acidfast7

no! chains are part of the future ...

Darth Lefty 

What bugs me about the options for cycling is the maintenance interval.

BMW advertised its shaft drives as maintenance-free on the early 1200 bikes, but after a few failures well publicized by the Internet, added oil changes every IIRC 12,000 miles. It shouldn't ever go out. That's for bikes ranging from >100 to <200 hp. Dynamic shaft drive gets 6-8000 miles lifetime when ridden by a normal human, making 1/4 hp? That's a serious engineering failure.

Harley carbon fiber belt drives used to be 60,000 miles, are now "inspect only" until they get too threadbare. That's with around 100hp. The Gates web site says, "In laboratory testing, the Carbon Drive System lasts more than twice the life of chain" but does not list an actual number.

Dave Cutter

I am 100% with you on that one! I can't imagine what life would be like if my cars had regular flats and required frequent tire and drive train (chain) replacement as well as lubing every couple hundred miles.

I have two new tires, new chain, brake pads, and bar tape ready to mount on my regular ride before the weather warms. Pretty much my springtime routine. I some ways... that does seem like a lot of parts and work.... for a couple thousand miles or so of cycling. And on the other hand.... it doesn't cost a lot and with very little time and effort the bicycle will be like new.

I love my modern alloy Fiji. But a part of me........ thinks modern materials and designs mixed with a little innovated engineering could produce a near maintenance free 10 or 12 pound bicycle that wouldn't cost a years [or even a months] wage. Yet that other part of me.... finds real comfort and beauty in an old skinny steel tubed 10 speed with down tube friction shifters.

I guess I really want it all.

tcs

Welcome to the difference of having an energy slave (in the form of 116000 BTU/gal. gasoline) do the work of transporting you vs. pedaling yourself around. 50,000 mile no maintenance shaft drive? Easy. Flat proof tires? Off the shelf. Bearings with absolutely weather-proof seals? Those designs exists. Wanna ride that bike? I don't.

The world awaits your innovations, and we'll all be able to say we knew you back before you revolutionized world transport.

tcs

Okay, you're the Dynamic product manager, meeting with your engineering team. Increased weight, increased drag (friction), increased cost: what are you willing to trade off for more service life?

Darth Lefty 

That's a bad question to ask me, that's why I'm an engineer and not a PM!

Dave Cutter

Apparently.... you pitch your tent in the can't-have-it-all camp. Of course engineering has it's limits.... but most of the limits mentioned here aren't so much related to physics... as to checkbooks. There is an old [engineers] saying about solving most [engineering] problems by "waving a checkbook" and watching the solutions appear. But that saying is in opposition to your idea of checkbooks following solutions. Maybe it works both ways!

It might be a tad difficult to sell ultralight bicycles.... until the powers-that-be lift the minimum weight limits on racing bicycles... that have (IMHO) stalled cycling progress. The rules once protected racers.... mostly from themselves. But now just protects the status quo of a handful of global brand names. Instead of real progress.... we all need to be satisfied with electric shifters moving a chain on yet one more back wheel cog.

I am NOT complaining! I love the current state of the modern bicycle. But they aren't that far from the robust improvement of the safety bicycle.... that we saw and rode fifty years ago. The first half century of two wheel innovation.... went much better than the last.... IMHO.

H.S.Clydesdale

I agree there is not much innovation in bicycle design. That is in large part because the buyers are conservative and generally wont buy something that is altogether different, like a shaft drive. The only way they will, is if it wins races. (Even though racing bikes are ridiculous for the average person. Its like we are all driving around in ferraris.)

I think, if dynamic are to mainstream the driveshaft, they need to win races. I doubt they can win the tour de france with a driveshaft, but they might have a chance in cyclocross. That is, if it is, in fact, a better technology. I think they should make a cyclocross model and start giving it to riders. It will be heavier, but the advantage of a clean drivetrain might give the dynamic riders the edge.

Or hell, MTB races would be an even better application.

I have to believe that the shaft drive is actually not so hot, and not able to compete on a professional level, which is why dynamic has not pursued this strategy.

trailmix

Alex Meade is a framebuilder in Lexington, KY. Here are a few pictures from his website of a custom built shaft drive commuter.
https://www.alexmeade.com/

Jax Rhapsody

personally, I see the belt and shaft system being aa novelty item on bikes such as custom built lowriders, ratrods and the like. Although, I have wanted to do both on a beach cruiser. the shaft could be good on an offroad bike if it was strong enough. the other setback is at least from my pov is hub gears are weak and expensive compared to derailures and chains. Otherwise I wouldnt mind a cross bike of mtb with a shaft drive and geared hub.

a guy at a lbs I go to told me of a company who made a cx or mtb that had a geared hub and another on converted to be used as a crank- which sounds good on paper. It was a flop. hell, I wouldnt mind building an aawesome trike that was shaft driven

Jax Rhapsody

with a geared hub. Damn phone.

2_i 

Hmm, he argues with weather protection for the shaft, but then provides no mounts for fenders in his shaft bike. Should I be trusting here??

trailmix

If you look at the left dropout detail shot, there appears to be a threaded hole for attachments and what he calls a "fender stub" in front of the rear tire.

noglider 

Bicycles are one of the few remaining industries with garage inventors. Unfortunately, many inventors don't learn from the mistakes of the past. We see ideas returning and failing repeatedly.

The belt drive is interesting. I don't think you have to clean it, and it doesn't tend to get dirty anyway. I would carry a spare, though, and that's not so bad, as they're not so heavy.

tcs

Interesting that shaft drive has made bigger inroads in the bike share world than belt drive.

fietsbob

OK what is the crank to direct 1:1 gear in the hub ratio range choice in the bike,?

Given, you cannot change It, so it better be just right..

Italiansteel

I like my chainless Dynamic bicycle and have not had any problems. I check my nut weekly and grease the gears when needed. no big deal.

-=(8)=-

Does he have a shop, I mean work out of a bike store or something where the public can come and ogle?
I like the bike in the picture, but that looks just like the shaft on my old Dynamic 3sp. The Dynamic had a design flaw that, to me, makes some of them useless. It looks like they changed the new ones, though. I would love to find a bike that is belt or shaft but also has all the other stuff I am looking for.

trailmix

Mr. Meade doesn't have a showroom but you can check out his Facebook page, is has a lot of great photos of the building process. As far as I know he only builds custom order bikes.

Honestly, I don't have any experience with shaft bikes but when I saw this thread I thought you guys might like the pics.

phoebeisis

The filthy chain-
yeah nice to be rid of that,
but...maintenance most bike owners don't do ANY chain maintenance -and the drivetrains last until the bike is sold/forgotten.
I have a stainless steel chain- very very rarely oil it-but only after hosing it off-simple green-and really maybe once a YEAR-(2200 miles)-when I hear squeaking.
I'm not so sure a SS chain-or any chain-last much longer lubing it-
and the lube-ALWAYS attracts abrasive grit-
which stains clothing-and grinds away at EVERYTHING.
I have maybe 5000 miles on this chain-seems to work fine

Are you sure LUBING chains so often is necessary?

StephenH

Just looking over their website, if you stop and think about it, it is about 90% promoting internal geared hubs in lieu of derailleur systems, with the shaft drive being somewhat incidental to that. But suffice it to say, you eliminate most of the derailleur/chain issues on a bike just by going to a geared hub even if used with a chain. Single-speed chain bikes tend to require very little maintenance compared to a derailleur system.

From what I have read in the past, it seemed a lot of the issues with the Dynamic bikes were problems with the company more so that problems with the product. If you sell your product as a cool alternative to regular bikes, you can make a case for that. If you sell it as the greatest thing since sliced bread, and imply anyone would be stupid to use anything different- well, you better have a wonderful outstanding product, OR great warranty/return policies, OR you wind up with some pretty bitter people venting on the internet.

A couple of people have mentioned the belt drive. I wouldn't have any problem using one of those, the lack of a derailleur being the main drawback to them. Some friends of mine use belt drives as the timing chain on their tandem. One drawback to belt drive on a regular bike is you have to have some place where the frame breaks apart to put the belt through- you can't "break" the belt like a chain.

Jax Rhapsody

There's also a guy on youtube who built a hydrostatic bicycle. Not sure if he developed it anyfurther. I told him it should have at least threespeeds somehow.

tcs

Dynamic seems to be the only bike company building shaft drive bikes that most posters here know of. Here's a little youtube market survey from a year and a half ago of shaft drive bikes of the world - and it looks like they missed Sonoma. I'm pretty sure most if not all of these use the Sussex shaft module, and doing a google images search of 'Sussex shaft drive' I find even more production bikes fitted with their shaft.

And, as previously mentioned, then there's bike share. A few minutes surfing found: Los Angeles, Tampa, San Francisco, San Diego, Anaheim, CalState Fullerton, Texas A&M, University of Buffalo, Bordeaux, Xiamen, Marseille, Milan, Vicenza, St. Etienne, Clermont, San Paulo...

Null66

Harley's are NOT high horsepower by any means...
Less horsepower then many bikes with 1/3rd their displacement.

Darth Lefty 

This is true but it's a marketing decision. Every time Harley tries to innovate they are punished by their customers. They have twice developed more powerful liquid-cooled engines; the one in the 70's died at the hands of AMF before reaching market, and the V-Rod never got many buyers. They tried to push into sport bikes but never got many buyers there either, and killed the division only a few years ago.

It's also not really relevant to the discussion, which is why should belts and shafts for bicycles not last indefinitely with a 1/4hp human cranking on them?