Chain

[Nicky S]

the rear sprocket looks fine and i dont think it has ever been changed the front sprocket is a renthal one and it is 14t i think and that was put on last year so i dont want to change the front one back one i dont mind to much about.

[Nicky S]

Originally Posted by leedsmatt7

http://www.stealthproducts.co.uk/

boom, look no further! They sorted me out sprockets, chain and delivery for less than £80 on a DID x-ring. MWAHH!!!

Oh and if ya wondered, its gold!

ummmmmmmmmm looks good myt have to have a look into this

You really should buy the sprockets too, the way a chain wears to the sprockets is unique. So if you put a new chain on srockets which already broke a chain in, you'll ruin the life span of your new chain. At £80 you are a hundred times better off just getting the whole lot replaced. Any bonce with a tool kit and a paddock stand can change their sprockets but you'll need someone with a chain riviter kit to swap the chains over which you'd have to do anyway so tbh. If you dont swap the lot your been a bit silly IMO.

Ask nicely and a local orger may even come along to make sure its all done tipity top if you wanna do it all ya self to save even more money.

[rictus01]

Originally Posted by Nicky S

the rear sprocket looks fine and i dont think it has ever been changed the front sprocket is a renthal one and it is 14t i think and that was put on last year so i dont want to change the front one back one i dont mind to much about.

given the size difference the front will wear 4 x as quickly under normal use, and the fact you've had an old chain on it would have increased the wear rate somewhat, I know you say "last year", but what's that in mileage, 20k/30k ?

for the cost of a couple of sprocket (and you can pretty much get any size you want) I wouldn't be messing about myself.

Cheers Mark.

[yorkie_chris]

Smaller front sprockets are a bad idea.

At one fell swoop you are increasing the force on the sprocket teeth for the same drive force. And, increasing the tensile stress on the chain.

FAR better is to increase the size of the rear, which for the exact same front sprocket tooth pressure and chain tensile stress will give increased drive force!

Just to add...

Originally Posted by rictus01

given the size difference the front will wear 4 x as quickly under normal use, and the fact you've had an old chain on it would have increased the wear rate somewhat,

... and a worn sprocket is much harder on the chain. In some respects, chain life can be limited to that of the CS sprocket.

A tip that I was put onto many years ago was to buy three (or more) counter shaft sprockets with each chain/sprocket set and even out the wear by rotating those CS sprockets in order at each service regardless of wear. Each CS sprocket gets used three or more times depending on intervals and what is done, or not done, to destroy the chain by the time the chain is spent.

Combined with regular cleaning and an oiler it is possible to get exceptional or at least well above average mileage from a chain.

Cheers

Originally Posted by yorkie_chris

Smaller front sprockets are a bad idea.

At one fell swoop you are increasing the force on the sprocket teeth for the same drive force. And, increasing the tensile stress on the chain.

FAR better is to increase the size of the rear, which for the exact same front sprocket tooth pressure and chain tensile stress will give increased drive force!

There was a write up on ihpva.org (I couldn't find the article) that went into the math explaining this in some detail. The gist of it, iirc, is that the force on each tooth is proportional to the cosine of the angle that each link makes across the sprocket (the sharper the angle the greater the losses) before even considering the effect of the reduced number of teeth and bearing surface area.
From a good chain drive setup to a bad one, we can be looking at a 1-2% decrease in efficiency which may not sound like a lot but that is 1-2% less horsepower to the road.

Cheers

[yorkie_chris]

The problem with swapping front sprockets around like this is the cost of lock washers, to do it by the book you should replace the nut each time!

Not a huge problem. There is the book (which I mostly stick to) and then there is real life. I figure that I can use that washer at least six times before I throw it away by only using a single edge on the nut at each change <= I thought everyone did that. That is two washers for each chain/sprocket set.