Anyway, these days he doesn't participate in those shinanigans and has his own company called California Bearing (http://www.californiabearing.com/). It is not a skateboard bearing company and I'm sure he sells more bearings in an hour to the government than he sells to skateboarders in a year. He simply chose NMB to produce bearings for skateboarding to his specs. He then washes them all in his certified clean room and relubes with his own lube. He says good things about Bones Swiss, (which are apparently still made by WIB in switzerland even though the company was sold to NSK and then to the Canadian company Roto Precision), and Ninja bearings that are made by a quality bearing manufacturer in Japan. So I don't doubt he will praise Oust if they perform well in the measurements and tests he performs
FWIW, recent measurement of Biltin showed that the Abec 7 model measure out to the same as the Abec 3 Biltins. Similarly, the Pleasure Tools Abec 7 has tolerances in the 3 range as well. He says this is common with the Chinese bearings and that Chris and Ed may not even know that their suppliers are burning them. But that's what they get for dealing with the Chinese industry I guess.
-Rich
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- Phoenix, AZ, USA
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Rich, curious about the OUST test/comparison? Any word yet?Rich Stephens wrote:I'll report what he finds. I've heard a lot of good things about Oust.
FWIW, the free spin timing test is not very accurate for comparing bearings. What matters is how the bearings work when they have our body weight on them. I'll report on the methodology used to test them in the lab when I find that out.
-Slim
Thanks.
"UP" grades.. tho derogatory to gravity sports
I had Eric cut down and off-set a Randal for me a few years back..It turned out to be a wickedly turny truck. I have recently sent off a box of RTX/TTC for him to put his magic to! True 8mm axles make the difference that nothing else can!! Wes E hit it on the mark re: loads Do yourself a favor,and make Geezer X work overtime.
ENJOY!! (while you can)
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Modified Trucks
Hey Geez, I got my trucks back, I've only ridden one set, but I'm impressed, nice work, really nice. I'll probably send you some more. Thanks Lots - Paul Howard
I just dig slalom!
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I'll report what he finds. I've heard a lot of good things about Oust.
FWIW, the free spin timing test is not very accurate for comparing bearings. What matters is how the bearings work when they have our body weight on them. I'll report on the methodology used to test them in the lab when I find that out.
-Slim
FWIW, the free spin timing test is not very accurate for comparing bearings. What matters is how the bearings work when they have our body weight on them. I'll report on the methodology used to test them in the lab when I find that out.
-Slim
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- Phoenix, AZ, USA
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Please do consult with your friend. I would venture a guess that he has already done the test with OUST and has chosen not to compare NMB with OUST. I will be quite surprised to see a NMB engineer say that his product is inferior to another bearing.
TK said it best, it's not the board, it's the rider. Given that, I will try to find the best bearing for me, I need all the advantages that I can gather.
Anyway, I am willing to make this statement right now.
Do the test yourself.
Take ANY bearing with any spacer or no spacer configuration and CRANK down the axle nut and spin, time it. Now take the same configuration and replace the bearings with MOC 7 or 9 and do the same thing. Use a torque wrench or just be as fair as you can, it probably won't matter anyway. Doesn't matter which one goes first, just do the test and do it as fair as you can.
OUST will take the abuse of out of axis loading and still spin longer. This is what happens in a turn in a bearing, side loads. The simple static test will simulate this.
Just try it yourself.
This simple test along with my hours of conditioning precision bearings over the years and THE RIDE is what has convinced me. I bet you will end up replacing your RACE bearings with OUST if you choose to believe in your own simple test.
The truth does not hurt, it's a good thing.
YOU decide what the truth is regarding your choice in bearings, YOU have to ride them.
OUST: Straight out of the box FASTEST, they are durable as well.
This is my personal opinion, nothing more.
TK said it best, it's not the board, it's the rider. Given that, I will try to find the best bearing for me, I need all the advantages that I can gather.
Anyway, I am willing to make this statement right now.
This is why they work.By a significant percentage, it is my opinion that OUST will have less rolling resistance in any load bearing axis orientation in a comparison test with any other skateboard bearing manufacturer.
Do the test yourself.
Take ANY bearing with any spacer or no spacer configuration and CRANK down the axle nut and spin, time it. Now take the same configuration and replace the bearings with MOC 7 or 9 and do the same thing. Use a torque wrench or just be as fair as you can, it probably won't matter anyway. Doesn't matter which one goes first, just do the test and do it as fair as you can.
OUST will take the abuse of out of axis loading and still spin longer. This is what happens in a turn in a bearing, side loads. The simple static test will simulate this.
Just try it yourself.
This simple test along with my hours of conditioning precision bearings over the years and THE RIDE is what has convinced me. I bet you will end up replacing your RACE bearings with OUST if you choose to believe in your own simple test.
The truth does not hurt, it's a good thing.
YOU decide what the truth is regarding your choice in bearings, YOU have to ride them.
OUST: Straight out of the box FASTEST, they are durable as well.
This is my personal opinion, nothing more.
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- Phoenix, AZ, USA
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Cool.
TK is the surgeon on this one, straight to the bone quickly.
OUSTS are just outstanding bearings. Don't knock them until you have tried them and I have used NMB's over the years, good bearing, nothing like MOC 7 or 9 OUST. I've had and have all sorts of great bearings, PT's, Bones, SIMS GOLD SHIELDS, NMB's, Hoovers, one offs just about every 608 that would work, I've traded secrets over the years with John Gilmour on dentist drill drive conditioning lubricating techniques and it is odd that we came to this from two different avenues...
Lot's can be overcome with GZ-X machine werks 8mm axles with proper facing on the hanger/nut, proper spacing and OUST.
That's my story, I'm sticking to it.
TK is the surgeon on this one, straight to the bone quickly.
I've since had ceramic bearings and other bearings as well. You have to make sure that the wheels have the correct sized spacer and speed rings/nut/hanger face that do not rub or create friction along the length of the axle. THEN you can use OUST to combat any other descrepancy that you introduce.adam trahan wrote:In all of my years as a skateboarder, I thought that it took my "conditioning" a race bearing to get them like I want them to spin. I've a set of Sims Racing Bearings that I have been taking care of since day one. They get the full surgical instrument sonic cleaning, then conditioning with dental drill drive lubrication (colloidal teflon) and then brushed out after each skate.
But the older I get, the less time I have...
So I bought a few sets of Pleasure Tools Bearings (non ceramic, sealed) because they are ABEC 7 and inexpensive. Nice bearings but they have a break in period and it just takes them a while to get to a point to where they spin nicely. I use them for nearly all my riding and I do like them...
On a chance, I bought some Oust MOC 7 and put them in my Turner wheels, cranked them down and WHAM! Spin forever right out of the box. Riding them is a gas, you just forget about bearings, no worries, they just go fast.
Try this test.
Take a comparable bearing and tighten down on a truck (speed washers or what ever you use) and spin, time it.
Take a OUST Moc 7, same set up and do the same...
This is just a free spin test. Once your board is all set, you can feel the difference in the ride (maybe it is simply psychological)
OUSTS are just outstanding bearings. Don't knock them until you have tried them and I have used NMB's over the years, good bearing, nothing like MOC 7 or 9 OUST. I've had and have all sorts of great bearings, PT's, Bones, SIMS GOLD SHIELDS, NMB's, Hoovers, one offs just about every 608 that would work, I've traded secrets over the years with John Gilmour on dentist drill drive conditioning lubricating techniques and it is odd that we came to this from two different avenues...
Lot's can be overcome with GZ-X machine werks 8mm axles with proper facing on the hanger/nut, proper spacing and OUST.
That's my story, I'm sticking to it.
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- Team RoeRacing
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- Pat C.
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Bearings share axial loads? I don't think so.
Sorry, I just can't see how the slight press fit of the bearing into the wheel can be made to share the axial load of the wheel across the 2 bearings. It would seem to me that if I can press the bearing out of the wheel with my finger, then the maximum axial load possible in that direction for that bearing is very small indeed.2nd, with that said, the bearings will still work as a Pair and share the load because by being pressed in the wheel and locking the outer rings,
When I'm exerting an axial load on the wheel towards the truck, only the bearing on the inside of the wheel can exert much force against the wheel (acting against the flange in the hub). The other bearing is being pushed OUT of the wheel, and has no flange to act against. So it cannot carry a load. This was the intent of the "experiments" described, to show how that works (maybe it wasn't described too well).
So I guess this engineer disagrees with the other engineer.
How about this for an experiment: Would your engineer be willing to race a slalom course using wheels where the hubs have had either inside flange removed?
-- Pat
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A good experiment to visualize things except it ignores the existence of the urethane wheel around the bearings and the forces acting on the bearings via their outer surface thanks to the wheel moving/flexing.
For what it is worth, here is what the bearing engineer sent me:
===
"First off, Spacers dont support bearings, they preload the inner ring and make the bearings work as a "pair" and will help share the load and will eliminate the axial play (end play)
2nd, with that said, the bearings will still work as a Pair and share the load because by being pressed in the wheel and locking the outer rings, but not to the degree it does when you preload the inner rings. The bearings will take on more load without the spacers but not double. Say he's right and it is double. My Skate Bearings anyway have a 912 lb radial load rating and a 456 lb axial load, EACH BEARING. Even of all your weight and momentum is on one bearing only it would still handle it no problem. The fact that the bearing will take on more load without the spacer is true but not a factor in the speed. The fact that the balls are "pre-loaded" up against the raceway when using spacers will slow you down more that adding a little load to the bearing. When you are kickturning add a few pounds load. No big deal. Bearings are designed to carry heavy loads.
===
Further comments, corrections, explanations anyone?
-Slim
For what it is worth, here is what the bearing engineer sent me:
===
"First off, Spacers dont support bearings, they preload the inner ring and make the bearings work as a "pair" and will help share the load and will eliminate the axial play (end play)
2nd, with that said, the bearings will still work as a Pair and share the load because by being pressed in the wheel and locking the outer rings, but not to the degree it does when you preload the inner rings. The bearings will take on more load without the spacers but not double. Say he's right and it is double. My Skate Bearings anyway have a 912 lb radial load rating and a 456 lb axial load, EACH BEARING. Even of all your weight and momentum is on one bearing only it would still handle it no problem. The fact that the bearing will take on more load without the spacer is true but not a factor in the speed. The fact that the balls are "pre-loaded" up against the raceway when using spacers will slow you down more that adding a little load to the bearing. When you are kickturning add a few pounds load. No big deal. Bearings are designed to carry heavy loads.
===
Further comments, corrections, explanations anyone?
-Slim
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- Pat C.
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It depends on how long the spacer is.
Try this experiment: Take your speed rings, bearings, and spacers. Place them on a 5/16" bolt (or 8mm bolt) tighten with a nut as tight as you can. Spin the bearings. Compare the spin when the nut is loose. I'll bet there is no difference. That's because all of the "Pre loading" is carried by the inner races of the bearings, and the spacer. There is no axial load that is loaded against the balls and the outer races. The same will happen in your wheels AS LONG AS THE SPACER IS EXACTLY THE RIGHT LENGTH, OR SLIGHTLY LONGER THAN THE EXACT RIGHT LENGTH.
Try this series of experiments:
1) Normal wheel / bearing / spacer setup ; very tight nut.
2) Normal wheel / bearing/ spacer with a speed ring inside the wheel (Simulates a long spacer). very tight nut.
3) Normal wheel / bearing / spacer that has been sanded/filed down. very tight nut.
The "speed" of the wheel will be 2 > 1 > 3 (Setup 2 fastest)
The "stability" of the wheel to resist axial motion will be 3 > 1 > 2 (Setup 3 most stable).
Until skateboard wheels are made with a "hub nut" that can exert an axial force on the outside face of the outer race of the bearing, we are indeed only relying on one of our 2 bearings per wheel to carry the entire axial loads when turning. Perhaps this is where someone got the "2X" the force notion? (Comparing the standard skateboard wheel against some other, more ideal design?)
-- Pat
Try this series of experiments:
1) Normal wheel / bearing / spacer setup ; very tight nut.
2) Normal wheel / bearing/ spacer with a speed ring inside the wheel (Simulates a long spacer). very tight nut.
3) Normal wheel / bearing / spacer that has been sanded/filed down. very tight nut.
The "speed" of the wheel will be 2 > 1 > 3 (Setup 2 fastest)
The "stability" of the wheel to resist axial motion will be 3 > 1 > 2 (Setup 3 most stable).
Until skateboard wheels are made with a "hub nut" that can exert an axial force on the outside face of the outer race of the bearing, we are indeed only relying on one of our 2 bearings per wheel to carry the entire axial loads when turning. Perhaps this is where someone got the "2X" the force notion? (Comparing the standard skateboard wheel against some other, more ideal design?)
-- Pat
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I guess I could wait for Wes to confirm but if what he is saying is as you have described, I don't see much difference. Bearings with spacers (etc.) attempt to hold the bearings in one place on the axle, but as the wheel flexes during a turn, side (or angular) loads will still be exerted on the bearings relative to how the wheel is spinning. I.e. the bearings may be "straight" for the axle, but not straight for the path the wheel itself is trying to turn and the urethane will be pushing on the bearings.
The spacers and speed rings also do not do anything to increase the grip of the inside of the wheel to the surface of the bearing. All they are doing is holding the inner bearing race more stationary: the rest of the bearing still moves just as much and is subject to the same loads overall. No?
Am I missing something? If the above is correct, no reduction of loading during turning is accomplished by running spacers and tight nuts, so all you are left with is the loss of straight line speed from pre-loading the bearings.
-Slim
The spacers and speed rings also do not do anything to increase the grip of the inside of the wheel to the surface of the bearing. All they are doing is holding the inner bearing race more stationary: the rest of the bearing still moves just as much and is subject to the same loads overall. No?
Am I missing something? If the above is correct, no reduction of loading during turning is accomplished by running spacers and tight nuts, so all you are left with is the loss of straight line speed from pre-loading the bearings.
-Slim
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- WesE
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"Riding vert" involves side-forces being put on the skateboard due to abrupt changes of direction. These accelerations imput the same side-loads on 608 bearings that "street riding" does.Rich Stephens wrote:Can you explain "why", perhaps with some technical language to support your claims? It would be helpful. Thanks.
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- Team RoeRacing
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I see, I think what wes means is when the two bearings dont have a spacer and ring to keep them straight they will,durning a hard turn(side load) tilt and get all crooked inside the relativly soft plastic Hub causing minute friction. Add a spacer and rings and proper nut tension and the whole mess stays more alligned , especially during side pressure like you get during a hard turn, thus resulting in less friction and more speed. How he got the "twice as much " part is anyones guess.
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I think what I was asking for was something to back up this claim:
I'm not an engineer. I'm just trying to make sense of conflicting advice.
I see you say "load" not "pre-load". So, you are pre-loading the bearings by use of spacers and washers (or bosses) and then claim a wheel with no pre-load, takes on "at least twice the load".Bearings not supported by the proper spacer take on at least twice the load as bearings that are set up properly
I'm not an engineer. I'm just trying to make sense of conflicting advice.
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- Team RoeRacing
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Glen, please, don't insult me...
Slim, I believe Wess of Virginia. No one, and I mean no one, wrenches more than him. He also skates all disiplines including ramp, vert, pools, fences, ditchs, Slalom and Banked Slalom. He does them all well. He is also very thrifty and researchs every bit of equipment in order to get maximum value. Now I'm sure this Ron of California is a smart guy. But I know Wes of Virginia personally and he is smart AND skates a whole lot. That said, I believe wes has answered your "why" question in his previous post .
"Bearings not supported by the proper spacer take on at least twice the load as bearings that are set up properly (setup with the proper spacer). Because of that, one can extrapolate that a wheel without the proper bearing spacer will not be as fast as the same wheel that has been properly setup. It’s as true for riding vert as anything else. Any variation of skateboard turn, including kickturns and grinds, will put side-loads on bearings. No amount of industry mumbo-jumbo will make me reconsider. "
HE also used the word "extrapolate" which in my book qualifies as Technical language. TK
Troy, what might your thoughts on the subject be?
Slim, I believe Wess of Virginia. No one, and I mean no one, wrenches more than him. He also skates all disiplines including ramp, vert, pools, fences, ditchs, Slalom and Banked Slalom. He does them all well. He is also very thrifty and researchs every bit of equipment in order to get maximum value. Now I'm sure this Ron of California is a smart guy. But I know Wes of Virginia personally and he is smart AND skates a whole lot. That said, I believe wes has answered your "why" question in his previous post .
"Bearings not supported by the proper spacer take on at least twice the load as bearings that are set up properly (setup with the proper spacer). Because of that, one can extrapolate that a wheel without the proper bearing spacer will not be as fast as the same wheel that has been properly setup. It’s as true for riding vert as anything else. Any variation of skateboard turn, including kickturns and grinds, will put side-loads on bearings. No amount of industry mumbo-jumbo will make me reconsider. "
HE also used the word "extrapolate" which in my book qualifies as Technical language. TK
Troy, what might your thoughts on the subject be?
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- WesE
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It makes sense that a guy who markets bearings would say that spacers are a detriment to bearing performance. He is blowing smoke. Bearings not supported by the proper spacer take on at least twice the load as bearings that are set up properly (setup with the proper spacer). Because of that, one can extrapolate that a wheel without the proper bearing spacer will not be as fast as the same wheel that has been properly setup. It’s as true for riding vert as anything else. Any variation of skateboard turn, including kickturns and grinds, will put side-loads on bearings. No amount of industry mumbo-jumbo will make me reconsider. The advantage of using the proper spacer has been known to me for like 15 years prior to my slalom riding.
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Re: Bearing preload
Eric, I know a guy who is a bearing engineer, and not only does his bearing company (California Bearing) provide bearings to NASA and private industry, but he also orders a specific NMB bearing to market as a skate bearing since he himself is a skater. His opinion on the speedring and preload issues is this:Eric Wallgren wrote:Speedrings or no, it's virtually impossible to preload your skateboard bearings.
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"It use to be and still is general skate theory to use spacers and tighen up your wheels real snug. The spacer will force the ball track to ride against raceway shoulder (duplexing/Preloading)adding stability and elliminating the "loose Play" however, adds friction. From an Engineering and skaters point of view, I think for street skating, the pounding, jumping off rails, etc., I would use spacers with the nut snug to elliminate the "Loose Play"... The bearings will "share the load" in the wheel giving the bearing/wheel more strength and stabilty, will handle more of a beating but you will give up speed, quickness and the bearings will wear faster.
....But for me, (Im strickly a Vert/Pool skater) and other Vert skaters I recommend a different setup. For Vert the bearing application is different than street skating. You want stability and strength when your street skating, but VERT, halfpipes, pools, etc. you want speed and quickness. Rather than running the bearings as a "Duplexed Preloaded Set" mentioned above, you want the bearings to run as independant high speed radial bearings with Low starting and running torque. Dont use the Spacers and only tighten the wheel bolt, lightly snug, to eliminate most of the slop. Sometimes if too loose it seams like you dont need bearings but when you stand on it and add 120 or more pounds of load and get traveling in one or more directions, the bearings will rotate and the inner ring will not spin on the axle, but you dont want alot of "loose play' or "slop" either. Lightly snug !!! By not tightning the the nut too tight, the bearings will have less preload and will run like a "high speed radial" bearing."
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I guess the question is whether for slalom the stability is more important or if speed is. If the use of 8mm axles takes away the typical axle slop anyway, then perhaps there is no reason to run the spacers and washers at all since you'd get speed that way (and not need the stability).
Here's what Ron of California Bearings says on preload:The only way to get excessive preload would be to omit the spacers, or apply so much pressure by over torquing the wheels nuts that you collapsed the spacer.
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"A 608 has about a 7-9 pound max preload limit. 608's in Precision Duplex Pair applications like pairs I supply to NASA for the cameras on the outside of the space station, have just a 4-5 lb Preload. Anymore than that the bearings will fail to turn and wear extremly fast. Tighten that nut down real hard and you could add 20-30 lbs of preload !!! Bottomline......I think spacers preload the bearings too much for VERT skaters but is good for the Street Skaters where speed and quickness isnt as much of an issue as stability and strenghth."
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Me again. I'm totally convinced that the 8mm axles are the way to go, I'm just confused on running spacers and rings or not. Any further comments?
BTW, if you guys haven't tried them, you might want to try the NMB bearings from California Bearing (or you can get them from skatelab). They test every bearing they can get their hands on vs. the NMB - so that if they find something better they can source that one instead. So far, the NMB is tops. Here is a review of the Biltins, for example:
"I just checked out these Biltin Bearings. Not bad for inexpensive Chinese. There are no inner ring steps, No labryinth Seal or inner ring design. By the way the so-called ABEC 7 bearing measured out to ABEC 3 tolerances in my lab. As far as I can tell, the ABEC 3 , 5 and 7 sold by Biltins are the EXACT same bearing. Maybe they dont even know it and their bearing supplier is just slipping ABEC 3's past them Certifying to ABEC 7. These Biltins ARE NOT ABEC 7. Im sorry , its true. Not a bad concept to manufacture the bearings with extended inner rings to eliminate the spacer and washers. However, This has nothing to do with how "fast" or smooth the bearings are. I tested them against the NMB SuperPrecision Bearing and the starting and running torque values were double!! on the Biltin bearings versus the NMB Bearing. That means the biltin bearings take more energy to get up to speed and stay at top speed. The NMB Bearing really blew away the Biltins on the Running Torque test. That means the Biltins slow down faster while the NMB SPS Bearing holds its speed with little or no effort. I wont even get into the Smoothness test which the NMB bearing obviously has the lowest values of any 608 Ive Tested and Inspected."
I think they sell the NMB skate bearing direct for $23, retail is like $30 or something at Skatelab and other shops. And for the record, I have no connection to those guys other than being a satisfied customer. Their webpage on that NMB bearing is http://www.californiabearing.com/skate.htm
-Slim
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Bearing preload
Speedrings or no, it's virtually impossible to preload your skateboard bearings. There should be, in order, on your axle, assuming you're not using Abec11 Biltin bearings:
speedring/bearing/spacer=distance between bearing seats in your wheels+a couple thousandths of an inch/bearing/speedring/nut.
If you're on my trucks you can leave the speedrings out. If you're on Biltins you need nothing. The "speedrings" and spacers are "Biltin" to the bearing. I think they're the best thing ever.
The only way to get excessive preload would be to omit the spacers, or apply so much pressure by over torquing the wheels nuts that you collapsed the spacer.
The idea behind true 8mm axles is that the wheel nuts are simply a retainer. The are ****just**** snugged down, and the bearing fit on the axle is so close that there is virtually no axial play, and the axle is so straight, that the contact patches of your wheels are perfectly parallel, which minimizes drag, and maximizes possible lateral grip. If you ride two identical setups, one with perfect axles, and one with typically misaligned factory axles, the difference on a real slalom course is remarkable.
factor in longer kingpins and good bushings, and it's a night and day improvement.
speedring/bearing/spacer=distance between bearing seats in your wheels+a couple thousandths of an inch/bearing/speedring/nut.
If you're on my trucks you can leave the speedrings out. If you're on Biltins you need nothing. The "speedrings" and spacers are "Biltin" to the bearing. I think they're the best thing ever.
The only way to get excessive preload would be to omit the spacers, or apply so much pressure by over torquing the wheels nuts that you collapsed the spacer.
The idea behind true 8mm axles is that the wheel nuts are simply a retainer. The are ****just**** snugged down, and the bearing fit on the axle is so close that there is virtually no axial play, and the axle is so straight, that the contact patches of your wheels are perfectly parallel, which minimizes drag, and maximizes possible lateral grip. If you ride two identical setups, one with perfect axles, and one with typically misaligned factory axles, the difference on a real slalom course is remarkable.
factor in longer kingpins and good bushings, and it's a night and day improvement.
Rich,
I've had Eric do about 5 Tracker hangers for me. I have found no problem at all with his system. With the 8mm axle and the way he machines both the hanger and also the nut. Works like a charm. And I'm not messing with speed-rings. I like it.
What I think is Key with this system is the straight 8mm axles. My Pleasure Tool sealed Abec3's fit perfectly on the GeezerX axles. As good as on the much more expensive PVDs that I've bought.
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Anyone know what that somewhat-purple looking top bushing is in the picture above of Eric's reworked Trackers?
I've had Eric do about 5 Tracker hangers for me. I have found no problem at all with his system. With the 8mm axle and the way he machines both the hanger and also the nut. Works like a charm. And I'm not messing with speed-rings. I like it.
What I think is Key with this system is the straight 8mm axles. My Pleasure Tool sealed Abec3's fit perfectly on the GeezerX axles. As good as on the much more expensive PVDs that I've bought.
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Anyone know what that somewhat-purple looking top bushing is in the picture above of Eric's reworked Trackers?
Last edited by Glenn S on Tue Jan 13, 2004 4:55 pm, edited 1 time in total.
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- Geezer-X
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Hey!!
I haven't been checking in so very often, seeing as how if I'm not at work or consulting, I'm standing in front of a lathe making axles. Seth, feel free to call, the # is on the website. In the mean time I'll leave you with this...



These are the newest MMW Team trucks. 8mm 4140 CrMo axles, machined in bearing seats, longer kingpins, reshaped pivots and bushing seats, custom NOS Tracker bushings, and custom media blasted finish.
These are the newest MMW Team trucks. 8mm 4140 CrMo axles, machined in bearing seats, longer kingpins, reshaped pivots and bushing seats, custom NOS Tracker bushings, and custom media blasted finish.
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I see that when trucks are modified with 8mm axles, one of the things that is done is that the hanger is modified to have a boss that eliminates the need for speed rings. Have you machinists thought about this from a bearing engineering standpoint?
My gut feeling is that the speed washers, being somewhat forgiving, may actually be better as there is less chance the bearings will be given too much preload when tightening the nut down. (I guess the same issue exists with the biltin bearings and their hard built in spacers and washers).
Any thoughts?
-Slim
My gut feeling is that the speed washers, being somewhat forgiving, may actually be better as there is less chance the bearings will be given too much preload when tightening the nut down. (I guess the same issue exists with the biltin bearings and their hard built in spacers and washers).
Any thoughts?
-Slim
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