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Shims for Valving

karpi

Monkey
Apr 17, 2006
904
0
Santiasco, Chile
Hey guys, since its kinda hard to get a hold of shims for valving down here, a friend of mine was thinking of making some shims here. He has the tools and stuff to do it, question is... what materials and processes does it need? Please refrain from simply saying "just buy some, it'll save you a lot of problems", cause even if we can't do it, it be interesting to know... :D
 

ocelot

Monkey
Mar 8, 2009
395
10
Canadastan
I guess they're mostly stamped... But if you want to "red neck" it, you could probably try cutting it out from a piece of stock (after drilling/boring it of course) on a lathe using a part off tool.
 

jonKranked

Detective Dookie
Nov 10, 2005
85,558
24,181
media blackout
shims are not stamped, or machined, or forged. They grow high in the mountains of the himalayas, are harvested by the abominable snowman, and are then sorted by mountain trolls.

another of the bike industry's dirty little secrets.
 
Aug 4, 2008
328
4
I assume you will now need an investment to the tune of tens of thousands of $?

Where do I transfer the money? Know what... Ill just post my CC number here.

Pleasure doing business with you. Partner.
 

atrokz

Turbo Monkey
Mar 14, 2002
1,552
77
teedotohdot
Just use stainless shim stock. Gauge thickness based on what is being run now. Might have a slightly different modulus of elasticity, but if you're re-shimming the shock, then who cares.
 

Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
Yeah a mate of mine used to punch his own shims. If you've got the tools (which are pretty simple, but need to be quite precisely made otherwise you get rough edges), all you need is shim stock (0.1, 0.15, 0.2, 0.25mm thick high carbon steel sheet basically) and you can get into it. If it's not for stuff you're selling, the grade of material isn't all that important either, poorer grades of steel will die in maybe 10-12 months depending how often you ride, but if you're revalving that often then it's not really a big issue.
 

atrokz

Turbo Monkey
Mar 14, 2002
1,552
77
teedotohdot
anyone else have any comments or links I could read? thanks!

Allow me to reitterate.

Just. Use. Stainless. Shim. Stock.

Shim stock is uber cheap.


Do you plan on punching these out? You said he has the 'tools' to do this (which could mean almost anything) but then ask the process. I can tell you that the shims I took out of my older Fox unit were punched (as is evident by the 1/3 cut, 2/3 break), but I doubt you'd want to invest in punches and dies, so do you have access to someone with a laser, waterjet, or the like?
 
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Steve M

Turbo Monkey
Mar 3, 2007
1,991
45
Whistler
Allow me to reitterate.

Just. Use. Stainless. Shim. Stock.

Shim stock is uber cheap.


Do you plan on punching these out? You said he has the 'tools' to do this (which could mean almost anything) but then ask the process. I can tell you that the shims I took out of my older Fox unit were punched (as is evident by the 1/3 cut, 2/3 break), but I doubt you'd want to invest in punches and dies, so do you have access to someone with a laser, waterjet, or the like?
It's not that hard to make a punch/die set if you have access to a lathe. It's about the simplest tooling in the world really!
 

atrokz

Turbo Monkey
Mar 14, 2002
1,552
77
teedotohdot
It's not that hard to make a punch/die set if you have access to a lathe. It's about the simplest tooling in the world really!
Yup.

If you know what the hell you're doing, understand the meaning of clearance (and the formula to achive the correct clearance), and pick the right material and heat treat. edit: you'd be supprised how little people actualy know about how to make a simple die. I saw a first year apprentice chamfer a die. He's probably sweeping bathrooms now.

If OP wants this info, I can provide it.

-Certified Tool and Die maker.
 
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karpi

Monkey
Apr 17, 2006
904
0
Santiasco, Chile
jajajaj coke can idea sounds fun... but arent coke cans made of aluminium? hahah

anyways, he has a small oven for heat treat, a bunch of differents lathes and Im pretty sure he can punch out stuff, I gotta ask him. He works at a factory and tells me he has "a lot of tools" to make this work, plus a lot of experience, and apparently his boss is getting interested in it too.

So, just to put together the info so far.

No heat treat necesary?

Steel from a steel roll and punch them out from a die. The die being made from a lathe. Am I getting this correctly?
 

atrokz

Turbo Monkey
Mar 14, 2002
1,552
77
teedotohdot
No heat treat necesary?

Steel from a steel roll and punch them out from a die. The die being made from a lathe. Am I getting this correctly?
No heat treat to the shims themselves. You don't want to make the shims brittle. Stainless will work better than high carbon as it won't tarnish or erode over time inside your shock.

Obtain the shim thickness you need. Have him machine out a punch and die from something like A2, msg me with the shim thickness and I'll tell you the clearance (or google "die clearance calculator") and press requirements. Heat treat it to be about 50-55rc (depends on the material), and grind the tops of punch and die to make them sharp.
 

drastic.

Monkey
May 16, 2011
145
0
pleasanton, ca
idk what fork you are using, but in the boxxer rc 2011 model:

.15mm thick
6.10mm inside diameter

3 diff shim widths:
21.34mm OD
15.85mm OD
13.90mm OD

may not be of use directly for your application, but atleast you have a sense of some sized shims that are used in a current fork.