Stripped seat bolts

Tightening up the KH29 prior to a Muni ride last night, I noticed one of the under-seat bolts is spinning and won’t tighten, in this case, one of the four which fastens the seat to the seat post. That is, the hexagonal head of the bolt is spinning in its hexagonal hole in the plastic seat (under the foam), and so will no longer tighten. This is the second time I’ve had this problem with a plastic KH seat base.

Anybody have a similar problem, and, if so, how have you solved it?


I think it’s a pretty common problem. I thought about making up a couple of “U” bolts (a square U), one each side of the saddle, so they can’t spin, or even welding all four bolts onto a square metal plate. But it’s not happened to me yet, so I haven’t had reason to try it.

I think I’ve seen a thread about somebody who made a thicker metal plate for the bolt heads to grip onto (I haven’t taken a KH seat apart yet, but apparently the bolts are square-headed and are held still by square holes in a rather weedy metal plate, which strips).

I’ve put nyloc nuts on both my KH seats instead of the useless standard nuts, so they don’t need to be done up so tight to stop them falling off, and so far so good - no stripped bolts.


I had that problem…A CF base cleared it right up.

I’m afraid I’m thinking the same thing.

You wont regret it.


The CF is a great upgrade for any type of riding. Short of that your best option would be some double threaded u bolts (which apparently were stock on miyatas at one point) or just trying to attach the bolts some other way. Welding works but a lot of people find that when they take their cover off the plate is broken so there is nothing solid to weld onto (since they break at the front holes most often). Another option is taping the bolts down so they don’t spin, but this only works for a short time. On my CF (round holes) I just saturated the bolts with contact cement and put tape on top. It hasn’t failed yet (a year?).

go with the cf base, especially since you pretty much have to rip your seat apart (as like 4 of mine) to get at the head of those bolts.

if you have a dremel tool, you ‘might’ (i was able to once in about 7 bolts) be able to make a slot in the end of the offending bolt to hold with a screwdriver as you work the nut with a wrench.

get a cf base! you will be the happiest boy in the land