Cassette and Wheel compatibility

[Portellini]

Hello guys,

I bought a 1990's road bike. Used for a very fine price and condition. Except the gear shifters that don't work.

I went to my mechanic to make a repair plan in order to know how much would I spend to fix the bike.

I also wanted to put on some new wheels that I purchased for a hybrid bike (yes, road wheels) and my mechanic say that those wheels (a recent model) wouldn't work with the 7gear cassette it came with and would only work with newer 8, 9 or 10 gear cassettes.

Is this true?

Kind regards,

Pedro Portela.

[nfmisso]

Sort of. For your wheels to work with a seven speed cassette, you need a 4.5mm spacer; no big deal.

[Joe_W]

Make sure the frame spacing is correct: Older road bikes have a distance between the dropouts of 124mm whereas new road wheels have an over locknut distance of 130mm. If it is a steel frame it can be widened (it is only 3mm per side), though you should be careful when doing that. Nigel (and I belive one of the Georges and of course DaveM) can comment on the tensions that you create by cold setting a bike frame, for some of them this is (related to) their daily work. I have done this to three frames so far, one of them is being abused regularly (old road bike converted to a cyclocross) and seems to hold up very well. The dérailleur hanger has to be realigned then (no big deal). However, I take no responsibility for any damage that you might do to your frame.

[nfmisso]

(11-01-2011, 03:57 AM)Joe_W Wrote:  Make sure the frame spacing is correct: Older road bikes have a distance between the dropouts of 124mm whereas new road wheels have an over locknut distance of 130mm. If it is a steel frame it can be widened (it is only 3mm per side), though you should be careful when doing that. Nigel (and I belive one of the Georges and of course DaveM) can comment on the tensions that you create by cold setting a bike frame, for some of them this is (related to) their daily work. I have done this to three frames so far, one of them is being abused regularly (old road bike converted to a cyclocross) and seems to hold up very well. The dérailleur hanger has to be realigned then (no big deal). However, I take no responsibility for any damage that you might do to your frame.

Joe; excellent point. I do not know '90's bike history well enough to know if it would have 12xmm or 130mm rear spacing..... On my SR, which is '80s; the 130mm OLD hub is a bit tight, but not significantly so. I also did not do anything with the derailleur hanger, and the RD is very smooth shifting and quiet in gear, so okay. My SR is plain gauge cro-mo, and thus very for giving of being stretched a bit.

[DaveM]

A 7 speed road bike would have 126mm spacing in the rear. If it's steel easy to spread it to take a 130 wheel. Often, you don't even have to coldset it, you just flex it open a bit when you slide the wheel in. On Aluminum or carbon frames though, this is not recommended.

However, the new wheels may be 135 spacing if they are "hybrid" wheels. Hybrid bike often have the mtb rear spacing. 126 -> 135 might be pushing it a little.

Are the shifters on the bike broken? Do you already have replacements you want to use. There's a variety of ways to mix 7 speed parts and 8/9/10 speed parts. But you need a plan before you just start buying random stuff and then try to figure out how to make it all work together.