hi bike set up 7-speed on back cass

johnnyboy4711

i bought an old bike(2 speed front) 7 speed rear cassette.
It needed a wee bit of pimpin and as a result i bought wheels on ebay and pedals,saddle etc.
The wheels i bought were fitted with an 8 speed cassette so i think a 7 would not fit on only with the aid of a spacer.

So what I am wondering is this

dont want to have to change the rear derailleur from 7 to 8 so is the spacer plus the 7 speed cassette on the 8 speed hub the handiest option?

also one last thing what sort of 7 speed cassette ratio would you recommend for for a nice mix of flat and small hills?

Total newbie to putting a bike together but loving it all the same!!!



thanks in advance
johnnyboy

Morgan

Yes, if you use a 4.5mm spacer you can fit the 7-speed cassette on the 8-speed hub. Should be able to pick one up in your local bike shop.

The ratio for the cassette will depend on what front chainrings you're running. You can see a few possibilities here:
http://www.chainreactioncycles.com/Models.aspx?ModelID=958

johnnyboy4711

cannot find a number on the bottom front ring but the outer one(of 2) is 52 teeth.
as i said bike was set up with 7 speed ,
option 1
would it matter too much if I jam on an 8 speed cassette or can the rear derailleur handle it?(as rear hub is an 8/9)
Would it be more likely a 7 speed derailleur?
(so i can put an 8 speed cassette on or do i have to change the derailleur also?)

Option 2
get a 7 speed cassette(still not sure on the ratio to get!)
put a spacer on the 8 speed hub to make it 7 compatible.

any help would be great !
the machine is looking great after the new shoes on it!

thanks
john

Morgan

The rear derailleur would get on just fine with an 8-speed cassette. However, if you have indexed shifting (i.e. it clicks from one gear to another) then it won't work. Friction shifters would be fine.

In your situation I'd just go for the 7-speed cassette.

To decide what ratio cassette to get you can spend hours here:
http://www.sheldonbrown.com/gears/

johnnyboy4711

went into a bike shop in galway asked him about converting 8 speed hub to 7 he looked at me like i had just come off the mars lander!!!
where can i pick one of these up cheap?
thanks
john

ps whats Nigels new shops phone number anyone?
john