tandempower

A couple people have told me that bicycles aren't as simple mechanically as cars because cars have plug-and-play parts to replace whereas bikes require more fine-tuning and adjustment. This got me thinking about the idea of shaft-drive bikes, but when I googled it I found that the manufacturers that make such bicycles don't sell the drivetrains as retrofittable components for existing bikes.

Do you know of a shaft drive system that can be bought and shipped as a retrofittable system without shipping the entire bicycle? This seems like a big obstacle to making shaft-drive a readily available option for most people. I would think a lot of people's cycling and maintenance experience would be improved by plug-and-play shaft drive systems?

What do you think? Are there also drawbacks? Why haven't there been retrofittable market options?

fietsbob

Retro-fit-able? No .. so scratch off retrofitable .. build a frame around one, if you can already build Frames , maybe.

Any I've seen the right chainstay houses the shaft and the frame is Made around the shaft drive feature.

Dynamic Bicycles - Chainless Technology

Even the New Belt drive Schemes have frame modification or design requirements So belt stays as a continuous loop.



Both Cars and Bicycles are a Lot more complicated than they were 100, or even 50 years ago.

Now if You have a Shop Capable of building Bike frames already then Maybe there are cut and re weld Possibilities ..

Wilfred Laurier

I believe the main thing holding shaft drive bicycle back has been the poor quality of the available shaft drive bikes, especially the drive system itself. I will believe they have a sufficiently decent design when I see it, and I have yet to see it.

BlazingPedals

How many kits are out there to retrofit cars for chain drive?

Little Darwin

As I recall shaft drives are less efficient than chain drives (possibly due to the crank rotation being 90 degrees offset from the shaft rotation)... so along with the extra weight, it is an option I will skip. Also, just like cars, every model of bike would need a specific shaft length (even if we assume standardization of drive gear and u-joints). Wouldn't it be fun to have to find someone who stocked a 743mm drive shaft rather than just asking for a 10 speed chain since you can adjust the length with a $10 tool?

However, I have never heard of someone saying maintaining a bicycle was harder than maintaining a car. Also, I don't understand how someone could think that a car is plug and play. I can understand that a car mechanic who doesn't understand bicycles may not know how to adjust a bicycle, but that is lack of familiarity, not some mystical plug and play in a car. If cars were truly plug and play, mechanics would be just as rare as computer repair shops... I pass 3 or 4 mechanics on my commute, plus a car dealer or two (with fully staffed garages) and I pass exactly one small computer repair shop.

Another aspect/example... You could probably list every component from every manufacturer that has ever existed for every bicycle ever made and still have a smaller listing than the available gaskets for cars built in the last 10 years.

And what's more? I can adjust every aspect of shifting on a bicycle with 5 screws and 2 cable adjusters... and it stays adjusted just as well as a car does. Admittedly there are people who claim that they have to adjust frequently, but there are many others that will tell you that once adjusted, bicycles just work unless something happens to mess it up.

Do you think that when a clutch gets replaced on a car it is as easy as replacing a cassette on a bicycle wheel? The process to install and adjust many car components (including clutches) is best left to professionals or good shade tree mechanics... On a bike, any idiot can swap cassettes with a couple of $10 tools (chain whip and lock ring tool, and there are ways to get around the chain whip by using the bicycle's own chain). I can replace a cassette faster than I could drive to one of the four mechanics I pass during my commute.

For $200 a cyclist can get every tool they are likely to need to work on any bicycle, with an additional new $10-$20 tool needed occasionally when some new technology arises (like a new style of bottom bracket). For $200 a car mechanic would get one of the tool chests needed to hold the tools needed to work on one make of automobile. If that is plug and play, I never want my bicycle to be plug and play.

Go to the auto-parts store, and you will find an aisle full of maintenance manuals for amateurs (admittedly much of the content is similar in each). But if you get the larger generic manual (does Chilton's still make one?) and a generic bicycle manual will be at least as comprehensive at 1/4 the size.

I like my car, and it is more complex for a reason, it does more than a bicycle. But, you need to be careful in trying to use a car to demonstrate how to simplify bicycle maintenance.

JohnDThompson 

Shaft-drive bikes had a brief period of popularity in the late 19th and early 20th centuries, but were soon supplanted by chain driven sprockets. Shaft drives tend to be heavy, have relatively high internal friction compared to chains, and offer limited gearing options. Every few decades someone tries to resurrect the concept, but it has yet to really catch on.

fietsbob

a Fat Bike with a sand friendly (ie. not easily contaminated) Shaft drive would be Nice ..

But I agree the demand it be Light and Cheap makes it hard to have a reliable System.

Dan Burkhart 

And every time they resurrect it, they try to pass it off as a new concept.

Retro Grouch 

Who ever told you that? I'd say the polar opposite was true. Campy, SRAM and Shimano are independent manufacturers who produce the plug-and-play parts found on virtually all modern bicycles.

Darth Lefty 

People who are not racing put up with lots of inefficiencies in their bikes, including terrible overall quality, balloon tires, suspensions, upright posture, weight, etc. If the attraction of an IGH is that it is more protected and less fussy than a derailleur, can't you make the same case for a shaft drive? That's the choice I made when I was motorcycling, to have a nearly maintenance free shaft drive and not a chain that needed oiling every other tank; but there you can just add more throttle...

The Dynamic model I saw wasn't really great. Other than the shaft drive the rest of it was a perfectly conventional hybrid. I think if it were better for the price, I'd be more interested.

dynaryder

Shafts are much less efficient than chains or belts. There's not one,but two 90° offsets;one at the cranks and one at the hub. There's also the shaft that has to be spun. I've seen folks convert their V-Max motorcycles from shaft to chain and get a nice BHP increase without any other mods.

bikepro

This is the reason front wheel drive cars with transverse mounted engines are more fuel efficient. There's no drive shaft to turn and the rotation of the engine crankshaft is in the same plane as the rotation of the wheels. The same is true of a bicycle chain. Everything turns in the same plane. A bicycle shaft drive is very inefficient because it requires gearing to change the plane of rotation two times.

tandempower

If (retrofittable) shaft drive is a bad idea for various reasons, what about a sealed-drive chain system? It would be the same idea as a sealed BB but there would be a whole 'chain case' that would bolt onto the side of the bike with a simple connection to, say, and internally-geared hub. What drivetrain could be more plug-and-play than that? Granted it would add weight but for commuters or others who care less about weight, it would be like having a total chain-guard for a drivetrain that never had to be greased or adjusted, and could be replaced with minimal time, effort, and skill when necessary. I'm not saying it would be the ideal bike but for the masses it might be an improvement over many current designs.

I was just quoting something said to me by a bike mechanic, probably in defense of his own skill relative to auto mechanics. The point is that if someone complains that bikes aren't simple enough, my imagination goes to work figuring out what it would take to make that an indefensible claim.


Interesting to read everyone's posts on this thread so far. Thanks for posting.

Darth Lefty 

They exist.

BlazingPedals

Belt drives exist too, if you're in hate with chains. The internal gearing they require is also a big efficiency loss.

MichaelW

You can service a modern bike at home with a handful of tools. No computer diagnostics required.

Shaft drive FAQ
Dynamic:
Can existing bikes be retrofitted with a shaft drive?
No. The shaft drive requires a specially designed frame. All of our bicycle frames were designed specifically for use with the shaft drive, ensuring the highest levels of performance and reliability.

Sussex:
Can existing bikes be retrofitted with a shaft drive?
No. The shaft drive requires a specially designed frame. This frame is engineered with a wider and narrower bottom bracket shell and special dropouts where the shaft drive connects to the rear wheel.

Gates Carbon belt drive is much more efficient and lighter than shaft. The efficiency is pretty good compared to deraileurs when you compare systems that are not mint, spotlessly clean and unworn
Motorbikes have excess power so efficiency is not so critical

BlazingPedals

That statement is laughable.

spdracr39

They are attempting to fix something that isn't broken.

Little Darwin

Full chain cases were available on some older bikes, but there has to be some reason that they faded into oblivion. My guess is that it was additional work when chain maintenance was needed. My guess is that to lube the chain, the chain guard had to be at least partially removed. I suppose a completely sealed chain case with seals at the crank and hub could be designed that would include an oil bath to eliminate the need to lube as often, but when it came time to lube the chain, you would basically have to do an oil change. And replacing the chain would be extra work compared to a standard bicycle...

MichaelW

Sunbeam made a famous bike (in 1908)with a full chaincase oil bath, serviced by a simple drain and refill. Chain life is almost
indefinite in an oil bath

tandempower

I found this link to a bike with a sealed-chain drivetrain: Nuseti mountain bike features a sealed drivetrain

While it would be unpopular from the supply-side for just about everyone involved, it would be good to have a retrofittable version of this, like a sealed bottom-bracket cartridge. If you could take an old bike and retrofit it with a rear-wheel/sealed-drivetrain that is little more work than replacing the old wheel and the bottom bracket with a new cartridge, it would be an attractive option for many people. It would mean less business for bike shops and big box bike sales but I don't see why that's a good reason to oppose it as a development.

Certainly no one could say that such a drivetrain was more tedious to service than a car, except it would be unservicable, except maybe by special shops where the systems could be re-built and re-sealed.

I don't see why they would need oil changes. Sealed bottom-bearing cartridges don't require servicing. There's not enough friction to burn the oil/grease, is there?

Little Darwin

I think oil changes would be needed, but probably not very frequently. Definitely not every 7,000 miles like the engine oil in my Subaru, possibly more like the transmission fluid... which is to be checked (not necessarily changed) every 30,000 miles. I wouldn't push foreverr with components like the current bikes, since the light weight components could wear faster than more robust components... but it could be extended further depending on materials used, and construction details of the sprockets and chain.

If someone rides 3,000 miles a year, an oil change every 10 years would definitely be reasonable. Or if one rides 1,000 miles per year, then it becomes 30 years between changes...

I like visually inspecting my bike's chain occasionally, but I guess I could get over that. I also like to be able to handle almost anything on the trail, but even if I had to repair a chain on the trail, I could definitely get back home without any oil if I needed to, it is not like a car where expensive damage could result from lack of lubrication.

Anyway... I don't think I will be running out to replace what works well for me, but I could see a well marketed solution getting a reasonable share of the market.

Stucky

That is the funniest thing i have ever heard!

Bikes are EXTREM<ELY simple! Very few moving parts; very few things to go wrong; very few interdependent systems!

You have some bearings on the few moving parts; some cogs and chainrings; and a couple of little sliding guides known as derailures, which simply move your chain from side to side a few eighths of an inch. Nothing could be simpler.

A car, by comparison, has a few thousand pounds of mechanisms, all interconnected; and each one of those many hundreds of parts are each more complex by themselves, than your entire bicycle! You could rebuild your entire bicycle with less trouble and in less time than it would take to change just a waterpump on a modern car!

I think whoever told you that fallacy, either knows nothing about cars or bicycles...or is on some serious narcotics!

Adding a heavy, more complex; more precise shaft drive system, would only increase complexity, while offering absolutely no advantage.

There's a reason that derailer bikes proliferate: They work; and are simple and cost-effective.

The REAL solution, is to simply educate yourself about basic bicycle mechanics. There are plenty of videos on Youtube which will explain to you how derailers work; and how to adjust them. Trust me, once you understand the simple principle, it is EASY! It is extremely easy to fine-tune just about bike so that it shifts like butter. It's pretty much the most basic, simple mechanical principles. There are two screws on a derailer to turn- which limit how far to the sides it can go. That's it! Watch a few videos; try it a couple of times- you can be a master of it by tomorrow.

[Probably best NOT to try replacing the waterpump in your car though, if you think a bike is complex....]

BlazingPedals

You mean the universal-fit, plug-and-play waterpump? Or the OTHER one?

CliffordK

I suppose those are the car drivers that have never had a timing light. Never tried adjusting points or tappets. Never twisted a distributor body to get it set just right. Never adjusted a clutch, and never set the spark plug gap.

One of the things that is occurring today is the "100,000 mile tune-up".

To achieve that , the cars have more and more electronics, sensors, and computer control, all fine-tuning the engine, as long as the users fit into the box the manufacture intended.

Still, I've had moments when the car stars and runs... one gets across town, turns off the engine, and the pesky "check engine light" comes on. One sensor has failed, and the engine refuses to start (why they don't incorporate a limp mode once the computer determines the sensor fault is beyond me).

If electronic shifting catches on with the bike world, I could imagine a world where the computer would be sophisticated enough to set its own derailleur stops and such. Auto brake adjustment?

Of course, cars usually get their tires balanced... would this be equivalent to truing a bike wheel?