I was gifted this Klein Quantum from my grandfather years ago and he has since passed so the frame is very sentimental. A couple years ago now it suffered a catastrophic rear derailleur failure, two pedal strokes after hopping on I heard metal pinging on the pavement and the derailleur was no more. The mounting bracket is toast and bent, in my research most claw type derailleurs are on the lower end and I would like to turn this into my weekend rider for working out with modern components (and learn more about the bike building process along the way, currently work on my commuter but wouldn’t call myself particularly competent). With all that said what options would exist for a more quality derailleur?
by Zman8713
3 Comments
You could let it be welded or Go for a gearhub, but then you’d need Something to Pension your chain or Go for Like KMC hl1.
IMO, the only way to permanently repair it to original condition is to have a new dropout and hanger assembly welded on. Finding someone to repair an aluminum frame will be difficult. You’d have to search for a custom frame builder who works with AL. The only one I know of off the top of my head is Stoemper (edit: Rock Lobster still works with AL), though I have no clue if they’ll do repair work to old frames. It’s not going to be cheap.
Some cheaper stop-gap alternatives is something like the universal derailleur hanger: https://problemsolversbike.com/products/universal-derailleur-hanger or maybe modifying a chain tensioner w/ hanger: https://problemsolversbike.com/products/chain-tensioner-with-hanger
I wouldn’t consider either of these a permanent solution, though.
You could get an eccentric bottom bracket: https://velo-orange.com/collections/bottom-brackets/products/eccentric-bottom-bracket-bsa With this, you could run the bike as a single speed, fixed gear, or with an internal geared hub as u/penny_the_black suggested.
EDIT: Another expensive option is building up a new rear wheel around a WI Eno hub: https://www.whiteind.com/product/eno-flip-flop/
Looks like a great fixie