Changing chainrings

the_jackalcp

How easy is it to change chain rings? Is it a 10 minute job or somewhat more protracted involving crank removal etc.

The reason I ask is I current ride 53/39 which is normally absolutely fine for my riding. I have recently been in search of more challenging riding and struggled a little on some hills and wished for a few easier gears. My current chainrings will soon need replacing so I am wondering whether to get a new set of rings and a cheap compact chainset or buy a fancy compact and simply change the rings out depending on where I will be riding.

The later option seems attractive due to the option of so many different sizes but it kinda depends on the easy of change over. Any thought appreciated

Thanks

fto-si

It's easy...must be as i can do it!
Just remove the bolts and they come off over the pedal

the_jackalcp

my logic suggested that might be the case

Cheers

redddraggon

You won't be able to fit a chainring smaller than 38 (Shimano 130mm) or 39 (Campag 135mm) by the way.

briank

Changinng the rings is stroll in the park - simply undo the five allen bolts which hold the rings onto the crank spider. Somtimes the slottted nut can turn and you have to contrive a way to hold it while undoing the nut, but that is very rare.

However......compact rings will not fit on a standard road crank! The key dimension here is PCD (Pitch Centre Diameter) also called BCD (Bolt Centre Diameter)
The five bolt holes in the chainring form a circle: the PCD is the diameter of that circle. The five bolt holes in the crank spider of course also form a circle and the PCD MUST be the same as the rings' or you simply can't bolt them all together,

Ordinary Shimano cranks and rings have a PCD of 130(mm). The smallest inner ring you can get with that PCD is 38 toioth. Shimano compact rings and cranks share a PCD of 110mm, and, because the bolts are closer in towards the centre of the axle, inner rings on compact sets can be smaller typically 24 tooth.

the_jackalcp

Briank, I appreciate your explaination. I obviously didn't make myself clear, nothing unusual there then.

I realise that 38 T is the smallest you can get on a standard crank hence why I am considering a compact as you can get 34T all the way upto 52T. A good range ot options, even more so as everyone is saying they are a quick change.

Thanks

nmcgann

Theoretically this is an easy job, and it will be fine most of the time. However, if you are unlucky one of the nuts will spin and not loosen or will jam on it's thread - at which point you discover that a lot of the chain ring nut tools don't actually fit or will grip properly (the cheap park tools one is a waste of money).

I actually had to cut a ring off a brand new Shimano crank a while back so I could hacksaw a stuck ring bolt off :roll:

Neil