Seriously rusted retro mtb safe for indoor trainer?

[ultrazenith]

I've got a retro MTB frame that's slated to be used on an incoming smart trainer, but the rear triangle is a bit on the rusted side. There's a bit of worming under the paint on the mid seat tube, and loads of surface rust on the seat and chain stays. What's the worst that can happen if one of the steel tubes is rusted all the way through? Will it be a slow failure, or will I be catapulted onto the floor, or be impaled through the ass with a metal shard, or worse?

 

[Markybeau]

The worst that could happen?

A cold steel enema

If you have those kind of doubts about it maybe take it easy to start with. Check the usual stress points after use. Next time go a little harder. Don't think steel will let go with a sudden fracture unless you're going crazy on it.

 

[greencat]

No-one can say. But steel tends to give warning in the form of bending, creaks and cracks before it fails. And if it's not anything exotic, chances are there's plenty of material.

Conversely, steel also rusts from the inside as well as the outside. Give the affected areas a few stabs/taps with a screwdriver. If you make a hole, it may be best to leave it. Old steel frames are two a penny.

 

[highlandsflyer]

I personally wouldn't. Take a good look at it inside at least.

 

[Mike Muz]

The worse that can happen is it fails and if you're riding out of the saddle in a sprint/attack, you fall to the side, hit your head on the radiator, and smash your skull, before either brain damage or bleed to death. If the former, I will then sell you a nice bike to put on the trainer, at twice what it's worth. If the latter I hope you don't feel guilty that you've messed up your widdow's central heating system.
Do yourself a favour, buy a bike that isn't as f***ed ( (they're quite cheap really) and ride that instead.

BTW, hello retro inmates, I'M BACK!

 

[Ippikin]

Perspiration is corrosive and there is a lot of it when 'riding' indoors. If your steel frame wasn't rusty to begin with it soon will be! I also think steel is the best material for static training as the forces which the frame is subjected to are quite different to balanced riding. As others have said steel rarely fails suddenly and is a reliable frame material. As such you have chosen well! However I would recommend you rub some rust prevention product such as Owatrol oil on the frame & rusty bits (including saddle rails) and wipe down /re apply as necessary.

 

[Woz]

You could always ask the "smart trainer" what to do instead of us lot.

 

[ultrazenith]

Deep down I knew the sensible answer was to not take the risk doing something dumb like using a potentially rusted frame. It's just a shame to not be able to use this frame, from my first proper MTB owned since 1994, for anything more than a wall hanger :/

 

[greencat]

Deep down I knew the sensible answer was to not take the risk doing something dumb like using a potentially rusted frame. It's just a shame to not be able to use this frame, from my first proper MTB owned since 1994, for anything more than a wall hanger :/

Well, if you are really fond of the frame another option is to weld some additional structural pieces onto it. Since it's not going to be ridden outside, it's doesn't matter what it ends up looking like or how heavy it gets.

 

[bikeworkshop]

It's very rare for anything but expensive race frames or bikes that have been living in the sea to actually fail.
Weakest tube point for rust failure tends to be the chainstay by the rings, especially if its had chainsuck.

I'd stand alongside the bike lean it away, then push hard with the foot on the bb. Listen and look.
Honestly the dropouts are a lot more likely to fail in bikes of that period.
I see a few broken dropouts a year, usually drive side, often matched with a bent axle or a 135 hub in 130 spacing (or vice versa) but can only think of a couple of (high end) rusted through frames in decades.
In both those cases you could rotate the frame and hear the sound of heavy rain