eddiearniwhatev

Hello

I am presently attempting to replace my destroyed Suntour Perfect 6 Speed freewheel. As discussed in another thread, I saw fit to tighten it while on bike tour overseas and it subsequently rather abruptly gave up the ghost, as they say.

Since I'm in rural Ireland, I can't order an "old stock new" one from Ebay, which seems the ideal thing to do, but I'd have to pay a whole lot for it plus wait for quite a while.

From what I can tell calling the various bike shops within bus distance, it might be possible to locate a Shimano Freewheel locally which will fit the cycle.

My question is, are Shimano and Suntour cogs cross compatible? Would it be possible for my present cogs and spacers to be transfered from the old broken freewheel to the new one? I have rebuilt freewheels this way before, making a custom bike, but I don't recall the brand of the cogs.

Thanks!

cny-bikeman

The cogs can't be transferred. Even if you could find a ST body, removing the 1st two cogs off an ancient ST freewheel will not be an easy task - best done with a freewheel vise (very hard to find these days) mounted in a good vise and a strong chain whip or at a minimum two chain whips. You don't even need a freewheel tool in order to remove the old ST if one is not available (destructive removal). Suntour Perfect freewheels pre-dated indexing, so any complete 6 speed freewheel is compatible, as is 5 speed. It seems odd that no bike shop has advised you to go that route.

FBinNY 

Since hub treads are standardized (pretty much), any freewheel can be substituted as a unit. However, there is virtually zero cross compatibility between freewheel sprockets and bodies. There will even be compatibility issues within brands, ie. Perfect sprockets mostly don't fit Winner bodies.

As I see it, you need to buy any freewheel, or fined a used Perfect freewheel of any size and transfer your sprockets onto it. I wouldn't go the transfer sprockets route, unless I had a non-replaceable freewheel size range in near new condition since it's the sprockets that wear not (usually) the bodies.

eddiearniwhatev

Oh. thanks!

Andrew R Stewart 

No mention yet of any indexing compatibility concerns. As long as the shift levers are friction holding a Sun Tour freewheel can be subbed with a Shimano. But if the gear system is an indexing one (with no friction option) then the cog to cog spacing will likely be different between the two brands. Since this bit of data hasn't been made known by the OP... Andy.

cny-bikeman

As I noted Suntour Perfect freewheels were pre-indexing.

Andrew R Stewart 

cny- You are correct. In my haste I missed your reference. Andy.

vintage cellar

I can't think of a single case where one brand of Freewheel cogs fits another brand. Definitely not Shimano and Suntour.

Interchangeability was never a big feature in the bike world.

eddiearniwhatev

I'm not running with index shifters. Never have, never will. For this very reason, it's easier to manage changing components with friction shifters. Threw a Shimano freewheel on the hub, works great of course. I just wish I could get my paws on an NOS Perfect freewheel. Maybe once I get back to the states.

dedhed

A modern Shimano HG freewheel with ramps will likely shift better than the old suntour

Homebrew01

I used Suntour Perfects back in the day. They were fine, but no better than anything else, so no reason to seek them out.