Crashed due to chain/derailleur fault.

[black'n'yellow]

Poor blokes come off his bike and all he gets is "Did the chain come off front/back,the back first/rear first?"
Yes i know that wasn't said I'm being sarcastic

I think it's called "trying to understand the problem, in attempt to answer the question" - don't seem to be getting very far though...

 

[little dilbert]

Here are some pictures of the drive train to help identify it. Hopefully someone could kindly tell me if it's a free wheel or a free hub based on the pictures, and likely sizes of replacement parts . Also does the chain and/or cassette look visibly worn?

I'm aware that the saddle and handlebars need to be reset.

 

[little dilbert]

I think it's called "trying to understand the problem, in attempt to answer the question" - don't seem to be getting very far though...

As in post #9, I can't be sure if the chain slipped or not, all I know that the pedals did not drive the wheel. As it's an old bike it could be as marzjennings says in post #8 and be a problem with the ratchet mechanism.

 

[Gary E]

Not sure what can be said other than what's already been said above, just wanted to say Nice Wing-nuts

 

[shouldbeinbed]

Poor blokes come off his bike and all he gets is "Did the chain come off front/back,the back first/rear first?"
Yes i know that wasn't said I'm being sarcastic

you mean people trying to answer the question he asked and diagnose the problem from limited initial information.

 

[shouldbeinbed]

as for diagnosis, no juddering or clattering & a straight give up doesn't imply the chain derailing, more that the internals somewhere have failed or are sufficiently worn that they cant take a high power low cadence grind. But with it being an old bike - when was the chain or any of the cogs last changed? The chain could be significantly stretched and gear teeth worn sufficiently to make for an uncommonly smooth and easy unshipping of the chain.

Also not seeking to point a finger but if something unusual (i.e. not a puncture etc) has happened to you before on a different bike then what is the common factor in the problem? Possibly have a look at your riding style or deep down maintenance/servicing regimen.

 

[little dilbert]

as for diagnosis, no juddering or clattering & a straight give up doesn't imply the chain derailing, more that the internals somewhere have failed or are sufficiently worn that they cant take a high power low cadence grind. But with it being an old bike - when was the chain or any of the cogs last changed? The chain could be significantly stretched and gear teeth worn sufficiently to make for an uncommonly smooth and easy unshipping of the chain.

Also not seeking to point a finger but if something unusual (i.e. not a puncture etc) has happened to you before on a different bike then what is the common factor in the problem? Possibly have a look at your riding style or deep down maintenance/servicing regimen.

I am replacing the freehub/freewheel once I know which it is. Probably the chain as well.

Additionally I don't know the last time the chain/cassette was replaced as I have not owned it since new and have not replaced them myself.

 

[andsaw]

I had something like this on a peugeot 10 speed back in 1980, cant remember the model no, and im pretty sure the ratchet on the rear cassette had sheared, cant even remember what i did think i bought a motor bike, but its like a cheap socket wrench going, the teeth in the wrench wear down to the point it cant grip it then slips when undoing a nut and usually taking skin of the knuckles, if so, the sudden slip and combination of pressure makes the chain jump up and down enabling it to jump the sprocket if all that makes sense.

 

[fossyant]

That looks like a five speed freewheel, ie its not a cassette.

It's also filthy, Christ, that amount of crud in it can cause issues too. Five to seven speed freewheels are readily available, and certainly get a new chain.

 

[andsaw]

I thought that's what they call them theses days, what's the difference between a cassette and freewheel, not long since i been back into cycling properly, have things changed that much with the rear cogs then, i will have to google.

 

[sidevalve]

Strip the whole lot down and clean it. In it's present condition it could literally [well nearly] be anything. Only then will you be able to tell what's worn, what's just "bunged up" with cack and what [if anything] is broken. When you know what you're dealing with then make a list of "bits to get" and start off on a parts hunt.

 

[fossyant]

A freewheel has the teeth screwed onto the freewheel body. You can remove the freewheel and sprockets. A free hub has the freewheel as an integral part of the hub, and the sprockets just slide on and off.

Main advantage has been the moving of the bearings further out for the hub, and also easier to change gearing ratios.

To be honest, if you don't know the age miles that freewheel has done, I would just replace with a new one and chain. Under £30. You will need a freewheel remover, which is either splined or slotted.

For us to know, you would need to remove the wheel from the bike,clean the crud off the end of the freewheel, and if you look between the hub and freewheel, there will either be a number of splines, but I suspect there will be two slots cut into the body given its a five speed, meaning its old.

 

[little dilbert]

Thanks for replies.

I'm pretty sure it's a freewheel, and it's certainly 5 speed. Is it advisable to keep it as 5 speed or would it be much hassle to replace it with a 7 speed freewheel?

 

[fossyant]

If the down tube shifters are friction, then you should be able to swap for a 7. Axel width should be 126mm, it's now 130mm for 8-11 speed systems

 

[mickle]

Its a freewheel. Quite possibly the original one which would make it forty years old.