Bicycle Mechanics - Seatpost size

The micro adjust clamp of my seatpost often slips my 200+ pounds hit a hard bump (little ridge things are worn down). I was going to replace the seeatpost but noticed that neither Nashbar or Performance carried the right size. The seatpost is stamped 31.4. It's from a 1996 Mongoose NX73 mountain bike. Are 31.4's still out there? Or, will a 30.9 or 31.6 work without needing shims?

Thanks,

you could probably squeeze in a 31.6... i've put 26.8 seatposts into 26.6 frames without too much difficulty. however i am not saying that is what you should do, nor am i saying that it's healthy for the frame.

Originally posted by blwyn
The micro adjust clamp of my seatpost often slips my 200+ pounds hit a hard bump (little ridge things are worn down). I was going to replace the seeatpost but noticed that neither Nashbar or Performance carried the right size. The seatpost is stamped 31.4. It's from a 1996 Mongoose NX73 mountain bike. Are 31.4's still out there? Or, will a 30.9 or 31.6 work without needing shims?

Thanks, There are a couple Kalloy 31.4s in the QBP. You may need a hammer to get the 31.6 in and don't come asking how to get it out.Nothing wrong with shims.Use cheap beer can.

If a 31.4 cannot be found then I would suggest having your local bike shop hone the seattube out to a 31.6. It is important not to use a seatpost that is too small as it could cause the frame to crack due to the extra compression needed to wrap the smaller post, and it will likely slip anyhow. If you cannot find a suitable post that is the right size have it honed (shouldnt cost much) - hopefully the mechanic will know what to when you ask him to do this. That is the best solution for both you and your frame. Good Luck.

-Ryan

Thanks for the suggestions. I can't imagine any of the local mechanics honing out the frame. They are more of the parts changer variety of mechanic than machinists. So, I'll look for one of the Kalloy's, and if that doesn't pan out I guess I'll have to drink a few beers. My wife suggested a soda can might work, but what does she know about good shim stock anyhow? A beer can it wll be!