Shimano vs SunTour freewheel spacing
 

As far as 7speed goes, do Shimano and Suntour use the same spacing? Or can I use a set of indexed Suntour 7speed shifters on a Shimano equipped 7speed bike?

Tim

The suntour/shimano 7 speed index stuff is generally incompatible.Suntour used one spacing at the small end of the cassette and another at the big end. shifter pull and derailer throw are also different than Shimano. Having said that sometimes you get lucky and mixing the stuff will work or sorta work. If you got it, try it,but don't spend money on it. In order to get suntour index barcons to work on one shimano bike I have I aslo needed a suntour iindex RD.

Thanks Sydney, somehow I knew you'd be the one to figure it out.

Tim

The cog spacing is not exactly the same but it is close. I've used Suntour freewheels in Shimano indexed drivetrains (both 6- and 7-speed) with no problems. But the cable pull requirements of the rear derailers are different and you will likely have difficultly mixing Shimano and Suntour shifters and rear derailers.

Spacing's different. The Suntour spacing is closer together on the big cogs than Shimano while it's further apart on the small-cogs. You can kind of adjust the derailleur so that it works in the middle gears of the Sintour freewheel, and sacrifice the others. Or what I've done is removed the cogs on the Sintour freewheel, added 0.2mm shims between the big cogs to increase the spacing to Shimano specs. Then ground down the thicker spacers between the small cogs. This ends up creating a Suntour freewheel with Shimano spacing.

However, the Suntour teeth profile is not as easy-shifting as the Shimano. So... I grind bevels into the corners of the teeth on the Suntour cogs so that they're angled, similar to the twisted testh on the Shimno freewheels. :)

Back when I had a Suntour XC Pro-equipped bike, I got a set of wheels for it that were built up with a Shimano cassette hub. The only way I got it to work properly was to use Suntour cassette spacers between the Shimano cogs. It was the best shifting bike I've ever owned.