31.8 to 28.6mm front derailleur adaptor, shim?
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31.8 to 28.6mm front derailleur adaptor, shim?
I bought a 31.8 FD on ebay by mistake. I would rather make it work than re-sell it. I know you can buy a shim to make the reduction but it cost almost as much as the derailleur.
Is there another,(cheaper) solution?
Is there another,(cheaper) solution?
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Which 31.8 F.D did you buy? The tourneys come with a range of shims that can take the 34.9 derailleur all the way down to 28.6. The only thing i'm not sure of if the plastic brackets that hold the shim in place are compatible with your derailleur.
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I've used the Tourney/Acera/Alivio shims on a Dura Ace (mine), so I would guess it would work on a 105.
You can also MacGyver a shim with a Coke can and a pair of tin snips.
If your local shop won't give/sell you one, let me know... I'll see if I can dig one up.
You can also MacGyver a shim with a Coke can and a pair of tin snips.
If your local shop won't give/sell you one, let me know... I'll see if I can dig one up.
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I could possibly MacGyver a shim. Perhaps with a strip of inner tube and then it wouldn't slip. I guess the rubber would decay after awhile and lose it's position but by then I could get the real mccoy.
Thanks for the idea PlatyPius.
Thanks for the idea PlatyPius.
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I've used a heneiken can to shim a 31.8 down. It worked fine. It was just annoying as hell if you ever had to adjust the derailleur position/rotation.
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I pulled the same fummducker as TMH a while back and I wasn't willing to try to find the same model with the correct clamp. A PVC shim worked perfectly the first time, and it's kept working for 6 or 7 years. I painted it black to match the frame, but you can make it out here:
https://home.comcast.net/~jeff_wills/...es/bike025.htm
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If you have a local shop, check with them. I know I have 3 or 4 of those shims in a drawer on my bench. Leftovers from replacing broken/worn out derailleurs. I also remember that the 105 triple I put on my touring bike had one of those shims in the box as well. You shouldn't run into any compatibility issues.
#9
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From a touch of math I make this out to be a .063 inch shim that you need. That's pretty much spitting distance to a 1/16 shim. If you can get some 1/16 or .060 to .065 sheet metal or HARD plastic it would make an acceptable shim. But I totally agree that you don't want to use rubber or electrical tape or anything else that is soft or will creep over time.
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Ive got some of the shimano shim sets in my box of bits. the plastic frames are quite wide. so presumably would fit mechs that are thinner section.
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I went to 2 local shops today and the reply was, we can order it for you. I can do that. I think I have something that will work though.
The plastic part that Velox rim tape is wound on. I cut the rib out of the middle on 2 of them. They are thin enough to be flexy so it was easy to go on the tube. It seems they will do the job.
Good thing is the seat tube is white so I might not even have to cut it down to hide it.
The plastic part that Velox rim tape is wound on. I cut the rib out of the middle on 2 of them. They are thin enough to be flexy so it was easy to go on the tube. It seems they will do the job.
Good thing is the seat tube is white so I might not even have to cut it down to hide it.
#13
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I went to 2 local shops today and the reply was, we can order it for you. I can do that. I think I have something that will work though.
The plastic part that Velox rim tape is wound on. I cut the rib out of the middle on 2 of them. They are thin enough to be flexy so it was easy to go on the tube. It seems they will do the job.
Good thing is the seat tube is white so I might not even have to cut it down to hide it.
The plastic part that Velox rim tape is wound on. I cut the rib out of the middle on 2 of them. They are thin enough to be flexy so it was easy to go on the tube. It seems they will do the job.
Good thing is the seat tube is white so I might not even have to cut it down to hide it.
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I just took a seat post shim I had and split it into two and then spred it a bit to shim a 31.8 105 FD to 28.6.
Works great.
Works great.
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I recommend metal as a shim, not rubber or plastic.
You don't need tin snips for a coke can. It's extremely thin. You can use regular scissors, and it's still extremely easy to cut.
It takes me a lot of trial and error to size my shims, but it definitely isn't rocket surgery.
You don't need tin snips for a coke can. It's extremely thin. You can use regular scissors, and it's still extremely easy to cut.
It takes me a lot of trial and error to size my shims, but it definitely isn't rocket surgery.
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Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.