Cassette change query

[jack smith]

I've been fitting chains all day for 20 years on the small small ratio so the chain just clears the relaxed derailleur,never been a problem yet

I dont see why you wouldnt want the longest chain possible without rubbing, surely thats the way to maximise use of the gears

 

[shadow master]

I dont see why you wouldnt want the longest chain possible without rubbing, surely thats the way to maximise use of the gears

Exactly right if you put almost any bike in its smallest ratio the chain clears the deralliuer by about 7\8mm at this rate the system can wear a bit and still not rub the mech and easily make the big big ratio if your stupid enough to use it

 

[MikeW-71]

I would leave the front as is; a triple will only go down to 30 teeth, giving you approx 12% lower gear, but you will need to buy a triple crankset, new shifters and possibly a new bottom bracket; lots of faffing about and expense.

Going to a 28 tooth cassette will give you approx 11% lower gear for the cost of a new cassette and chain. Going for a 32 tooth cassette will give you a 22% lower gear for the additional cost of £15 on a new rear mech. This is what I would do if you want the max benefit.

^^ I'm with him.

You'd be surprised how much difference an extra 3 teeth make.

 

[wam68]

Ahh i think i do it the opposite way so i always have the chain as long as possible just so it dosent drag on the rear mech, i put it in the two smallest cogs and pull tight until the chain is just under enough tension not to flop about, then thr chain is as long as possible for the larger cassettes

Jack can you explain how you do this. Buddy wants to change his cassette from an 11/ 25 to a 12/30 for a few hill climbs he is planning.

Do you thread the chain through the rear mech while using the small / small ratio to get the correct chain length.

 

[jack smith]

Yes just run the chain through as normal and put it in both small rings, then pull the chain together until it dosent rub on the mech, then remove that mank links from the new chain, this is the best way to sort a new chain because then you maximise the chance of useable gears, if its any longer it will rub... But you always want the longest chain possible so you can use the larger cogs so it makes sense to do it this way.