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I weigh about 120 kilos. Saddle rails bend.

I don't care about the weight of the saddle, just how strong the rails are and how comfy it is (I admire but have no desire to emulate people who cycle standing up. I have a bmi over 30, give me some credit for voluntarily cycling 20 miles a day)

Ne Mo
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    There are tons of clydesdales on bse, so welcome! You might want to look at seats sold for either touring bikes or mountain bikes. Even a 50kg person when jumping off a ledge can exert several Gs, and effectively weight 200kg or more. The only thing to avoid would be cheap saddles and racing saddles. Adding a suspension post or getting a suspended saddle (with springs or dampers) will also reduce the forces on the saddle rails. – RoboKaren Aug 25 '17 at 09:17
  • I know a guy your weight and with the same problem and he went for massive, thick (as in, thicker than most found nowadays) steel rails as were found on bmx saddles years ago (before the weight watch trend). It helps, and he finds the seat comfortable, but I can't really make this into an answer as I wouldn't know where to find such saddles fitting your seat tube nowadays. – stijn Aug 25 '17 at 09:38
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    I would think steel. I had an aluminum saddle fail and it hurt. – paparazzo Aug 25 '17 at 09:51
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    @RoboKaren I can back you up on tourers -- the rails on mine are CrMo. – Chris H Aug 25 '17 at 10:58
  • If your budget allows, I'd look for a good full suspension frame (i.e. both front and back wheel mounted on shock absorbers). I'm not a doctor, but I'd suppose that forces which lead to regular saddle rails getting bent are not a good thing for your spine either. (I guess that the rail bending comes from shocks rather than from your mere sitting on the saddle and being a bit overweight.) – Pavel Aug 25 '17 at 11:34
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    Full suspension is heavy and saps pedaling energy. A suspension seat post does wonders in multiple ways. – RoboKaren Aug 25 '17 at 18:21
  • Sounds like you're sitting on the saddle expecting it to hold all your weight, all the time. Is it possible your bike is quite upright in design? Try putting more weight on your pedals, especially when going over a bump or similar. This is called unweighting the saddle. – Criggie Aug 26 '17 at 03:40

1 Answers1

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As the diameter is standard (sort of) steel rails will be stronger than aluminium*. But I'm surprised at saddle rails bending. When I started cycling regularly I was about 100kg and even the roughest bits of road didn't come close to that kind of force. You may benefit from a suspension saddle post for reasons of both comfort and damage avoidance. Steel has a further advantage in that it's tougher than any of the other common materials for saddle rails, i.e. it can handle repeated stresses better without failing.

Do you ride very rough roads? If you get the occasional pothole or bump it's worth taking more of your weight on your feet just for a moment (you don't have to pedal while doing this assuming you don't have a fixed gear bike).

* Both carbon fibre and titanium saddle rails exist and are strong. However they're usually used to make bikes light rather than strong and are unlikely to be available for anything other than road saddles (comfort was specified).m Their brittle failure modes (carbon in particular) make them a bad choice in this case of unusally high stress.

Chris H
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  • Carbon fibre or titanium will surely be much stronger than any aluminium rail? – Daniel Shillcock Aug 25 '17 at 08:25
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    @DanielShillcock I hadn't considered the possibility of carbon fibre. Given its failure mode that would seem like a bad thing for the OP. Ti (like carbon fibre) is generally an expensive way to save weight, so I doubt it would be much use. Edited – Chris H Aug 25 '17 at 08:37
  • @ChrisH maybe not. All things considering carbon components tend to be designed with a much higher yield strengths due to the failure mode being catastrophic. So if the forces encounter are just enough to bend steel, the same component in carbon may do just fine. – Rider_X Aug 25 '17 at 22:48
  • @Rider_X that's a good point. But I wouldn't fancy trying it in this case of a rider who bends normal saddle rails. Also a direct comparison would be hard as carbon rails are unlikely to fit a comfort saddle,and it sounds like the last thing the OP needs is a hard saddle – Chris H Aug 26 '17 at 06:29