Bigger Cassette ,longer chain.

[Banjo]

I presently have an 11/25 cassette , have just picked up my new 11/28 from lbs plus a new 105 chain.

Does the 3 extra teeth on the largest cog equate to 3 extra links in the chain? It currently all works perfectly so hoping to get it as good after fitting the nice new shiny bits.

 

[Moodyman]

Put new cassette on.

Wrap chain from big ring (smallest gear) at back to big ring at front. DON'T put it through derailleur yet.

Where chain meets its tail, add 4 individual links 9 (2 whole links). These 4 links will equate to the links lost when the chain is fed into the derailleur.

When chain cut to length, install.

 

[redjedi]

Hi

Give Bicycle Tutor's website a go.

This video explains chain length very well.

 

[youngoldbloke]

- or you could use chainlengthcalc

 

[Hacienda71]

It will only become an issue if you go largest front ring to largest back ring. A gear combination you really should not use due to the chain line, but if you want to get it right Moodymans method is the one I have always used.

 

[Smokin Joe]

Unless the present chain is absolutely on the limit an extra three teeth on the rear sprocket won't matter. It's only when you increase the size of the chainrings you need to worry.

 

[Banjo]

Many thanks for the quick responses everyone, your advice greatly appreciated.

I have fitted it and been out for a spin around town, all seems good. Went up our local ball buster hill and the 3 extra teeth are just what I needed.

I could ride up almost anything with the 25 cassette on a short training ride but meeting the same hill at the 90 mile point was a different story.

I seem to go up at the same speed just spinning a bit quicker so all in all a success .

 

[Garz]