1x11 gearing on a bent

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[XAP]Bob
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Re: 1x11 gearing on a bent

Postby [XAP]Bob » 22 Jan 2019, 11:51am

I never found that an issue on my rapto... not that I spent all that much time in the lower ratio.

A ‘non click’ shifter (twist or bar end/downtube) makes it much easier of course.

Economically hard to justify if course
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

UpWrong
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Re: 1x11 gearing on a bent

Postby UpWrong » 23 Jan 2019, 8:06am

There seems to be a consesus that having a wide normal range with granny option of some kind is good.

I've been playing with gear calculators configuring for a compact double and a wide range 10-speed cassette (avoiding the expense of moving to 11-speed). I like the look of a 34/48 double and 12-36T cassette:

http://ritzelrechner.de/?GR=DERS&KB=34,48&RZ=12,13,15,17,19,22,25,28,32,36&UF=1990&TF=90&SL=3.3&UN=MPH&DV=teeth

Or I could stick with 9-speed Alivio 12-36T cassette since i have all the bits but that cassette is heavy and more gappy:

http://ritzelrechner.de/?GR=DERS&KB=34,48&RZ=12,14,16,18,21,24,28,32,36&UF=1990&TF=90&SL=3.3&UN=MPH&DV=teeth

Might make more sense to try that first since I have all the bits and see how I get on with the range and the compact double, and the trigger shifter.

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Tigerbiten
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Re: 1x11 gearing on a bent

Postby Tigerbiten » 23 Jan 2019, 2:11pm

I'd be more inclined to go with an alpine double vs a compact double.

Shrink the chainrings to 44-30 or 44-28.
Basically you're only running the middle-inner rings off a triple in a double setup.
Then ditch the 36t sprocket and replace it with an 11t one.
This will bias the gears more towards closer spacing at the top end without losing any range.
Main downside will be slightly worse chain wear.

Luck ........... :D

StephenW
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Re: 1x11 gearing on a bent

Postby StephenW » 25 Jan 2019, 5:53pm

David Gardiner of Laid Back Bikes is trying a 1*12 setup on his demo Nazca Fuego. You could ask him how it is going.

I've mentioned this before, but I think it is nice to avoid really small chainrings, as they seem to give a spongy feel to the drivetrain. I think this is mostly due to frame flex, but may also be sag in the chain. So I think having very large sprockets is a good thing, as it gives low gears without small chainrings, and we know that recumbents need low gears.

UpWrong
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Re: 1x11 gearing on a bent

Postby UpWrong » 25 Jan 2019, 9:05pm

I agree large chain rings+large sprockets are more efficient because of lower chain tension, and also less friction because cogs below 14T have increasing friction losses. I saw some figures which were a deterrent to using 11T or smaller in particular.

I shall give a 34/48 compact a try with a 12-36 nine speed cassette. At least that's only 3 thumb pushes on an Alivio rapid-fire shifter to get from highest to lowest (2 pushes to get from 7th to first) and I'm hoping that starting off on 48:36 will be comfortable. We'll see.

UpWrong
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Re: 1x11 gearing on a bent

Postby UpWrong » 26 Jan 2019, 6:20am

StephenW wrote:David Gardiner of Laid Back Bikes is trying a 1*12 setup on his demo Nazca Fuego. You could ask him how it is going.


I wonder if that's using Sunrace's 11-50T 12-speed cassette. I can't see a shifter with a gearing indicator for that though and I wouldn't like to be shifting blind on a 'bent.

My proposed 2x9 configuration with a 12-36T 9-speed cassette is pretty much the equivalent of a 1x12 using an 11-46T cassette, although such a thing doesn't appear to be available.

mark aldridge
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Re: 1x11 gearing on a bent

Postby mark aldridge » 26 Jan 2019, 2:26pm

Like a lot of the posters I have been playing around with my gearing over the years. I live in an areaf the country with a lot of steep choppy hills where it is difficult to build up any momentum hence err on the side of low gears.
I run a Toxy ZR with Schlumpf Mountaindrive and have become expert at low speed balancing and controlling wheel spin on steep up hills.
My workaday Windcheetah runs an old Campag mtb triple chainset at the front with a 14 tooth inner ring. The middle and inner rings are rear sprockets mounted on a cut down section of a freewheel body. All very ingenious and in theory you could have an 11 tooth inner ring (11 X 50 lowest gear anyone?)
All my set-ups are non-indexing and it has taken a lot of practice to enable smooth gear changes.
As with everything in life the body adjusts to a multitude of it-will-do situations that enable you to just get on with other things.

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Tigerbiten
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Re: 1x11 gearing on a bent

Postby Tigerbiten » 27 Jan 2019, 8:44am

11 X 50 lowest gear anyone?

11/50x26"= 5.7"......... :twisted:
That's getting down to the range of the original "Ice Trike" that went the south pole.
I think that had a 5.5" first gear.
Even 14/50X26" = 7.3"
And I thought I was bad with a 9.8" first gear.
But silly low gears do make hill climbing easy, just not fast ......... :lol:

I agree with "go for it" once you have an idea of what you want.
Run it for a bit and find out what you like and don't like about the new setup.
Then be willing to modify it to get it closer to your ideal.
It took me 4 years to get my trike setup for me.

Luck .......... :D

hercule
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Re: 1x11 gearing on a bent

Postby hercule » 27 Jan 2019, 5:43pm

Coincidentally 9.8” is my bottom gear on my trike too...

20” wheel

48 - 36 - 24 chainset (145 mm cranks)

11-34 9 speed cassette

Sturmey 3 speed hub gear

Not simple, but it gives me plenty of levers to play with! I can’t detect any significant drag from the IGH, unlike my earlier experience of a Schlumpf Mountain Drive which was like pedalling with rubber cranks :roll:

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squeaker
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Re: 1x11 gearing on a bent

Postby squeaker » 28 Jan 2019, 6:49pm

hercule wrote:I can’t detect any significant drag from the IGH, unlike my earlier experience of a Schlumpf Mountain Drive which was like pedalling with rubber cranks :roll:

Interesting (but going OT). I recently fitted a Schlumpf MD to my WAW velomobile (52T chainring so 21T equivalent when engaged) and that feels really soft in low ratio, which I put down to the extra chain tension causing 'things' to flex (that's something you don't get with a rear hub reduction gear). However, I'd previously run a 24T small chainring (and a 22T as a trial before that) and I don't recall thinking either of those felt especially soft so maybe it is something in the MD? Or perhaps we are very sensitive to such things - a bit like wheelspin, which I really notice even if it's trivial.
"42"

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[XAP]Bob
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Re: 1x11 gearing on a bent

Postby [XAP]Bob » 28 Jan 2019, 7:21pm

I never felt that the HSD was mushy
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

hercule
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Re: 1x11 gearing on a bent

Postby hercule » 28 Jan 2019, 10:07pm

squeaker wrote:
hercule wrote:I can’t detect any significant drag from the IGH, unlike my earlier experience of a Schlumpf Mountain Drive which was like pedalling with rubber cranks :roll:

Interesting (but going OT). I recently fitted a Schlumpf MD to my WAW velomobile (52T chainring so 21T equivalent when engaged) and that feels really soft in low ratio, which I put down to the extra chain tension causing 'things' to flex (that's something you don't get with a rear hub reduction gear). However, I'd previously run a 24T small chainring (and a 22T as a trial before that) and I don't recall thinking either of those felt especially soft so maybe it is something in the MD? Or perhaps we are very sensitive to such things - a bit like wheelspin, which I really notice even if it's trivial.


My previous experience of the MD was on my steel Kettwiesel, which has a straight power side chain run to the rear cassette so not much (apart from the frame I suppose) to flex along the way. Even my OH noticed it (and she's not a cyclist). I have heard that they improve as they wear in but despite putting a fair few miles on that machine (it was my first 'bent trike), we never noticed it.

UpWrong
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Re: 1x11 gearing on a bent

Postby UpWrong » 3 Feb 2019, 10:16pm

Zach Kaplan's comments on the MD here are that it resulted in a lot of boom flex,
http://www.bentrideronline.com/messageboard/showthread.php?t=144548

UpWrong
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Re: 1x11 gearing on a bent

Postby UpWrong » 3 Feb 2019, 10:30pm

My conversion to a 2x9 is work in progress. I've installed a wheel with an XTR hub, Deore M592 shadow RD and Alivio shifter with a 34/48 compact double. Whilst the shifter technically can change 3 sprockets at a time, in practice my thumb can only manage 2 at a time. The shifting isn't very slick with it up on the stand at the moment. Think I'll fit a new chain to see if that improves it. Changing on and off the largest sprocket can be a little rough, particularly the change off it into second. Wish I'd decided on the new chain before struggling to refit and lengthen the old one. I had a issue with the connecting link contacting the slightly projecting RD mounting bolt. I had shimmed the SRAM RD previously but thought I wouldn't need to with the Shimano. I'll take another look at the clearances with a new chain and new connecting links.

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squeaker
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Re: 1x11 gearing on a bent

Postby squeaker » 4 Feb 2019, 10:00am

UpWrong wrote:Zach Kaplan's comments on the MD here are that it resulted in a lot of boom flex,
http://www.bentrideronline.com/messageboard/showthread.php?t=144548
Oooh, nice link. Worth looking at the onward FB link for the pix. (I'd never heard of Mitas tyres either!)
"42"