I'm planning on having a go at xc racing next year and am just putting a race bike together to start training properly.

I've gone as light as I can reasonably afford – so Kinesis frame, SIDs, XT/XTR drivetrain, Mini Pros, AC hubs on Alpines, etc hopefully around the 20/21lb mark – but am wondering what people reckon is best chainset wise for the majority of races – a standard triple or a 2×9 set up?

I know the answer isn't going to be the deciding factor in whether I win or lose, but as I'm building the bike from scratch, I'm just interested in what people think is likely to serve me best.

FWIW, on my old 'xc/trail' HT, I ran 26/36 and found it fine for general trail riding…

Thanks in advance! MM

i'm going to try something like 26/38 next – folk on here seem t have got on well with that.

For my racing I'm going 1×10 with the new Shimano stuff arriving this month. Easily the lightest way to get most of your gear ratios with a 36t cassette.

Im staying 3×9 at the moment … I used to run 29:42 upfront but i like to ride in mtns too … When i have 2 geared bikes ill try racing on 2 x 10 or 1 x 10

Double all the way for me, 28/40 on 9 speed with an 11-34 or 28/42 with 11-36 10 speed, very similar, but spot on IMO.

I am not the most physical of riders (think Ollie Beckinsale, but without the muscle 😕 ) but I race with a 29/42 Middleburn Duo set up with an 11/34 cassette without any trouble, and ride that bike on Dartmoor occasionally. Most of my racing is at Newnham, so maybe other courses have much fiercer climbs?

So I would say, yes 2×9 is the way to go if you have a lightish bike.

Whatever works for you. The weight of a chainring will not matter a jot.

Whatever works for you. The weight of a chainring will not matter a jot.

I think you're missing the point – it's all about the look on the line. 😉

If I was buying new (ignoring the XT and XTR 3-ring chainsets already in my garage…) for XC, I'd be looking at a 2×9/10 setup, probably the XX.

Not strong/fit/stubborn enough for 1×9/10.

And while (lack of) weight counts, its more the ability to run the big ring across the cassette that interests me.

I like 29/44 up front with a 12-27 cassette and Dura-Ace rear mech at the back.

2×9. 11-32 and 26/38 Brilliant set up. If I built up a proper race bike, it would have that gearing, or maybe 26/40. 2×9 (or 2×10) is the way to go. Triples are as much use as quadruples. And you don't need to spend silly money on sram xx either. Oh, and don't use middleburn chainrings like in the picture. They're useless.

footflaps likes pedalling really hard.

I can't push the pedals like him so I have gone for 40/26 on triple cranks with the 40T in the middle position.

That way I can use the cross-over gear so I effectively get an extra 2 low gears in the big ring compared with a triple setup.
I still haven't used top gear in a race this year so I might give a 38 a try.

Thanks guys, that's given me food for thought – I reckon I'll try 2×9 to start with. I reckon 26/36 will probably be enough to get me started as I had a baby 3 months ago so it'll be a while before I get some proper power back, plus I have those rings in the garage! 🙂

I like the idea of less crossover, etc. so hopefully a double will work well – I can always up the rings as I get fitter/stronger.

Thanks again for the advice! MM

P.S Would most of you guys recommend an 11-32 or a 11-34 cassette for a double set up?

Cheers!

11-34 definitely, 11-32 is absolutely rubbish in comparison.

Cynic-al – are you mocking me or serious? Be nice, I can't tell!

That way I can use the cross-over gear so I effectively get an extra 2 low gears in the big ring compared with a triple setup.

Nail. Head. That's the big advantage, you just don't need to spend as much time shifting on the front and you don't get so much duplication of ratios.

Agree with 11-34, no reason to have an 11-32. Footflaps obviously lives somewhere flat or is actually Chris Hoy.

Thanks Njee!

And yes, I had worked out about the cross-over before – that's why I ran 2×9 on my trail bike, I was just wondering if people found that in racing the courses actually dictated the full range of gears. (I'm glad to hear most people feel they don't!)

26/26 x 11-34 it is then. That should certainly get me started anyway.

(Oh and btw, all good points on the tyre thread – I think I'll have to bow to your superior knowledge and experience despite what my mate says… shame he's already built the wheels with comps! Nevermind though eh, if I prove to be any good at this racing malarky I can always get them rebuilt with revs!)

Whatever works for you. The weight of a chainring will not matter a jot.

IME it's less about weight than having to shift less often on the front. I used to use a double since I had it on an old Cannondale and it worked very well. With much wider range cassettes available now it is only going to be better.

You will have a stiffer, and tougher set of wheels for using Comps, no doubt about it. I doubt you'd have had problems with Revs, but you certainly won't with Comps, I wouldn't worry!

A 12 tooth gap between rings will shift better, I'd consider 24/36 or 26/38 if I were you.

Yep, thanks Sam… I think Cynic-al got the wrong end of the stick as I didn't ask what would be best weight wise, I was only asking about what people found to work better.

A 12 tooth gap between rings will shift better, I'd consider 24/36 or 26/38 if I were you.

Really? That's interesting! Will take your word for it and go for a 26 and 38 set up in that case.

Any recommendations on 38t chainrings?!

Yeah cheers re the wheels, I'm sure they'll do the job nicely – the rims look great!

TA Chinook are the best bet IMO, Starbike in Germany usually have decent stock, they can be a bit elusive over here.

I swapped over to a 40/28 setup on a triple (40 middle position) with a SLX 11-28 9 spd cassette a little while ago.

it's great, just enough gears for the downhill and roady sections and plenty of room left on the 28-28 for silly steep stuff.

seems to work here in Scotland, worked nicely for the Malverns too.

christ knows where you ride on 22-34.

Njee – every heard of single speeding – you don't need gears to go fast.

I have raced the NPS (stood next to you on the podium at Margam Park, the hilliest course), Southern XC, Midlands XC, riden all the 7 Stanes courses, Highlands courses, SXC courses all on 29/44 and 11-27 and my legs are very skinny.

It wasn't a bad thing, I just meant that that's a narrow spread of gears and one would have to be pretty strong to make it work, as you clearly are!

Of course SSers can get up plenty of stuff, but I would say for the average person, a wider cassette would be a better bet. It wasn't a personal dig, quite the opposite in fact.

i have 4 set ups on my mtbs….
1×9 xtr with 11-34 35 or 39 or 32 depending on the course…
2×9 with truvativ noir….ti rings 39-28
2×9 with cannondale si with ti rings 39-27
2×9 with si again….29-42
never struggle on anything….oh except 35t single round margam park…

I'd not have thought 36 up front would be enough to be honest. I often find myself well into the big ring on descents, but then I try and play to my strengths and hammer all the descents and flats (since I am so sh*t at climbing).

I used to have a Middleburn Duo 29/42 and that was pretty good – did all my riding on it actually and never really suffered. Having only two rings was good – because they were basically in between the usual three rings, I ended up shifting at the front much less often, which was nice when hammering.

Btw, sorry to break this to you footflaps, but singlespeeding is feasible and fun to some, but it's not efficient.

I think the thing I find with small cassettes is that it cancels out the advantage of the double, and the ability to use the whole cassette, you start (well I would!) needing to shift on the front far more, which for me, defeats the purpose of the object.

Of all the 29/44 Duos I have, the Middleburn is the worst performing – seems to offer a very poor change. The best was the Cannondale CX-2 which is no longer available, although I'm still eaking miles out of the two sets I've got left.

As for SS, never said it was efficient, although I was always tempted to enter an NPS on one just to see how I did, but never had the balls – would have been dropped like a stone on the line, but I reckon would have caught back up on the hills. Sadly I'm no longer fit enough to stay with the bunch on gears, let alone SS.

Not sure I'd use a Middleburn Duo again after having used XTR to be honest. Wasn't much lighter, and wasn't as stiff. Plus the spider's just a bit of alu so the rings aren't that stiff either resulting in not great shifting under power etc.

although I was always tempted to enter an NPS on one just to see how I did

People did, I'm struggling to think of names, but I know I've seen people do it.

I use a triple up front with a 22 32 44 and a 9 speed on the back 11-25 which i think saves a bit of weight off the cassette compared to an xt or xtr cassette.Works for me.

I assume with all this talk of 2×9 it still uses the std shifters? Just adjust the screws for Hi and Lo so that chain can't come off?
Never tried 2×9 etc but interested in trying.
I notice people saying 40 on middle ring location, is that the largest? Could a 44 go there?

I use a triple up front with a 22 32 44 and a 9 speed on the back 11-25 which i think saves a bit of weight off the cassette compared to an xt or xtr cassette.Works for me.

Aye, that saves more weight than just running a 2×9. I used to run a 12-27 cassette, but got annoyed with shifting on the front the whole time, sure that wastes significantly more time than the weight loss saves!

Cassettes are cheap though!

yeah a 44 could go there… BUT you need to be careful on inner ring size, simply as shimano states a max diff between ring sizes for shifting/fit in the front mech – it's something like 12 or 15 teeth difference between rings

I just don't really have the legs to use a 44 off road, find a smaller big ring a lot more usable.

I've been using 2×9 for many years now, since like Sam, being introduced to 2×9 on an old Cannondale hardtale. Currently using a 42/30 with a 11-32. It's used for everything from general trail to XC to 24hr solo. A 36/26 seems very low to me, as you're talking of XC racing here. I'd struggle to spin that gear fast enough to keep up with pack on descents. But if you've already got 36/26 rings, and are a spinner rather than a pusher, then just give them a go and see…

talk here has pretty much convinced me to give 2×9 a go on my xc racer resurrection- really like the concept of something like a 38 or 40 in the middle at the front, and a 26 inner ring, allowing full use of the cassette in the 38/40.

40 in the middle at the front, and a 26 inner ring

That's whatt I run, I like it.

I'd struggle to spin that gear fast enough to keep up with pack on descents

36/11 is still a pretty high gear, you're unlikely to be handicapped much! One tends not to be spinning on the descents at all, it's only really off the start that a higher gear can be of use! Some of the top World Cup guys are running single rings around that size, it's not really an issue.