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Low friction material for a bushing
- Thread starter SamI
- Start date
Make the bushing from 6/6 Nylon. It is easy and not expensive. If it works you could make them for others that have same issue. And a nice simple lathe project.
Turcite is made for just this type of application. Self lubricating but not as brittle as oilite or bronze bushings.
(link for reference - not researched as a purchasing option) https://www.boedeker.com/family/turcite
And, as pointed out before I would incorporate seals, o-rings or other method of keeping dirt out.
(link for reference - not researched as a purchasing option) https://www.boedeker.com/family/turcite
And, as pointed out before I would incorporate seals, o-rings or other method of keeping dirt out.
Thanks guys for the suggestions. I think I would certainly incorporate an O ring recess into the spacers and / or bushing. From doing a little more research about it would seem that the ones supplied by the manufacturer are IGUS bushes. Not entirely sure what the materials used are but they advise using a hardened aluminium shaft or stainless steel for wet environments which confirms my suspicion that there isn't a need for both the bush and the shaft to be made from a bearing material.
Another plus for making them myself is to experiment with different offsets to alter the geometry of the bike. Quite excited about making a few and doing some back to back testing!
I shall look into the availability of the various materials mentioned above and see what would be the most suitable. I like the idea of the oil filled bronze but i suspect that Derlin (or Turcite which seems to be a variant) will be the more readily available alternative.
Another plus for making them myself is to experiment with different offsets to alter the geometry of the bike. Quite excited about making a few and doing some back to back testing!
I shall look into the availability of the various materials mentioned above and see what would be the most suitable. I like the idea of the oil filled bronze but i suspect that Derlin (or Turcite which seems to be a variant) will be the more readily available alternative.
Sami-
I've been out of the game for the most part since I raced the Megavalanche a few years back. Just during the train-up, I broke two fingers in my hand, sustained a neck injury that still causes big issues, got a puncture wound from a branch in my leg from crashing into a tree, ruptured the saphenous vein in my right leg (twice from riding too soon after injury), had blood clots between my shin and peretoneum, and more bruises than I can remember.
I have had 3 VPP (DW link) bikes, and all of them ate pivot bearings. Most of the cartridges are doubled for single race bearings, some use double row bearings. The doubles are very expensive and last a year (at 100 km of singletrack a week). I have not had any issue at the shock eyes on those bikes. One thing I've noticed after servicing lots of Fox (I made Fox parts in the CNC shop I worked at in "99-'00), Rock Shox, and CC shocks is that the tolerances in the bushing eye are broad. I suspect they tolerance match the mating parts. Sometimes, bushings press in and out easily, other times it's sketchy. Some of my RWC kits have fit better than others. One kit I installed on a Fox was so tight that the bearings got brinelled, so I get what you're saying. Oilite or other bronze sounds great from the point of view of this forum, but I think it is too hard and will ruin your shock eyes. If you achieved a perfect press fit with bronze, it might be okay, but I think up until now that aluminum has been the choice because it is light and soft enough to be sacrificial. Maybe hard plastic is the way to go, or some bushed combination. But combining rigid and soft material brings us back to the status quo of a soft bushing and aluminum inserts.
When I'm doing a lot of riding, I wash, oil, and re-grease once or twice a week. That keeps everything working and dialed. I just don't give crud a chance to accumulate.
I've been out of the game for the most part since I raced the Megavalanche a few years back. Just during the train-up, I broke two fingers in my hand, sustained a neck injury that still causes big issues, got a puncture wound from a branch in my leg from crashing into a tree, ruptured the saphenous vein in my right leg (twice from riding too soon after injury), had blood clots between my shin and peretoneum, and more bruises than I can remember.
I have had 3 VPP (DW link) bikes, and all of them ate pivot bearings. Most of the cartridges are doubled for single race bearings, some use double row bearings. The doubles are very expensive and last a year (at 100 km of singletrack a week). I have not had any issue at the shock eyes on those bikes. One thing I've noticed after servicing lots of Fox (I made Fox parts in the CNC shop I worked at in "99-'00), Rock Shox, and CC shocks is that the tolerances in the bushing eye are broad. I suspect they tolerance match the mating parts. Sometimes, bushings press in and out easily, other times it's sketchy. Some of my RWC kits have fit better than others. One kit I installed on a Fox was so tight that the bearings got brinelled, so I get what you're saying. Oilite or other bronze sounds great from the point of view of this forum, but I think it is too hard and will ruin your shock eyes. If you achieved a perfect press fit with bronze, it might be okay, but I think up until now that aluminum has been the choice because it is light and soft enough to be sacrificial. Maybe hard plastic is the way to go, or some bushed combination. But combining rigid and soft material brings us back to the status quo of a soft bushing and aluminum inserts.
When I'm doing a lot of riding, I wash, oil, and re-grease once or twice a week. That keeps everything working and dialed. I just don't give crud a chance to accumulate.
Are the bushings the top hat bushings for the shock or the swingarm/ link bushings?
If you want the premium feel, roll your own needle bearing set up using a hardened shaft for the needles to roll on and a suitably sized hardened outer cage to press into the frame. Or make up a ton of bushings from Delrin at once and simply change them out at regular intervals. If you make up a little press kit to press them in and out it won't take long. I think Turner went with (maybe still does) bushings for the support and the limited rotation of most suspension bearings. His had grease ports for each bearing though. That by be another option - that way you'll be able to force any grit out that gets in there and lube them at the same time.
If you want the premium feel, roll your own needle bearing set up using a hardened shaft for the needles to roll on and a suitably sized hardened outer cage to press into the frame. Or make up a ton of bushings from Delrin at once and simply change them out at regular intervals. If you make up a little press kit to press them in and out it won't take long. I think Turner went with (maybe still does) bushings for the support and the limited rotation of most suspension bearings. His had grease ports for each bearing though. That by be another option - that way you'll be able to force any grit out that gets in there and lube them at the same time.
If the needle rollers are not spinning they will wear divots in the shaft. My Jaguar uses needle rollers on the rear suspension fulcrum shafts and these only travel through about 15° it wares divots in the shaft bush. I made bronze bushes with grease channels and fixed the issue for good.
Have the shafts coated or plated with a low friction material such as hard chrome or titanium nitride, make the bearings from a low friction low wear plastic material such as PEEK filled with PTFE and carbon as seen here https://www.ensingerspi.com/material.cfm?material=PEEK
This combination should last a good deal of cycles, everything may be done in the home shop aside from the plating or TIN coating.
This combination should last a good deal of cycles, everything may be done in the home shop aside from the plating or TIN coating.