I am a bit confused. I did an upright conversion to a 72 Schwinn Continental for a son. It worked nicely in friction mode. I thought I would treat him to aluminum wheels and indexed, as he seems to enjoy the bike. I got a Shimano 5 speed SIS thumb shifter and an Exage Motion rd. I was using a bent tooth 14-28 Shimano freewheel on it and of course all index cable housings. No luck, as it seems to pull a fair bit too much cable.

I am confused. I successfully went indexed 6 speed on my vintage Super Sport so thought this would be easy. Am I missing something?

Index shifting for a 5-speed freewheel?

​​​​​​Shimano 5-speed and 6-speed shifters are made to index with the 5.5 mm spacing between sprockets on older 5- speed and 6-speed freewheels (or even, some new freewheels made as replacements). Without indexing, and because chains with protruding rivets are no longer widely available, https://www.sheldonbrown.com/speeds.html

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personally, at 5 speed, I would just leave it as friction. it will be smooth shifting with the toothed rear. I had this on a 1x8 town bike setup and it works super nicely

Yep, that is what I have read, so not sure what is going on. I will probably just put the friction thumby back on. I may go back co op for another shifter just to ensure my sanity.

A common reason for almost but not quite proper cage travel per index click is improper cable routing at the der anchor bolt. Also Shimano twist tooth freewheels (Uniglide cogs) were made years before indexing came to the market. There's no reason why Shimano would make those cog set spacings to a future and yet to be designed spec. Not saying the cogs are a different C-C spec but one measurement is worth a lot of ink. Andy

Yep, checked cog spacing vs several other freewheels I have. I also paid attention to the cable routing at the cable anchor bolt at the derailleur. I may try it in a different orientation too. Thanks.

If you are pulling too much cable consistently across the cogs, you might be able to use a hubbub alternate cable routing at the rear derailleur.

Alternate cable routing was born out of DA 74XX compatibility and Shimergo of mixing Shimano and Campagnolo components.

It works on the premise that where the cable is attached effects the amount it moves; like a fulcrum. In essence moving the attach point closer or further from the pivot impacts how much a derailleur moves “up to a point” for the amount of cable.

It might also work with a 7 speed shifter, but it does take some experimenting. I think it is about a 10% change. And depending where you position the tab you can fine tune it. With the spacing on a 5 speed freewheel you should be able get close enough.

John

I will explore several of those options perhaps

Same here. I've got a few bikes set up this way.