Chainless Bikes. What do you think?

The only advantage is that they require slightly less maintainence. The disadvantages are increased weight and decreased efficiency from a chain drive. They also use a lot of non-standard parts that may end up being impossible to get replacements for.

I've been looking at getting the Incline® Hybrid Cruz 7 (shaftdrive) has anyone ridden this type before. I just want to know what you think.

Try this link. It's a cruiser...reasonably priced.

www.dekrabike.com

Quoted post said:

never heard of a shaft drive pedal bike. I will have to check it out.

i saw one in my lifetime... the bike was over 100 years old, was cool to look at.

I test-rode a 'Zero cycle' ( http://www.zerocycles.co.uk/ )shaft-driven bicycle at a bike show a few years ago. I only rode it inside and within a fairly small roped-off area, but in that situation it accelerated just like the chain-driven bikes that I also rode that day. It felt no different in terms of efficiency to that of its chain-driven counterparts.

Regarding efficiency: A chain can be around 99% efficient, but only when kept properly lubricated and free from dirt, etc. Bevel gears (as found in shaft-driven bikes) are not all that less efficient; they are around the 98%-99% efficiency mark, when correctly lubricated. As the shaft (on shaft-driven bikes) is enclosed in an oil-filled compartment it is always kept at its lubricative optimum, so long as the oil is changed as per the maintenance manual instructions. Unless the drive chain on a chain-driven bike is shielded from the elements and dirt, lubricated and cleaned regularly then it will rarely be operating at its optimum efficiency level. So real-world comparisons between shaft drive and chain drive bicycles concerning their respective efficiencies would be very close.

Of course, factoring in power loss from a planetary gear hub tilts the balance towards favouring the chain drive. But if single speed is the order of the day, then that is not a concern.

However, for commuting a few miles each day, and in other similar usage scenarios, a shaft-driven bike with a planetary gear hub is a very good idea

Interesting. I didn`t know that really exists. System is very similar to car engines if I saw right.

I don't have any personal experience with one, but I someone I ride with brought out his shaft-drive mountain bike one day. Apparently the biggest problem with the thing is that it's very hard to get it dialed in properly. Any slight misadjustment in the drivetrain and it would make some very bad grinding noises.

Ideologue said:

Regarding efficiency: A chain can be around 99% efficient, but only when kept properly lubricated and free from dirt, etc. Bevel gears (as found in shaft-driven bikes) are not all that less efficient; they are around the 98%-99% efficiency mark, when correctly lubricated. As the shaft (on shaft-driven bikes) is enclosed in an oil-filled compartment it is always kept at its lubricative optimum, so long as the oil is changed as per the maintenance manual instructions. Unless the drive chain on a chain-driven bike is shielded from the elements and dirt, lubricated and cleaned regularly then it will rarely be operating at its optimum efficiency level. So real-world comparisons between shaft drive and chain drive bicycles concerning their respective efficiencies would be very close.

From the web site you linked to:

Question: How efficient is the shaft drive system? Answer: The performance of the shaft drive system ranges from 90 to 95 % efficiency. In comparison, the efficiency of a good clean chain may be up to 98.5% efficient.
People have periodically been trying to push shaft driven bicycles as the next big thing for the last hundred years. If it really was such a good idea, we would all be riding them by now.

artmichalek said:

From the web site you linked to:

Question: How efficient is the shaft drive system? Answer: The performance of the shaft drive system ranges from 90 to 95 % efficiency. In comparison, the efficiency of a good clean chain may be up to 98.5% efficient.
People have periodically been trying to push shaft driven bicycles as the next big thing for the last hundred years. If it really was such a good idea, we would all be riding them by now.

Yes. And I bet those figures are slanted towards favoring the shaft drive. Chain/cog drives are really damn efficient. I bet it's 98.5% even when you've got a dirty chain. The system generates virtually no heat and almost all of the energy is tansferred to drive, with the exception of a tiny bit of chain stretch and maybe a tiny bit of heat (i.e. the chain may get a little warm). Any gear system generates heat. I would guess that the oil in that closed system would be quite warm after riding for awhile. I would also guess that the case might even be warm to the touch after miles of riding. Heat = inefficiency. It's tough to beat a chain drive system for efficiency.

artmichalek said:

From the web site you linked to:

Question: How efficient is the shaft drive system? Answer: The performance of the shaft drive system ranges from 90 to 95 % efficiency. In comparison, the efficiency of a good clean chain may be up to 98.5% efficient.
People have periodically been trying to push shaft driven bicycles as the next big thing for the last hundred years. If it really was such a good idea, we would all be riding them by now.

Oops! My figures were based on the little bit of reading I have been doing of late on involute gears (spiral bevel gears). For a seemingly odd and unknown reason many of the bicycle shaft driven bikes use a lesser efficient cog system in their transmission. If they used involute cogs then they really should be getting around the 98% mark.

meehs said:

Yes. And I bet those figures are slanted towards favoring the shaft drive. Chain/cog drives are really damn efficient. I bet it's 98.5% even when you've got a dirty chain. The system generates virtually no heat and almost all of the energy is tansferred to drive, with the exception of a tiny bit of chain stretch and maybe a tiny bit of heat (i.e. the chain may get a little warm). Any gear system generates heat. I would guess that the oil in that closed system would be quite warm after riding for awhile. I would also guess that the case might even be warm to the touch after miles of riding. Heat = inefficiency. It's tough to beat a chain drive system for efficiency.

I don’t doubt that in normal circumstances the roller chain certainly is more efficient than cogs. But unless the bicycle is being used for racing, looking at the pros and cons of each system the conclusion would have to be that there is not much between the two.

Remember that drive chains produce heat too. But the heat is spread out over a long chain and a much larger surface area. Chains are also out in the open and quickly lose their heat to the environment. Cogs in a housing, however, do not dissipate their heat so well, ergo it remains in the small and enclosed space within. I would imagine that the heat buildup inside the shaft housing could be a good thing as it will lessen the viscosity of the oil bath, so there would be less resistance for the immersed cogs to turn through.

That is what I think anyway.

I am designing a power-assist bicycle at the moment. My final drive will be via an inverted tooth chain. Inverted tooth chains are even more efficient than roller chains, but they will not work in standard derailleurs. My bike is mainly for off-road usage at slow to moderate speeds, so it does not have to be as efficient as a regular road bike. From the BB an inverted chain drives an internally positioned, mid-mounted roller chain derailleur. That in turn drives another internal shaft that goes on to drive the rear wheel via a second inverted tooth chain. All the chains will be shielded from the elements and lubricated constantly with an oil drip system. There are many reasons why it is designed this way; I will not get into it here, as I would be typing for hours! But one advantage is extra ground height as the first sprocket is tiny (on a 1:1 ratio with the front derailleur shaft) so I have no vulnerable large chain wheels that would inevitably get bashed on high ground or rocks.

Ideologue said:

I am designing a power-assist bicycle at the moment. My final drive will be via an inverted tooth chain. Inverted tooth chains are even more efficient than roller chains, but they will not work in standard derailleurs. My bike is mainly for off-road usage at slow to moderate speeds, so it does not have to be as efficient as a regular road bike. From the BB an inverted chain drives an internally positioned, mid-mounted roller chain derailleur. That in turn drives another internal shaft that goes on to drive the rear wheel via a second inverted tooth chain. All the chains will be shielded from the elements and lubricated constantly with an oil drip system. There are many reasons why it is designed this way; I will not get into it here, as I would be typing for hours! But one advantage is extra ground height as the first sprocket is tiny (on a 1:1 ratio with the front derailleur shaft) so I have no vulnerable large chain wheels that would inevitably get bashed on high ground or rocks.

Interesting concept. Someone had a prototype downhill bike at one of the trade shows last year that was like this. It was a fully enclosed system with a pair of roller chains. Depending on how your enclosure is set up, you can probably ditch the oil drip. There's also a much easier way to do the mid gearing than using a roller chain derailleur. Shoot me a PM, and I'll send you the details.

Ideologue said:

I am designing a power-assist bicycle at the moment. My final drive will be via an inverted tooth chain. Inverted tooth chains are even more efficient than roller chains, but they will not work in standard derailleurs. My bike is mainly for off-road usage at slow to moderate speeds, so it does not have to be as efficient as a regular road bike. From the BB an inverted chain drives an internally positioned, mid-mounted roller chain derailleur. That in turn drives another internal shaft that goes on to drive the rear wheel via a second inverted tooth chain. All the chains will be shielded from the elements and lubricated constantly with an oil drip system. There are many reasons why it is designed this way; I will not get into it here, as I would be typing for hours! But one advantage is extra ground height as the first sprocket is tiny (on a 1:1 ratio with the front derailleur shaft) so I have no vulnerable large chain wheels that would inevitably get bashed on high ground or rocks.

Very cool! You're actually building the bike or just developing the design concept? If you build it, it would be really cool if you could post some pictures of it here when it's complete! 🙂

artmichalek said:

Interesting concept. Someone had a prototype downhill bike at one of the trade shows last year that was like this. It was a fully enclosed system with a pair of roller chains. Depending on how your enclosure is set up, you can probably ditch the oil drip. There's also a much easier way to do the mid gearing than using a roller chain derailleur. Shoot me a PM, and I'll send you the details.

Thanks. PM sent.

I was originally going to use two or three mid-mounted planetary gear hubs to provide a wide range of gearing, but soon found that to be a bad idea. Most standard gear hubs are made using cogs from powdered metal, which are not very strong. Using several Rohloff hubs would be too expensive. And of course, using several gear hubs would be way too inefficient.

So, after reading about a Dutch inventor called Bauke Muntz in issue #11 of VeloVision magazine ( www.velovision.co.uk ), who designed a compact derailleur, I decided to develop a similarly designed system. I need a massive gearing range, as I will be towing a heavy trailer off-road and also riding at high-speed in combination with the assist motor(s).

As the design stands currently the bike will have two gearboxes to handle rider power. The derailleur gearbox will have 12 sprockets inline on a front shaft. The smaller sprockets will be attached to a mechanism that moves them laterally along the shaft as required to either remove the spaces, in between them and the sprockets next to them, or to open-up a space (the space needed to accommodate the drive chain). With most of the spaces removed the sprockets will be very compact and thus Q-factor will be minimized. The driven shaft of the derailleur system will also have several sprockets, but they will be mounted on a sliding sub-shaft. The driven sprockets slide laterally to ensure the drive chain is always in a dead straight line with the driver sprocket (no chain bending). The derailleur will repeat no ratio and averages around 12% between each one of the 23 ratios. The lowest derailleur gear at 80rpm at the BB will propel the bike at 4.25mph. The highest d’ gear will be good for 61.6mph at 80rpm at the BB and 100mph at 129.9rpm.

A second gearbox will have about 4 or 5 ratios. This gearbox is for changing gear when the bike is stationary (it is similar to car/motorcycle gearboxes, but using chains instead of oil-immersed cogs). It is also a back-up gearbox incase the derailleur breaks in the middle of remote wilderness. The third reason for this gearbox is to provide an even lower ratio than the lowest derailleur gear (as the lowest sprocket would be too small on the derailleur system, or the highest would be too large). The second gearbox will have larger, stronger sprockets so it will be able to cope with higher torques such as would be required when pulling a 250kg trailer up a slope in mud!

meehs said:

Very cool! You're actually building the bike or just developing the design concept? If you build it, it would be really cool if you could post some pictures of it here when it's complete! 🙂

Yep, designing and building (when the design is finished). I have been working on it for over three years now; I have been learning about how to design bikes at the same time! I have pretty much made my mind up about how it work, so with hope it will be built within six months.

I will definitely post some pictures when it is complete.

There was an article in "Australian Cyclist" a little while ago about a (custom-built) bike with a toothed rubber belt drive.It used a Rohloff hub and had a removable dropout so the belt could be replaced.
Very quiet,durable,belts cheap to replace,no lubing required.

stevebaby said:

Very quiet,durable,belts cheap to replace,no lubing required.

True, but belts are much less efficient than chains as they have to be bent around the cog. As Mike Burrows wrote 'they are better on packaging machines'!

CharlieBear426 said:

I've been looking at getting a chainless bike. I live in Montana and would mainly be using the bike to get to work and school both are only a couple of miles from where I live. This will be the first time I've had a bike in about ten years. I'm looking for real opinions on these bikes. Also what suggestions do you have about the brands of chainless bikes? I was wondering if anyone knew how easy these bikes are to maintain or is it expensive to repair them.

I've been inspired by this thread so I thought I'd try my bike chainless this weekend. The cranks just seemed to spin without the back wheel turning at all and it didn't change gear very well. Pedalling seemed to be really easy though.

I have decided to put the chain back on.