doctor-bond
Feature Bike
I wasn't aware 8 speed became available that long ago. I probably stopped being into biking, at least following the latest gear, around 95 probably right about the time I got into the rave scene and Djing!I doubt very much an early 90s bike will have a 34 rear. 12 28 was the most popular cassette sometimes 30 or possibly 32. Also a lot of early 90s had 110/74 bcd, so you wont get smaller than 24 on the front.
A second had pair of wheels with a 5mm longer 8+ speed freehub will be only as much as buying cassette, crank, chain, shifters. Plus its plug and play, rather than trying to rig 8 onto 7.
But as i said abouve a mid 90s bike will have all that straight off without expense or drama.
I am having trouble finding anyone selling 58bcd cranksets. Seem a lot rarer than 64.If you use an MTB 5 arm 94/58mm crank set (Shimano M563, M737 for starters) then the 58mm inner will go as low as 20T. Fit a 28 or 30T on the back and you have around a 19" gear - which is all I need on a loaded tourer on Dartmoor.
If you have a 7s hub you can fit a 9 or 10 speed cassette, just leave off the smallest sprocket and run 8-from-9 or 9-from-10. Obviously you need a matching shifter and rear derailleur (7/8/9 speed derailleurs are interchangeable, despite what Shimano may tell you). 10 speed is totally different.
I don't use ebay. I boycotted it after a couple of nasty false damage claims when selling where they got item for nothing and second time basically blackmailed me to offer item (record collection) at huge reduction. They clearly seemed professionals at doing that.If you search '22 crankset' or '22 chainset' on ebay, sort by price: lowest to highest and condition: used there are plenty of options for £20 or less
Some are 4 x 104 with 64bcd inners but still gets you the 22t inner you want.
https://www.retrobike.co.uk/threads/kirk-revolution-400-wheel-set-exage-hubs.480852/page-2If you haven't got the bike, surley buying a mid 90s bike with 8 speed would answer all your issues. They will still be rigid, probably have a lower bcd crank than early 90s 110/74 (if you want lower than low gearing), chains and cassettes of quality easy to find and cheap too. Plus will probably come with Vs instead of cantilevers.
Try a 95 / 96 marin Eldridge or pine mountain. £150.... job done.