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Drivetrain

Posted: Tue Feb 24, 2015 10:25 pm
by ZeroDarkBivi
Interesting article on the blogspot about 1x drivetrains. It appears that these have been adopted by more bike packing racers, including TD winners Mike hall (XTR 1x10) and 2014 supremo, Jefe Branham on Sram XX1. Even Brant Richards recommends this for a TD bicycle. I would be interested to know how many components Jefe got though on that ride, as my own experiences of XX1 are mixed; good when it's clean, but wears out surprisingly quickly; chain, cassette, jockey wheels... But at least it doesn't suffer from chain suck, my main reason for moving from a 2x setup, which I still prefer for shorter events. The internal gear hub is a great concept for touring, but the Shimano Alfine (11 speed) is just not robust enough, and the Rohloff is just so expensive, heavy, draggy...

So, what are your experiences with this key part of the system? Does anybody still think Rohloff is the way ahead, or has the uber-hub been left behind now? What is the key to keeping it all running smooth on a long ride?

Re: Drivetrain

Posted: Tue Feb 24, 2015 11:22 pm
by Ben98
The divide record was held by a Rolhoff equipped bike in 2012, they can't be that slow :wink: http://twentynineinches.com/2012/08/03/ ... e-whalley/
My plan is to go with the biggest single ring I can up front (38t narrow wide I think) and an 11-40 10 speed cassette out back, as riding a single speed means I'm used to cranking up hills. But then again, I've never actually done the divide so its all speculation :geek:

Re: Drivetrain

Posted: Wed Feb 25, 2015 12:17 am
by Mark E
I use a rohloff rear for most of my riding-the main attraction being I never have to do anything to it and it keeps working in the winter! However, it is heavy and for that reason I am contemplating 1x10/11 for racing long distances in the summer when it will hopefully be drier. In good conditions, the drawbacks of mud clogging mechs etc become much less of an issue. I'll continue to use the rohloff for winter training rides and maybe for events in more remote areas as it removes the potential for a drivetrain problem that would take up more time than you save by not using a rohloff

Re: Drivetrain

Posted: Wed Feb 25, 2015 1:50 pm
by mountainbaker
I've been running 1x10 for a few years on different bikes, and I will be 1x10 this summer on Tour Divide. 11-42 out back, and probably a 34 up front. I use a 32 here, but it's hilly and very steep, lots of 25+% hills around. I've gone for the 42 rear so I have a super low gear for those climbs where I'm totally spent.

Re: Drivetrain

Posted: Wed Feb 25, 2015 2:03 pm
by Brothersmith
mountainbaker wrote:I've been running 1x10 for a few years on different bikes, and I will be 1x10 this summer on Tour Divide. 11-42 out back, and probably a 34 up front. I use a 32 here, but it's hilly and very steep, lots of 25+% hills around. I've gone for the 42 rear so I have a super low gear for those climbs where I'm totally spent.
I feel a bit of a big girls blouse now, I have 30 x 11-42 on my Krampus and only just cope with that in the Peak :???:

Fago has a 9 speed triple, but gets used for everything from backpacking to fast road touring so I like the versatility it gives with out constantly having to change chainrings to suit the trip. Could be tempted by XT 2 x 11spd though if that ever comes to the market :wink:

Re: Drivetrain

Posted: Wed Feb 25, 2015 5:25 pm
by mountainbaker
Don't worry, I feel like a wimp whenever I see Ian beasting a cliff like hill in wales on singlespeed.

Re: Drivetrain

Posted: Wed Feb 25, 2015 9:08 pm
by fatbikephil
When I built the ice cream truck I used a 27t up front (middleburn rs7 uno) with a one up 42t rear. This is OK for all but the steepest climbs and 27-11 allows pedalling up to 20mph on the big FB wheels which is more than enough. In fact once middleburn sort out there thick thin rings I'm hoping to go down to 26 or 24 which will give a proper granny gear and still have a top gear which is tall enough. 32 is the absolute biggest ring you need on a mountainbike I reckon unless you are riding lots of tailwind assisted forest tracks.

Hub gears are too heavy, too inefficient and to dear plus are unbodgeable if they break. Derailleur gears can still be made to work if they get bent or at worst you can single speed them for a gyh

Re: Drivetrain

Posted: Mon Mar 02, 2015 10:36 am
by VeganGraham
"...and the Rohloff is just so expensive, heavy, draggy..."
...Hub gears are too heavy, too inefficient...

You can't make a myth true just by repeating it.
http://www.rohloff.de/en/technology/spe ... asurement/

Re: Drivetrain

Posted: Mon Mar 02, 2015 2:07 pm
by ZeroDarkBivi
Interesting stuff, but from what I read of this Rohloff pseudoscience it confirms that the internal gears are relatively less efficient in the lower 7 gears, unless the comparative dérailleur system is filthy or worn. The expense of the new system is considerable, but balanced against reduced running costs of cassettes, however, there is no denying it is also heavier than a 1x setup, as well as being an inelegant solution.

All that said, I am still considering getting a Speehub for long trips in sub-optimal trail conditions (the UK norm), I just wish the technology / engineering would have developed a bit more over the last 16 years!

Re: Drivetrain

Posted: Mon Mar 02, 2015 4:31 pm
by jameso
There's no steep hills on the TDR route (apart from a couple of quite short ones) so it's not really representative of back-country bikepacking, but there's a lot of mud at times so reliable trumps light. I had a 34 ring and a 28 bottom gear and it was ok, a 32 would have been plenty low enough for all but one short ramp. For other trips I prefer a triple with a cut-cassette 16-32 or similar at the back. Minimalising gearing is all well and good but only the pricey kit has the range I'd want for a really good trip - ie high altitude, real mountain trails etc where a 29er needs a 22-34 bottom gear. I'd move over to 1x11 once the cost gets a bit more realistic, as it will over the next 2 years. But 10T small cogs would be hopeless in the mud after a number of miles, even the 12-13T cogs skip pretty fast once really dirty. So far I think my bike's had different gearing set up for each trip, 1-3 rings, 12-17 small cog / 25-34 large.
I've always thought the perfect system would be a wide-range, 5-7 speed hub gear. I'm not sure if planetary gears would let something like that stay light and relatively efficient. I rode a friends Rohloff bike a few times during one trip and I can't say I liked it, but I have a 7 speed Nexus bike that feels quite snappy and direct.

Re: Drivetrain

Posted: Mon Mar 02, 2015 11:27 pm
by Backcountrybiking
Pinion?

Re: Drivetrain

Posted: Tue Mar 03, 2015 12:00 am
by Dave42w
ZeroDarkBivi wrote:as well as being an inelegant solution.
Why are gears running in a nice, clean, protected oil bath an inelegant solution? Especially compared to dragging a chain sideways out of alignment.

Re: Drivetrain

Posted: Tue Mar 03, 2015 12:48 am
by Mark E
I take the point about rohloff's being more difficult to cobble back together if they break in the middle
Of nowhere. Still attractive though for general winter riding in the uk into opinion. I've had mine for 4 years, done 3 bb200s on it, and ridden 2 or 3 times a week through several winters with minimal maintenance and have changed the oil once and cables twice. Also had 3 or 4 chains. On a bike with an ebb/horizontal dropouts, it is possible to set it up reasonably
Elegantly? It is still noticeably heavier than a 1x drivetrain though and the different weight distribution takes a bit of getting used to.

Re: Drivetrain

Posted: Tue Mar 03, 2015 10:34 pm
by fatbikephil
Dave42w wrote:
ZeroDarkBivi wrote:as well as being an inelegant solution.
Why are gears running in a nice, clean, protected oil bath an inelegant solution? Especially compared to dragging a chain sideways out of alignment.

Pinions, especially small ones, are a lot less efficient than chain and sprockets as there is a lot of sliding between gear teeth when they mesh. Probably better than a der system with a shagged chain covered in mud, but its easy to clean and oil a muddy chain. Rollofs have nylon shear pins which are replaceable in the field if you bust them plus I used too know a guy who ran a rollhof which a much smaller chainring than recommended without problems so I guess it boils down to personal choice and wallet size. Just wish someone would bring out a wide ratio 5 or 6 speed hub gear with the same build quality and sealing as rohlof but a lot lighter.

Re: Drivetrain

Posted: Tue Mar 03, 2015 10:51 pm
by JohnClimber
Both my Rohloff's aren't draggy, they hardly see any maintenance and the chain and cogs are the originals with 2500 miles on one and 800 on the other.

Yes they are a bit heavier but you don't notice it when you've got the wheels rolling. I'd have one on every bike if I could afford it.

Re: Drivetrain

Posted: Thu Mar 05, 2015 9:47 am
by Bearbonesnorm
I think it's becoming obvious from reading this thred, that we need Sturmy to release a wide ratio 3 speed ... 1 gear for going up, 1 for going across and 1 for going down :-bd

Image

Re: Drivetrain

Posted: Thu Mar 05, 2015 10:05 am
by chris n

Re: Drivetrain

Posted: Thu Mar 05, 2015 10:12 am
by Bearbonesnorm
-25%, 1:1 and +33% wide enough? http://www.sturmey-archer.com/en/produc ... tail/s-rk3
No, I was thinking something with a bit more range Chris.

Re: Drivetrain

Posted: Thu Mar 05, 2015 10:25 am
by chris n
Hmmm, I was going to say 'like the old AW then', but that had the same ratios. The S-RK3 gives a similar spread to a MTB triple.