I've recently changed my bike to a 2×9 setup (24/36 and 11-34) to try it out as much as anything.

Ratio-wise. I've found it great – 'big' ring for most stuff with the granny ring there to save you for the steep/long climbs.

BUT, I've noticed that the chain's been falling off quite a lot to the side where the big chainring would originally have been, particularly if I happen to back pedal when hitting a bump (eg to level the pedals)

I've not changed the position of the front mech or shortened the chain since going from triple. I guess that shortening the chain to only what's required now may help but I do also wonder if dropping the mech lower would help though it's limited in how far down it can go by clearance to the swingarm when at full compression (bike pictured below in triple chainring guise) and also by rubbing the cage since it's wider lower down.

So what's your 2×9 setup? I don't really want to have to run a bashing unless I really have to.

Just drop the mech a little, it will be fine.

I ran a 44/32, then 42/30, now 40/28, as you've found I can now just stay in the big ring 90% of the time and only drop down occasionally. Never found the chain dropping off the 'big' ring to be a problem, presumably you've adjusted your limiter screw to stop the mech moving that far?

What's the problem with using a bash?

Def shorten the chain imo. Though I still found mine bounced off the big ring sometimes, so I got a Blackspire Stinger – pretty cheap and should work ok without a bash I imagine?

I've never really "got" twin set ups, other than getting rid of the big ring for DH and so on bikes. You still have to use a 3 position mech, and a 3 position shifter, and you've not really saved any weight (inners must be what 50g?) and you made the bike less useful.

What real world gains?

pedal forwards when aligning pedals.

Why are you running a granny Clubber? 1×9 would make things easier, esp with that wide spaced cassette.

Genuine question btw – from your posts you sound like a strong rider, and there's so few climbs in the UK that are really long and steep enough to merit dropping into a rhythm in the granny.

You still have to use a 3 position mech

No you don't, you can run a road mech, or an SLX or XX double.

I find the ratios more useful personally, the chainline's better so you get less chain rub on the front mech. It's no different to road bikes, most on here seem to run compacts, that's basically what you're doing on an MTB!

Njee – Yeah, limit screws all adjusted 🙂

Grumm – No inherent problem with using a bash but I just don't think it's really necessary so I'd rather not fork out for one!

Nickc – better clearance, same useful ratios so no downside (assuming I can stop the chain dropping 🙂 ) – it's the big ring that's gone, not the inner.

Cynic-al – thanks 😉

Garry, I'm back to reasonable fitness now (baby related complete lack of fitness about a year back was painful!) but I'm big/tall/heavy so on longer climbs (especially with a 36 instead of a 32), the lack of the lower ratios would be a drag and I've taught myself to be a spinner rather than a grinder.

I did it for a while for ground clearance reasons. Just gone back to 3×9 as we have a big trip coming up that involves some roads. Dont have any clearance issues anymore which I think is down to prob just being a bit of a better rider on rocks and logs than I was a year or two ago.

Genuine question btw – from your posts you sound like a strong rider, and there's so few climbs in the UK that are really long and steep enough to merit dropping into a rhythm in the granny.

Really? You must be super-fit then – so there's nowhere in the Lakes or Scotland you would use the granny ring? I don't use it all the time but often enough – especially since I put a 36t 'big' ring on.

Grumm – No inherent problem with using a bash but I just don't think it's really necessary so I'd rather not fork out for one!

The state of mine since I put it on suggests it is necessary for me – also it will save it's cost in knackered chainrings surely.

McBoo – I'd agree – If I was going to be doing a fair bit on the road like your trip, I'd go back to a triple but I just never use the big ring off road (and even with 2×9 it's not a major issue on road most of the time) so it seems pointless to me to actually have it.

I don't really bend/damage chainrings grumm so I don't think it'd serve any purpose beyond stopping the chain dropping and I'm pretty sure that can be solved in other ways.

I hear you clubber, same reason for me. Was a nice bit of enlightenment for me going back to a big ring after a couple of years and not gauging huge chunks out of logs as I crashed through them, rather than pick the bike over them. Have been riding with guys much better than me who ride "light"……I think I might have been paying attention for once which is nice.

…..anyway, your thread, not all about me and my musings.

Shorten the chain and put a medium cage mech on there – I found that made a big difference.

Anyone want to swap a long cage XTR rear mech for a medium one? 🙂

Really? You must be super-fit then – so there's nowhere in the Lakes or Scotland you would use the granny ring? I don't use it all the time but often enough – especially since I put a 36t 'big' ring on.

No I'm not fit and no I don't use the granny. It's maybe a style thing as much as anything, but the only place I've found the granny useful is on very long, relentless climbs where you just need to sit in and spin – like riding up a ski slope say. We have relatively few of those climbs in the UK. It's also a good bail out gear on a long ride when you just have nothing left.
34 x 11-34 gets you a good spread of gears – if I can't get up something steep using a ratio of 1 (!) then I'm not getting up it, granny or no granny.

Yep, style. I could no doubt get up pretty much everything with a 1×9 but I could also most likely on a SS but I choose not to.

Looking at the pic of my bike, I think my rear mech is probably medium cage anyway. It's certainly shorter than the long cage XT one that was there before.

A bit of a follow up.

I looked at dropping the front mech but the swingarm meant that it could only go down about 4mm and meant that there was still a lot of room between the outer cage and the chainring teeth.

I then noticed that the mech (950 XTR) is much longer (the cage is much deeper, presumably designed to cope with a 48 large ring) than the Hone one I have lying around spare so I'm going to swap them round which will mean being able to run the mech at least another 5mm lower, possibly more.

Correct, M950 mechs were designed for M950 chainsets which had either 46 or 48t big ring, it wouldn't shift as well on 44, let alone a 36! Why not get an SLX double?

I have a 2×9 with no bash set up. All I did was shorten the chain and then set the mech up for the new chainring. I didn't move the mech on the frame but carefully set the limit screws and the cable tension (as its the cable tension that controls the position of the mech on the 36)

My guess would be if you shorten the chain and slacken the cable a bit you will be fine.

As for those who don't understand the 22 / 36 chain ring 11/34 cassette combo this gives me gears to spin at 3 – 28 mph which is what I need offroad. I'd love to see you "granny gear is for weaklings heroes" climb carn ban mor without one. I'd love to see the folk that pedal at 30+ mph offroad all the time

I agree with Mr Agreeable, put a med cage mech on and shorten the chain so its just long enough for big/big to run nicely. This is what I have with a 22/36 and 11-32 and no bash, and I didn't move the front mech down as it shifts better with it up where it should be.

The shorter mech and chain stops alot of the chain slapping about too.

I certainly don't think granny rings are for weaklings – I don't really see the point in not having one except on XC race bikes. But, I personally find that I have so little momentum that it's actually not much help, and climbs are often easier in the middle ring.

So far I'm finding 28/40 an excellent combination, do the vast majority of riding in the 40, with the 28 for steeper/slower stuff. But again, I wouldn't choose than on anything but a light XC bike.

njee – IIRC you are probably rather fitter than the average STWer are you not?

I have the set up so I can use 1-7 on the cassette in granny. This gives you a lot of close together low gears. change down to granny gear at the botttom of a climb and use the intermediate gears – there is always one lower if you need it

Don't move your mech down, it should be setup as though you have 3 rings, otherwise it won't work (ignoring the swingarm problems). You should shorten your chain, that's one of the advantages to running such a setup.
Also, I can understand you not wanting to get a bash guard, but they do help keep the chain on. How about grinding off the teeth of a well worn outer chainring? Will also save you getting constant scars at the back of your calfs… 😉

njee – IIRC you are probably rather fitter than the average STWer are you not?

Quite possibly, and I do ride a 21lb FS bike, which helps. But, like yourself, I can think of climbs all over the place that I certainly couldn't ride with a 36t 'granny' ring, just think that a 22/34 is a bit low on all but the smoothest stuff, just find the back wheel spinning out on rocky stuff. I suppose as long as you keep the cadence high you should still be moving at a reasonable pace. Horses for courses and that…

The chain's already shortened and the rear mech is a medium.

With the front mech dropped (and I understand why in theory you shouldn't since it's profiled to work with the middle ring in a certain position) it works fine so I'll be interested to see how it goes out on the trail.

You're doing well on the 'loads of faff for no real benefit' scale here clubber 😉

It's not exactly on topic, but got to agree with grumm, TJ and njee20. If you don't think you need a granny you haven't ridden in Scotland, and if you are a mountain biker you should do. Even on the local stuff from my door I can be in the bottom 3 gears on the granny for 10 mins or more, and I am reasonable fit. As TJ said, try Carn Ban Mor, Ben a Bhuird, Torridon loop without a granny and you will be pushing a long way

I'm sure clubber will regret making a bonfire of all his old triple chainsets, granny rings and assorted triple setup paraphenalia now Capt Mainwaring, oh yes indeedy.

As for the jokes he made further up about being able to re-fit a triple anytime he liked if the ride required one, he'll have cause to rue that too.

The silly silly living the opposite end of the country from scotland man that he is :angry:

It's not really a lot of faff though, just a bit of fettling which frankly I enjoy doing 🙂

I'm not really sure who Capt'n Main's comment are aimed at – Garry I guess.

Well, as you know clubber, I class giving a bike a wash as pointless faffing 🙂

More following on.

Chain shortened, mech lowered by a couple of mm (the Hone actually was worse because of the shape of the cage so I stuck with the XTR) and it worked perfectly last night.

Oh, I zip tied an old Judy elastomer into the top of the cage (since the chain will never go that high since there's no big ring) which stops it being able to jump up much when in the middle ring – old trick from back in the day.

Anyway, works for me, the ratios are spot on and it's great when riding over logs 🙂

got a pic of the elastomer thing?

not sure I need one in the cage as my chain doesn't come off anyway, but it sounds interesting

22/36 is spot on as you say

Yeah, I'll get some pics later. It's nothing clever though but just means that the space in the mech cage that's above the middle ring is filled in, stopping the chain going up when you hit bumps.

I had a problem running an old M950 F/mech on a new M960 chainset – it wouldn't shift properly due to the M950 being designed for bigger chainrings, as Nick says. Try a different front mech.

GB

I did and actually found that for my frame, the Hone was a worse fit. Anyway, it works fine now so the 'problem' isn't really one.

bit of a highjack, sorry.

Have you tried a triple but with a road cassette?

I have found recently running a std triple and 11-34t that the jumps on the rear cassette are sometimes too big and wonder what a close ratio cassette but running the triple would be of help? Or should I just buy 11-32's instead of the 34's??

i found with a roadie cassette everything was hard work, evvectively your grany to big sporcket is not far off a 32t middle to 34t sprocket.