polyamide (Nylon 66/polycaprolactam) bushings instead Swingarm & Linkage Bearings

[Rampart]

Hi all
my linkage bearings went to a better world







I decided to save a bit on bearings, and go for polyamide bushings. A common thing for ATVs, cars and motorcycles. I'll write here how long they will last.








I paid 13 USD per 100cm polyamide rod (used 15cm) and blank for ruined pin. Still have to buy one screw. Also I paid the workman (a friend of mine) for the manufacture of three bushings and one pin - 8 USD. So budget of repair no more than 25 USD + a lot of stuff just in case.

 

[(F5)]

They get a considerable loading on then as they have to pass on the leverage. Think I've tried and failed on a small roadbike in the past. Maybe tried on my old DT or KDX in the past. Have some left over material but can't remember. Too long ago and a bash on the head since.

But simple to try and measure wear/ovalisation. Measure free play wheel off ground. There will always be a little. Write it down and check after a ride. Ride quality will be affected if you bind it up too tight and under load won't ever be as smooth as rolling bearings.
Once bearings are toast however they will be worse and often people don't notice that.

 

[Leo]

Had used Nylon bushings in my DT in the past. (used grease fittings)
Nylon hold well the loads and wear.
But there more drag and suspension sit a bit lower.

If it was me, I would use polyurethane (it's more flexible) for shock bushing. In order to avoid bending stress on shock shaft

Nice test. Post yours results after

 

[pscook]

A fellow on here sold a kit for the entire rear suspension, I believe it was Synergy Cycles? I'll search. But he used FRP so it would hold up to the demands and wear considerations. I can't tell if your material has any reinforcement, or if it's just plastic.

 

[pscook]

Here's the original thread for the bushing kit-=
http://www.gasgasrider.org/forum/showthread.php?t=15428&highlight=bushings

Note that it just replaces the roller bearings and seals, you must reuse your sleeve bushings.

 

[Rampart]

I can't tell if your material has any reinforcement, or if it's just plastic.

like i said - it's polyamide with graphite filling

 

[pscook]

like i said - it's polyamide with graphite filling

Sorry, I didn't see anywhere in your original post that it has graphite in it. While the graphite offer structural support, or is it just for lubrication? Does the graphite carry or distribute the load? I'm not an engineer, so these are honest questions. I'm just trying to learn.

 

[Rampart]

Sorry, I didn't see anywhere in your original post that it has graphite in it. While the graphite offer structural support, or is it just for lubrication? Does the graphite carry or distribute the load? I'm not an engineer, so these are honest questions. I'm just trying to learn.

My mistak, sorry.
As I understand it - graphite for lubrication.
As they say in our sites, it has a coefficient of friction 2-3 times lower compared to polyamide 6. Resistant to impact loads.
This is common, I do not know how to look correctly on your youtube, but in my is looks like this https://www.youtube.com/results?search_query=капролоновые+втулки

 

[arminhammer]

http://www.johnstonplastics.com/mech-nylon/

 

[motopsycho87]

Ooh this is interesting. Can you post the dimensions you made them too please, my linkage etc is due a refurbishment soon and sounds like an interesting project!

 

[Rampart]

Ooh this is interesting. Can you post the dimensions you made them too please, my linkage etc is due a refurbishment soon and sounds like an interesting project!

I have interesting thoughts after installing the bushes, I'll post later.

 

[(F5)]

Pass the ream.
They compress a bit huh?

 

[Rampart]

for now linkage is fine, i inspect it few days ago. Just one bushings that run with self-made pin (bad polishing) have little wear.

 

[motopsycho87]

I rebuilt the bike I'm going to have for road fun with oilite bushes. They're a bit tight after they've been press fit into the swingarm / linkage etc, and needed a little taking out to fit and spin nicely.