2x10 drivetrain

robst3

I'm thinking of going for a 2x10 drivetrain on my new 456 carbon build. SRAM make it very simple to choose the correct bits, shimano not so much...

I've identified the following bits that could be used in a 2x10 setup:

XT M786 front mech http://www.chainreactioncycles.com/Mode ... elID=67203
SLX M663 rear mech http://www.chainreactioncycles.com/Mode ... elID=52333
SLX HG62 casette http://www.chainreactioncycles.com/Mode ... elID=69268

This leaves me around £180 for chainset and shifters but I am struggling to work out what would be compatible? Any suggestions would be appreciated 8)

The Northern Monkey

i suggest you buy the 10sp xt rear mech from rose bikes for £33 delivered...

njee20

Anything will be compatible, a lot of it depends on what ratios you want to run. £180 for both isn't that much, I'd get SLX, flog the rings and fit some TA Chinooks of your choosing, unless you want 22/36, when I'd get that.

I'd get it all from Rose too, cheaper than anywhere in the UK!

robst3

I was under the impression the SLX is a bit tougher?

But yeah - I haven't decided where to buy them from yet- just working out what I want first!

What i'm confused about is if a dedicated 2x10 chainset and dedicated 2x10 shifters are needed? Also whether SRAM shifters/chainset will be compatible with the shimano bits above.

supersonic

No, you don't need a dedicated shifter, though some SRAM are available as two speed for the fornt. Neither dedicated chainset - triples with a ring removed works: even 9 speed chainsets are fine.

Merlin are doing a complete deore set up (with brakes!) for just £260. Is a triple though chainset though.

The Northern Monkey

you can't mix and match shifter makes and rear derailleurs.

If you have SRAM shifters, you need SRAM rear mech.
If you have SHIMANO shifters, you need SHIMANO rear mech.

Then you can use any chainset/cassette combo you like as long as its 10sp.

robst3

Thanks guys.

So if I used a 3x10 set of shifters what happens to the 'extra' shift when using it with 2x10?

I would go for that set up from Merlin but I already have those brakes

The Northern Monkey

you set the front mech stops so the shifter won't go any further than the 2nd click

njee20

Nothing, you adjust the stop screws to only utilise the bottom 2 positions. I did it for years before 'proper' doubles.

robst3

Sweet! So if I go for a 3x10 SLX setup, swap out the middle and outer rings with a larger middle and a bash guard, adjust the stop screws etc it will be a fully working 2x10?

And I would be able to revert back and forth between 3x10 when I fancied it?

cooldad

Yes and yes

robst3

happy days

robst3

Hmm one more issue - if I stuck with the 22t inner ring, what to go for on the middle? 36 or 38 maybe? I've got the option of an 11-36 or 11-34 casette... :oops:

The Northern Monkey

I've got 27x42 up front.. is good on the Boardman!

felix.london

But one of the main benefits of a dual ring is the fact that you can use the whole of the cassette in either ring

If you're (in theory) just removing the big ring then surely there will be no difference in the chain line so when using the small ring you cannot utilise the whole cassette

Or have I got this wrong?

welshkev

22-36 on my SLX double and bash but i only run 9sp not 10, not sure how much difference that would make :?

robst3

felix.london wrote:

But one of the main benefits of a dual ring is the fact that you can use the whole of the cassette in either ring

If you're (in theory) just removing the big ring then surely there will be no difference in the chain line so when using the small ring you cannot utilise the whole cassette

Or have I got this wrong?

That's kind of what I was thinking... But then if you look at the M660 chainset from shimano there is an M665 dual ring version which is exactly the same but with larger inner/middle rings and the outer swapped for a bash guard. So it must work?

felix.london

doesn't make sense - if they are exactly the same then why am I not allowed to use the smallest sprockets when using the granny ring of my 3-ring set-up?

I ditched the idea of converting my 3-ring to a dual because I presumed the spacing of the rings would be different on a 'proper' dual-ring chainset :?

robst3

the SLX dual (M665) has a quoted chain line of 46.8mm, the SLX triple (M660) has 50mm.

Not sure if that means they are identical or not?

Guessing they are and the dual is measured to the point in between the inner/middle ring whereas the triple is measured to the middle ring.

This thread makes it seem like they have the same chainline (if measured to the same point)

http://singletrackworld.com/forum/topic ... slx-triple

EdW

Slightly off topic, but have you considered 1x10. That's what I went for with my Carbon 456. You get quite a large range of gears with a 11-36 cassette (I run a 36T chainring up front).

And, you only have to buy a rear mech & one shifter.

cooldad

Still no point in using small/small. You get the same ratios but better using bigger cogs.

robst3

I briefly considered it! What chainset did you go with for that? Is it okay on steepish climbs?

Nice looking 456 btw 8)

EdW

I've got a Race Face Respond chainset with a single specific chainring.

I was quite surprised at how well it climbs. Personally I don't think I really needed the lower ratios of my old 3x9 setup, I just used them out of laziness & because they were there. If it gets to the point where I need a lower gear it's probably quicker to get off & walk.

I do prefer to pedal slow in a high gear than fast in a low gear though.

njee20

If you're buying a new chainset and going 22/36/bash there's no reason at all to not buy the proper SLX double.

FWIW I've also gone 1x10 on my race bike, on an XTR M985 chainset (had to get a custom ring for the 88mm BCD) 36t with 11-36 block, and love it. Would probably still go for a double on a more trail orientated bike though.