XE007

Hello bikeforum,
I have a technical question regarding this front derailleur shifter.

Does anyone know if this left 3 speed shifter has a cable pull ratio of 1:7 as the 8 speed right shifter?
I want to use this shifter for my 8 speed rear derailleur for a simple 3 speed setup.

I have three 1.8mm thick cogs with 3mm spacers between them giving me 4.8mm of cog spacing.

I only want to move to friction shifting as a last resort.

Thanks. I checked internet search but no concrete answer.

70sSanO

Somewhere buried in the archives, someone has measure front derailleur cable pull.

I personally feel it would be an absolute miracle that a Shimano 3 speed FD shifter matched the pull needed for an 8 speed, not 6, 7, or 9, RD pull.

I have often thought that if someone wanted an “almost” single speed it might be possible to run 2 or 3 cogs and just have minimal shifting.

The first hurdle would be having the ability to set limit screws to just a few cogs. You can use longer screws, but you might lose contact with the stops.

If that is possible you can use a right shifter and just block off the un-needed shifts.

As for your FD shifter for RD shifting, if by chance it is “somewhat” close to any RD speed pull, and you can break apart a cassette with full cogs, you might be able to space it match the pull; within chain width reason.

It is an interesting question that hopefully someone has tried to tackle.

John

XE007

Thanks. That is what I feared. Knowing the cable pull on this front shifter would really help. I simply got tired of the market pushing for more and more cogs making biking not so fun. I am glad I still have my ene friction thumb shifter but indexing a 3 speed would be so easy. I wish I had not taken my bike apart to get it painted just to test this lol.

70sSanO

But an easy work around is to use a 7 or 8 speed right trigger shifter and just use the first 3 clicks.

People have blocked off shifts for years. I’ve run 7 cogs with 8 speed shifters. You need to make sure the low limit screw is not set too close that it wedges the shifter pawl.

The only caveat is setting the RD limit screws to cover only 3 cogs. If you can do that you’re should be home free.

John

XE007

Thanks again. I will definately look at that. I did not want to consider it because I have a very short straight handlebar (putting together a cruiser folding bike) and my DiaCompe brake handles,which seem bulky, take up a lot of room on the right side with my grips.

Thanks and if I test the pull ratio using the 3 speed once I am done rebuilding the bike, I will report back with the pull ratio.

70sSanO

That would be beneficial.

John