How many extra chain links for new cassette ?

sibike

I am probably going to replace my cassette from an 11-28 to a 11-32 to help the knees and hopefully get up climbs easier . I will also be replacing the rear derailleur and chain but have no idea how to work out how many extra links are needed . My front chainrings are 52/36T if that helps . Below are the links to my shopping list which are hopefully what I need ( other retailers are available ) :
http://www.chainreactioncycles.com/shim ... prod116506

http://www.chainreactioncycles.com/shim ... prod116489

http://www.chainreactioncycles.com/kmc- ... prod132778

If you think i'm wasting my money let me know or if you have gone down this route with success also let me know .
many thanks …..

milemuncher1

sibike wrote:

I am probably going to replace my cassette from an 11-28 to a 11-32 to help the knees and hopefully get up climbs easier . I will also be replacing the rear derailleur and chain but have no idea how to work out how many extra links are needed . My front chainrings are 52/36T if that helps . Below are the links to my shopping list which are hopefully what I need ( other retailers are available ) :
http://www.chainreactioncycles.com/shim ... prod116506

http://www.chainreactioncycles.com/shim ... prod116489

http://www.chainreactioncycles.com/kmc- ... prod132778

If you think i'm wasting my money let me know or if you have gone down this route with success also let me know .
many thanks …..

With a 52-36 semi compact up front, and an 11-32 cassette, you’ll be close to the limit as far as capacity and difference is concerned, but not at the limit, of a medium cage rear mech. The chain whip will be the bigger issue, unless you’re running about 118 links. If the top jockey wheel is getting too close to the big sprocket, and you can’t move it away sufficiently by turning the angle of dangle ‘b screw’ clockwise, you can lower the cage and pulleys using an extender like this.
https://www.wolftoothcomponents.com/products/road link



They think it won’t be necessary though.

arlowood

I've always used this neat calculator and it's never let me down

http://www.machinehead-software.co.uk/b ... hcalc.html

A quick check of differences between a 52/28 and a 52/32 suggests that you will need one extra link over your existing chain length

sibike

thank you

cooldad

Or measure it properly once you've fitted the new cassette. Measure round big/big excluding the mech plus a link.

sibike

cooldad wrote:

Or measure it properly once you've fitted the new cassette. Measure round big/big excluding the mech plus a link.

Is that the way a bike shop would it ?

ridgerider

There's no magic to this. I follow the rule that you don't want the rear mech to self destruct when you select small cog at front and small at rear (for whatever reason!). Feed the chain round these cogs and then chose the length of chain that leaves a gap the thickness of a finger between the underside of the upper rear mech jockey wheel and the chain below as it travels forward to the chainset. That gives you the longest length chain you should be running with.