Upgrading

[Loki62]

Just bought Sora 7 speed triple shifters for my Dawes Super Galaxy. They work fine on 7 speed, but I cannot get them to work on triple. The chainset is a Shimano Deore LX triple will work on small and middle rings or large and middle rings, but not on all three rings. Tried for three days, ready to give up. "Help" are they not compatible.

Loki62

 

[PpPete]

So the shifters (the bits on the handlebars) are Sora.... what about the front derailleur mech? Is that triple compatible too ?

 

[RecordAceFromNew]

As PpPete suggested it could be a double/triple issue, but also potentially imcompatibility between road shifter and mtb front mech. If you have a mtb mech (e.g. deore/alivio/acera/xt/xtr etc.) then they expect more cable pull than a sora (which is road) front shifter can provide, and it will have difficulties pulling the front mech across all 3 front rings. What is the make and model of the front mech?

 

[Loki62]

So the shifters (the bits on the handlebars) are Sora.... what about the front derailleur mech? Is that triple compatible too ?

Shifters are triple, front mech triple Shimano Deore LX

 

[Loki62]

As PpPete suggested it could be a double/triple issue, but also potentially imcompatibility between road shifter and mtb front mech. If you have a mtb mech (e.g. deore/alivio/acera/xt/xtr etc.) then they expect more cable pull than a sora (which is road) front shifter can provide, and it will have difficulties pulling the front mech across all 3 front rings. What is the make and model of the front mech?

The front mech is Shimano Deore LX triple what would you recommend for front mech?

 

[Smut Pedaller]

Hey there, like RecordAcefromnew said, Shimano Road front shifters are not compatible with Shimano MTB front mechs. They have different cable pull ratios. You could try using a road triple front mech; the only thing to watch out for is that road triples are typically 53-42-30 and MTB triples are usually a fair bit smaller at 42-34-24 typically so the mech cage may not perfectly match the radius of the chainrings.

What setup did you have before you got the Sora triple shifters?

 

[PpPete]

The front mech is Shimano Deore LX triple what would you recommend for front mech?

Tiagra Triple or 105 Triple. Just make sure you get one with the correct downtube diameter. Guessing that if you are seven speed, you may have older 531 framed Super Galaxy...in which case you need a 26.8mm band.

Hey there, like RecordAcefromnew said, Shimano Road front shifters are not compatible with Shimano MTB front mechs. They have different cable pull ratios. You could try using a road triple front mech; the only thing to watch out for is that road triples are typically 53-42-30 and MTB triples are usually a fair bit smaller at 42-34-24 typically so the mech cage may not perfectly match the radius of the chainrings.

What setup did you have before you got the Sora triple shifters?

Betcha it was bar end shifters !

 

[RecordAceFromNew]

The front mech is Shimano Deore LX triple what would you recommend for front mech?

Unfortunately your question reminds me of the joke about asking direction, where the answer is "If I were you I wouldn't start from here..."!

The trouble of using a road triple front mech, is that there is a chance it will have trouble shifting onto the outer ring because they are designed for narrower, road chainline compared to that of a mtb chainset which you have. What is the existing chainline (distance between centre of seat tube to centre of middle ring)?

If your chainset is old enough to have a square tapered bb, then one can potentially cheat by using a non-standard (for the chainset) bb with shorter spindle to deal with that, provided that there is enough clearance between chainset and frame.

Alternative solution is to choose shifter carefully (e.g. Campag front pulls about the same amount of cable as Shimano mtb, or use bar-end shifters). Mixing Campag and Shimano rear drive components will open up new issues that require careful planning, however.

This and this might help you decide.

 

[PpPete]

Unfortunately your question reminds me of the joke about asking direction, where the answer is "If I were you I wouldn't start from here..."!

The trouble of using a road triple front mech, is that there is a chance it will have trouble shifting onto the outer ring because they are designed for narrower, road chainline compared to that of a mtb chainset which you have. What is the existing chainline (distance between centre of seat tube to centre of middle ring)?

If your chainset is old enough to have a square tapered bb, then one can potentially cheat by using a non-standard (for the chainset) bb with shorter spindle to deal with that, provided that there is enough clearance between chainset and frame.

Alternative solution is to choose shifter carefully (e.g. Campag front pulls about the same amount of cable as Shimano mtb, or use bar-end shifters). Mixing Campag and Shimano rear drive components will open up new issues that require careful planning, however.

This and this might help you decide.

The chainline difference is only 2.5mm though, there is usually enough spare capacity in front mechs to cope, but as RAFN suggests a very slightly shorter spindle BB will likely get you out of that hole if you are struggling.

Bizarely older Galaxy's (late '80s) don't have this problem.... even though the front mech was designed as a double, and long before anyone had the bright idea to use MTB components on a tourer, it still works if you just bung a triple chainset on the original square taper - the mech has enough capacity for three rings, even with a less than optimal chainline.

 

[RecordAceFromNew]

The chainline difference is only 2.5mm though, there is usually enough spare capacity in front mechs to cope, but as RAFN suggests a very slightly shorter spindle BB will likely get you out of that hole if you are struggling.

Bizarely older Galaxy's (late '80s) don't have this problem.... even though the front mech was designed as a double, and long before anyone had the bright idea to use MTB components on a tourer, it still works if you just bung a triple chainset on the original square taper - the mech has enough capacity for three rings, even with a less than optimal chainline.

I suspect for the present situation it boils down to vintage i.e. which LX chainset the OP has, and how it was set up. I think most if not all modern two-piece Shimano mtb chainsets with HT2 outboard bb's (therefore including the LX) are designed to run a 50mm chainline (vs 45mm for road) irrespective of bb shell width.

If that is what the OP has, he might also be able to cheat by swapping spacers around on the BB. For octalink bb's one might also be lucky to be able to get a shorter one, but the choice/chance will be more limited.

 

[PpPete]

I must admit, I'd sort of excluded the possibility of HT2 Outboard...based on the fact that the rear is 7 speed. Pretty sure a Super G would have been 9 speed by the time HT2 came along. 7 speed could have been sq taper or Octalink.... hence likely to be a 47.5mm chainline

Of course there is no telling it's original.... my own Galaxy started life with 2 x 6 DT shifters and is now a triple 9 Shimano drive train but operated by Campag Ergos via the hubbub mod - so who can tell.

Loki62 - we need pics !

 

[Loki62]

Hey there, like RecordAcefromnew said, Shimano Road front shifters are not compatible with Shimano MTB front mechs. They have different cable pull ratios. You could try using a road triple front mech; the only thing to watch out for is that road triples are typically 53-42-30 and MTB triples are usually a fair bit smaller at 42-34-24 typically so the mech cage may not perfectly match the radius of the chainrings.

What setup did you have before you got the Sora triple shifters?

They were bar end shifters. No problem with those just thought I'd upgrade.