Custom shim needed - any recommendations?
Custom shim needed - any recommendations?
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Discussion

option click

Original Poster:

1,178 posts

255 months

Monday 25th January 2016
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I'm trying to find somewhere / someone who will make me a one-off steerer tube shim - everyone who has got back to me so far has said they can't help, presumably because they only do bulk orders.

I need something like this to take a 1 1/16th inch steerer up to 1 1/8:


Does anyone have any recommendations?


rhinochopig

17,932 posts

227 months

Monday 25th January 2016
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You could use the skin of a coke can if you can't find a proper one. Layer the skins until you achieve the right diameter.

option click

Original Poster:

1,178 posts

255 months

Monday 25th January 2016
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That had crossed my mind, but only as a last resort as it seems like a bit of a bodge.

With these feet

5,733 posts

244 months

Monday 25th January 2016
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Can't you just roll a piece of Aluminium to do that?

richardxjr

7,561 posts

239 months

Monday 25th January 2016
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^ yeah that. 1/16" is approx 1.5mm, so you need some 0.75mm thick alu. Beer can shims work fine on seatposts so would also work.



Edited by richardxjr on Monday 25th January 15:14

ALawson

8,054 posts

280 months

Monday 25th January 2016
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Could you 3d print one?

http://www.racewaredirect.co/


option click

Original Poster:

1,178 posts

255 months

Monday 25th January 2016
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Have ordered some 0.8mm sheet to see how that works.

matt-ITR

892 posts

218 months

Monday 25th January 2016
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Trying to think what the possible use could be and can't think of anything where it might be sensible to use a shim!

option click

Original Poster:

1,178 posts

255 months

Tuesday 26th January 2016
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Pretty straightforward really, one of my bikes has an unusual steerer size and I want to use a standard 1 1/18th stem.
Using shims is absolutely fine.

Edited by option click on Tuesday 26th January 10:58

BadgerBenji

3,534 posts

247 months

Tuesday 26th January 2016
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matt-ITR said:
Trying to think what the possible use could be and can't think of anything where it might be sensible to use a shim!
Don't ever do a headgasket on a Honda RC45 as the cams are gear driven, and the cam carrier is then shimmed to get the correct amount of mesh on the gears. Shims are used in lots of engineering it's not a bodge, it's just a way to take up wear/make adjustments.

gazza285

11,116 posts

237 months

Tuesday 26th January 2016
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matt-ITR said:
Trying to think what the possible use could be and can't think of anything where it might be sensible to use a shim!
Got any Shimano hubs?

Fastpedeller

4,339 posts

175 months

Tuesday 26th January 2016
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How about a piece of 28mm copper tube from plumber's merchants, or plastic tube?

Barchettaman

7,253 posts

161 months

Tuesday 26th January 2016
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A seatpost shim from 27.0mm to 28.6mm would be ideal, but I can only find 27.2mm to 28.6mm.

I would bet it would work OK anyway.

matt-ITR

892 posts

218 months

Wednesday 27th January 2016
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gazza285 said:
Got any Shimano hubs?
Bit different to a steerer tube.
I've used them several times on a seatpost - but for some reason I think (incorrectly it seems) that it seems a bit wrong on a steerer tube where its not static.

option click

Original Poster:

1,178 posts

255 months

Thursday 28th January 2016
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Barchettaman said:
A seatpost shim from 27.0mm to 28.6mm would be ideal, but I can only find 27.2mm to 28.6mm.

I would bet it would work OK anyway.
I did think about that, and I know of someone who did this and then filled the remaining tiny gap with a Coke can spacer
http://www.retrobike.co.uk/forum/viewtopic.php?t=1...

I'd prefer to do something that's only one shim - going with multiple layers seems more risky.
Anyway, the Aluminium sheet arrived yesterday so I'll post the results up here..

TwistingMyMelon

6,507 posts

234 months

Thursday 28th January 2016
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Decent bikeshop shirley? I know my one would have loads of bits lieing around to test/bodge it through to at least try different options

option click

Original Poster:

1,178 posts

255 months

Saturday 30th January 2016
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AlmostUseful

3,319 posts

229 months

Sunday 31st January 2016
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That's a very neat resolution.

Barchettaman

7,253 posts

161 months

Sunday 31st January 2016
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Good work there, well done

thanetspeedshop

503 posts

219 months

Monday 1st February 2016
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Robert M. Pirsig said:
His handlebars had started slipping. Not badly, he said, just a little when you shoved hard on them. I warned him not to use his adjustable wrench on the tightening nuts. It was likely to damage the chrome and start small rust spots. He agreed to use my metric sockets and box-ends. When he brought his motorcycle over I got my wrenches out but then noticed that no amount of tightening would stop the slippage, because the ends of the collars were pinched shut.

"You’re going to have to shim those out," I said.

"What’s shim?"

"It’s a thin, flat strip of metal. You just slip it around the handlebar under the collar there and it will open up the collar to where you can tighten it again. You use shims like that to make adjustments in all kinds of machines."

"Oh," he said. He was getting interested. "Good. Where do you buy them?"

"I’ve got some right here," I said gleefully, holding up a can of beer in my hand.

He didn’t understand for a moment. Then he said, "What, the can?"

"Sure," I said, "best shim stock in the world."

I thought this was pretty clever myself. Save him a trip to God knows where to get shim stock. Save him time. Save him money.

But to my surprise he didn’t see the cleverness of this at all. In fact he got noticeably haughty about the whole thing. Pretty soon he was dodging and filling with all kinds of excuses and, before I realized what his real attitude was, we had decided not to fix the handlebars after all.

As far as I know those handlebars are still loose. And I believe now that he was actually offended at the time. I had had the nerve to propose repair of his new eighteen-hundred dollar BMW, the pride of a half-century of German mechanical finesse, with a piece of old beer can!

Ach, du lieber!

Since then we have had very few conversations about motorcycle maintenance. None, now that I think of it. You push it any further and suddenly you are angry, without knowing why.

I should say, to explain this, that beer-can aluminum is soft and sticky, as metals go. Perfect for the application. Aluminum doesn’t oxidize in wet weather...or, more precisely, it always has a thin layer of oxide that prevents any further oxidation. Also perfect.

In other words, any true German mechanic, with a half-century of mechanical finesse behind him, would have concluded that this particular solution to this particular technical problem was perfect.

For a while I thought what I should have done was sneak over to the workbench, cut a shim from the beer can, remove the printing and then come back and tell him we were in luck, it was the last one I had, specially imported from Germany. That would have done it. A special shim from the private stock of Baron Alfred Krupp, who had to sell it at a great sacrifice. Then he would have gone gaga over it.

That Krupp’s-private-shim fantasy gratified me for a while, but then it wore off and I saw it was just being vindictive. In its place grew that old feeling I’ve talked about before, a feeling that there’s something bigger involved than is apparent on the surface. You follow these little discrepancies long enough and they sometimes open up into huge revelations. There was just a feeling on my part that this was something a little bigger than I wanted to take on without thinking about it, and I turned instead to my usual habit of trying to extract causes and effects to see what was involved that could possibly lead to such an impasse between John’s view of that lovely shim and my own. This comes up all the time in mechanical work. A hang-up. You just sit and stare and think, and search randomly for new information, and go away and come back again, and after a while the unseen factors start to emerge.

What emerged in vague form at first and then in sharper outline was the explanation that I had been seeing that shim in a kind of intellectual, rational, cerebral way in which the scientific properties of the metal were all that counted. John was going at it immediately and intuitively, grooving on it. I was going at it in terms of underlying form. He was going at it in terms of immediate appearance. I was seeing what the shim meant. He was seeing what the shim was. That’s how I arrived at that distinction. And when you see what the shim is,in this case, it’s depressing. Who likes to think of a beautiful precision machine fixed with an old hunk of
junk?