Seat post not holding angle adjustment

[Kuma601]

The Gippieme "Sprint" seatpost is a one bolt type. Recently it has begun slipping allowing the saddle to tilt back. I can start the ride out with it being level and by the time I get home, it has tilted a few degrees. I have it quite snug but it still slips. Any suggestions on what I can do to eliminate this?

Nice 25.0 seatposts are far and few these days. I'd like a 2 bolt type but I don't know if this type existed in later times. I have a vintage 3T that also slips so my back-up is.

[Retro Grouch]

My first suggestion would be to try some blue loctite on the bolt.

[onespeedbiker]

Usually the problem with some 1 bolt seatposts (not grooved) is the mating services become too smooth so stop sliding even after the bolt is tight; I have a newer Nitto S-65 that has the same problem. The Campy Super Record have a grainy cast surface that held it in place. The best thing to do is rough up the mating surfaces or just throw a little dirt on the surface which works amazingly well. One thing that I have done when I have a slipping seatpost is to lay a half round bastard file one of the surfaces and bang it with a hammer; this will leave a hash-mark in the metal that will give the other surface something to bite on.

[JCavilia]

the roughing-up is probably good advice. In addition, you might want to tighten the bolt a lot more. I'm not sure where "quite snug" falls on the torque scale, but the recommended torque for single-bolt clamps is quite high. I think some manufacturers say in the range of 300 inch-pounds, or 25 foot-lb. With a short allen wrench that means on the order of 75 pounds of force at the end of the wrench. That's way more than I'd describe as "snug."

I use loctite for a lot of things, but here I don't think the problem is the bolt loosening. To get the most out of the torque I liberally grease both the threads and the interface between the bolt head and its socket. But don't get any grease on the mating surfaces of the clamp. In fact, before you rough them up, you might try degreasing them with a solvent like alcohol, then grease the bolt and torque it hard.

[tihsepa]

Get a Thomson. Problem solved. They are available in 25mm.

[Kerry Irons]

My first suggestion would be to try some blue loctite on the bolt.

My advice would be the opposite (sort of): grease the threads so that you can fully tighten the bolt. The odds are good that the bolt is not loosening so Loctite would not help.

[Kuma601]

I had it apart to look at it, it is indeed very smooth and over the time it has begun slipping, it is somewhat polished. Just backing the screw a 1/4 turn allows it to slide. I'll roughen up the mating surfaces and see how it goes.

Thanks!