seat post collar position?

on-yer-bike

What is the correct way to position the gap in the collar in relation to the gap at the the top of the seat tube? I have had a carbon seatpost crack in a steel frame right where the gap falls (yes I did use assembly paste). Does it actually make any difference to offset it?

ride_whenever

Generally you should line them up, if you dont then there is a lot more friction between the tube and collar as you tighten the bolt leading to either slipping seatposts or rounded bolts.

Try to always use a torque wrench for tightening anything carbon and check inside the frame for burrs. For cabon the less torque the better.

bondurant

Just to be contrary I've seen advice (from Thomson) for the seat post collar's gap to be on the other side of the seat post's gap on carbon frames, and lined up on metal frames. As per these instructions in fact:

http://www.bikethomson.com/wp-content/uploads/instructions/CollarFull.pdf

on-yer-bike

Bondurant wrote:

Just to be contrary I've seen advice (from Thomson) for the seat post collar's gap to be on the other side of the seat post's gap on carbon frames, and lined up on metal frames. As per these instructions in fact:

http://www.bikethomson.com/wp-content/uploads/instructions/CollarFull.pdf

This is why Im asking. Ive heard so many different views.

on-yer-bike

Actually Thomson say 180 degrees with carbon frame or carbon seatpost or both. They also say max torque 2.8 Nm which is very little indeed. Especially when you consider a Ritchey torque key is set to 5 Nm. I dont know if the Thomson collar works in a different way?

rrsodl

Bondurant wrote:

Just to be contrary I've seen advice (from Thomson) for the seat post collar's gap to be on the other side of the seat post's gap on carbon frames, and lined up on metal frames. As per these instructions in fact:

http://www.bikethomson.com/wp-content/uploads/instructions/CollarFull.pdf

That is exactly what I read one should do with a carbon fibre seatpost. I wish I bookmarked the link now.