Shaft drive Ebikes?

[tommie]

Whats out there at the moment?

Pros and Cons?
- Extra weight? Reliability??

I see Bafang have a 250watt Motor with shaft drive on the market, is it frame specific?

http://www.bafang-e.com/en/components/component/motor/mm-g330250-2.html

 

[tillson]

Whats out there at the moment?

Pros and Cons?
- Extra weight? Reliability??

I see Bafang have a 250watt Motor with shaft drive on the market, is it frame specific?

http://www.bafang-e.com/en/components/component/motor/mm-g330250-2.html

View attachment 23911

Interesting. Does the front cylindrical portion adjacent to the motor form the bottom bracket by fitting into the housing on a standard frame? If not, I'm guessing this is only available to manufacturers to use in specially built bikes. A neat unit though.

 

[Deleted member 4366]

These things are all great ideas, but you have to think about how you're going to get them fixed when out of warranty. You'll most likely end up with a worthless pile of junk. Until now, it's a struggle to get a BBSxx motor through the warranty period without it needing something. When you add to that issues with the drive-train and rear hub, it doesn't look so promising.

Bear in mind that that arrangement needs a special frame, so the whole bike will be rendered useless if you get any problems with that thing.

You can't beat the simplicity of a rear hub-motor with separate controller and battery on a conventional bike with derailleur gears. Everything is cheap and serviceable, so you'll get years of low-cost enjoyable electric cycling.

 

[anotherkiwi]

You can't beat the simplicity of a rear hub-motor with separate controller and battery on a conventional bike with derailleur gears. Everything is cheap and serviceable, so you'll get years of low-cost enjoyable electric cycling.

You can equal it with a mid-drive with external controller and derailleur gears Mostly because it mounts in aluminium frames without torque arms and you get high torque when you need it and speed when you need that too!

 

[Emo Rider]

Whats out there at the moment?

Pros and Cons?
- Extra weight? Reliability??

I see Bafang have a 250watt Motor with shaft drive on the market, is it frame specific?

http://www.bafang-e.com/en/components/component/motor/mm-g330250-2.html

View attachment 23911

Way back when, I was learning mechanical drafting, we learned that direct (chain drive) was more efficient than shaft drive. The rational was that there was an unavoidable power loss every time you changed the direction of the delivery of power. The figure I recall was a 7% loss @ 90 degrees. I did own a shaft drive motorcycle (Honda Goldwing) and numerous Suzuki and Honda chain drives. I did not miss chain maintenace. While I knew there was a power loss for the Wing, it had lots of power to make up for it. However, there is no upping the power, legally, on an ebike to compensate for the loss of power to the wheel.

 

[Gubbins]

Also bear in mind that the only way to travel longer distances on an ebike is to ride above the cut-off which is where an extra few percent loss in efficiency would be noticed..

 

[mike killay]

Also bear in mind that the only way to travel longer distances on an ebike is to ride above the cut-off which is where an extra few percent loss in efficiency would be noticed..

Or switch the power off and ride slowly!

 

[mike killay]

I don't know why people find bike chains so offensive and want to replace them with carbon belts or shafts.
Mine might be greasy, but I keep my legs away from it.
Never had a problem.
Mass production of chains means that they are cheap.
Belt drives need frames that open=extra cost.
Shafts will certainly cost extra.
Yet chains remain the most efficient way of transmitting power.

 

[NRG]

I'm all for the KISS principle where possible

 

[Gubbins]

I'm all for the KISS principle where possible

I can relate to the last two letters.. not sure about the other two tho.

 

[Deleted member 4366]

I'm all for the KISS principle where possible

Who woke you up from the dead?

I'm also a good kisser. Blokes mustn't ask me to prove it. I'm strictly red blooded.

 

[NRG]

Somebody had to come back and haunt you!

 

[rower]

I don't know why people find bike chains so offensive and want to replace them with carbon belts or shafts.
Mine might be greasy, but I keep my legs away from it.
Never had a problem.
Mass production of chains means that they are cheap.
Belt drives need frames that open=extra cost.
Shafts will certainly cost extra.
Yet chains remain the most efficient way of transmitting power.

I'm interested in shafts and belts because I have no problem paying for a premium product if that's a guarantee of a reliable service life.

With my ebike I've already had to take it back to the shop because of a crap chain, and it's a bit of gear which I'm having to clean and oil at least fortnightly. Not a huge amount of work but it's just more crap that you've got to have lying around to use when necessary which I'd rather not.

If a shaft/belt system opens up the possibility of yearly or even further apart servicings and maintenance work then they have my interest.

 

[Gubbins]

I'm interested in shafts and belts because I have no problem paying for a premium product if that's a guarantee of a reliable service life.

With my ebike I've already had to take it back to the shop because of a crap chain, and it's a bit of gear which I'm having to clean and oil at least fortnightly. Not a huge amount of work but it's just more crap that you've got to have lying around to use when necessary which I'd rather not.

If a shaft/belt system opens up the possibility of yearly or even further apart servicings and maintenance work then they have my interest.

Full agree and you have put my feelings forward quite succinctly. What does a belt cost? £60? More?
The Cost.. Chains seem to be around the £20 mark and I buy two or three a year so not much difference there, and modern cassettes have become really expensive when they need changing so a new belt every few thousand miles doesn't seem so bad.
The oil.. If you oil regularly the chain and cogs soon become a black sticky mess which means a change of clothes even to do menial tasks that involve getting anywhere near the chain or risk black tooth marks that resist washing and annoy hell out of her indoors!
The gear changer.. I fell off and bent the derailleur which apparently is a common consequence of a spill and even though I had it fixed it isn't as smooth as it was before.
The weight.. Its an e-bike and I dont lift it over walls, gates or styles so not worried about a bit of extra weight.
On the negative side, belts need to be run at a much higher tension than chains and I have read of BB's succumbing earlier than expected so I am not sure how previous Bosch bearing weaknesses might react to this, but even so if I could convert my Giant e-bike to such a Belt/Hub drive I would but as mentioned it needs a special frame so not possible which is why my next bike will be a belt driven hub geared ebike.

 

[rower]

The weight.. Its an e-bike and I dont lift it over walls, gates or styles so not worried about a bit of extra weight.

I have done this. Got a puncture last November and didn't have a spare tube on me. Couldn't walk the bike back on the road so had to go through footpaths which all had awkward kissing gates I couldn't fit the bike through.... Not recommended

As soon as Schwalbe get their act together and bring their airless tyres to the UK next year I think I'll be about ready for a minimal maintenance bike that requires barely any repair tools while out and about.

 

[soundwave]

https://shop.carbondrive.net/shop/belt.html?___store=en&___from_store=en

 

[tillson]

Full agree and you have put my feelings forward quite succinctly. What does a belt cost? £60? More?
The Cost.. Chains seem to be around the £20 mark and I buy two or three a year so not much difference there, and modern cassettes have become really expensive when they need changing so a new belt every few thousand miles doesn't seem so bad.
The oil.. If you oil regularly the chain and cogs soon become a black sticky mess which means a change of clothes even to do menial tasks that involve getting anywhere near the chain or risk black tooth marks that resist washing and annoy hell out of her indoors!
The gear changer.. I fell off and bent the derailleur which apparently is a common consequence of a spill and even though I had it fixed it isn't as smooth as it was before.
The weight.. Its an e-bike and I dont lift it over walls, gates or styles so not worried about a bit of extra weight.
On the negative side, belts need to be run at a much higher tension than chains and I have read of BB's succumbing earlier than expected so I am not sure how previous Bosch bearing weaknesses might react to this, but even so if I could convert my Giant e-bike to such a Belt/Hub drive I would but as mentioned it needs a special frame so not possible which is why my next bike will be a belt driven hub geared ebike.

Why are you buying 2 to 3 chains per year? What do you do to them? I ride about 3000 miles per year on my bike and get a minimum of 2 years out of a chain. Just put plenty of grease on it and ride until the teeth start falling off the sprockets. Then replace the whole lot for about £20. KMC chain is excellent.

I’ve seen people fannying about measuring chain stretch and sprocket wear. Forget it on an ebike, it makes no difference because the motor supplements for a bit of lost efficiency. It’s a different story on a road bike for racing, every bit of power is precious.

I think carbon belts are a bit of a gimmick. A nice length of well greased KMC, can’t beat it.

 

[Gubbins]

Why are you buying 2 to 3 chains per year? What do you do to them? I ride about 3000 miles per year on my bike and get a minimum of 2 years out of a chain. Just put plenty of grease on it and ride until the teeth start falling off the sprockets. Then replace the whole lot for about £20. KMC chain is excellent.

I’ve seen people fannying about measuring chain stretch and sprocket wear. Forget it on an ebike, it makes no difference because the motor supplements for a bit of lost efficiency. It’s a different story on a road bike for racing, every bit of power is precious.

I think carbon belts are a bit of a gimmick. A nice length of well greased KMC, can’t beat it.

Yes Tilson that's exactly the point.. I know of others who never do anything with a chain and they seem to last for ages but I dont want to deal with all that greasy build up, and a new drive train for mine will cost a bit more than £20.. I think the cassette alone was in the £50's last time I asked at LBS. Enter stage left.. SW with a link!!

 

[Gubbins]

I have done this. Got a puncture last November and didn't have a spare tube on me. Couldn't walk the bike back on the road so had to go through footpaths which all had awkward kissing gates I couldn't fit the bike through.... Not recommended

As soon as Schwalbe get their act together and bring their airless tyres to the UK next year I think I'll be about ready for a minimal maintenance bike that requires barely any repair tools while out and about.

On 3 occasions I have had a rear wheel puncture I have chosen to walk the 2 miles or so home rather than mess about with taking the wheel off and changing the tube. Why is it always the rear? Ebikes don't turn over easily..

 

[soundwave]

http://www.continental-bicycle-systems.com/en-gl/Ebikes/eBike/48V-eBike-System/48V-Drive-Units/48V-Revolution