Theoretical vs Actual Low Maximum- 105 SS Rear Mech....

lvquestpaddler

So, I've tried searching for a definitive answer to this without success.... the SS is rated 25-30T, the GS is rated 28-34T maximum low gear.
Just bought a 105 groupset from CRC, and wasn't sure what I'd get (Black Friday pick'n'mix) as it said Medium RD and also gave the SS details...turns out it's the SS with the 11-30 cassette.

So what I need to know is will it take a 32 or 34 cassette? I found lots of stuff relating to the GS mech saying despite the 34T max it would happily go to 40T, but nothing on the SS to say it too was "conservatively sized" at 30T??

Has anyone some real experience of trying this out? I have a SunRace extender in my boxes of random spares but trying to avoid that route....?

TIA

lvquestpaddler

Oh sorry, forgot to add it's R7000...

trevor.hall12

My mate runs a 34 on an Ultegra 6800 with no issues ,tge b screw needs turned in pretty much all the way but it works fine
If you're worried a roadlink will get you up to 36 if you needed it

lvquestpaddler

Cheers, always a concern how the changes are affected in the wee cogs once the b-screw is wound in and less contact on the cassette....I see good old Microshift do an 11-32 for £25 might be worth a punt though seems wrong to be upgrading the groupset and putting on a cheapo cassette....but then could see if it does work ok and keep it for the trainer....( Reviews of the slightly dearer Tifosi ones that go 11-34 aren't good)....

lesfirth

Your best plan is to save yourself time and hassle and sell the parts you dont want on Ebay and buy what you do want.
The R7000 mech already has a bit like a roadlink.
I had a 5800Gs mech working very well with a sram 11/36 cassette. I changed to a bike with R8000 gs mech and could not get it to work with the sram cassette. A shimano 11/ 34 cassette worked fine as it should. Trace Velo guy on Youtube recons you need a shimano cassette with Hyperglide ( Shimano patented tooth shape on the cogs) to work with latest series of Shimano rear mechs. I agree with him.
I think you might be wasting another £25 on a Microshift cassette.

super_davo

Difficult to say what the max you can run, it will depend on your frame and the mounting point of the mech.

I would certainly fancy your chances of getting away with a 32 with the short cage, I have run most generations of Shimano 2 over capacity and got away with it (albeit not R7000...). 4 might be pushing it though.

If that doesn't work then as above sell your SS and get a GS, won't be too far out of pocket and that was a great deal from CRC.

trevor.hall12

lesfirth said:

Your best plan is to save yourself time and hassle and sell the parts you dont want on Ebay and buy what you do want.
The R7000 mech already has a bit like a roadlink.
I had a 5800Gs mech working very well with a sram 11/36 cassette. I changed to a bike with R8000 gs mech and could not get it to work with the sram cassette. A shimano 11/ 34 cassette worked fine as it should. Trace Velo guy on Youtube recons you need a shimano cassette with Hyperglide ( Shimano patented tooth shape on the cogs) to work with latest series of Shimano rear mechs. I agree with him.
I think you might be wasting another £25 on a Microshift cassette.

100

lesfirth said:

Your best plan is to save yourself time and hassle and sell the parts you dont want on Ebay and buy what you do want.
The R7000 mech already has a bit like a roadlink.
I had a 5800Gs mech working very well with a sram 11/36 cassette. I changed to a bike with R8000 gs mech and could not get it to work with the sram cassette. A shimano 11/ 34 cassette worked fine as it should. Trace Velo guy on Youtube recons you need a shimano cassette with Hyperglide ( Shimano patented tooth shape on the cogs) to work with latest series of Shimano rear mechs. I agree with him.
I think you might be wasting another £25 on a Microshift cassette.

% agree on the cassette .I had someone change to a Sunrace and it wouldn't drop to the last 2 cogs coming down.
Put on Shimano and it was perfect

MattFalle

Running 11-30 on SS on the turbo bike with no problems at all - i changed the B screw for a longer one in anticipation of setting up issues but not needed at all.

cn't see sn issue with a 32 at ll tbh.