Commuting - LOSE THE GREASY CHAIN! Delta C-Drive @ Performance ($430, free bag)

Ok, we've talked plenty about shaft-drive bikes. Here's a belt drive bike that is being sold at a major marketer:

http://www.performancebike.com/product_images/500/30-0202-ALU-SIDE.jpg

Price is not too bad. I like the rack, fenders, front disc, belt drive, 3-speed hub.

I won't buy one, because I prefer a high performance machine. But basically, I think this belt-drive wonder is pretty kool. What do you think?

Belt drive makes a lot more sense than shaft drive. It's nearly as efficient as a chain, and only slighty heavier.

The only downsides are that you can't bend the belt sideways like you do with a chain and derailleur, so you'll have to use a geared hub. Also, they're not as strong, but that's probably not an issue with most people.

Personally, I have no issues with a chain, but for those that do this may be a great option!

Az

I don't know how strong these belts are, but belts are used for all types of things, such as engine timing, motorcycle drivetrains, etc, so it could be as strong as the designer wanted it to be.

When I first saw this bike at performance, I immediately wondered whether replacement belts were available now - and whether they'd be available in two years, five years, etc.

I've seen them on motorcycles and wondered when someone would move it to bikes. Guess I'm opposed to change, even with internal hubs I'll be sticking to chain. After all, with an internal hub and chain guard there isn't much 'greasy chain' to worry about.

Belt drive worked fine on my Harley. I am considering a chain drive Triumph. I would be very interested in taking a BD bicycle for a test ride. I DO oil/maintain my chain, and it would be nice to not have to fuss with it!

One thing that might be bad on this bike is that the front disc looks a little cheesy. But I suppose if it caused any issues, you could step up to a BB7 without much trouble or expense. I have seen a lot of cheap bikes - department store bikes - with disc brakes, and I wonder if the brakes are good.

If I were given the task of designing a practical commuter bike, and I had something like this for the result, I would be proud.

You don't *have* to buy the bike from Performance, either. I was just impressed that the Big P had decided to carry a belt-drive machine. If I see one at a local store, I'll ask for a test ride.

On an apples-to apples comparison, eliminating chain lubrication would seem to be the only benefit of a belt, that and less mess for a rider, but at the expense of having no options for shifting except an internal hub. A chaincase could remove the biggest negative of an exposed greasy chain without eliminating options for derailleur shifting.

I am very curious. I just switched to a Nexus 8 along with a chainglider (chaindragger). I'm not convinced that the chainglider isn't robbing valuable power from my pedaling. Belt drive is a very appealing idea to me.

Browsing the site of the belt system manufacturer (http://www.cycledrive.com), it doesn't look like it will work with frames not specifically designed for chain drive. I'm definitely looking into this in the future. I would be willing to try it if it would work on my crosscheck

Browing the site of the belt system manufacturer (http://www.cycledrive.com), it doesn't look like it will work with frames designed for chain drive. I'm definitely looking into this in the future. I would be willing to try it if it would work on my crosscheck

It's not going to work with any bike where the chainstay goes through the loop of the chain, because the belt is continuous and not made to be broken. See the elevated chainstay (beltstay?) on the Delta. I suppose if you had something like a Proflex 857 (I had one), you might be able to do a belt-drive conversion.

at the expense of having no options for shifting except an internal hub.

Yes, but if you buy, for example, a Bianchi Milano, you have no options for shifting except an internal hub. I'm talking about a bike here, not just a technology in the abstract. And for a practical commuter on fairly level terrain, an internally geared hub is not a bad idea at all.

Probably no belts at the local criterium any time soon, though.

On an apples-to apples comparison, eliminating chain lubrication would seem to be the only benefit of a belt, that and less mess for a rider, but at the expense of having no options for shifting except an internal hub. A chaincase could remove the biggest negative of an exposed greasy chain without eliminating options for derailleur shifting.
How many bicycles are there that have chaincases and external gears? (-especially front and rear gears-)....

I'd agree that technically one could build an enclosure around the entire front and rear derailler system of a bicycle and see some maintenance benefits, but I've never seen anyplace doing it....
~

I don't know how strong these belts are, but belts are used for all types of things, such as engine timing, motorcycle drivetrains, etc, so it could be as strong as the designer wanted it to be.

When I first saw this bike at performance, I immediately wondered whether replacement belts were available now - and whether they'd be available in two years, five years, etc.

The issue with belt drives is TORQUE. If you just put a smooth-belt drive on a bike, it'll work fine at high RPMs, but it'll slip at low speeds, for instance if you stand up to mash on a hill.

Cars and motorcycles don't have this problem due to a more complicated (and much heavier) transmission, as I understand it.

It looks like the Delta C-DRIVE uses a toothed belt, which I'm sure can support a lot more torque that a smooth belt.

I don't know how strong these belts are, but belts are used for all types of things, such as engine timing, motorcycle drivetrains, etc, so it could be as strong as the designer wanted it to be.

When I first saw this bike at performance, I immediately wondered whether replacement belts were available now - and whether they'd be available in two years, five years, etc.

I would imagine that the belt they use is not so specific in size and design that you would not be able to get a replacement from a shop that sells all types of belts. But..........

most toothed belts are 5 ply with incredibly strong "strands" running the length of the belt. They can handle enormous torque loads, far more than any cyclist will put out.

one benefit of belt drives is that they are silent and there is no bouncy chain syndrome when riding over big bumps etc.

Some guy in Vancouver has a stretch cruiser lowrider about 12" long, with a 6' long belt drive. Looks pretty damn cool with the billet aluminum toothed pulleys.

I'm totally intrigued with this goofy little bike. I normally commute in full-on sweet road bike mode (high-performance clipless pedals, spandex, etc.) and just throw on a messenger bag to carry my work stuff. My ~30 mile round trip commute is just too long to be comfortable in street clothes and tennis shoes, so I'll continue to use the road bike for that.

But... the road bike is incredibly annoying for around-town trips, since it'll mess up my pants, I'll have to carry a second pair of shoes, I have to fear it being immediately stolen, etc. This bike might be just the ticket for grocery-getting. I was looking at Breezers, but they're overkill, twice the price, and weigh even more than this beast.

Has anyone actually ridden one?

- Warren

BTW, I've never even heard of Sturmey Archer, and that makes me a little leery. At least the Breezers come with Shimano stuff, which I consider a generally pretty reliable name. Hrm. Decisions, decisions.

- Warren

BTW, I've never even heard of Sturmey Archer, and that makes me a little leery. At least the Breezers come with Shimano stuff, which I consider a generally pretty reliable name. Hrm. Decisions, decisions.

- Warren

You've never heard of Sturmey-Archer? :) They're probably one of the best-known and oldest bike parts makers in history (http://en.wikipedia.org/wiki/Sturmey-Archer) (though now bought-up and moved to Taiwan as of 2000 :(). The Sturmey-Archer 3-speed hubs powered basically every 3-speed English bike made from the early twentieth century on. Many of which were very much designed for practical commuting use for many years and thousands of miles with low maintenance. Sheldon Brown is a fan, too: http://sheldonbrown.com/english-3.html#sturmey

The old Sturmey-Archer three-speed hubs are somewhat large and heavy, but verrrrry reliable and can shift when standing still, which is great in traffic.

I don't know of any significant differences in reliability between internal-geared hubs from Sturmey-Archer, Shimano, SRAM, or Rohloff (which I believe are the four manufacturers today). I bet Sheldon Brown, or someone else who has built a lot of internally-geared bikes, could provide more information there.

Awesome! Thanks for the info moxfyre!

- Warren

Awesome! Thanks for the info moxfyre!

- Warren

You can no longer claim to be a Newbie now that you've heard of Sturmey-Archer ;)

That's neat. I'm sure there's been a toothed belt drive somewhere before, but it's still good to see. I can think of a few FS MTB frames that a belt drive could slip into, too.

(after Googling a bit)

Cool, it's more pervasive than I thought. Here's a folding belt-drive bike from Europe:
http://www.strida.co.uk/

On an apples-to apples comparison, eliminating chain lubrication would seem to be the only benefit of a belt, that and less mess for a rider, but at the expense of having no options for shifting except an internal hub. A chaincase could remove the biggest negative of an exposed greasy chain without eliminating options for derailleur shifting.

They are quite popular in the beach areas of Lithuania. No grease, no sand build up to destroy parts, and no rusty chain.

This belt-drive bicycle is nothing new. They are sold in Japan in the MILLIONS and have been for nearly 20 years. Some "genious" just decided to bring them stateside. The bike you see before you is a Japanese commuter bicycle (without the front basket).

The question of if will work or not has already been answered by the millions of people that ride them every day. In Japan, of course, the loads are not intense. People get on them and float between home and train station at unimpressive speeds and unspectacular loads. Very few riders weigh more than 150 lbs. and you will rarely see a rider standing on the pedals mashing up the torque or the rpm.

They seem to work well under those conditions and the belt drive helps keep the rider's clothes clean. No more pants cuffs or skirts blackened with chain goo.

did anyone notice the geometry? the chain and seat stays are above the bottom bracket.

most toothed belts are 5 ply with incredibly strong "strands" running the length of the belt. They can handle enormous torque loads, far more than any cyclist will put out.

one benefit of belt drives is that they are silent and there is no bouncy chain syndrome when riding over big bumps etc.

A well-lubed chain coupled with an internally geared hub is virtually silent, too.

If the belt does break while on the road, how do you repair it?

A well-lubed chain coupled with an internally geared hub is virtually silent, too.

If the belt does break while on the road, how do you repair it?

You put on your spare. Much lighter to carry than a chain :)

I'm sure that the belt itself will be a periodic maintenance kind of item - ie replace every 3 years or 20,000 km. Same as on a motorcycle or car, whether you need it or not.

I seriously doubt one will ever need to replace the belt on one of these bikes. I mean, if a timing belt in a car can last 100k miles, I think we can worry about other things.

I would be curious as to how many people on this borad who pine for low matinence, internal hub commuter bikes will actually buy one.

I was considering picking up a KHS Green for my wife after she's done gestating #3 (her sense of balance is *way* off due to pregnancy right now), but this looks like it might be a very attractive option.

It's been years since she's been on a bike and after watching people get hit by cars while going to NAU in Flagstaff, she's pretty skittish. I think that eliminating the chain and the subsequent worry about grease spots, stuff getting caught, etc. might be a good way to nudge her back into riding. Of course, eventually I want to get her a bakfiets she she can haul around all three tykes at once and get groceries.

Edit:

Here's some reviews. Most of the complaints seem to center on the gearing of the SA 3 speed. I wonder if the slippage problem was caused by incorrect tension:
http://www.amazon.com/Delta-CDRIVE-26-Inch-Hybrid-Bicycle/dp/B000FGYKYG/ref=sr_1_2/102-1879855-9515329?ie=UTF8&s=sporting-goods&qid=1187880516&sr=1-2

I seriously doubt one will ever need to replace the belt on one of these bikes. I mean, if a timing belt in a car can last 100k miles, I think we can worry about other things.

Timing belts see WAY less torque than this belt drive bike will. Camshafts only take a few ft.*lbs. to turn if that (you are only overcoming the force of a few valve springs) whereas a cyclist can easily put out over 200 ft.*lbs. of torque. Aside from heat, the belt drive on a bike will experience a much worse operating environment than a timing belt would too with being open to the elements.

And for a practical commuter on fairly level terrain, an internally geared hub is not a bad idea at all.



Or in hilly terrain with the right chainring / cog combination. A Nexus 8 has a 305% spread from low to high... I'm running one on my bakfiets and do just fine loaded in Burlington. (which is fairly flat compared to the rest of Vermont)

I can't tell from the photo - but I wonder if the rear cog (or whatever they use with a belt) is changeable. This would allow you to tune your gearing for your terrain.

For average commuting and folks like my parents, I think belt drive's would be ideal. Less maintenance, grease, don't have to worry about riding over sandy and destroying you driveline.

I can't tell from the photo - but I wonder if the rear cog (or whatever they use with a belt) is changeable. This would allow you to tune your gearing for your terrain.

Looks like 28T or 30T sprockets are available

http://www.cycledrive.com/specs.html#

Click the components link.

Dangit. Now I'm going to have Mike Meyers on the brain all day.

Timing belts see WAY less torque than this belt drive bike will. Camshafts only take a few ft.*lbs. to turn if that (you are only overcoming the force of a few valve springs) whereas a cyclist can easily put out over 200 ft.*lbs. of torque. Aside from heat, the belt drive on a bike will experience a much worse operating environment than a timing belt would too with being open to the elements.

Maybe a bad comparison, maybe not. How about the many motorcycles that are belt driven. I snagged this from a BMW review:

"The F800 features a powerful, torque-rich 800 cc parallel-twin engine (the first in BMW’s history), a new suspension system and maintenance-free belt drive."

Little bit more torque than 200 ft lbs, sealed off from the elements though it is...

Maybe a bad comparison, maybe not. How about the many motorcycles that are belt driven. I snagged this from a BMW review:

"The F800 features a powerful, torque-rich 800 cc parallel-twin engine (the first in BMW’s history), a new suspension system and maintenance-free belt drive."

Little bit more torque than 200 ft lbs, sealed off from the elements though it is...

Not a good comparison if you're going to base it solely on torque; that F800 is only putting out 86 Nm (or 63 ft-lbs) of torque.

But, a motorcycle weighs several times more, and therefore resists acceleration more than a bicycle. So the pressure being put on the drive belt is greater despite the lower torque output.

Maybe a bad comparison, maybe not. How about the many motorcycles that are belt driven. I snagged this from a BMW review:

"The F800 features a powerful, torque-rich 800 cc parallel-twin engine (the first in BMW’s history), a new suspension system and maintenance-free belt drive."

Little bit more torque than 200 ft lbs, sealed off from the elements though it is...
Read that review again... :) http://www.motorcyclingblog.com/article/the-new-bmw-f800-s-st

"At the heart of these machines is an all-new 798 cc twin-cylinder engine that produces an impressive 85 hp and a punchy 63lb/ft of torque." (should be lb-ft, not lb/ft)

That 63 lb-ft of torque is a lot less than what a cyclist can produce!! People assume that because a car/motorcycle engine is more powerful, it must produce more torque. That's not the case at all. A human being may not be able to spin his or her legs at 5,000 RPM, but our legs--even bent--are very long levers. A human on a bike produces a lot more torque than most engines.

Sure, but show me a person that can push a 400-lb motorcycle past 70 mph... ;)

Sure, but show me a person that can push a 400-lb motorcycle past 70 mph... ;)

Give me a steep enough hill, and I'll take you up on that :)

When that bike is cruising at 70 the torque required is probably quite low, right?

You mean you can do it uphill? ;)

"An object in motion tends to stay in motion", so at cruise, it doesn't take a whole lot of effort except to overcome wind resistance.

Formula 1 cars don't put down huge amounts of torque, either. A small engine like theirs is only going to make small explosions; big torque comes from big motors and big explosions. The thing is, an F1 car puts it down so quickly that the power is much higher (if you can't increase displacement, you add revs), and its 19,000 rpm redline allows for really short (i.e., torque-multiplying) gearing.

But anyway...

Torque from the motor is only coming from one direction, though. The other force vector -- the momentum, stationary or moving, of the vehicle itself -- is what adds to the stress on the driveline. A cyclist can their body weight in torque, but they're only going to push their own body weight plus another 20-30 lbs.

My car put down 131 ft-lbs on the dyno; I weigh around 210. I don't think I'll be able to damage any parts inside my car's transmission, but if I could somehow put a bike chain in the car between its motor and its 2900-lb chassis, that chain's going to be in a lot of pieces pretty quickly.

Torque alone isn't everything...

You mean you can do it uphill? ;)
Uphill both ways! In the snow! :D


Torque alone isn't everything...
Absolutely. But in terms of a smooth-belt drive, torque pretty much determines when it will slip I think. So that's been one of the main issues with making belt-drive bikes I would guess. As you've pointed out, a drive belt can be very, very strong.

I wouldn't use a smooth belt, but a toothed belt would be fine. Smooth belts are only good for driving devices on both sides of the belt, like an alternator and power steering pump and a/c compressor, etc.

Radio-controlled cars have toothed belt drives, too, for less weight and easier maintenance than a chain drive, plus greater design flexibility than a direct gear drive (sometimes there's one long belt connecting the front & rear differentials).

Absolutely. But in terms of a smooth-belt drive, torque pretty much determines when it will slip I think.

No, I don't think so. The size of the pulley also matters. A big pulley is less inclined to slip than a small one, because the tangential force is less.

did anyone notice the geometry? the chain and seat stays are above the bottom bracket.

That is so that the belt doesn't pass through the rear triangle, since you can't break and rejoin a belt like a chain.

That is so that the belt doesn't pass through the rear triangle, since you can't break and rejoin a belt like a chain.

Wow, a lightbulb just went off in my head, I'm glad you pointed that out! Very interesting.

That's probably been a major impediment to building belt-drive bikes... you have to change the frame structure significantly. You can't just slap a belt-drive cog and chainring on a regular bike and try it out.

My Harley has a 95cui built motor. It weighs 650lbs. Despite the stoplight launchs and downhill engine braking,I've got 25k miles on the stock belt. I've only ever adjusted it when changing the rear tire,and it's easily got another 10k left in it. Also,I picked up a rock in the drivetrain once that put 'dents' in the belt teeth. After a few miles the dents were gone. There's an old myth about rocks cutting belt drives,but I've yet to see any real evidence of this.

As for the human-engine comparo: I haven't gotten around to dynoing my Harley,but similarly modded engines have produced 110-115lb-ft. I say you can't produce,and sustain,that much torque with your legs. I can show you dyno charts proving how much torque an engine makes. Where are the charts for a person? Until I see some experimental results that show how much torque a human produces,then the whole argument is moot. :p

As for the bike,my Swobo has a 3sp and is geared way low for DC. If the C-Drive had a 7+ sp,I'd seriously take a look at it. As it is,I'm looking at putting a SRAM S7 on the Swobo. Anyone know what the rear spacing for the C-Drive is? At that price,it might be worth it to spend a few bucks to upgrade the rear hub.

Not a good comparison if you're going to base it solely on torque; that F800 is only putting out 86 Nm (or 63 ft-lbs) of torque.


Torque at the crank is a lot less than the torque at the rear axle (if I remember these terms right). Especially the instantaneous torque from a high-RPM clutch drop. (unlike on a bicycle, it's the rear sprocket on a moto that is transferring the greatest torque).

It's a ridiculous debate anyway. A belt CAN be designed that is strong enough to contain even YOUR pedaling strength. Whether THIS belt is strong enough can only be determined by riding the bike. One has to hope that the bike designers, like the moto designer, has specified an appropriate part.


Finally, if the stresses are so much higher on a belted bike than a belted moto, why are motorcycle chains much larger than bicycle chains?

As for the human-engine comparo: I haven't gotten around to dynoing my Harley,but similarly modded engines have produced 110-115lb-ft. I say you can't produce,and sustain,that much torque with your legs. I can show you dyno charts proving how much torque an engine makes. Where are the charts for a person? Until I see some experimental results that show how much torque a human produces,then the whole argument is moot. :p
Well, an exercise physiologist could probably haul out enough charts to make our heads swim...but you can make a pretty good estimate on your own.

The greatest torque will happen when the rider is mashing at low rpms. Standing to climb a hill, for example. In this case, the downward force on the pedal is pretty much equal to the person's body weight. And the cranks provide a lever arm of 17 cm or so -- call it three fifths of a foot.

So a 200-pound rider will exert a maximum torque of around 120 ft-lb; comparable to your Harley. The motorcycle engine, of course, has a lot more power -- but that's because it's delivering the same torque at a much higher rpm.

Wow, a lightbulb just went off in my head, I'm glad you pointed that out! Very interesting.

That's probably been a major impediment to building belt-drive bikes... you have to change the frame structure significantly. You can't just slap a belt-drive cog and chainring on a regular bike and try it out.

For the record, Phantoj noted it first, in response to someone asking about conversion.

I'd like to believe I would have figured it out independently, but you never know.

Let's not forget the effect of gears as well since this is what enables a 110 lb-ft motor to move a 1+ ton auto. The engine drives a transmission which multiplies the torque and there is the difference in size between the engine output shaft and the tire which also multiplies torque. There is really no comparision between the forces this belt needs to handle compared to what moves a motorcycle or automobile.

There is a slight mechanical advantage gained from the crank arm length vs the crank ring radius but that's about it. This belt will probably never see more than about 500 lbs of force acting on it.

This system seems like a really good idea to me. I guess I'm not surprised that it's common in Japan and other places. I think I'll go down to my local P** bike shop and see if I can take a test ride.

More than just the belt drive, the whole bike seems nicely thought out. Disc in the front, where it matters, not in the back, where it complicates things. It's not retro, but it's not hideously ugly like a lot of modern "commuter" bikes. Comes with a rack and real fenders. Only thing I would probably ditch is the suspension seatpost - it looks like it has a sprung saddle.

Ramble: When I was a wee 'un, I built a primitive suspension seatpost - I found a metal pipe about the diameter of my seatpost and welded (I think I actually had my dad weld) on a flange to the pipe. Then I stuck a spring under the flange; the spring was about 3" diameter, and pretty stiff. I greased up the post and it actually worked OK, except the saddle would spin around the wrong way if you stood up. I even figured out a solution for that - a little anti-rotation linkage. This was on an old Murray road bike - back before the commercial advent of suspension posts.