Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 03-09-11, 10:35 AM   #1
phil15241
Senior Member
Thread Starter
 
Join Date: Jul 2005
Bikes:
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
1" to 1-1/8" soda can stem shim?

I currently have a 1 inch steerer and a 1-1/8 inch stem. Instead of buying a shim, I was wondering if it was okay to make my own shim out of a soda can. To me, an 1/8 of an inch isn't a huge gap to fill. What are your thoughts?
phil15241 is offline   Reply With Quote
Old 03-09-11, 10:41 AM   #2
AngelGendy
Nipples of Steel!
 
AngelGendy's Avatar
 
Join Date: Feb 2011
Location: ABQ
Bikes: Borthwick, Specialized, Ross
Posts: 414
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Any LBS will have the correct shim, soda cans may be too soft, $2 is cheaper than a bent frame....
AngelGendy is offline   Reply With Quote
Old 03-09-11, 10:45 AM   #3
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 19,730
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 466 Post(s)
9/8-8/8=1/8 diameter, half that is a 1/16th, difference in radius,
shim has to be that thick , soda-pop cans are way thinner, so ..

So, .. +1. Just go Buy the right shim
fietsbob is offline   Reply With Quote
Old 03-09-11, 10:47 AM   #4
corkscrew
Senior Member
 
Join Date: Mar 2009
Location: Boise, ID.
Bikes:
Posts: 1,252
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Shims are cheap - hell I bought one only to find that my new stem came with one.
corkscrew is offline   Reply With Quote
Old 03-09-11, 10:57 AM   #5
BCRider
Senior Member
 
BCRider's Avatar
 
Join Date: Mar 2008
Location: The 'Wack, BC, Canada
Bikes: Norco (2), Miyata, Canondale, Soma, Redline
Posts: 5,456
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The number of layers you'll need to fill that gap will make the soda can shim idea a non starter. The resulting stack of layers will be far more flexible than you imagine since it'll be very difficult to insert the last layer or two that you actually need to fill the gap properley. It may not look like much of a gap to your eyes but that is your lack of metal working experience coming into play. On wood projects a '32nd or '16th here and there isn't a big deal as wood is flexible. But with metal fits you need to be worried about a thou or two. That's a whole different level of acceptable tolerances. This is why seat posts come in 0.2mm size steps.

So this is not the place to go cheap. Get yourself the proper shim.
BCRider is offline   Reply With Quote
Old 03-09-11, 11:08 AM   #6
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 29,688
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 232 Post(s)
Like the others I agree that given the stakes and the economics you should just go out and buy the right shim. It isn't that you couldn't build up 1/16" with soda cans, but that you need good uniformity of thickness along with flex so the stem clamp can compress the shim onto the stem.

Shims made for the job are nicely concentric, and split in the back to compress along with the stem. I simply can't imagine not buying one unless it's an emergency someplace in the outback.

In that case the best shim can be made by winding gummed carton tape (wet so the layers stick) onto an oiled steerer (so it doesn't stick) until it's built up to the right thickness. Let it dry and stabilize, then slide off and trim the length to fit within the stem, and carefully make a 1/16" slot along the length for compression.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.

Last edited by FBinNY; 03-09-11 at 11:14 AM.
FBinNY is offline   Reply With Quote
Old 03-09-11, 02:38 PM   #7
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Bikes: 1987 Bianchi Campione
Posts: 28,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Any decent LBS should have the actual shims floating around. Shimming with soda cans, for something as critical as the handlebars is NOT a good idea.
operator is offline   Reply With Quote
Old 03-09-11, 10:55 PM   #8
daveizdum
.
 
Join Date: Jun 2009
Bikes:
Posts: 199
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
An unscrupulous LBS did this to me once. I didn't know they had done it until I disassembled the fork for cleaning. As was mentioned above, a soda can is too thin. The LBS dealt with this by folding the can over itself several times. What I found was a messy wad of folded and crumpled aluminum.

So the answer to your question is yes, you can do it, because it was done to me and I didn't know it for several years. But I don't recommend it, because you may not have the same luck I did, and a real shim doesn't cost much.
daveizdum is offline   Reply With Quote
Old 03-10-11, 03:11 AM   #9
zzyzx_xyzzy
headtube.
 
zzyzx_xyzzy's Avatar
 
Join Date: Sep 2008
Bikes:
Posts: 804
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm assuming you have a threadless fork and headset, else the question doesn't make a lot of sense. What hasn't been mentioned, is that on a threadless headset, it's pretty essential that the bottom face of the stem be aligned square to the steerer. Don't see how you can achieve that while wrapping up tape or 19 layers of soda can (did you know soda cans these days are about 0.08mm thick? They're about right for putting 27.2 seat posts in frames reamed to 27.4.)
zzyzx_xyzzy is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:22 PM.