Shimano MTB/Treking RD with 105 (ST-5703) shifters

gtd.

My touring bike has 105 ST-5703 STI shifters, 105 FD-5703 front mech,105 RD-5701 GS rear mech, R565 130/92 cranks with SG-X 50,39,30, rings, Tiagra 10 speed 12-30 cassette and HG CN-5701 chain.

I could do with a bigger cassette for getting up hills when loaded for touring. What rear mech and cassette could I fit?

I usually spin along around 60-80 rpm which increases to 90+ but as I run out of gears it drops off a fair bit.

DiscoBoy

I have experience of using your dérailleur with a maximum 32T rear cog on two bikes (albeit with double chainsets).

You could also change your chainset.

Do you really need less than 1:1 drive, though?

Ber Nard

As far as I know you can fit any 10 speed MTB cassette but sprockets much larger than 30t (34 or 36, say) would need a long cage MTB rear mech. For it to work with your shifters you'd need to buy a 9 speed mech, not 10 speed.

I'm running 10 speed Dura Ace bar end shifters, an SLX 11-32 10 speed cassette and 9 speed XT mech on my tourer and it shifts perfectly.

SLX is very good kit for the money.

Hope that helps.

Rob

arthur_scrimshaw

GTD. wrote:

My touring bike has 105 ST-5703 STI shifters, 105 FD-5703 front mech,105 RD-5701 GS rear mech, R565 130/92 cranks with SG-X 50,39,30, rings, Tiagra 10 speed 12-30 cassette and HG CN-5701 chain.

I could do with a bigger cassette for getting up hills when loaded for touring. What rear mech and cassette could I fit?

I usually spin along around 60-80 rpm which increases to 90+ but as I run out of gears it drops off a fair bit.

I think the pull ratios between Shimano road and mtb shifters are different so an mtb rear mech won't work with a road shifter. With the GS rd you can go to a 32 cassette and maybe chance your arm running a 34? Another approach would be to drop smaller than the 30 chainring although you would need to check if this was possible.

arthur_scrimshaw

Ber Nard wrote:

As far as I know you can fit any 10 speed MTB cassette but sprockets much larger than 30t (34 or 36, say) would need a long cage MTB rear mech. For it to work with your shifters you'd need to buy a 9 speed mech, not 10 speed.

I'm running 10 speed Dura Ace bar end shifters, an SLX 11-32 10 speed cassette and 9 speed XT mech on my tourer and it shifts perfectly.

SLX is very good kit for the money.

Hope that helps.

Rob

Using bar end shifters is a good way around the incompatibility issues with road and mtb kit but the cage length on an RD is not a factor in how big a cassette you can run, a long cage length RD is simply to accommodate the triple chainset and keep the chain tensioned correctly over the large range of gears.

gtd.

DiscoBoy wrote:

I have experience of using your dérailleur with a maximum 32T rear cog on two bikes (albeit with double chainsets).

You could also change your chainset.

Do you really need less than 1:1 drive, though?

Shimano tech docs state the RD-5701 GS can only use with a 32T rear cog with a double

I did think about mtb triple.

One of my routes has some very steep farm track sections of the byway loop in the Howardian Hills. last time I encountered almost 3000ft of climbing with my camping trailer on the back. I had to get off and push the bike and trailer up the hills between Northallerton and Sherrif Hutton

Not a fan of barcons, had duraace down tube shifters originally, didn't like them either.

gtd.

Arthur Scrimshaw wrote:

I think the pull ratios between Shimano road and mtb shifters are different so an mtb rear mech won't work with a road shifter. With the GS rd you can go to a 32 cassette and maybe chance your arm running a 34? Another approach would be to drop smaller than the 30 chainring although you would need to check if this was possible.

Can only run 32T cassette with double, can't get smaller chainring with 92mmx5 bcd

Was hoping a RD-M610 or M615 long cage mech would work as the cage has enough capacity for the triple with a front difference capacity of 22T and can run a low sprocket size of between 32T and 36T with a high sprocket of 11T

Ber Nard

Arthur Scrimshaw wrote:

Ber Nard wrote:

As far as I know you can fit any 10 speed MTB cassette but sprockets much larger than 30t (34 or 36, say) would need a long cage MTB rear mech. For it to work with your shifters you'd need to buy a 9 speed mech, not 10 speed.

I'm running 10 speed Dura Ace bar end shifters, an SLX 11-32 10 speed cassette and 9 speed XT mech on my tourer and it shifts perfectly.

SLX is very good kit for the money.

Hope that helps.

Rob

Using bar end shifters is a good way around the incompatibility issues with road and mtb kit but the cage length on an RD is not a factor in how big a cassette you can run, a long cage length RD is simply to accommodate the triple chainset and keep the chain tensioned correctly over the large range of gears.

I don't think it's the fact that they'e bar end shifters that solves the problem otherwise they wouldn't work with a road mech - they don't have the option to switch between pull ratios. As I understand it, 10 speed road/9 speed MTB is OK but 10 speed road/10 speed MTB isn't because Shimano changed to a different cable pull ratio for their 10 speed MTB gear.

You will need a long cage mech to cope with a triple and a wide ranging cassette, yes, but you will also need an MTB mech if your going bigger than 32t. No road mech other than SRAM's WiFli I know of can cope. Long cage MTB mechs are longer than long cage road mechs as well.

gtd.

Is this due to the introduction of Dyna-Sys in the 10 speed Shimano MTB groupsets??

gtd.

Just worked out the total capacity for a 11-32 and 11-34 cassette
(Largest Ring - Smallest Ring ) + (Largest Sprocket - Smallest Sprocket) = Capacity
(50-30)=20 + (34-11)=23 20+23=43T
(50-30)=20 + (32-11)=21 20+21=41T
So I need a 9 speed MTB mech to run a larger cassette and work with my 105 STIs? I've been looking at the old SLX as Rob suggested.
According to the tech docs a SLX RD-M662 GS has a total capacity of 35T so I'll need an SLX RD-M662 SGS which has a capacity of 45T

gtd.

Picked up a XTR Shadow M972 SGS mech, just waiting for new chain and cassette. Fitted the mech, shortened the cable as in the manual. I was worried that the spring being to strong for the shifter but seems fine, lots of space for when the new cassette comes.

Was looking for the manual again for the b screw setup but Shimano Tech Docs isn't working properly.