Chain length

[laneylovesbeer]

I’ve just switched my cassette from a 42 tooth to a 28 tooth cassette. Should I take a few links off the chain. I don’t need the 42 tooth. The gravel bike is only used for commuting on tow paths

 

[Cycleops]

Yes, you should. There are various methods. Big front chainring to big rear cassette, not through the derailleur, plus two links, works quite well.
Alternatively check the legion of threads on here.

 

[Ming the Merciless]

Your rear derailleur will cope just fine as it must have been handling a sprocket around 28t on the 11(?) - 42t cassette you removed. But if starting with a new chain and the 11-28t cassette you’d opt to have it shorter.

 

[laneylovesbeer]

I had a unused 105 cassette in the bike shed. Just threw it on. Going to check there’s no skipping etc as the chain is 3 months old. If all good I’ll shorten the chain. What’s the need in shortening the chain? Apart from weight saving?

 

[Sittingduck]

Crisper shifting

 

[Cycleops]

Might be worth tweaking the B screw a bit.

 

[slowmotion]

Instead of advice from a voodoo shaman consulting his chicken entrails, why not try a spot of science?

http://www.machinehead-software.co.uk/bike/chain_length/chainlengthcalc.html

 

[Ajax Bay]

why not try a spot of science?

What you share isn't science: it's maths and you have to go and collect data. Higher error opportunity. Why not just do what @Cycleops has specified?

 

[slowmotion]

What you share isn't science: it's maths and you have to go and collect data. Higher error opportunity. Why not just do what @Cycleops has specified?

I thought that maths is a subset of science.