I have a specialized allez sprint with a proprietary seatpost. The clamp only has one bolt. I have it tightened to 13.6 nm (the max torque listed on the seat post) however after a ride it always begins to tilt a few degrees back. I have put carbon assembly paste on the interior of the clamp, which seemed to help a bit but still seems to slip. What’s can I do to prevent this. I am a relatively large rider. (6ft 1, 195lbs
by Foreign_Cricket8778
8 Comments
Longshot: How are you tightening to 13.6 Nm? In one continuous smooth motion, or are you starting and stopping a ~~low~~lot? If you’re starting and stopping much after you cross the ~10 Nm point, get an extension on your wrench so you can clear the saddle, and spin non-stop. Static friction will bite you in the ass and show higher torque than is actually achieved when you start/stop.
EDIT: spelling
Correct me if I’m wrong,
I think that seatpost clamp might be for oval rail seats, i.e no matter how hard you tighten the screw, the clamp won’t hold the rail snuggly on your round rail saddle.
My DIY instinct would be to wrap some electrical tape on the rails to beef them up a little.
I’ve had massive issues with the this style of cup and cone seat post clamp. I’m glad someone else has the problem so I know it isn’t just me, but yet you weight less AND your seat is much further forward. I think these style fundamentally do not work unless you’re lightweight.
Its kinda sad how these seat clamps have these issues, it is so easy to get it right with the top clamp style or double bolt style.
Try adding some carbon grip paste should help stop the slipping
What kind of carbon paste are you using? There’s differences between brands. I use Motorex, that has a rather fine texture for creaky parts and Dynamics, which has bigger particles to prevent actual slippage.
The latter helped on my Ritchey 1bolt seatpost, that had a similar clamping mechanism.
I have this seatpost, 13.6 Nm and just a drop of carbon paste. Tightens from the right side.
Are you sure there isn’t another bolt? I have a similar style seat post and mine has another one on the back side to change the tilt.
Carbon paste