Bicycle Mechanics - Sheared Saddle Bolt

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : Sheared Saddle Bolt


thompsw
05-21-09, 04:03 AM
On my ride yesterday, 65 miles into my 70 mile ride I had a huge surprise when I suddenly found myself standing, saddle-less. The saddle binder bolt (not the seatpost binder bolt) on my Easton EC90 31.6 layback seatpost had sheared. No, I didn't crash.

Has anyone run into this before ?

Some facts:

1) I built the bike about 2 months ago and have perhaps 1000 miles on it -- This bike is lightly used, most miles going on my rando-bike.

2) yes, it was torqued properly to spec, using a torque wrench

3) I weigh 135-140 pounds

I called Easton who is mailing me a new bolt. They had no questions about where I'd acquired the seatpost etc. leading me to wonder if this is a fairly common occurrence. However, having said that, the much much older EC90 seatpost in my other bike has not had a problem ... knock on wood.


z415
05-21-09, 08:46 AM
Um, my friend has the same problem, but it was a single speed mtb with a cheap generic seatpost. I'm guessing you just happened to be unlucky.

noglider
05-21-09, 09:47 AM
This is not the first such story I've heard. It sounds terribly dangerous, and you were lucky. I'm tempted to revert to two-bolt seatposts, though they are rare.


tellyho
05-21-09, 11:38 AM
Damn. It's a good thing you didn't find yourself standing with a seatpost up your ass.

If you just ride it that way, you'd save yourself 250 grams!

HillRider
05-21-09, 07:45 PM
I have an Easton EA50 aluminum two-bolt seatpost on one bike and with 10,000 miles there have been absolutely no problems and I've never heard of any common problems with any of the Easton Al posts.

I wonder if the carbon seatposts have lighter and/or smaller bolts.

thompsw
05-22-09, 04:51 AM
It's a pretty hefty bolt. I'm not sure what the actual measurement is, and of course it's metric, but it looks like about 1/4". As z415 said, I was probably just unlucky.

Without the saddle it would make for a great, lightweight, hill climbing bike ... for short steep hills that is !

noglider
05-22-09, 10:12 AM
From rec.bicycles.tech:



A friend had his break causing him to fall onto the rear wheel while
attached to the pedals and had his anus ripped open. Let your
imagination take care of the weight saving and convenience of a single
bolt.

Jobst Brandt


LINK (http://newsgroups.derkeiler.com/Archive/Rec/rec.bicycles.tech/2006-04/msg01750.html)