Riders and mechanics fitting or replacing a front derailleur clamp on a bike with a 31.8 mm seat tube.
This is a 31.8 mm front derailleur clamp in a silver finish. It closes around a 31.8 mm round seat tube and tightens with a hex bolt, and the tab on the clamp has a bolt hole for a braze-on style front derailleur.
It is sold individually, so you get one clamp. Check the diameter before you fit it: the clamp is made for a 31.8 mm tube and will not grip a smaller or larger one properly.
31.8 mm diameter
Sized for a 31.8 mm round seat tube.
Braze-on style mount
The tab has a bolt hole for a braze-on style front derailleur.
Hinged, hex bolt
A hinged clamp that closes with a hex bolt, as pictured.
Clamp
Great for
Maybe not for
Made for a 31.8 mm diameter round tube only, and sold as a single clamp. Measure your seat tube before you order.
Measure first, then tighten evenly
Measure the seat tube with a caliper before you fit the clamp, because tube sizes such as 28.6, 31.8 and 34.9 mm are easy to mix up. Set the derailleur height and angle before you do the clamp bolt up, and tighten it firmly without over-cranking, as too much force can mark or dent a thin-walled tube.
