Rear Gears

[jethro10]

Can someone explain why there seems to be two general types.

One long

and one short

I assume advantage and disadvantages of each?

thanks
Jeff

 

[MacB]

short limits the size/No of teeth, you can run on the back, the more teeth the easier the gear. If you want to run a wide ratio cassette, 11-32/11-34, you need a long mech.

 

[jethro10]

Ok, that makes sense. So.....why not use a long one all the time, just in-case you feel like changing rear gearing.
What would be the advantage of a shorter one then?

Jeff

 

[PpPete]

Some people consider long cage to be ugly/unfashionable/extra weight.
Most of us just put up with the jibes - we need those gears!

 

[MacB]

Some people consider long cage to be ugly/unfashionable/extra weight.
Most of us just put up with the jibes - we need those gears!

Would be my understanding though I'm sure that some will also have convinced themselves that short is faster I'm sure there is an element of difference with chain length required etc, but not so sure it would be appreciable in any real sense.

 

[Tollers]

Long is also more vulnerable to bashes

 

[TheDoctor]

short limits the size/No of teeth, you can run on the back, the more teeth the easier the gear. If you want to run a wide ratio cassette, 11-32/11-34, you need a long mech.

Not exactly. The long cage lets the mech cope with more chain - so you can use a triple. An MTB mech will cope with more teeth on the cassette - you can have a road mech with a cage as long as you like and it'll still struggle with more than a 28T cog on the back.

 

[plantfit]

The long cage is designed to cope with a triple chainset and larger cassette, as on a mountain bike, the short cage mainly for double chainset and smaller cassette as on a road bike. hope this helps

Rog

 

[hubgearfreak]

Some people consider long cage to be ugly

oh yes, whilst the short cage doesn't look at all like a badly packed kebab

 

[andrew_s]

Ok, that makes sense. So.....why not use a long one all the time, just in-case you feel like changing rear gearing.
What would be the advantage of a shorter one then?

The ones with shorter cages generally have the angle of the parallelogram set at a shallower angle. This means that the top jockey wheel doesn't move downwards so fast as it moves inwards and remains closer to the sprockets.
It means that the shifting is better, but it limits the size of the largest sprocket you can use.

 

[jethro10]

Ok, thanks.

A lot closer now in my understanding.
Jeff