Faulty freewheel?

mmxbreaks

Heya,

Had a freewheel changed a few weeks back and since had an accident. Cycling out of saddle, left leg plummeted down with zero tension (chain had come off somehow and possibly caught wheel side) which took me down very hard. Lots of bad injuries, blah, blah.

I'm trying to figure if I can 'blame' the freewheel. 'Cos I don't see how this would be my fault. On rotation if there was slippage due to a faulty freewheel could that cause the chain to slack and ultimately fall due to brief tension loss? Or could it be excessive exertion down onto the pedals (I mean I cycle hard, but don't see how a bike wouldn't be designed to take that)? Seems all rather perplexing to me anyway. And now I don't trust my bike. Chain wasn't loose nor too taught.

Bike: Marin Inverness 2010 single speed, 7 months old, freewheel about 6 weeks old (crash a fortnight ago but holidays meant the new wheel was only in play for about a week of riding).

I need a cycling boffin to help me understand this/work out if I can pull up the manufacturer on this.

centimani

Unless you can re-create something like the force you were using at the time..you're going to struggle.
It may well operate perfectly up to a given point (and should operate perfectly ALL the time), but then have slipped, perhaps the force at that point made the pawls slip.
But you're never really going to know.

It's just as likely your chain slipped.

Hope you're recovering ok mmx,

flappy8

Once the pawls in a free wheel are under tension its almost inconceiveable that they would let go as you added pressure.

+1 with chain slip. I had an issue on my Sirrus couldn't see it. I put it on a stand and after messing about for hours & saw a moment when the chain slip between 2 cogs at the front. When I recreated it while on the bike it looked like it was slipping at the back but it wasn't.

mmxbreaks

The likelihood of a chain slip on a single speed bike should be drastically reduced though, non?

As the freewheel was new, and not ridden much, I suspect it's possible that riding it under pressure did cause it to slip (it needs to tighten, perhaps it wasn't quite maxed out). I'm trying to visualise it in my head. If that happened then the rear would have been turning for a brief moment at a different pace to the pedals which most likely f-ed the chain and caused it to slip off.

Other than cycling conservatively when I get back in the saddle I can't think of any more ways of minimising it happening again.

:?

Bobbinogs

Perhaps when honking you knocked the chain just at the wrong time and it shipped off the chainring? When honking do you weave a great deal? Perhaps that could have just helped to ship the chain, albeit unlikely? Perhaps the back wheel hit some oil which caused a spin, and it was the fact you your leg dropped quickly that caused you to go off balance and then everything went south from there ?

I guess the problem is that you are never really know what happened but you might want to change the freewheel just so that you help rebuild your confidence. Good luck with the recovery, physically and mentally.

centimani

mmxbreaks wrote:

The likelihood of a chain slip on a single speed bike should be drastically reduced though, non?

As the freewheel was new, and not ridden much, I suspect it's possible that riding it under pressure did cause it to slip (it needs to tighten, perhaps it wasn't quite maxed out). I'm trying to visualise it in my head. If that happened then the rear would have been turning for a brief moment at a different pace to the pedals which most likely f-ed the chain and caused it to slip off.
Other than cycling conservatively when I get back in the saddle I can't think of any more ways of minimising it happening again.

:?

I see where you're coming from here, its the same as fitting any freewheel, single or multiple sprocket, however much you tighten it when first fitting it to the wheel, you always get that 'lurch' when you apply more pressure...until it's tight. feels like you're riding on butter, like a sudden slip of the wheels.
But a couple of weeks after (even a week after as you state) ?...its always happened on the first ride for me.
Its something i'm always concious of when renewing a freewheel, but not after a week or two, unless you'd been riding very steadily up to that point.

Again, while i sympathise, it'd be impossible to prove, even if that were the cause.

mmxbreaks

I'd felt slippage on the first two rides, then think I was working at home and not riding followed by a holiday. I rode the bike for two days of commuting after coming back and on the fifth/maybe sixth or more trip with it was accident time. I mean I was peddling f-in hard out of the saddle to overtake so I may have given it that last slam of slippage into its tightest position... however, at the expense of a broken shoulder, rib, with some added bruising and mega road rash.