mtnbke

I have a question that obviously I don't know the answer to:

How do you respace a 6/7 speed freewheel to work with 8 speed indexing?

With a cassette you only have to remove the spider to free up the individual cassette cogs, and then you can respace the cassette to whatever you need be it shimano 7/8/9 or Campy 8/9, or even Suntour spacing in all the variations. Worst case scenario one would just have to have spacers machined.

However, I've never taken a freewheel apart, and although I suspect it is not nearly as involved as it has the reputation of being intricate and complicated, I was curious if freewheels had "spacers" in the same way as a cassette freehub. If it does then I can simply "respace" the freewheel.

Anyone have insight into how freewheels are constructed, and how one would respace a frewheel to work with Suntour Superbe Pro 7 speed indexing?

I'm pretty sure an IRD 7 speed freewheel might not be spaced correctly for these shifters.

Also: friction is NOT an option. I'm just not a fan, and never will be.

lord_athlon

Most freewheels have different sized wheels that spin on. Newer hyperglide ones can slide on, but its not an issue like that. Think of it as a unit, and not like a cassette. Its a freewheel assembly. Are you putting brifters on an older bike?

mikeybikes

Just use the alternate cable routing with your 8 speed shifters and 7 speed freewheel. I've done it before:

https://www.sheldonbrown.com/gloss_aa-l.html#alternate

sciencemonster

A 7 speed freewheel has the same spacing as an 8 speed cassette - 5mm. Don't have to do anything.

n any case, with a SHimano freewheel, you can't really shave much off the spacers as there are two tiered sections to the different cogs. If you thin down the spacers, I think you would run into trouble where the #4 and the #5 cogs go on - the #s 5, 6, and 7 cogs need to be held tight by the rest of the cogs.

mikeybikes

Not quite with Shimano. 7 Speed is 5mm, 8 speed 4.8mm. Thus, you use the alternate cable routing. I think campy is 5mm.

sciencemonster

Oh, sorry - I don't know anything about Shimano. I would put money on .2mm x 5 = 1mm spread out over the 7 gears won't make a difference, but with the shimano freewheels I have dealt with the middle spacer has a slight hollow indentation in it to compensate for compression where the cogs change size - I have sanded down the spacers a touch and made it work.

You need to be careful which model Shimano 7 speed freewheel you get - there are cheap Chinese ones out now that have some of the big cogs bolted together so you can't change out or respace cogs on them.

furballi

I have 7-speed and 8-speed SRAM cassettes. Same spacing (confirmed with Mitutoyo digital caliper). The 8-speed cassette has one more cog. I use 7 or 8 interchangeably, depending one which one is on sale.

mtnbke

OP here. My first project uses Superbe Pro downtube shifters on Kelly Take-Offs for poor man's integrated shifters on a 68cm bike (I can't reach the downtube!).

My concern on that build is that an IRD freewheel either has different cog width or different cog spacing than what was intended for Superbe Pro 7 speed indexing. Any one know the cog width or cog spacing for 6/7 speed Superbe Pro?

The second build is a Mavic SSC 8 speed indexing build. Again I'll be using the Mavic downtube shifters on Kelly Take-Offs. According to the Mavic tech literature these should work with six, seven, or eight speed freewheels while indexing. I'm running this on a 126mm hub, so it will be either a 7 speed freewheel, or a an "8 of 9 on 7" type of setup. I have some modern Mavic M10 cogs from Mavic cassettes I could use, if they would work on a freewheel.

Does anyone else swap out pulleys to gain the benefits of the patented Shimano pulley? I'm hearing this is as significant as the Suntour slant parallelogram...