http://www.chainreactionhub.com/latest-news/1283-first-look-shimano-chainsets-for-big-wheel-mountain-bikes

yess.

new BCD. 😥

I wondered how all those people had struggled on without special 29r chainsets until now. Thankfully they will all be saved.

new BCD.

Nope, just aligning with XX1.

Surprised they’re still flogging the dead horse that is the tripple.

Are they launched on 1/4/14?

Why no 29er specific shifters? That’s what I really need.

a 32T middle ring is too hard to push and the 24T small ring is not low enough for some climbs.

Are they having a giraffe?

Just for balance mikewsmith, it also for those poor soles riding “27.5” and 29” wheels.”

Gear ratio’s and bigger wheels has been something Ive raised before. IME, as for the 650b wheel size, the 10sp 11-36 cassette works fine with the 24t granny ring and 34t middle.

I can see merit for introducing a lower set of ratio’s for a 29r, bigger circumference and all that shizzle, for those who are not as fit or strong as others. Good to put as OE on the ‘cheaper’ models within a range perhaps?

I can see the reason it may not fare too well aftermarket, is for the current fashion/trend towards 1x. Bit like stupidly narrow bars and 150mm stems were de-rigeur BITD. Funny how that one died a death 🙂

Balls, I’m going to have to change both my cranksets now.

I best compose a thread about how the marketing men and forcing me into buying more new parts for my bike even though I don’t think I really need them, or do I?!?

Middleburn have already beaten them to it, albeit with a 20t granny ring

These have been available in XT and SLX versions for a few months already.

Well I must be a complete idiot, i’m running a 2 x 9, 22/36 rings, 12/36 cassette and square taper bb on my 29er. Then I go and load it up with camping gear. I mustn’t be having any fun at all getting it so wrong

Can anyone explain this

M770 (9 speed) comes with 44-32-22
M780 (10 speed) comes with 42-32-24

So why do they need to change the BCD to get 22teeth on a 10 speed ring

Come to think of, is there any reason why you cant use 9 speed chainrings with a 10 speed chain

(Yes I’m a bit nerdy with gears)

So why do they need to change the BCD to get 22teeth on a 10 speed ring

They changed it on the middle, not the inner (or have they?). 104mm won’t accept a 30t in anything other than those funny offset designs.

Come to think of, is there any reason why you cant use 9 speed chainrings with a 10 speed chain

Usualy not, but some (particulalry 8 speed) are too wide to accept the narrower chain.

Yep, your right, the inner is still 64

Still wondering why Shimano have only do 24 teeth chainrings for 10 speed up to now