Snapped saddle bolt

Tony666

There I was, happily five miles into a 65 mile ride when I heard a loud snap come from my bike. The saddle then wobbled and fell off. I’m surprised I didn’t fall off as well as I was trying to brake and unclip while standing up, fearing the seat post would disappear where the sun don’t shine. Indeed at first I couldn’t get my feet unclipped and was looking for an area to gracefully fall over sideways!

I did stop safe and sound though and then looked at my bike expecting the worst. My first thoughts were that the carbon seat post had snapped as my saddle was lying about 20 feet in the road behind me. Luckily it wasn’t, it was the bolt holding the saddle onto the post that had snapped right through.

I have no idea how or why this happened. I wasn’t going fast (luckily as I don’t like to think what would have happened if it had snapped while I was going downhill at speed). My bike (a Felt) is only two years old and is always well maintained and kept dry. The last time I adjusted the saddle was about three months ago so I wonder if I might have over-tightened the bolt. But in all my years of riding, both now and as a kid I have never had this happen before. Has anyone else?

Bunneh

This has happened to me once on the old MTB. I was struggling up a long uphill, sat down; as I pedalled the saddle just fell off, as did I. Thankfully there were no cars directly behind me and I managed to get up, pick up the saddle and checked what had happened.

Looking at the seatpost I saw that the bolt that goes through the fitting to secure the saddle had somehow sheared off. I was lucky really, I was only a few miles from home so just stood up and rid home. On the way back a guy pulled over and said he'd seen what had happened and offered me a lift - there was no way my bike would fit in his boot so I just thanked him and declined; never accept lifts from strangers unless it's a cute blonde woman in a BMW.

I have found that if I sit back too roughly the seat will pull back a little making it arch up, so maybe that's what caused the shearing off. The seatpost I have now has 2 bolts, one at either side, so I hope that's much safer.

*edit* I keep spelling 'pedal' wrong...WHY?!

orderodonata

I've never had a bolt shear on my bikes, but I've seen plenty of them in a former life in engineering.

When I got a carbon bike I bought a torque wrench and I always use it now for bolts, but it still surprises me how "not tight" a bolt has to be sometimes!

If you greased the bolt that makes it easier to over tighten without realising, or maybe corrosion caused by different metals? Might just have been a duff bolt though, hard to say.

Hope you got home ok?

Tony666

Yes thanks my wife came and got me :oops:

Ok, well new bolt is fitted and me thinks I need to take the bike out for a test ride :P

Monty Dog

I once rode 35 miles home over the Hampshire downs with my saddle in my back pocket - my glutes were killing me by the time I got home! There are a number of reasons bolts snap, particularly due to over-tightening, stress-cracking and corrosion.

abike

I had this happen to me twice so far, on a single Surly. The first time it was an aluminum bolt, the second a stainless steel A2-70 THE bolt. I'm wondering if there is a stronger (titanium) piece that can take the stress. Don't they test these things before they use them? It was a near disaster each time, with injuries.

Moonbiker

Same happened to me ITM brand post. Had to buy a new seat post as I lost the shaped metal bolt top bit that clamped the rails somewhere on the road.