Here's a clever thing. It's already been on the forum after Gkam84 spotted it on Kickstarter but we thought we'd give it some news time too, because it looks like a really neat idea.
Even with plenty of practice, changing a rear wheel isn't the easiest of tasks. Remember to shift down to the little cog, undo the QR, pop the wheel out and wrestle it out of the chain. You're left with the wheel (including the mucky cassette) and your trasmission all dangling everywhere while you fix your flat.
Enter the Hubdock. Essentially it's a two-part hub: the cassette and freehub stay put and you can remove the rest of the hub my undoing the quick release on the non-drive side. Look at this video if you're unclear:
Okay, the bloke in the video removes the standard rear wheel like a complete numpty. But even so, there's lots to like about this design. Obviously the big draw is that the transmission stays in place. There's no messing with the chain and getting oil all over your hands and no danger of things getting knocked out of alingment. It keeps tension in the chain too, so there's much less chance of the chain coming off the chainring when you're changing the wheel. Also, if you break a drive-side spoke you can simply take the wheel off and replace it, you don't have to take the cassette off as all the spokes are accessible.
Any downsides? Well, not any that we can think of, other than it's going to be a bit more expensive than a standard hub. Your first production run hub will cost you $379 on the Kickstarter pitch. Okay that's not cheap, but they're basically hand built. That's less than a Chris King hub would set you back. And there's nothing about the technology that necessarily makes it expensive. It's a simple concept.
Do we need it? Well, it makes life easier. It's all very well saying you've never had trouble changing a rear, but there's no doubt this system would make it a much simpler process. You probably never had any trouble with downtube shifters, but you've got STIs/Ergopower/DubleTap now, right? Just saying.
We're fairly confident that this is going to catch on. Especially since we asked someone very much in the industry loop about it, and got a winkey smiley in return...
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They tried this back in the 60's this was done, known as Cinelli Bivalent hubs, but they never caught on. The front and rear wheels were even interchangeable.
Article:http://classicrendezvous.com/Italy/Cinelli/Cinelli_BiVal_B-Guide.htm
photos:http://classicrendezvous.com/Italy/Cinelli/Cinelli_parts.htm
Only one slight concern - If you fit "normal" rear wheel and fail to tighten quick release wheel will generally stay in place when weight applied to bike. However I'm not sure same applies here..........Do the two parts collapse and the wheel jam in the stays/brakes.
Maybe I'm reading too much into it but it does need to be mistake proof..........After all, punctures only happen when it's raining, dark and at the end of a tiring day.
I carry plastic gloves for such events......fraction of the cost.
Nicolai did something similar in MTB land a few years ago, but their system left the cassette attached and the disc attached too!
Has the system been tested in rain/mud?
I recently sent the team behind this hub an email, to highlight this story and hopefully to get them to interact with us about some of the concerns above.
I have just had an email back, I will add a couple of things.
There will be a mountain bike version put up next week. They will also be adding more rewards.
I will post back when I've had more contact. I will go through the comments above and form some of your concerns into questions to ask them.
Nice idea in theory but is removing a conventional rear wheel really enough of a faff to justify splashing out on a whole new hub? Maybe I'm unusually technically gifted (unlikely) but I find this a 30 second job at best. I won't be removing my R45's any time soon, kthxbye.
Looks like a great concept to me, and I have to say the idea of easily changing a drive side spoke is appealing. If the implimentation is good then I can't see why it wouldn't succeed. And Rob, also a great point about the use for discs. Now if only we had a concept that worked for the disc and cassette simultaneously...
Seems like a recipe for a bent axle to me. And god knows what happens when you bend an axle on a design like this.
If this is reliable it would be great for any spoke changes for long audaxes. I hope it does well. Good to see people going for it.
I think they've possibly missed a trick and, instead of applying the technology to the drive components, should apply it to disc brakes.
The problems I see with discs in the pro peleton come down largely to wheel changes. You need to change a wheel with one with the correct size disc. Changing the wheel results (usually) in disc rub. Set up has less margin for error than rim brakes.
Having the disc remain with the frame/fork and caliper would allow quick and easy disc brake wheel changes with no compatibility worries.
Rob
I hope Jan Heine won't mind me quoting from his excellent book ''The Golden Age of the Handbuilt Bicycle'' referring to a 1952 Rene Herse he says 'The hubs are equipped with Herse's special extra-large flanges. When the rear wheel is removed, the freewheel remains in the frame, so the rider avoids having to touch the chain when repairing a flat tyre.' Not much new under the sun is there?
no indeed, cinelli had one too, called the bivalent hub, see http://italiancyclingjournal.blogspot.co.uk/2008/09/cinelli.html
(link via @ITALIANCYCJOURN on twitter)
I mainly run on tubulars in combination with Stan No tubes milk. So if I need to remove the wheel it is for packing the bike. Remember the steel frames with the little knob to hang the chain on to keep it tensioned? That helps and is all it takes from my point of view.
Regards,
Dr. Ko
I remember other innovations being dismissed as a 'solution to a problem that doesn't exist', among them disc brakes and suspension on MTBs, dual control levers and, variously, 9-, 10- and 11-speed gear systems.
'I think these guys have found a solution to a problem that doesn't exist.'
It certainly exists for the bloke trying to remove a rear wheel on the video.
Not for most of us, I'd think.
like the principle but it looks like it might be limited by having to work with existing standards. If it was possible to add an oversized axle a la MTB then I guess you could beef it up and alleviate any concerns over strength.
top marks for lateral thinking though.
I think one crucial factor is that you would need to get the hub for your rear wheel(s). Personally this seems like a hassle and cost that outweighs the benefit.
But the questions about the torque and stress on the cassette seem valid. The worst time this could fail you is when you're laying the power down in a sprint or a 30% climb.....and for that reason I'm out.
Questions about the strength of this design should be put in context. Think about the strength of existing hub designs. Pawls, threads, splines, hollow axles, ball bearings. All are made out of small steel components that are plenty strong enough. Bottom bracket designs where the axle splits in the middle to allow disassembly don't seem to be a problem, so hub axles should be no different. Think about the clutch in you car, its a similar principle.
do you ever worry about the splined interface between your cassette and your freehub failing? or the one between your crank and your bottom bracket axle? I can't see how this is any different. certainly a well-designed splined interface would be orders of magnitude stronger than the pawls in a freehub
Nice idea, not sure if its a must have...
My solution: take a few plastic gloves in the saddle bag.
I'm with Crikey and mhtt on this one - it just seems to be adding an extra point of torsion and weakness to one of the most pressure-bearing points of the bike. If you get chainsuck or somehow mangle your rear derailleur in the rear wheel then I could see those sprockets shearing off, and you'll be left with a bike that's unrideable, rather than one that can be botched together.
I mean, is taking your back wheel off such a massive pain in the backside? I think these guys have found a solution to a problem that doesn't exist.
there is no word about the driveside component of the hub, how it is bolted to the frame, how the cassette stays on, will it be secure enough to work with disc brakes?
This is a very good idea but it is not a new idea, I have seen british roadsters from the 1890s with it (Sunbeam I think). French Constructeurs used it also in the 40s and 50s. I wouldn't be surprised if it became standard. The sprocket/freewheel unit could be bolted onto the frame offering a very secure attachment for the motive power to be driven through.
We're fairly confident that this is going to catch on. Especially since we asked someone very much in the industry loop about it, and got a winkey smiley in return...
then why do they need kickstarter to fund it?
if any existing industry player liked the concept, then they would back it
neat idea but no way it could deal with the awesome amounts of torque I put out with my massive quads
great idea, would have made yesterdays bearing maintenance a lot easier!
Well now....
I'm not keen because the weak point in the system would seem to be the joint between the freewheel and the axle. Shimano moved their drive side bearings outwards when they introduced the cassette, creating a stronger, better supported axle arrangement.
I wonder how it would cope with a year or two of wear and bumpy roads? Or how introducing a compression joint would affect the whole rear triangle on a bike?
That video is possibly the worst bit of promotion I've ever seen; the rider in yellow has never ridden a bike before, and the grey baggy shirt?
As you've noted, rear wheel removal should be simple; small sprocket, undo quick release, bang top of tyre. Not unwind quick release until it falls apart...
Also got to be heavier...
bearings and ratchet could still be inside the sprocket unit. The joint could be just as strong if not stronger than a plain axle if designed correctly. Think of the driveshafts seen in motor vehicles, eg universal joints, plenty strong if the right steel alloys are used. Weight is not really an issue, might add an extra couple of ounces, so what.
I completely agree - from a conceptual point of view (rather than this particular implementation) I think the concerns about torque and 'stress' are not worth worrying about. Almost identical arrangements have been used for donkeys years with no problems, e.g. GP bikes, which can produce quite a bit of torque.
There's lots of ways of making a system like this work, this may be one - I honestly don't know.. but it won't torque transfer and stress localization issues that stops it being used.
So once these catch on, and the need to get intimate with the cassette regularly decreases, how long before some wag comes up with an aero cover for the drivetrain/casette?!
In fact, would the next step be tighter integration of the drivetrain and casette?
Lovely idea.
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