Help please! - Alternatives to 7sp Suntour Accushift Plus freewheel

[FiveAlpha]

I've just picked up a great condition 1990 Centurion Radius, with (yup!) a Suntour Radius groupset. Perfect, except that the previous owner, wanting lower gears, has swapped the rear mech and freewheel. The rear mech isn't an problem (I have 3 others to choose from), but the current freewheel is a 6 speed Shimano. It doesn't seem to work well, and I've read that the cable pull was different between Suntour and Shimano in the early days of indexing, which might explain it.

It's standard fitting - 1.37"x24t thread, for 1/2"x3/32" chain, but I don't know the cog spacing. Are there any Suntour experts who can help?



Short version - does anyone know of a 7 speed freewheel, compatible with Suntour Accushift Plus?

Thanks

 

[KermitGKona88]

I've just picked up a great condition 1990 Centurion Radius, with (yup!) a Suntour Radius groupset. Perfect, except that the previous owner, wanting lower gears, has swapped the rear mech and freewheel. The rear mech isn't an problem (I have 3 others to choose from), but the current freewheel is a 6 speed Shimano. It doesn't seem to work well, and I've read that the cable pull was different between Suntour and Shimano in the early days of indexing, which might explain it.

It's standard fitting - 1.37"x24t thread, for 1/2"x3/32" chain, but I don't know the cog spacing. Are there any Suntour experts who can help?



Short version - does anyone know of a 7 speed freewheel, compatible with Suntour Accushift Plus?

Thanks

I think SunRace are the go to freewheels at the moment.

 

[FiveAlpha]

I think SunRace are the go to freewheels at the moment.

Thanks - I just had a quick look at their website and, unhelpfully, they don't specify what the centre-to-centre spacing is, so I don't know what would index properly. I think I need 5mm.

 

[dirttorpedo]

I have a similar issue - I'm running shimano gears and derailleur with 7 speed command shifters. I don't believe there is anything modern today that will match the old Suntour indexed pull ratios. I'm using the command shifters in friction mode as my solution. I have read that you can replace the suntour indexing plates with microshift ones to change the suntour stuff to shimano ratios. I have a set of 8 speed microshift bar ends and am tempted to muck about with them to see if that will work, but have not had the courage to try it yet.

 

[FiveAlpha]

I have some Command Shifters as well - there was a guy who machined some 10-speed plates, but the price was extremely high, so mine are still in the packet, waiting for a project.

I think I might have to run this Centurion with friction gears - I am not paying eBay prices for a Suntour freewheel!

 

[pigman]

The problem might be the SIX speed Shimano freewheel. See if your 7 speed system plays with a 7 speed Shimano freewheel, which are cheap and readily available

 

[FiveAlpha]

The problem might be the SIX speed Shimano freewheel. See if your 7 speed system plays with a 7 speed Shimano freewheel, which are cheap and readily available

Thanks - I haven’t tried a Shimano 7, but have heard that they aren’t quite a match, so indexing might not be possible, or work poorly.

They cost about 100kr (£12) so could be worth a shot. If it doesn’t work, it will be a paperweight, as I don’t have any other freewheel bikes!

 

[legrandefromage]

according to Sheldon Brown, Suntour and Shimano 7spd spacing are both 5mm

 

[legrandefromage]

...and just to be fernickerty, I'm running 8spd RSX shifters on a shimano 600 6spd freewheel, Campagnolo Record hub all indexed ok despite the 5mm spacing of the freewheel

AND Suntour XC pro shifters on Shimano 8spd with Deore mechs

and and and, theres Suntour 7spd thumbies on a Sachs freewheel which is also 5mm spacing

As long as you have a Suntour rear mech of similar era, it should all index fine.

 

[legrandefromage]

https://www.yellowjersey.org/Suntour21.pdf