Saddle Sliding Back On Rails

[Hip Priest]

Over the last few weeks I've noticed that my saddle gradually moves backwards during long rides. I start off comfortable, and end up 2-3cm back, having to stretch foward to get on the hoods.

I've tried the obvious thing of greasing the bolt and tightening it hard using a long hex key, but all to no avail. I just wondered if anybody had any other suggestions before I splash out on a new seat post.

 

[Norm]

I'd try wrapping something thin round the rails, an old inner tube or some electrical / masking tape maybe.

 

[Pauluk]

Do you think that the clamp is failing to grip the seat rails? When the clamp is tight, is there a small gap between the top clamp jaw and the bottom clamp jaw.

 

[cyberknight]

I'd try wrapping something thin round the rails, an old inner tube or some electrical / masking tape maybe.

Exactly what i did, solved the problem.

 

[Hip Priest]

Thanks to you all. The tape / tube sounds promising. Which one worked for you cyberknight, my fellow back-sliding hombre?

 

[cyberknight]

Black electrical tape as it was the first thing to hand, i just wrapped the part of the rail i wnated to clamp and its not moved since.

 

[Hip Priest]

Right, well you and norm may have saved me a few quid here. I've got some electrical tape in the garage. Cheers.

 

[User482]

I tried tape but it just slid back with the saddle! After tightening the bolt, try rocking the saddle back and forth, quite hard. I found that this allowed the bolt to be tightened another half turn. So far, so good.

 

[Hip Priest]

I tried tape but it just slid back with the saddle! After tightening the bolt, try rocking the saddle back and forth, quite hard. I found that this allowed the bolt to be tightened another half turn. So far, so good.

Cheers.

I'm test-riding the leccy tape in the morning. If that fails at least there's another possible solution between me and the new seat post.

 

[Globalti]

Tape won't work, it will just gradually creep.

You need to investigate the problem properly - why are the clamps not clamping the rails securely? Has one of the clamps got a crack or been distorted?

 

[mickle]

Its not uncommon for the clamping compnents of a seat post head to become distorted by overtightening if made of steel. For which the second best solution is to reform the offending part(s) using whichever blunt tools fall soonest to hand.

 

[ttcycle]

I had the same problem, the surfaces of the clamp and the seat post had no friction area so eventually especially due to bumpy roads the saddle would move back and tilt after a ride despite being tightened up thoroughly.

LBS offered the perfect solution- sticky backed sandpaper - a small strip stuck on either side of the seat post so that the clamp has a surface with friction to hold onto- not had a problem since.

 

[Globalti]

Shim the rails with a cut-up Coke can.

 

[lpretro1]

I wouldn't faff about with shims and bits of sticky back plastic or whatever. The little grooves in a seat post clamp get worn over time and no amount of tightening will get around that. If there is the slightest bit of movement then all the force is going through the seat clamp bolt. It will finally break and if it goes then it could be a very, very nasty outcome. Get a new post with a new clamp - preferably one with a twin bolt adjuster - safer.

 

[Hip Priest]

I wouldn't faff about with shims and bits of sticky back plastic or whatever. The little grooves in a seat post clamp get worn over time and no amount of tightening will get around that. If there is the slightest bit of movement then all the force is going through the seat clamp bolt. It will finally break and if it goes then it could be a very, very nasty outcome. Get a new post with a new clamp - preferably one with a twin bolt adjuster - safer.

Thanks - I think this worth considering. Quick seat post question - My current seatpost is 27.2mm / 300mm. I know I'll need a new one of the same diameter, but how important is length?