Replacement seatpost clamp: Thomson

Spikes

New member
Today I found a nice solution for Chance frames that need a new seatpost clamp. It works for frames with the "tab" (through which the bolt goes) and probably for frames without.

The Slim Chance I restored came with the original seatpost clamp, but it looked hideous. I decided to order a lookalike at danscomp. I looked great but unfortunately, the hex bolt is not very strong. The tab on the frame striped a bit of the hex bolt, killing the complete clamp. Back to square one.

The backward facing tab on the frame can be removed, but I didn't want too. I was afraid to damage things. This tab is not exacly in the middle. It is slightly off centre. I saw the Thomson clamp and noticed it has a gap off-centre on the same side. I ordered one in black, size 28,6 and it fits like a glove! A great solotion for your Fat or Slim. It is really well made, is very elegant and even comes in silver if you like.
 

northerndave

New member
I've got to find a replacement clamp for frame I've just picked up. Top suggestion although the slot on the Thomson looks almost too off center. Have you got a picture fitted at all?
 

Spikes

New member
I've got to find a replacement clamp for frame I've just picked up. Top suggestion although the slot on the Thomson looks almost too off center. Have you got a picture fitted at all?

To my knowledge there are two types of clamps for the bikes from 1990+. One with a tab that is off-center and one without a tab, but with two small ridges at both sides of the slot. The latter usually had a green seal and/or a small plastic sheet glued onto.

The Thomson fits the one with the off-center tab perfectly. I put it on a 1991 Slim Chance and it was a perfect match. On my 1999 Chris Chance road I have the more modern seatpost with the green seal. I had to file of the two small ridges at the rear and. It took me 5 minutes with a Dremel.
 

northerndave

New member
Take makes sense. My 97 buck has the reenforced gusset and no tab and my Yo has the tab. I think all had the green seal collar though.
 
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