During the last few years, I've had a broken saddle rail every year or so. It always breaks just in front, or just behind the clamp. I wonder what the reason could be, and how I can avoid this.

Here are two pictures: Detail Overview

Some information:

  • I'm ~75 kg (165 lbs), so not exactly heavy
  • I'm only cycling on paved roads, no bumps whatsoever, roughly 12 km (7.5 miles) / day
  • My bike is an ordinary city bike, Shimano Nexus 7 speed, roller brakes, size 37-622 tires, no suspension
  • Most (affordable) saddles over here in The Netherlands are by a single brand 'Selle Royal'. Therefore I expect the size of the rails would be the same for all of them, and shouldn't be an issue
  • Two years ago I replaced the clamp, because the old one looked worn out. This seemed to solve my problem, but today, I found it broke again

I found this question (Saddle Rail Failure?) but was wondering if there could be other reasons.

UPDATE 20 aug 2018

I spoke to the guy at the bicycle shop. According to him it is probably caused by a combination of the rails not being centered properly, and maybe also the way I ride over (speed)bumps. So Andrew, you were right after all, I guess (although I would have to wait another year to be sure ;-) ).

  • What kind of bicycle? Tire size? Suspension? How do you ride over bumps? Do you leave your weight on the saddle or do you take your weight off the saddle? Jul 31, 2018 at 19:12
  • @andrew, I updated my question. I'm not sure what kind of bumps you're referring to, I can only think of speed bumps, but with a size of say, 2m and a speed of 20 km/h that wouldn't be a problem right? I'm definitely not getting out of my saddle for those 😉.
    – Berend
    Jul 31, 2018 at 19:51
  • 3
    I wonder if you ride with your body all the way forward on the saddle, placing a lot of torque on the rail. This would probably be because the frame is too large for you or the handlebar is offset too far forward. Jul 31, 2018 at 22:27
  • 1
    @Swifty This morning I paid extra attention to bumps, and indeed I found a tree root that had pushed the pavement up a few inches. I'm calling the papers :-)
    – Berend
    Aug 1, 2018 at 14:13
  • 3
    I had the same problem once. What solved it for me was to lower the nose of the saddle. When you ride with a high nose, you tend to put a lot of weight on the nose. When you ride with a low nose, you tend to put more weight on the rear part of the saddle. I did not believe that this could help at the time, but time has proven this strategy to be correct. Aug 1, 2018 at 14:16

2 Answers 2


The clamp in your seat post is unusually narrow, and this generates higher than normal high bending forces on the seat rails. A seat post with larger clamp should solve this problem.


Looks like a cheap clamp with only a single bolt. I think the best option would be to get a proper seat post with two bolts and tighten them to the correct torque with a torque wrench.

Saddle rails usually don’t break. I’m not even aware of any stronger or otherwise reinforced options (e.g. for heavy riders).

  • That may be so, but even a cheap clamp shouldn't break so often. I'll certainly look into a more sturdy type, but I think it will at best only fix the symptoms, not the root cause.
    – Berend
    Aug 1, 2018 at 14:09
  • It's not the clamp but the saddle rails that breaks.
    – ojs
    Aug 1, 2018 at 17:18
  • A cheap clamp could have insufficient clamping force on the rails, thus allowing one rail to flex more than the other (e.g. when loaded sideways) which puts more load on a single rail. This could also exacerbate fatigue wear. It’s hard to estimate from the photo but I think quality clamps are also wider/longer and have deeper grooves.
    – Michael
    Aug 1, 2018 at 17:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.