[Closed] Sealed Bike Drive

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Can't understand why it all hasn't taken off.

It's been done loads of times. Problems are it's heavy, the bevel gears cause friction and are a pain to service, and you get wind-up in the driveshaft.

That top one on flickr, has it come from cynical's special spoon products division?

Yep, shaft/gear drives are a lot less efficient than chains.

Just clicked that Flickr link - that's not a shaft drive, it's a derailleur-in-a-box, I know the bloke who made it...

Edit: I'm being slow today - it's you isn't it? 😉

Honest answer: because it's incompatible with all existing frames and gearing systems, so no manufacturer will take a punt on it.

Or there's this - a hub gear with Hebi chainglide.

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Shame Katz bikes aren't in production any more:

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Yep, shaft/gear drives are a lot less efficient than chains.

Less efficient than a drive train covered in gloop??

Yes - you need to get a chain pretty worn and rusty to reduce the efficiency much.

The problem isn't that other drive systems (belts, shafts, cables etc) are bad, it's that chains are so good.

These have been around for years.

Can see them being ok for round town type stuff.

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Hmm - sceptical - I was more thinking of derailleur jockey wheels/ cassette when they get bunged up with mud/grass/filth than the chain itself. I agree chains are good - but derailleurs are so last century. almost every other aspect of the bike has been rethought in light of new technology - except the drive. Time for a rethink in my opinion.

There are shed loads of alternative drive systems out there.

they just aren't mainstream

Just clicked the link, is that a home made carbon full suspensione (we'll not argue about URT right now) bike?

Well done if it is

You can seal anything with gears/chain in a case, but it makes little difference unless it's really crap outside, chain's, even worn chains are very efficient.

Reading had a bike hire scheme with shaft drive bikes. I never saw one actualy being used though. Which is a shame as the idea looked like an almostidentical ssytem to the Borris bikes but I guess Reading town center is too small to really need them, and they only had one docking station (at the station).

They make a re-appearance every few years, usualy as part of some design students final year project (would have to be some with a very short memory as it crops up every few years). Then don't take off as they're draggy and you can put a supprising ammount of twist in the shaft.

Objections to the derailleur are as old as the derailleur - engineering-wise it's terrible, yanking a chain off its sprocket under load. The British always used to look down on this French thing - it's not proper engineering, you know.

Problem is, like the chain, it actually works very well - it's still the most efficient transmission system, and with bikes, where you can't just add more horsepower if you want, efficiency is very important.

I have several in my collection, they became more popular in the States but as said previously, never really caught on over here.

The oldest one I have is from around 1906, as the keen eyed amonst you will also spot the wooden rims.

[url= http://www.flickr.com/photos/92428909@N02/ ][/url]

turq

The oldest one I have is from around 1906, as the keen eyed amonst you will also spot the [s]wooden[/s] [b]carbon[/b] rims.

😉

To be fair they're nearly as light 🙂

Objections to the derailleur are as old as the derailleur - engineering-wise it's terrible, yanking a chain off its sprocket under load. The British always used to look down on this French thing - it's not proper engineering, you know.

Problem is, like the chain, it actually works very well - it's still the most efficient transmission system, and with bikes, where you can't just add more horsepower if you want, efficiency is very important.

thats rubbish GATES said that their belt drive thingamijig was 0.0001 percent more efficient and i believe them!!!

bloody french bollocksing things up by trying to move things across sprockets

problem with sealing things is once the dirt gets past the seals its damn difficult for it to get out

Anyone remember these? 2wd anyone?
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thats rubbish GATES said that their belt drive thingamijig was 0.0001 percent more efficient and i believe them!!!

and how do you change gear with a belt drive that doesn't involve an inefficient hub gear or an inefficient gear box of some other sort?

LUDDITES!

Jeep actually had a pretty decent 2WD bike - it used driveshafts instead of a Bowden cable.

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how do you change gear with a belt drive that doesn't involve an inefficient hub gear or an inefficient gear box of some other sort

By using an efficient one?

And the Jeep bike is a re-badged Christini

That's the one, couldn't remember the original manufacturer 🙂

Any real world numbers on just how heavy and inefficient shaft drives are ?
A shaft drive working at say, 80%, has got to be better than a 99% efficient derailleur with the chain and rear mech tied in knots.

The ones I've tried, about 1kg heavier and probably 95% efficient compared to 98-99%.

Fine for pottering about on a city bike, not really for anything else.

Are we looking in the right place, though? With our legs being a measly 20-25% efficient in the first place?

Whats say we start there, hey?

Oi, Lance! Hold on a minute!

I very much doubt I'd notice a 3 to 4% drop in efficiency

Put it another way - the shaft soaks up about 3-4x as much energy as a chain. I certainly noticed it - and the spring as the shaft winds up is also a bit odd when you pedal hard.

Simple answer: if it was so good it would have happened decades ago 😉

You mean like 29ers, disk brakes & suspension?

I remember lusting after the Mountain cycles disks ages ago & everyone saying they were too heavy, always rubbed & there was nothing wrong with standard rim brakes... Didn't stop their development did it?

I've just changed the chain, sprocket and chainring on my hub geared bike after 4 years of all year round off road commuting. In that time I've never cleaned the chain beyond a quick wipe over with a rag and the application of whatever oil is lying around. The cost of the parts was £70 and in another 4 years the chainring will be reversed so it will be cheaper. No conditions I've encountered so far have stopped the drive train working.

The only advantage I can see with these alternatives is that for town bikes they are cleaner and belt drives are both cleaner and significantly lighter.

Ah but your hub gear is so inefficient as to render your views null according to this lot

You'll have people complaining about belt drive in a minute too

Unfortunately Gates don't do a setup to match my alfine gearing otherwise I'd be straight on that too.

http://www.pinkbike.com/video/218538/

Watch out as now have working with enough gears for Enduro

Wow, he's really ripping along in that^^ video..........

Wow, he's really ripping along in that^^ video..........

LOL.

Interesting that people are having a go at improving things though. Top man-in-a-shed-ing.

Think I saw your bike at the Dudes enduro?

Design skills over vid skills