Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Internal hubs?

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chewybrian
02-21-09, 06:08 AM
Is anyone using internal hubs for brevets? The generator front hub seems handy, although I want more than 3 watts of light. Can you get more? What brand/model do you prefer? Are they reliable? Any noticable drag?

The internal gear rear hubs I have seen all have drawbacks. The Nexus 8 speed is affordable, durable(?), but has only a bit more range than a 10 speed. The Rolhoff 14 speed has the range of a 27 speed, but a fat price. The Nuvinci seems ideal in every respect: unlimited ratios, shifting while stopped, decent range, except... 11 pounds! Worth hauling an extra half a bike worth of weight?

Are there other options? What is your impression of or experience with any of these hubs?


LWaB
02-21-09, 07:58 AM
I've only used a couple of internal hubs for brevets, Sachs Duomatic 2sp and SA 8sp. Both seemed OK, a bit of viscous drag was evident in the workstand but not on the road.

djwid
02-21-09, 09:00 AM
My current project bike will have a Rohloff (as soon as the frame arrives from NL). I will be trying it out on a few 200ks this year to see how she preforms. No experience today but I can report back in June ;)


spokenword
02-21-09, 09:36 AM
Is anyone using internal hubs for brevets? The generator front hub seems handy, although I want more than 3 watts of light. Can you get more? What brand/model do you prefer? Are they reliable? Any noticable drag?

Are there other options? What is your impression of or experience with any of these hubs?

I ride with Schmidt dynamo hub for brevets, and the drag is not noticeable. There've been more than a few daylight commutes wher I forgot that I left my lights running from the previous evening. There's an occasional vibrational 'hum' that can be felt when coasting between 10 - 15 mph., but otherwise there's little difference in performance.

I would not take the 3 watt limitation at simple face value. The latest generation of dynamo LEDs harness reflectors inside the bulb to create some pretty impressive results. The debate nowadays has turned from whether the latest dynamo lights are bright enough to see or be seen, to whether the lights are too bright and pose a danger in blinding oncoming motorists.

I don't have an internally geared hub, but I do know that if you plan on using a Nexus 8 on a bike with drop handlebars, you normally have to kludge some method for mounting the rapidfire shifter that was paired with it. There are supposedly 3rd party bar end shifters for the Nexus 8, but I don't know how well these products perform in real life.

Randochap
02-21-09, 01:31 PM
The bike below was seen @ PBP '07:

I'm very partial to understated, industrial-looking bikes, and as you can see, it is a pretty nice build with a silver Rohloff.

To my mind the Rohloff would be the only sensible option for an internally-geared brevet bike, although there are some geeks out there who swear by their old 3-speed Sturmey-Archers. And why not? They are reliable and time-tested. If you are an aesthete to the third degree, go for it.

The Rohloff, it should be noted, is not without issues. I have seen three with problems straight from the factory and have helped stranded world tourers with rebuild kits. Leakage and skipping seem to be the main problems. Spare gaskets, at least, are in order. I should add that I've seen others with nary a hiccup, once broken in.

As for hub generators -- they are very reliable, especially the SON. Resistance is futile ... I mean imperceptible. As spokenword has noted, there is no need take notice of the 6V/3W standard. Pair a hub up w/ something like the Schmidt Edelux and watch cars dim their headlights around an upcoming bend.

Bacciagalupe
02-21-09, 01:47 PM
The pros of an internal geared hub:
- lower maintenance requirements / very robust
- excellent protection from mud and dirt, due to sealed gears and better ground clearance
- can shift at any time, including when stopped

The cons:
- generally less efficient than derailleurs (i.e. you will need to expend more energy to attain the same speed)
- the hub itself can't be repaired in the field (though cable & chain fixes are not a problem, and there's less chance of damage overall)
- bike needs horizontal dropouts
- gearing range is narrower than with derailleurs


Generally speaking, I wouldn't use an IH unless you a) really don't care about completion times, and b) plan to use the bike for touring in remote areas or c) plan to use your randonneuring bike to commute.

wahoonc
02-21-09, 02:32 PM
The pros of an internal geared hub:
- lower maintenance requirements / very robust
- excellent protection from mud and dirt, due to sealed gears and better ground clearance
- can shift at any time, including when stopped

The cons:
- generally less efficient than derailleurs (i.e. you will need to expend more energy to attain the same speed)
- the hub itself can't be repaired in the field (though cable & chain fixes are not a problem, and there's less chance of damage overall)
- bike needs horizontal dropouts
- gearing range is narrower than with derailleurs


Generally speaking, I wouldn't use an IH unless you a) really don't care about completion times, and b) plan to use the bike for touring in remote areas or c) plan to use your randonneuring bike to commute.

The efficiency question if debatable. I have seen several studies and the overall efficiency depends on which gear each set up is in, the cleanliness of the chain (more important with derailleur systems). You would lose more efficiency by having your jacket unzipped than the difference between a well broken in and serviced IGH or a properly tuned and operating derailleur system.

Horizontal dropouts are not a requirement, you can run a chain tensioner. Admittedly the best set up is horizontal drop outs.

Also if you are concerned about range...get a Rolhoff and add a Schlumpf Drive (http://www.schlumpf.ch/schlumpf_engl.htm):D

FWIW I have less dependability issues with IGH than I have ever had with derailleurs. And I do still ride both with my preference being the IGH. Also check out a world's record (http://www.phased.co.uk/index.php?option=com_content&task=view&id=11&Itemid=7) that still stands today...set on an IGH:thumb:

Aaron:)

Randochap
02-21-09, 02:49 PM
- gearing range is narrower than with derailleurs

Wrong. As you can see on the pic I posted, the owner has chosen a pretty big chainring, presumably to favour the high end of the ratios. Say you wanted a very wide range -- choosing, say a 48T ring and 17T cog would give you a range from around 21" to over 110" (w/ 700C).

Anyway, rather than me writing a book, check out Sheldon's Rohloff page (http://www.sheldonbrown.com/harris/rohloff.html) and his IG calculator (http://www.sheldonbrown.com/gears/internal.html). Everything you need to know there.

znomit
02-21-09, 03:48 PM
The generator front hub seems handy, although I want more than 3 watts of light. Can you get more? What brand/model do you prefer? Are they reliable? Any noticable drag?


Yes you can get around 12W out of them with the right setup. The total efficiency is around 50% so thats 24W from your legs. :eek:
Basically every led you put in draws ~1.8W. Details here (http://www.pilom.com/BicycleElectronics/DynamoCircuits.htm).
At low powers the drag is not noticeable. I'm drawing about 9W with a 5 led setup and will be going back to a 2 or 3LED light because over a night it adds up. 3leds is plenty of light. and 2 is fine and 1 is more than a 3w halogen.

People rave about the schmidt hubs but the new shimano 3n80 is likely just as good.

Randochap
02-21-09, 05:11 PM
People rave about the schmidt hubs but the new shimano 3n80 is likely just as good.

At 490 grams, the DH- 3N80 gives the 570g SON 28 a good run for the money and quality is very good. I'm not aware of any resistance comparisons for this newer version. We know that the SON was slightly better than the DH-3N30, in these tests (http://www.vintagebicyclepress.com/VBQgenerator.pdf) (PDF)

However, the new SON 20R, weighing just 385 g, can be confidently used with the new LED lights as they come up to power at lower speeds than halogen. How much the lower wind resistance comes in to play is of less interest than the lower drag from the generator itself, due to using a hub designed originally for smaller wheels.

And who could resist the bling factor of this combo?
http://www.nabendynamo.de/produkte/bilder/Set_rot_140_187.png I might have to build a new bike just to match!:)

chewybrian
02-21-09, 06:36 PM
Thanks, everyone, for all the good info. The Nexus 3N80 seems like a good value. But 3W too bright? I run 11 watts of LED's now--tightly focused; blinding if you look right at it, but not spilling enough to seriously bother cars. I am thinking of setting up two 3W leds with the Nexus, using one or both as a high/low package.

I am less convinced, but still open-minded, about an IGH in the back. I may try it out on my commuter first. I'm itching to get building on the brevet bike, but taking time to look at all options. The only decision so far--chrome.

wahoonc
02-21-09, 07:32 PM
Need to take a look at the stuff coming from B&M the new Cyo (http://www.bumm.de/index-e.html) is getting rave reviews. It is less about the wattage and more about the reflector and the lumens. IMHO.

Aaron:)

bmike
02-21-09, 10:38 PM
ride the bike with the components you are confident with, on a frame and saddle that you are comfortable for all day pedaling - it can be fixed, 3 spd, single speed, or a carbon ti 11 spd electronic shifting wonder machine. they all work.

that said - i have a shimano nexus 8 on my cargo bike (bakfiets) - works great, and if i had a brevet bike built with it i would simply choose my chain ring and cog very carefully based on the terrain i would be riding in. (a friend has done a brevet series with a nexus 8) the nexus 8 has about 350% (or 305%? if memory serves) from low to high. tune the setup to match your style and terrain and it should work fine - if you like to mash the climbs tune it to the high end for cruising, if you like to spin - tune it to the low end for getting over those 15% grades.

if and when i ever update my drivetrain i would consider a move to a rohloff with tensioner. they are very impressive hubs - and like anything take proper set-up and care. had i known more about them when i built my IF i would probably have had the bike built around the rear hub.

for dyno hubs - i think you'd be hard pressed to notice the drag on the SON (and probably the shimano, but I've never used one). 3w is deceptive. even with dual e6 halogen lights i had plenty of light to ride all night... and for really stiff climbing i had my backup battery light that i would flick on and off. i have a new edelux awaiting time to mount up - from what i've read i won't be wishing for more light - even at low speeds.

rekall
02-26-09, 09:01 PM
(please someone tell me what a brevet actually is, i'm new to this concept; i have a vague idea, but...)

dunno about its performance in a brevet but my experience with an internally geared 3-speed sturmey archer (SRF3) has been nothing short of incredible. world of difference to single-speed.

chewybrian
02-27-09, 03:41 AM
(please someone tell me what a brevet actually is, i'm new to this concept; i have a vague idea, but...).

Check out RUSA (http://www.rusa.org/) for a full explanation. It's not a race, but a self-paced timed event. You get, for example, 40 hours to finish 600k. You have to follow a specified route, and reach a few checkpoints on the way within a (fairly wide) time window, and have your card signed at each. You must not receive any help between checkpoints. Any time under the limit is a winner, and the prize is fun and pride.

bobbycorno
02-27-09, 10:25 AM
And who could resist the bling factor of this combo?
http://www.nabendynamo.de/produkte/bilder/Set_rot_140_187.png

You're kidding, right? :wtf:

SP
Bend, OR

Randochap
02-27-09, 01:52 PM
You're kidding, right? :wtf:

Would I kid you?

rekall
03-02-09, 12:34 PM
Check out RUSA (http://www.rusa.org/) for a full explanation. It's not a race, but a self-paced timed event. You get, for example, 40 hours to finish 600k. You have to follow a specified route, and reach a few checkpoints on the way within a (fairly wide) time window, and have your card signed at each. You must not receive any help between checkpoints. Any time under the limit is a winner, and the prize is fun and pride.

cool, what's the corollary? i.e. untimed, 'everyone finishes,' with support.

chewybrian
03-02-09, 04:26 PM
cool, what's the corollary? i.e. untimed, 'everyone finishes,' with support.

That would be a "century" ride. You pay a modest fee, usually benefitting a charity or a bike club. You go 100 miles, or a "metric century" of 100k(@60 miles); no time limits. You'll get food and drinks at rest stops, and probably a support van, with a bike shop volunteer who can help you with flats and stuff. Odds are good you can find one nearby; it's good fun.

wahoonc
03-02-09, 07:50 PM
I would recommend starting with supported metric centuries, then try a regular century and move on to the Brevets. Randonneuring is definitely a different form of cycling from what most people are used to. I have done just a bit over the years, usually in support for another rider. (I could not make the time commitment for more than one or two rides a year at that period in my life).

Aaron:)