1x11 gearing on a bent

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UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

Still no cassette, but this looks good if I can make a customised 13-40T cassette:
http://ritzelrechner.de/?GR=DERS&KB=33, ... H&DV=teeth
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

In the name of science, I have ordered a Goatlink and a 40T expander sprocket :lol:
speedy7777
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Re: 1x11 gearing on a bent

Post by speedy7777 »

You probably went the right way with the double. My recumbent bike is set up with 44t single front ring and 11-40 - 10 speed cassette. After about a thousand K im finding id like a little more top speed (currently spinning franticaly to hit 60kmh) eg 48t or 50t. It would also be a better road bike if the gears had smaller gaps between them. But the simplicity of 1x is quite nice nice too. So a double would have suited me well and i might try it one day with a 11 -32 cassette but in the mean time maybe try a 46 tooth front ring.
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

I've been riding my RANS Stratus XP with its 3x9 and it's given me pause for thought. The triple on that is so easy and nice to use - it has SRAM X9 with its 1:1 actuation ratio. I believe the exact ratio is 1.1 to 1. My Paseo currently has a 2x9 using Deore RD, actuation ratio is 1.7 to 1. It's performance has deteriorated with use. (See https://www.artscyclery.com/science-behind-the-magic/science-behind-the-magic-drivetrain-compatibility/)The triple on the RANS is a 28-38-48 Spa chainset with Sora FD. Ring changes are easy and smooth with the 10T gaps.

So I either change my Paseo to 2x10 with XT-Dynasys (actuation ratio 1.2 to 1) or re-instate the 3x9 with SRAM X9. The double solution will use a 33-48 compact double. I'm wondering how slick or not the 15T change will be.
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

I have made up a 13-40T 10 speed cassette with XT RD mounted on a Wolf tooth goat link and XT shifter. Cabling and gear adjustment was very easy.
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UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

So got to do a test ride with the new configuration today. It felt strange to be back on it after 6 months of using other bikes. It will take me a while to get my confidence back. Have to says it's an easy machine to balance though. It's amazing how you can set things up on a stand but still need to make adjustments whilst on the road. I over-ran the bottom sprocket and had to screw the limit screw in a bit more. As a reminder this is the gearing,
http://ritzelrechner.de/?GR=DERS&KB=33,48&RZ=13,15,17,19,22,25,28,32,36,40&UF=1990&TF=80&SL=3.5&UN=MPH&DV=teeth

I seemed to be ok starting in bottom on the big ring. I will probably change the FD to an SRAM X5 double, which should make the pull onto the big ring easier. I will then have to weigh it if this really is my final config.
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

I have done some further rides and the 2x10 gearing is working out. I kept the SORA FD double operated by Deore LH triple shifter. I just had to rotate the shifter to make it easier. The XT RD and XT Dynsys shifter are a delight. A big improvement over the 9 speed Alivio. I removed a chain link to eliminate a small amout of chain wrap and all 20 gears are perfectly usable. With the 33/48 double and 13-40 cassette the RD is having to cope with 42T difference which is well within spec. The step up and down at the front (around 45% change up) is slick enough not to cause me grief.

So I just need to do a final weighing.
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

A quick update now that I have sorted the seat out and am riding this again. The 2x10 functions well. I use the small ring when stopping/starting, hills and when near junctions, otherwise the large ring does for flattish and downhill roads. I could probably do with a lower ratio, bottom gear is 20.5", however this would be difficult to deliver with the current double set up - road crankset Q-factor, compact double, short cranks, LH trigger shifter.

I have considered reverting to a road triple with 28/38/48 rings and an 11-36 which drops the bottom to 19.5" and would mean the middle ring would suffice most of the time. I have a triple and could get the cranks shortened, which leaves the front shifter problem. Presumably Tiagra flat bar 10-speed shifters would sort that, though a proper 10 speed FD to match would be advisable. I have a collection of 9-speed FDs which might work if there is a trimming function.

Or go with a 28-42 super compact double (with 11-36 cassette), keeping my FD shifter and cage. That gives more range than I currently have, but some of the gaps are bigger and there will be a theoretical drop in effiency compared to using the custom 13-40 cassette I put together.

EDIT: Or keep the 13-40 cassette and go with a 30-46 super compact double. Hmmm, going round in circles I think :roll:
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Tigerbiten
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Re: 1x11 gearing on a bent

Post by Tigerbiten »

Real old school triple thinking here.
Your 13-40 cassette has very even gaps of roughly 15% between gears.
Double that gives you roughly 33% between chainring.
Now a 30/39/50 road triple has that spacing.
If your cassette started at 14 then it's ~16% steps and the 30/40/53 triple lines up.
Going that way makes all the overlapping gears line up and shifts between the rings becomes very predictable.
Downside is you don't get any half step intermediate gears, but how often do you use that feature now.
Ps, Your custom cassette really needs a 42t big sprocket, not the 40t fitted .... :P

Luck ......... :D
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

Yes I am wishing now that I had bought the 42T Kore expander sprocket. Might see if I can still find one for an SRAM cassette.
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

I found a 42T expander cog for SRAM at a large discount, so have ordered one. The gap between first and second will be the biggest at 16.7% but might work ok as a bail out gear. Reviews are mixed. Some reports of slippage where there isn't enough chain engagement due to the derailleur position. We'll see.

If that works in the long run I can see me going to 2 x 11 with an 11-42 cassette. That uses standard components and is where Bacchetta and ICE have gone. Hopefully prices will drop and availability will improve over time for the 11-speed parts.
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[XAP]Bob
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Re: 1x11 gearing on a bent

Post by [XAP]Bob »

UpWrong wrote:I found a 42T expander cog for SRAM at a large discount, so have ordered one. The gap between first and second will be the biggest at 16.7% but might work ok as a bail out gear. Reviews are mixed. Some reports of slippage where there isn't enough chain engagement due to the derailleur position. We'll see.

If that works in the long run I can see me going to 2 x 11 with an 11-42 cassette. That uses standard components and is where Bacchetta and ICE have gone. Hopefully prices will drop and availability will improve over time for the 11-speed parts.



Sheldon always said that the mega range concept was actually much more usable on the road than the numbers suggested. The large drop gives you a bailout gear, so yes, accelerating out of it is always a bit of a chore, but let's face it when you're climbing your local steep hill that doesn't matter too much.
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.
nobrakes
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Re: 1x11 gearing on a bent

Post by nobrakes »

I use 2x11 on my CHR. 50-34 on the front, 11-42 on the back. It works beautifully other than a slightly too large jump between a couple of the high speed gears on flat roads at full gas. In general real world riding I never notice. It’s enough to get me up Talla which has kickers at well over 20%. I tried the Laid Back Bikes demo Metabike Daemon for a few weeks. The bike wasn’t really my cup of tea but the gearing was 53-39 with 11-46 on the back. I think this works even better than what I have. I might change my pointy end to 52-36 as going bigger would need a new crank spider, which on my bike is a power meter and therefore not really replaceable.

I don’t miss my triple at all. 1x11 I don’t like due to the lack of top end (I need to keep some low gearing for the Borders hills). Even with a 10-50 SRAM setup it doesn’t quite give enough. I think doubles with a dinner plate rear end work well though.

My drivetrain is quite a mix - SRAM 2x11 Brifters. Front end is a Sram compact double. Rear end is a Shimano XT cassette and XT long cage derailleur. The magic in the middle is a JTek shift mate. The JTek works really well, I’ve never had any bother with it at all.
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

My eThirteen SRAM 42T expander cog has arrived, in Red :lol: . It looks impressive and it's custom made to fit alongside an SRAM 36T sprocket. I have also joined the BHPC with the intention of participating in a couple of races. Bearing in mind that chainring protection is mandatory for racing, I am also getting the bits together for a 32-48 super compact double with chainguard. TBH, I have been wary of using an SWB on shared paths because of the potential to do someone a nasty injury with the outer chain ring, so the chainguard will put my mind at rest. It also stops the chain from shipping overboard as well which isn't a bad thing.

I shall be exceeding the RD capacity with 29+16=45T, by a couple of teeth. Having chain tubes will help to manage any slack in small-small which may occur. Bottom will be about 19" and top will be about 93", around 485%.
UpWrong
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Re: 1x11 gearing on a bent

Post by UpWrong »

I'm sure I've bored everyone senseless by now. I kind of got another perspective on this which is that it's about how you distribute your RD capacity between sprockets and chaing rings. For my RD, the spec says 43T but I waa suggesting stretching it to 45T with the double set up in the first image below. The second image shows a triple set up using 44T. With an 11-36 cassette it would also be 45T but I was interested in avoiding the inefficient 11T cog. The triple looks good to me because I could be on the middle ring most of the time.OTOH with the double set up I could be on the outer ring most of the time when i'm on open road, and a 13T smallest cog is more efficient than a 12T smallest cog. Which would you prefer and why?
gears.jpg
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