Breaking seat bolts

[Jisch]

I can't remember if I posted here or not about this? I know I posted over on the Rocky Mountain group in MTBR. Apologies if this is a repeat...

I have a Rocky Mountain Switch. Its a 6x6 AM/FR rig, but I ride mostly XC with it. I keep breaking the bolt that holds the seat onto the seatpost. It breaks when I am sitting down on it and roll over rocks or whatever. Basically it feels like the seat is acting like a lever and snaps the bolt. I've broken 3 so far. I don't have to tell you that riding without a seat sucks.

Its a Easton EA50 seatpost which has a bit of layback in the clamp, the seat is a Coda cheapie. I've tried centering the seat on the post to negate the leverage, but it doesn't seem to help. I just wonder if this seat/seatpost combo is no good.

Anyone go through something like this? I'm carrying spare bolts with me in my 'bak, which is a pretty crappy alternative to fixing the problem (there are delicate parts of my body which get impacted by the seat when the bolt breaks).

John

[MTBME]

I had a similar problem a long time ago that I solved by replacing with titanium bolts. Costs a little more but they held up better. But for a long term fix I would look for another seat post.

[Jisch]

Where did you get the titanium bolt? I'm sure I could go to the LBS and pay $20 for one... I got the replacements I'm using at Home Depot for $1.29 each.

John

[C.P.]

Jisch,

As I was reading your first paragraph, I was thinking it must be an Easton post w/ 1 clamp bolt (seen it before). I think I would agree w/ MTBME, and just get a different post. Something with a 2 bolt style clamp (rather then a single bolt)...notice that Easton changed the EA50 to a 2 bolt style for '06 (http://www.eastonbike.com/PRODUCTS/POSTS/post_ea50_%2706.html).
OTOH, If you're dead set on keeping it, go to a good hardware store, and find a hardened bolt to match the one that's there (if a socket cap screw in grade 8 is avail, that would be the hardest, but even a grade 5 would do). At least it might be a cheaper option then the TI route...

[Jisch]

I was thinking it must be an Easton post w/ 1 clamp bolt (seen it before). I think I would agree w/ MTBME, and just get a different post. ..

This sounds like the perfect justification to buy a new bike part! I wait for opportunities like this to appear. Two bike rides with my wife have been shortened due to bolt breakage. That should be enough evidence that a new post is needed.

The thing is I have a really nice Thomson post, but its the wrong diameter. I think I'll ebay that one and get another one. I could really use a longer one anyway - two reasons to get a new part - yes!

John

[heckler19]

John-

You can't beat Thomson. BTW, if the Thomson's a 27.2, you can probably shim it to fit your bike. Bikeman in Maine carries various sizes: http://www.bikemannetwork.com/biking/c/COMPSPSHM.

Al