justdon

Iam sure everybody has seen them.And maybe a few rode one.What is the opinion of these bikes with shaft drive?

Mr. Beanz

Don't be so sure, never even heard of them.

Edit: I did a search on them and now know why I don't know them. Not a bike that would interest me.

Flying Merkel

Shaft drive bikes are a 100 year old idea that comes & goes every few decades. No real benefits and a plethora of inherent problems. Shafties look cool though.

justdon

You guys know better than i do.But to me you would have problems going up hills and a few other places..

DTG

I just checked em out and they look cool. Not something I would get myself but the concept is cool.

Looigi

Basically, significantly heavier and more friction loss than chain drives, which is why Orville and Wilbur use chains to drive their propellers. Advantages can be long life, low maintenance, and not exposing mechanical hazards (pinching and cutting) and not subjecting the users and the immediate environment to oil and grease. Chains drives can be fully enclosed, which falls somewhere between in features/benefits.

There are also belt drives with their pros and cons.

Note all four setups have been used on various motorcycles and scooters since the 1920s... belts no so much as it wasn't until relatively recently that they were made strong and reliable enough.

tdister

I had one to try for a bit. I'm not always the best with words but it definitely wasn't anything I would want on a regular basis. It simply didn't have a good feel IMO. Felt inefficient and maybe numb(?) is the word I'm looking for.

Flying Merkel

Picture of an old shaft drive bike:



Very clean looking.

JanMM

Have never seen one. Have only read of them here. Haven't read much good about Dynamic shaft drive bikes. Except by those with an interest in the company.

Wilfred Laurier

The last shaft drive bikes i saw were in the late 90s with the name "Oxford" on them. I think making gears precisely enough to have a free-running drivetrain was too much to expect for the $400 or so the were selling for. The drivetrain felt notchy and had a lot of drag. I have never heard of "Dynamic." Almost all bikes are made by large Asian manufacturing businesses and the same product is often sold in different places under different names, or exported in great numbers to one place and not exist in another.

justdon

https://shop.dynamicbicycles.com/Runa...-Runabout8.htm

I hope this short cut comes out ok.But if no one has seen one this is one of their latest models..

Wilfred Laurier

I looked at the bike and I'm not convinced.

Most of the 'benefits' listed for the shaft drive are actually just bvenefits of the internally geared hub, which are found on a lot of chain-drive bikes that are lighter, easier to maintain, more efficient, and cheaper. And available in more sizes and styles of bike. And this is not even considering the poor quality of the shaft-drive bikes I have tried... if the quality is similar (and I can't imagine it would be to far off for the price) then it is certainly not something I would buy.


If you have a reason why getting rid of the chain is so important that you are willing to deal with the drawbacks then it might be a good choice for you.

bhtooefr

The biggest losses are from changing rotation direction, and a shaft-drive bicycle does so twice (once from transverse to longitudinal, then once again to transverse).

Most shaft-drive vehicles use one or even zero power transfer direction changes - most RWD vehicles (both motorcycles and cars) with shaft drive have longitudinal engine rotation (although a few motorcycles run transverse, and a few RWD cars are set up like front wheel drive cars in the rear), only requiring one change of direction at the rear differential, and most FWD cars have transverse rotation, and use a gear or occasionally chain drive to send the power back a foot or so (maintaining transverse rotation), then keep it transverse to the rear wheels (but some (I'm looking at you, Subaru and Audi) have longitudinal rotation, send it back, then turn it 180 degrees, then turn it 90 degrees, which is horrendously inefficient, but lends itself to a simple all wheel drive drivetrain).

You'll also notice that engine camshafts are universally driven by either a belt, chain, or geartrain, all of which preserve direction of rotation.

Looigi

Not totally universal. Ducati motorcycles used to use shafts running up the side of each cylinder to turn the (desmo) cams, and there were others.... Of course motor vehicles have a lot of excess horsepower, so a bit of loss in gearing and power transmission isn't as consequential as it is on bicycles.

bhtooefr

Of course Ducati would do something insane like that...

OK, cam drives are ALMOST universally ones that preserve direction of rotation.

Flying Merkel

Motorcycles can shrug off the weight & drag penalty that bikes can't. My Suzuki GS1000G is a shaft drive. Works better than a chain mostly because it's a touring bike.

I have not yet seen any convincing evidence that belt or shaft is better in the long run than a chain. There's been mutterings about problems with IGH that have 7 speeds or more- anybody can confirm or deny?

Wilfred Laurier

There were a few models, esp., those from Sturmey Archer, that was not able to be used with any reasonable chainring/cog ratio withough risking damage to the insides, which made them only useful for small-wheel bikes like folders... but they have fixed that, I think.
Shimano 7-speeds have been decent from the beginning, even if they have a little more drag than a derailleur. Their 8-speeds were decent from the Nexus range, and the Alfine 8-speed is great (thats what I have). I have heard mixed reports about the Shimano 11 speed.
THe Rohloff 14-speed is almost universally loved by those who have tried them.
I don't know about Sram stuff, which was originally made by Sachs before they got bought out. I expect it is decent.

fietsbob

You OK with having to go back to the remote seller for all warrantee help and service?

no local dealer to help . you buy at retail, then get a box shipped.

bhtooefr

Now, Sturmey-Archer even has a group based around the wide-ratio 8-speeds, that's set up for 30/25 gearing, for 622 mm wheels. (The problem is that first gear is the direct drive gear. However, that's also why they can do 30/25 - none of the gears are gearing down (multiplying torque), it's all gearing up.)
Although I thought the Shimano 8-speeds were a bit maintenance hungry...
No idea about the new G8 (I think that one is nearly vaporware) or the (recently discontinued) i-Motion 9, but I thought the (long ago discontinued) Sachs Elan 12 was known for being inefficient, heavy, and unreliable (and the Rohloff is why it doesn't exist any more)?

Wilfred Laurier

I know the original Nexus 8 speed was improved upon with two subsequent versions, including the 'Red Band' hub. And the Alfine is a slightly different design, including roller clutches and a centrelock disk brake mount.

I have had my Alfine hub for a few years and have not yet taken it apart. I will report back when I get around to it, hopefully later this winter before the good riding weather comes back and the Flying Spaghetti Monster (sauce be upon Him) sends the spring rains to wash the salt off the roads.

I never saw the Elan 12, and I suppose that is a good thing as I just read the article about it on SB's website and it sounds like a nightmare.
Basically, there are so many drivetrain options for modern bikes that if a truly inferior product like the Elan 12 comes out, it won't last long.
The Nexus and Alfine 7 and 8 speed hubs have been around for some time now, and they are still selling the Alfine 11 speeds, I think despitre some early problems. And the Rohloff has been available for quite some time with only minor variations (chain tensioners and disk brake mounts, etc).

tim24k

I looked at these bikes two years ago, at that time they told me you need to take the rear wheel off to clean and grease the shaft once a week. That's far more work/time then I put into my chain driven bikes. I was also told they only last 8,000 to 10,000 miles. It also takes much more time to R&R the rear wheel as well. Not some thing I like to hear about when I'm coming home in the dark and it's raining. :-( So at that time I asked myself why?

Burton

With the current issues getting specialty parts for existing commonly used technology five years down the road - I can't imagine what it would be like trying to get parts for something like that in 5 years. Even the first year would be tough.

chainlessguy

Seems there are a lot of posts in here from contributors that have no direct experience with or knowledge of shaft drive bikes. I do, so I am happy to get involved and bring some first-hand knowledge to this thread. Full disclosure - I have been involved in the manufacturing and sales of shaft drive bicycles for nearly ten years. But this said, safe to say I know a bit more about them than anyone else on this post. I have ridden bikes all my life. Every kind. And its true that shaft drive bikes are not for everyone. Different strokes. But shaft drive bikes are excellent for what they are designed for - clean, safe, incredibly low maintenance, easy to operate, and solid performance. Shaft drives for commuting in foul weather dramatically reduce maintenance time and costs. Shaft drives on folding bikes are clean and safe to handle and store. Shaft drive recreational bikes are easy to operate, very smooth to pedal, and easy to maintain. Shaft drive bikes are also outstanding for public bike share systems.

But this is not what most of this thread has been about - it has been about the performance of shaft drive bikes. I can tell you that today's shaft drive bikes offer every bit of the performance of a chain-drive internal hub bike, but without any external moving parts. For instance, the new Sussex 4th generation shaft drive - which is lighter, more efficient and more durable than previous shaft drives - is only about 12oz heavier than a chain. The efficiency loss of the spiral bevel gears in the shaft drive is 2% for each 90-degree turn. There are 2 in the shaft drive - one the front gearbox, one at the rear. Then there is some loss of efficiency from bearings and lubrication. This puts the shaft drive at about 90-92% efficient. All the time. No tune-ups or adjustments. The new 4th generation shaft drive from Sussex also is lubricated once when the bike is new, and then again at about 5,000 miles. No tools required. And as for the efficiency of a chain-derailleur bike, the reality is that these system vary tremendously in efficiency. Variables that effect riding efficiency on chain-derailleur bikes includes: condition and lubrication of chain, condition of teeth on sprockets, slack in chain, pitch angle from front sprocket set to rear, friction of front-rear derailleurs, efficiency of shifting, weight and material construction of gear components, speed of shifting, drop angle of tensioner, external weather conditions, and more. I hear people say that chain bikes are 97% efficient. Yeah, I read the same study. What this study also said was that this 97% efficiency was for a single-speed bike with a chain perfectly tensioned, aligned and lubricated. This does not represent 98% of the chain bikes on the market. Most chain-derailleur bikes are not even close to this rate of efficiency. In fact, even well maintained chain-derailleur bikes have very different efficiency from gear-to-gear. Some gears may be as high as 95% efficient in best case; some may be as low as 75% in worst case. Read the literature if you really want to know.

With all this said, after years of comparing the two, IMHO, its splitting hairs. People are not buying commuter bikes, folding bikes and hybrids in general because they are the most efficient bike in the world. They are buying these bikes for their function or enjoyment. So within the markets that shaft drive bikes are offered, they are just as efficient as their chain bike counterparts; but without all the key moving parts all exposed, which has its appeal both functionally and aesthetically. The weight comparison is nearly the same. The 12oz difference can easily be made up in other components on the bike. And despite what you might have read, a chain guard does not do the same thing as a a shaft drive. It certainly is not going to stop your bike from needing the same maintenance as without it.

I hope this information helps.

Wilfred Laurier

Great post, thanks.

Can you name a few manufacturers that are offering these new improved shaft drive systems you referred to? I suspect the basic ones like the op brought up or the oxfords I tried 10 years ago have something cheaper.

StephenH

Some quotes from the websites of Dynamic and Sussex (which appears to be the same or interconnected companies, that isn't clear);

"Our unique design minimizes weight and increases efficiency and performance far beyond any other shaft drive on the market..."

"How durable is the shaft drive?
"Our shaft drive is designed to have twice the life expectancy of a chain under comparable riding conditions."

"What maintenance is required for the shaft drive and internal gears?
"With our shaft drive, the only maintenance required is grease added to the front and rear gearboxes on a periodic basis - typically every 500-1000 miles. The frequency of this lubrication will depend on the amount and type of riding you do, and the quality of the grease used. More aggressive riders and heavier riders may need to add grease every 1-3 months, while more recreational or occasional riders may only need to add grease every 6-12 months. Grease is added to the front gearbox through a standard grease nipple (zerk fitting) on the underside of the gearbox using a grease gun. Grease is added to the rear gearbox simply by removing the rear plastic dust cover and applying grease right to the gear teeth. Typically, greasing the shaft drive takes less than 1 minute each time -- without getting grease on your hands or clothes." (On the Dynamic website, they talk about Gen. 3 vs Gen. systems, with the Gen. 4 requiring less maintenance.)

"The Dynamic Shaft Drive System is a unique “chainless” drive system..."- from the Sussex website

"Our shaft drive system uses CNC machined spiral bevel gears made from hardened chromoly, as well as sealed cartridge bearings, and cast aluminum housings. The shaft drive system was desinged to last 6,000-8,000 miles; however, this range can vary greatly depending on how the bicycle is ridden. More aggressive and heavier riders, and riders on hilly terrain will get a shorter life from the gears and bearings; more recreational riders on rolling terrain will get a longer life. "- from the Dynamic website.