my main full sus bike has a shimano hg73 chain fitted. my commuter's chain is shot so im think partially worn chain off the full sus goes to the partially worn commuter and new chain on to the virtually new full sus cassette.

what spec is the hg73, or, what wont it fit on?

commuter has an 8 speed hg40 block and friction shifters

for the full sus is hg73 a good alrounder or is there better for simular money out there?

come on i need this info….
desperate to get on chain reaction and spend…..

HG73 is a 9 speed chain and therefore won't work on the 8 speed block.

ah now this is what i needed.
the 8 spd has a sram pc48 on, i belive.i cant see these for sale on tinternet.is there an equivelent?

ps, not that i doubt anyone, but why wont it work?

This should do for a commuteror you could spend more. Nine speed chains are narrower so the cogs on an 8 speed cassette won't fit in the narrower gaps as well (if at all)

SRAM PC48

8sp chain

ok so now i need to say that ive looked at the cassette and thats pants too. so new nine speed and nine speed chain?
would i need a nine speed specific derailier for the rear ( bearing in mind its on friction shifters)
any reason this wont work? chainwheel thickness perhaps?they are nice BBB alloy chainwheels that i spent far to much cash on and are still in good nick.

The rear mech should work ok

Sorry mate that's rubbish.. 🙄 9 speed chains work on 8 speed blocks and cassettes ..end of, although some work better than others!

8 speed chains DO NOT work on 9 speed cassettes 😉

The 8 rear mech can work.. but 9 speed will work so much better although again a 9 mech will work with an 8 gear set…

😀

do nine spd cassetes have all the rations changed slightly from an eight or is it just another larger low gear "tacked on"
sorry if this is obvious but i have no idea.
im thinking nine speed is more common and with more choise would be a better way to go…

You would be right 😀

Shifters are the other thing.. of course 😉

Leave it 8 – it'll save you money. In my opinion (and be horrible to me if your opinion differs) the 8 speed chains last longer.