I’ve been racing a Rohloff for a couple of years now.
Despite what others say, I don’t find the slight extra weight, or the fact that all the weight is at the back, a problem.
Having recently built a singlespeed, I do notice the extra drag when I get back on the Rohloff though.

I’m thinking of maybe going for a best of both worlds, or compromise, depending on how you look at it, by building a 1×9.

Two questions then.

34×13 on the Rohloff gives me gears in metres of
1.6 1.8 2.0 2.3 2.6 3.0 3.4 3.8 4.4 5.0 5.6 6.4 7.3 8.3

32×11-34 would give me
2.0 2.3 2.7 3.0 3.4 4.1 4.6 5.3 6.3
So that would be like losing the bottom two and top two gears.

Is there a wider spread cassette available ?
I’m guessing no. 11 is the smallest that will fit around the freewheel and 34 is the biggest that the derailleur can cope with. Have I got that right ?

Is there any problem with chain flex using all 9 sprockets with one chain ring ?
Normal practice on 2×5 or 3×9 or whatever is not use big to big or small to small.
With one ring in the centre position of a triple chainset is it really OK to use all 9 on the back ?
Other people do, so it must work, I’m just worried that by losing the two bottom gears, I’m going to end up in 1st, which will feel like 3rd, at maximum grind with the chain at maximum flex.
Is that likely to be a problem ?

1×10 and you could get 11-36 cassette? Not sure if there is a 9ps 11-36?

There are 11-36 cassettes available for 9 and 10 speed. While you do lose the top end gears be honest with yourself about how much you’d use them- I know now I’ve gone without I don’t miss them. Also the low end gears- there’s no need if you’re fit, so you’ll probably be OK.

The only 11-36 cassette I can find is a SRAM XX at £208.
I’m starting from scratch, so as I’ve got to buy a cassette, derailleur and shifter,there’s no reason why I can’t go for 1×10 instead of 1×9, but £208 for a cassette ? I’m looking for spread of gears, not number of gears, so I can’t justify that.

Losing the top two gears is not a problem. I’m thinking of doing this for 12 hour races where I rarely use the top few gears on the Rohloff. By the time I get down to 1st, I’m usually thinking of getting off to push anyway, so losing the bottom two wouldn’t be too much of a hardship either.
I just thought that if there is an 11-36 cassette, I might as well go for that one.

http://www.merlincycles.co.uk/Bike+Shop/MTB++Parts/Transmission++Gears/Cassettes+-+MTB/Shimano+SLX+10+Speed+Cassette_CSHG81.htm

SLX 11-36 £54.99 RRP In stock at madison so should be freely available. You’ll need 10sp mech and shifter obviously but not probs running 1×10. It’ll be reet.

There are 10 speed 11-36s (not just XX), but not 9 speed, there’s a Deore level 12-36 if you’d rather sacrifice top end. You could modify it to an 11, but you’d end up with a jump between gears.

There is a deore 12-36 for 1×9 – currently running that on my Ridgeline 29er, with a 32T up front.
For 10 sp there is a shimano 11-36 XT cassette now…
http://www.chainreactioncycles.com/Models.aspx?ModelID=52281
Paul.

The 12-36 was designed with 29ers in mind, rather than 1×9, although it’s obviously potentially a good choice.

I found for the best chainline I moved one of the BB spacers to the non-drive side to move the chainring over a touch. Seems to give a better line with less of an angle up to the top of the cassette. Doesn’t seem to matter as much at the bottom of the cassette. Of course, this is only really possible with a 68mm BB if you’re using a BB mounted chain device as a 73mm BB only uses one spacer anyway which is effectively what your BB mounted chain device is.

Trouble with doing that is that it also puts your pedals out of line, i wonder about how that may affect your knees in the long run. Id put spacers on the chainring rather than play with BB spacers.

Thanks for the links.
I’d prefer to use SRAM than Shimano, and I’d prefer a twist grip anyway after getting used to one on the Rohloff, so it looks like I’m limited to 11-34 9 speed then.

I’ll probably stick with the Rohloff for trailquests, where the wider range of gears is useful for those long slogs up steep hoofy bridleways and fast road sections.
This 1×9 idea is for 12 hour races where the hills are shorter and there’s no proper fast bits. I’m sure I’ll manage with a narrower range of gears.

What’s this about chain devices though ?
I used a Rohloff chain guide and tensioner when I had a Rohloff hub on a full susser. I don’t use either now on a hard tail.
Will I need a chain guide on a 1×9 ?
I’ve still got the Rohloff one. Will that do ?

Wouldn’t 12-36 be a narrower range than 11-34 ?
I guess it was introduced to give 29ers the same gears as 26ers without altering the chain rings.

Go 1×10 for definite.

You’ll get used to running a trigger shifter in no time (and switching bikes too, I’ve got an Alfine on one bike which is back to front, and I don’t notice it, I just adapt readily!). With an 11-36 SLX or XT cassette, and a single 32T ring up front, you’ll have pretty much enough gears for any eventuality as long as you’re fit enough.

I’ve got a 1×9 with 32T ring and 11-32T cassette on one of my bikes, I only really miss the lower gears on long, steep climbs. But then the bike isn’t the lightest (30lb) and I’m not the fittest either! I never miss having a chainring any bigger up front either…

You’ll probably need a chain guide unless what you ride is really smooth. You may not need a full on downhill guide, but at least a bash + n-gear jump stop I would’ve thought. Locked off rear mech works as well but looks shit!

1×10, 32-11/36, jumpstop/bash on a 29er here. gets me up most things in our hilly area(might like a double up front for long days in big hills with a bit more kit on my back) if you are starting from scratch go 10. the xt shifter is very nice. if you like sram im sure the 10sp cassettes are coming or here in groups lower than xx.

Thanks again for the replies.
This is all forward planning for next years marathons, so maybe SRAM will have come out with a 10 speed 11-36 cassette and twist grip at a sensible price by then, if not, I’ll go for Shimano.
I’ve currently got a Rohloff and a single speed. If I’ve got to buy everything, hub, cassette, derailleur and shifter, I might as well go for the extra gear.
On the other hand, I could just see what 9 speed stuff I can pick up cheap second hand to see if I like it first.