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Building a mountain bike - what gears, chainset?

zed4

Prominent Member
Hi,

I've bought a used bike, but it's missing a few parts which I need to get sorted.

It has no chain rings on the back, and nothing at the crank, no bottom bracket, no cranks, no chainset.

It does have front and rear derailiers, they're XT. I guess I need to match up the derailier to the chain rings. What's the most desired configuration nowadays? Is it now better to for two stings at the front and more at the back, rather than the 3 front and 8 rear for example?

Thanks for any advice. I'm a little out of touch!

Dan
 

inzaman

Moderator
For mountain bikes 1x11 is the thing with a 32 ring up front and something like an 11-42 rear cassette which should get you up pretty much anything.
However as you already have a rear mech then you need to get the model no and match the shifters unless you have these, you can then work from that as to cassette etc.
 

NytMadn

Established Member
To be honest you might be best served buying a group set as so many parts are missing, I'd recommend a Shimano XT 10 speed set. Not at all pricy if you shop around a bit. That way you won't have to worry about making sure things match etc. (though that isn't difficult as long as you keep to 9, 10 or 11 speed and make sure the shifter and mech are the same brand)

As inzaman says the in thing is 1x11 or 1x10 with a range extender, I run the latter. It saves you weight in not needing a front shifter or mech while still giving you plenty of range.
 

John Simon

Prominent Member
Tricky old business. XT is quite high up the group set. Front chain rings are normally 22/32/42 and rear 11/32. New config is 2 chainrings and a larger range on the rear. I don't like this as the chain is too thin
 

zed4

Prominent Member
Picked up the bike, rear derailleur is a Shimano XT RD M760. Front has nothing stamped on it, but it's not mounted to the upright tube, it's bolted to the pivot for the rear suspension.
 

NytMadn

Established Member
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NytMadn

Established Member
Having said all this about new groupsets it'll be a fair bit cheaper if you buy second hand, you should be able to pick up a Shimano SLX/XT 1/2x9/10 set for about a 100 quid.
 

zed4

Prominent Member
This is the front derailleur. Any way of telling exactly what it is, and how many rings it will work with?

ImageUploadedByAVForums1451221484.791645.jpg
 

zed4

Prominent Member
To be honest you might be best served buying a group set as so many parts are missing, I'd recommend a Shimano XT 10 speed set. Not at all pricy if you shop around a bit. That way you won't have to worry about making sure things match etc. (though that isn't difficult as long as you keep to 9, 10 or 11 speed and make sure the shifter and mech are the same brand)

As inzaman says the in thing is 1x11 or 1x10 with a range extender, I run the latter. It saves you weight in not needing a front shifter or mech while still giving you plenty of range.

Sounds interesting. Presumably I can remove the front derailleur easily.

Will an 11 speed cassette fit any wheel/hub, or does it need to be particularly wide?
 

ifrank castle

Established Member
if you are willing to go second hand in terms of components, try pinkbike classifieds.

you can get some insane bargains on there at times, some bits aren't even used at all, some bits used a few times.
 

aVdub

Banned
What did the bike originally come fitted with.

It might not be as easy as just bolting something on that might not be compatible with that frame.
 

inzaman

Moderator
If it was me I personally would go the 1x11 and the XT 785 brakes if going new. In my opinion this will give you pretty much everything, unless you are going to use it for the road then a 2x11 would probably be better but I'm sure you wouldn't need a full susser for the road.

Firstly though I would check pink bike as mentioned above and weigh up the cost of a second hand 10 speed with an expander ring. It just really depends how hilly the terrain is you intend to ride on and your fitness. If not too hilly then you might not even need the expander and a 32 up front with a 36 max (and standard 10 speed cassette) should be good enough.
I have added a 40 tooth expander to my 1x10 but only really to get me up the Welsh hills as earlier this year I just felt I needed that slightly easier gear on a few hills. For where I live or ride though the 40 will most likely not be used.
 

NytMadn

Established Member
Sounds interesting. Presumably I can remove the front derailleur easily.

Will an 11 speed cassette fit any wheel/hub, or does it need to be particularly wide?

Yep shouldn't be hard to do, and the Shimano 11 speed cassettes fit on a standard freehub (unlike the SRAM 11 speed cassette which need a special freehub).

Pinkbike is good, the other main second hand place I use is Singletrack Forums, again some great bargains.

If it's got cheap discs then getting some proper Shimano hydros is a very good idea, great brakes.
 

zed4

Prominent Member
Thanks. I'm tempted to go for the £350 XT bundle with 3x 10 and brakes. That way it's all new.

Before I do, I'm going to ride my friends new bike which runs a 1x 11. See how I like it. Seems to be a more expensive option at £280 plus brakes as well.
 

zed4

Prominent Member
Having said that, the £350 system is XT M785. The £280 single 11 is XT M8000 which looks to be better.

Think I might go single 11 XT M8000 for £280 and add a set of XT M8000 brakes for £120.
 

clc.sheff

Distinguished Member
I would never go back to a 3 x system. Too much faff and too many unusable gears. 2 x if you want a decent range or 1x if not .

I prefer 2 x because I am heavy and ride on a lot of roads so I need a low bottom gear and high top gear.
 

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