Campy Question / Thin Spacers behind Chainring on Campy Cranks

[dana_e]

I have seen 2 super thin spacers behind campy chainrings next to the arm that has the bolt go into the back of the crank arm.

think ultra torque or modern campy (not the old five bolt style)

These are not listed in the parts catalog.

I have heard they are there to make up production tolerances, or something like that. They are a pain to get in there and bolted up and easy to lose.

Anyone have any thought on these washers,they are paper thin.

If you change chainrings they fall out and you may not notice them.

Are they needed? Are they a part that can be repalced?

What is the story with the mystery washer(s)?

Just to make it more confusing, in the old days, record had a spacer for behind the chainring, it is in the parts catalog, but is much thicker than the ones I am talking about.

Thanks, D

[oliver1850]

I have not seen them. If you had one and lost it, I would check the gap with a feeler gauge. Bolt the other 4 arms up tight, then measure the gap. You can then make another the right thickness with shim stock. You can get it from a local machine shop or industrial supply like MSC, McMaster Carr, or Wholesale Tool. Hard to make a round hole in it without a punch. I could probably make you a shim if you can measure the thickness.

[Peter B]

I encountered that spacer recently. I was chasing a crankset creak and had the rings off. I used a dab of grease to hold the washer in place during reassembly, but I can sure see how one might lose it.

I found this potential source for shim washers.

http://www.washersusa.com/shim.html

[ultraman6970]

Hi...

Are u talking about the washer that space the big and small chainring???

[dana_e]

goes between the outer ring and the crank arm

super thin

my centaur ultra torque had them

and my centaur carbon square taper

tres bizarre

[chismog]

I think this is what you want:
http://branfordbike.com/product/campagnolo-hidden-chain-ring-bolt-.4mm-spacer-975.htm

They are needed. If you tighten a 10s big ring without one, the ring is pulled too close to the arm. It will not run true and you will notice it.

The explanation for it is here:
http://branfordbike.com/articles/chainrings-pg68.htm

I should also note that while you can order them from Branford, Vecchio's/OldPotatoe probably stocks them too. And spud is a heck of a nice guy.

Cheers,
C

[oldpotatoe]

I have seen 2 super thin spacers behind campy chainrings next to the arm that has the bolt go into the back of the crank arm.

think ultra torque or modern campy (not the old five bolt style)

These are not listed in the parts catalog.

I have heard they are there to make up production tolerances, or something like that. They are a pain to get in there and bolted up and easy to lose.

Anyone have any thought on these washers,they are paper thin.

If you change chainrings they fall out and you may not notice them.

Are they needed? Are they a part that can be repalced?

What is the story with the mystery washer(s)?

Just to make it more confusing, in the old days, record had a spacer for behind the chainring, it is in the parts catalog, but is much thicker than the ones I am talking about.

Thanks, D

"I have heard they are there to make up production tolerances, or something like that."

Exactly like that. These, along with ERGO levers are hand assembled and sometimes you see these wee spacers/shims. Be careful, don't loose it.

The other spacer, FC-RE-006 was for 10s chainrings. It's not really confusing at all, really. 'Old days', like in 2005 or so.

For UltraTorque, the FC-RE-006 isn't there, the FC-RE-105(thicker one) still is and sometimes on the carbon cranks you see a 'no part number', thin shim.

[ultraman6970]

Had those cranksets and i dont remember seeing that washer ever. Interesting.

[wasfast]

I've seen them from time to time. One method I've used to tack them in place is some superglue. Just make sure the surfaces are grease free and let capillary action pull in the glue. Obviously, you want to ensure the shim is tight against the surface. At least then, you're not wrestling with it on the bike or bench or watching it vanish under the workbench.

[fuzzalow]

I have seen these washers on one of my 10speed Record alloy cranks. I have also lost this same washer and reassembled the chainrings without it.

I can't tell any difference. Finding a replacement washer like this locally ain't gonna happen. If it made a difference that I had to have this tolerance spacer, I'd put a spiral of guitar string in its place. The washer is very thin, I'd say no more thicker than a .013 unwound B string.

[dana_e]

go figure, they may turn up

[oliver1850]

I took the rings off a new UT. This one had one shim between the big ring and the arm. It is .574" (14.6 mm) in diameter. The hole is .326" (8.3 mm) in diameter. It is .004" (.1mm) thick. I'm guessing that they use only the one thickness. If you know you had two, you need a total of .008" shim. I would still check the gap by the feeler gauge method to be sure.

The diameter of a replacement could be a bit off, the critical dimension is the thickness. If you wanted to order from Peter B's source above, you could get one that's .562" od with a .375" hole. Part number Z9824 (.004"), or Z9828 (.008") if you wanted to get the right thickness with only one shim.

[sean]

It has to do with Torque issues and I'm pretty sure is a result of something that happend here in SF.

Campy was shipping UT cranks that were not torqued to spec and that "hidden" bolt was coming loose. I guy here in SF made campy foot the bill for his Cervelo because that bolt came looks and the chainring gradually sawed through the carbon.

I'm guessing it wasn't an isolated incident.

You'll also notice that some cranks are shipping with a little nub in the chainring bolt that will not allow you to easily remove it or change the torque.

[fuzzalow]

Wow, 0.1mm thickness. Enough to make a measurable difference, but with tolerances found in the real world , not significant.

Campy made the 53 chainring with recessed relief where it mounts to the crankarm spider to narrow the gap between the chainrings. I'd guess to accommodate the narrower chain for 10speed. This washer fits to fill the gap made by the inboard shift of the big ring? Although the recess on the ring looks deeper than 0.1mm.

After a few grappas at lunch, 1.0mm, 0.1mm, same thing eh?

[ultraman6970]

This is so weird, i never seen that thing ever in 3 pairs of UT. 1 i sold, the other set is 1st gen centaur UT regular and the rd pair is an 11 athena. No washer so far, even a carbon squared tapper came w/o it.

Really interesting, that thing is so thin that u can just cut a tin can and make one from it.

[oldpotatoe]

It has to do with Torque issues and I'm pretty sure is a result of something that happend here in SF.

Campy was shipping UT cranks that were not torqued to spec and that "hidden" bolt was coming loose. I guy here in SF made campy foot the bill for his Cervelo because that bolt came looks and the chainring gradually sawed through the carbon.

I'm guessing it wasn't an isolated incident.

You'll also notice that some cranks are shipping with a little nub in the chainring bolt that will not allow you to easily remove it or change the torque.

I'm guessing it's very isolated. I have seen quite a few UT cranks, all with the little plastic thing in the hidden bolt hole(comes right out) and seen ZERO hidden bolts come out.

[dana_e]

I had a hidden bolt come out too.

After putting on some old rings, to save the "new " rings for a special day

my style. i guess