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Front derailleur clamp thingamyjig - what size?

daniel_bdaniel_b Posts: 11,412
edited 16 April in Workshop
Afternoon all,

I need a new clamp for my turbo bike, and will also be changing the derailleur at the same time.

Something like this:

I have measured the seat tube diameter right above where this is currently fitted at 35.0mm.

So my question is would a 34.9 suffice, or should I be looking at the next size down, so it can be cinched up nice and solid - 0.1mm seems a tad risky for adequate tightening room.
Felt F70 05 (Turbo)
Marin Palisades Trail 91 and 06
Scott CR1 SL 12
Cannondale Synapse Adventure 15 & 16 Di2
Scott Foil 18


  • lesfirthlesfirth Posts: 1,381
    I would expect this clamp to be for a 34.9mm seat tube.
  • trevor.hall12trevor.hall12 Posts: 388
    You get shims/adaptors
    to wrap around if it's too big ,if you feel its not clamping right just put one on
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