Whats with 2x 10? Anyone gone "back" to a triple?

[trailgumby]

There's a photo of a bike with this set on it in the fatbike thread.

I'm guessing that's my shot of Aido's Moonlander from Belrose Bikes.

interesting thing is he says he rarely used "the pie plate" 42t granny gear as he mostly rides the flatter trails around Terrey Hills and the steepest he'd tackle would be the short sharp Manly Dam climb I already mentioned.

So gearing is very location dependent.

I also reckon a really big influence is the wider adoption of IMBA sustainability practices that basically limit grades to a maximum of 8 percent.

[toolonglegs]

Of course, IIRC SRAM have released a 1 x 11 with gigantic last sprocket.

Edit:
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I ran a 38/46 11-34 on my CX bike last season... I found the jumps between the lower gears to be huge. I can't imagine it would be much fun trying to keep a good cadence jumping between 10-12-14!.

[Mugglechops]

I also reckon a really big influence is the wider adoption of IMBA sustainability practices that basically limit grades to a maximum of 8 percent.

Slowly changing the tracks in Nowra to that. Which is great for the Singlespeed.

[Duck!]

The few times I rode 2x10, I found the chainrings on offer kept me out of the best part of the cassette!

I was an early adopter when Shimano introduced their 10-sp sets, which at that point didn't actually have 2x cranks on offer except in XTR, which well was out of my reach (SLX & XT both got 10-sp. as an add-on to the existing groups, rather than a full series update; I run SLX). The only choice to be made then was cassette size, 11-36 (the default) & 11-34. Conveniently, I fitted Shimano's marketing model of the average rider who spends the vast majority of the time in the middle ring. It can almost be thought of as 1x10, but with escape gears at each end.

When setting my spec, I crunched the gear numbers, thought about the majority of my riding and settled on the tighter cassette. The bigger small ring (24T vs 22T on the old set) and the smaller big ring 42T vs 44) mean I lose a small amount at each extreme from the 3x9 (the default 11-36 cassette virtually equalises the wall climber when compared to 22-34), but the mid-range is amazingly slick. When Shimano reconfigured the cassette range for 10-sp, they didn't just shove the extra cog in somewhere; they took one out & put two in its place, thereby tightening the jumps across a wider spread of the range.

I tried 2x on a a couple of different bikes, one a "trail" bike (Giant Trance 29er), with 24-36 pairing, and a Giant Anthem 29er, more race oriented, so with a 26-38 front pair. Both had the 11-36 cassette. Missing that "perfect" 32T ring, I was hunting for the right gear far more often, always in the cross-chained half of the cassette, and not really helped by the bigger wheels effectively increasing the final gear ratio over my 26er.

Sure 3x has a lot of overlapped gears (the same or very similar ratio can be found in a couple of different places in the cassette), more than 2x, but the most useable part of the range, at least for me, is found in the middle ring, where I can sweep all 10 rear gears. 2x has me hunting around to keep it in the sweet spot. The very small weight penalty of the third ring & bigger derailleurs is a small price to pay for the far greater versatility of the system.

[Duck!]

I also reckon a really big influence is the wider adoption of IMBA sustainability practices that basically limit grades to a maximum of 8 percent.

Wasn't quite how it was put to me when I did a IMBA trailbuilding course recently; maximum recommended average gradient measured over the run of a trail is 10%. Maximum recommended grade in any particular section is 15%, and in any case the trail grade shouldn't exceed half of the gradient of the slope you're riding across.

You're right though, the trend toward more gently-sloped trails reduces the need for wide gear ranges.

[trailgumby]

And the shimano triple has that brilliant carbon fibre and steel middle ring that lasts for ever (almost) and shifts so nicely. I have to admit I do miss it on the new steed.

I find I tend to use the granny ring on the 2x for anything that involves ascending as it tends to lock down the suspension and stop it bobbing due to the pivot location. So I'll probably go through front rings a bit more often especially sin e SRAM alloy stuff seems to contain a large percentage of cheese in the metallurgy.

[trailgumby]

I also reckon a really big influence is the wider adoption of IMBA sustainability practices that basically limit grades to a maximum of 8 percent.

Wasn't quite how it was put to me when I did a IMBA trailbuilding course recently; maximum recommended average gradient measured over the run of a trail is 10%. Maximum recommended grade in any particular section is 15%, and in any case the trail grade shouldn't exceed half of the gradient of the slope you're riding across.

You're right though, the trend toward more gently-sloped trails reduces the need for wide gear ranges.

Might have changed. I was going off my memory of the IMBA youtube vids I accessed via riderotorua.co.nz which are a few years old. Some places they say 8 others 10%. Their book on singletrack construction I think says 10. Of course the half rule is important. Much is dependent on local conditions and soil morphology. Some will sustain steeper grades others less.

but yes the days of 20% plus extended climbs are over. Tis getting too easy these days! Back when I were a lad...

[ozdavo]

but yes the days of 20% plus extended climbs are over. Tis getting too easy these days! Back when I were a lad...

In single track maybe, but fire trails can be built at up 25%


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[Duck!]

....fire trails can be built at up 25%

And more.... There's a couple in my area that my GPS has registered at a leg & lung-busting 34%!

[jacks1071]

The enduro I did recently had at least 3 hills at over 20% - I had to walk them.. On my old 26er with the triple I have no doubt that I would have ridden them and at a faster speed and with less leg burn than the "walkers" - eagerly awaiting the arrival of my triple

If I went 24/36 on the double that would have sorted me out for the climbs but I'd still be lacking in the top end.

If I got something like a 24/32 I'd be happy 90% of the time - just missing the top end. The triple gives me those ratio's plus a big ring for the fast stuff.

Hoping that the 24 is going to be low enough but reasonably confident it should be alright if not I should be able to chuck a 22 on without any major issues.

[Duck!]

24-36 is virtually the same ratio as the 22-34 found on the old 3x9 sets. It's not an exact match due to the 2-tooth differences at each end being proportionally different, but it's so close that you wouldn't notice it.

[jacks1071]

24-36 is virtually the same ratio as the 22-34 found on the old 3x9 sets. It's not an exact match due to the 2-tooth differences at each end being proportionally different, but it's so close that you wouldn't notice it.

Hope so, is that keeping in mind that the old bike was 26" and the new one is 29" ?

Triple arrived in the post today, probably won't get a chance to look at installing it until the weekend though.

[mitzikatzi]

for 29er
22x34=18.8 inches
24x36=19.3 inches

for 26er
22x34=16.8 inches
24x36=17.3 inches

some people use a 20t granny on 29ers
20x32=18.1
20x34=17.1
20x36=16.1

[trailgumby]

....fire trails can be built at up 25%

And more.... There's a couple in my area that my GPS has registered at a leg & lung-busting 34%!

Ah yes. There are a few in the mountains west of Yellomundee. Long ones too. Stinky brakes and blue/straw coloured rotors at the bottom!

[jacks1071]

for 29er
22x34=18.8 inches
24x36=19.3 inches

for 26er
22x34=16.8 inches
24x36=17.3 inches

some people use a 20t granny on 29ers
20x32=18.1
20x34=17.1
20x36=16.1

Hmm, so I'd still need say a 22 x 36 to get as low. I'll ride and see, I presume I can swap the granny ring out without any major issues.

[dale79]

I'm run a triple on my 29er, had a double on my old one and I struggled with out the granny gear

[Duck!]

for 29er
22x34=18.8 inches
24x36=19.3 inches

for 26er
22x34=16.8 inches
24x36=17.3 inches

some people use a 20t granny on 29ers
20x32=18.1
20x34=17.1
20x36=16.1

Hmm, so I'd still need say a 22 x 36 to get as low. I'll ride and see, I presume I can swap the granny ring out without any major issues.

Give it a shot with the stock 24 for a while & see how you go. If you go to a 22, you may lose a bit of shifting smoothness going up to the middle ring, due to not aligning as well with the shifting ramps.

[trailgumby]

I agree. More than likely the 24 will be fine. I was a sceptic too but it seems fine so far on mine.

[jacks1071]

Thanks Duck! - I havn't had time to install this yet. Hoping the 24 will be OK.

If I lose some shifting performance from granny to middle ring that'll be OK as long as it drops down alright I'm always very easy on all my bikes on the up-shift - shifting from big to smaller I think is a lot more critical.

[Sharkey]

for 29er
22x34=18.8 inches
24x36=19.3 inches

for 26er
22x34=16.8 inches
24x36=17.3 inches

some people use a 20t granny on 29ers
20x32=18.1
20x34=17.1
20x36=16.1

Hmm, so I'd still need say a 22 x 36 to get as low. I'll ride and see, I presume I can swap the granny ring out without any major issues.

The only other issue may be that the chain rubs on the front derailer bridge (the bit at the back joining the inside plate to the outside plate) because you will have to leave the derailer set at the existing height to clear the big ring. This would only happen when you are using the smaller sprockets of the cassette (or it may not happen at all). I ran 22/32/48 chainrings for a while and with the front der set to clear the 48, the chain was too low and rubbed when I was on the 22 and on anything beyond the 4th sprocket on the back. It was still usable - just changed to the middle ring when it started rubbing.

I also think that 2x10 doesn't give me a large enough range for the riding I do. I run 26/36/48 with an 11-32 cassette on a 26er. I like 11-32 because the spacing suits me better. One of my regular rides has a hill that you spend nearly 20 minutes in granny and I can just make it (usually) in 26-32. At the other end of the range, another of my regular rides sees the 48-11 getting plenty of use too.

[clackers]

I run 26/36/48 with an 11-32 cassette on a 26er. I like 11-32 because the spacing suits me better. One of my regular rides has a hill that you spend nearly 20 minutes in granny and I can just make it (usually) in 26-32.

Just be ready to choose your gearing wisely when you go to 29er, Sharkey ... you'll take an 11% hit all other things being equal!