Lower geared chainsets for Dawes or Ridgeback

[Brucey]

the thing that annoys me about the 'specifications' is that (IIRC) this info only includes the current parts they make. It seems to me that there are now hundreds of missing SI techdocs which relate to parts that have only recently stopped being made, many of which are still on sale.

There are also numerous other technical documents (tech tips etc) that used to appear on the Shimano USA website that relate to general issues, or explain the differences in the model line-up (eg differences between the various N8 hubs...)

BTW if you stay within shimano's specs for FD capacity and chainstay angle you will be OK, but if you use a mech at a higher angle the capacity is reduced. At a lower angle the capacity is increased slightly, but this (and/or smaller chainrings) risks that the mech fouls the chainstay.

I note with interest that some bikes (e.g. which have spare spokes mounted on the chainstay as a protector, or cable routing in the area) cannot even use the rated capacity of the FD without the tail fouling something.

cheers

[Erudin]

On my Surly LHT (52 cm, 26" wheels) I swapped out the 26t inner ring with a 22t last year with no problems since then.

Original chainset: Shimano Deore M590 Triple Chainset - 170mm - 26.36.48

Replacement inner ring: Shimano Deore M590 22t 4 bolt.

[DoctorRad]

BTW all of this swapping about is (IMHO) very much easier to do if you are using 9s or lower. Once you get into 10s the choice of mechs become more constraining. Quite recently I think that Thorn have given up speccing 9s parts on a lot of their bikes and this is the outcome; fewer 'real world' gearing choices for touring bikes.

I think the issue is that it is becoming increasingly difficult to spec new 8- or 9-speed parts of a decent quality now that even Deore-level kit has gone to 10-speed, and 105 is at 11-speed. Try finding new 8- or 9-speed shifters of decent quality that aren't NOS, for instance.

Out of interest, I know there is a difference in pull ratio between 9- and 10-speed Shimano MTB rear mechs, but is this the case for road mechs too? Will a 10-speed road mech index properly with 8-speed shifters and an 8-speed cassette? Is it wide enough to take an 8-speed chain?

[ukpacker]

On my Surly LHT (52 cm, 26" wheels) I swapped out the 26t inner ring with a 22t last year with no problems since then.

Original chainset: Shimano Deore M590 Triple Chainset - 170mm - 26.36.48

Wow Erudin that is impressive. I thought these front deraileurs could only cope with a max 22 teeth difference from smallest to largest wheel, I see that the Long Haul Trucker and the Panorama both use a Sora FD. That would certainly give me the low gear I require though can't see me ever using the highest. I don't even wear a helmet, the speed would terrify me.

Do you find the large steps between the gears to be an issue?
cheers
ukpacker

[Brucey]

...Out of interest, I know there is a difference in pull ratio between 9- and 10-speed Shimano MTB rear mechs, but is this the case for road mechs too? Will a 10-speed road mech index properly with 8-speed shifters and an 8-speed cassette? Is it wide enough to take an 8-speed chain?

10s road mechs will work with 6,7,8,9s shimano shifters (only 9s, 10s Dura Ace, and other 10s road shimano, of course) and the cage is wide enough (just, IIRC) to take most 8s chains. If you use 9s chain it'll work on 8s everywhere else and will go through a 10s rear mech a bit better, so I'd use that.

cheers