1x11 gearing on a bent

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UpWrong
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1x11 gearing on a bent

Postby UpWrong » 19 Jan 2019, 12:35pm

Anybody done this? Anyone done it on a Nazca? I know all the disadvantages in term of range and spacing compared to 3x9 (or even the legendary 3x7 :lol: ) but I still feel compelled to give it a go. Why? Well the front end of the bike looks so much neater without an FD, and it saves weight (no FD, shifter and cable, and lighter chain - maybe 350g).

I currently have an SA CS-RK3 dual drive IGH on my Nazca Paseo. In operation I quite like it, but in reality a shift of the IGH is only equivalent to 2 sprockets on a cassette. And unlike a Rohloff you still have to plan which ratio to stop in anyway. Broadly speaking a 1x11 gives the same function as a 2x9 and I think I can live with that by sacrificing the rop end.

As it happens I have a Mavic Crossride with an 8/9/10/11 speed compatible hub. Using that and switching back from a disc to a V-brake is going to save quite a bit of weight. Along with a lighter tyre (less worried about changing punctures than with the IGN) and the 1x11 gearing I reckon a weight saving of about 3-4 lbs which would be noticeable.

I'd probably run an 11-42 cassette in the first instance. Anybody used an 11-42 on a Nazca?

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Tigerbiten
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Re: 1x11 gearing on a bent

Postby Tigerbiten » 19 Jan 2019, 9:15pm

What do you want your bike for ??

Try carrying 2 liters of water and see how much slower you are on a normal ride.
The difference will be about how much faster you will be the reduced weight.
But the numbers I've seen is roughly an extra 20 lb in weight will only slow you down on average by around 1 mph.
If you're going to do a lot of stop/start riding in traffic or very hilly riding then maybe a bit more.
If it's a lot of very steady riding on the flat then you probably a bit less.
But don't expect that much of a difference in speed.

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

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

Postby [XAP]Bob » 19 Jan 2019, 9:18pm

350g isn’t two litres, it’s a drinks can
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 » 19 Jan 2019, 9:26pm

[XAP]Bob wrote:350g isn’t two litres, it’s a drinks can


Changing back to a derailleur hub, a V-brake and a lighter tyre as well will make a weight saving of more than 3lbs.

However, I take your point that weight saving is overrated in terms of performance gain. I think reducing the weight from 41.5lbs to 38lbs say will make it a bit easier to manage, e.g. when getting on/off trains.

Anyhow, hoping to try the bike out tomorrow with the extra foam pad on the back to reduce the amount of lumbar support.

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

Postby [XAP]Bob » 19 Jan 2019, 9:28pm

Ah, hadn’t spotted that far in ;)
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.

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Tigerbiten
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Re: 1x11 gearing on a bent

Postby Tigerbiten » 20 Jan 2019, 9:02am

UpWrong wrote:However, I take your point that weight saving is overrated in terms of performance gain. I think reducing the weight from 41.5lbs to 38lbs say will make it a bit easier to manage, e.g. when getting on/off trains.

I see what you're thinking and that may help when lugging it around.

42/11 will give you 3.8x gear range.
I assume your going for around a 25" to 100" gearing.
That will give you from ~5 mph @ 60 rpm to ~30 rpm @ 100 rpm.
Any slower and you'll get off and walk ........ :lol:
Depending on tyre size around a 44t chainring will give you that range.
With fat tyres a 42t chainring may be better.

Does that sound right ??

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

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squeaker
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Re: 1x11 gearing on a bent

Postby squeaker » 20 Jan 2019, 11:28am

UpWrong wrote:Anybody done this?
'Vangelo' on BROL has produced a range of tasty FWD Performers with 1 x 11 (IIRC).
HTH
"42"

Brucey
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Re: 1x11 gearing on a bent

Postby Brucey » 20 Jan 2019, 12:05pm

UpWrong wrote:….I currently have an SA CS-RK3 dual drive IGH on my Nazca Paseo. In operation I quite like it, but in reality a shift of the IGH is only equivalent to 2 sprockets on a cassette. And unlike a Rohloff you still have to plan which ratio to stop in anyway.....



The IGH range in a CS-RK3 is 178%. You can shift whilst stationary into gear 1. This means that if you make an unplanned stop in gear 3 and start in gear 1 you have a gear that is about half the size that you can shift into statically and start in. This is obviously not as good as a wider IGH range but it is about the same as four sprockets on the cassette and a lot better than a poke in the eye with a sharp stick.

Whether the gear range is adequate is dependent on the rider and the terrain. You can 'optimise your gearing' for every ride if you want.... My suspicion is that a well-ridden recumbent with a 1x11 gear setup (and an adequately low bottom gear) will see you spending a lot of time running in the smaller (eg 13T, 11T) sprockets, and the sprockets won't last long before they wear out.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

UpWrong
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Re: 1x11 gearing on a bent

Postby UpWrong » 20 Jan 2019, 8:51pm

Brucey wrote:The IGH range in a CS-RK3 is 178%. You can shift whilst stationary into gear 1. This means that if you make an unplanned stop in gear 3 and start in gear 1 you have a gear that is about half the size that you can shift into statically and start in. This is obviously not as good as a wider IGH range but it is about the same as four sprockets on the cassette and a lot better than a poke in the eye with a sharp stick.

Whether the gear range is adequate is dependent on the rider and the terrain. You can 'optimise your gearing' for every ride if you want.... My suspicion is that a well-ridden recumbent with a 1x11 gear setup (and an adequately low bottom gear) will see you spending a lot of time running in the smaller (eg 13T, 11T) sprockets, and the sprockets won't last long before they wear out.

cheers

Yes, but I'd rather be riding in the more efficient middle gear of the hub most of the time.

All the 11-42 cassettes seem to have 11T/13T as the smallest sprockets. I think the gap between those two would irritate me. There's a need to customise 11-speed cassettes to get desired gaps. Presumably they are designed for MTB use and therefore not optimal for 'bent road use. I reckon a 12-46 cassette would suit if one could be made up. However I'm not sure that's possible with such large sprockets.

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

Postby [XAP]Bob » 20 Jan 2019, 8:53pm

Schlumpf mountain drive and a decent sprocket size?
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 » 20 Jan 2019, 8:53pm

squeaker wrote:
UpWrong wrote:Anybody done this?
'Vangelo' on BROL has produced a range of tasty FWD Performers with 1 x 11 (IIRC).
HTH

Thanks for the reminder. They are FWD though so not sure if all the experience translates.

UpWrong
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Re: 1x11 gearing on a bent

Postby UpWrong » 21 Jan 2019, 11:39pm

On reflection, I think I would find the range rather limiting. A compact double with an 11/42 cassette would make more sense. However looking at the cost of 11-speed chainrings and 11 speed large sprocket cassettes I think I could live with an 11/36 cassette on a 10-speed double. Changing to an 11-speed double would cost around £305, whereas changing to a 10-speed double would be around £155 - having suitable rings is a large part of the saving.

A double with a large range cassette would mean being able to use the large chainring for everything apart from climbing. Even starting off would be ok because the bottom gear on the large ring would be in the low thirties (gear inches).

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Tigerbiten
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Re: 1x11 gearing on a bent

Postby Tigerbiten » 22 Jan 2019, 9:35am

[XAP]Bob wrote:Schlumpf mountain drive and a decent sprocket size?

A Schlumpf drive will extend the range.
But ........
I find mines an either/or drive.
Because you need to change 6-7 gears at the back when you shift ranges at the front then you either want to run in normal mode or shifted mode.
It takes to long time wise to be constantly shifting between ranges
So you'd want to try and arrange the shift speed to be in a gear you don't normally use.
That's why I've ended up with 2 chainrings on my HSD.
It's lifted the shift speed from ~14 mph which I can easily hit on the flat to ~20 mph which I cannot without losing my 9.6" first gear.

It's more a question of will you happy with the speed range of ~5-30 mph with this setup or do you want/need an extended speed range.
You'll really need to run it for a few thousand miles to get the experience of it before making your mind up if you like this setup or not and/or how you can modify it to make it better for you.
It took me 4 years with a modification after each year (minor, major, minor) to get my setup just right for me.
But now I've got so used to my extended speed range of ~2.4-50 mph with my drive setup that I wouldn't want to shift back to a more restrictive range.

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

Postby [XAP]Bob » 22 Jan 2019, 9:42am

Hence my thought of the mountain drive. Running ‘normally’ in direct drive, with a bailout option in an emergency stop situation.
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.

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Tigerbiten
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Re: 1x11 gearing on a bent

Postby Tigerbiten » 22 Jan 2019, 11:48am

Don't think it's worth it for the use you'd get from it.

You could up the chainring to around 56t which would up your gears by ~25%.
But the bottom 3-4 gears may still become to low to be useful on a two wheel bent.
Plus you will still have the 6-7 shift at the back to cope with as you up the range.