Friction Drive comes of age

[anotherkiwi]

From the horses mouth:

"In regards to tire wear, this also has been discussed in detail. My current test bike has hit 5000km on the original road tire. This is due to using a smooth metal roller that works perfectly in dry conditions but doesn't work at all in wet conditions. If you want to use your bike in wet conditions, this drive is not for you."

 

[flecc]

Not to him though...

I don't understand why you can't see it Recy, of his own admission it only works in totally dry conditions, making it too limited for consideration.

Which is what I've been saying, friction drive onto tyres doesn't work acceptably.
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[EddiePJ]

Which is what I've been saying, friction drive onto tyres doesn't work acceptably.
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"Acceptably" isn't a phrase that I would have chosen to use. At the very best, it is a rubbish and inefficient form of drive system. I have zero time for friction drive systems. And yes I have in the past had the misfortune to use one.

Past failing asides, this one hasn't exactly been quick off the mark either. http://www.shareroller.com/ with constant stalling and delays of getting into production.

You can only have so many doorstops, and every cycle related friction drive system should thrown into Room 101, along with the people that try to resurrect them.

 

[flecc]

"Acceptably" isn't a phrase that I would have chosen to use. At the very best, it is a rubbish and inefficient form of drive system.

I was being kind Eddie, since Recy is so enthusiastic about it.

In fact I had started to type about the gross inefficiency of friction drive onto the tyre and to rubbish what Kepler claims about it, but realised I'd be wasting my time.
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[Danidl]

Old (but good) ideas that don't quite work frequently become excellent when re-invented/revisited with new tech and the new thinking it can inspire. Thank goodness!
I think we've all had ideas before now that we've had to shelve because affordable or available technology was not around.
This iteration of the friction drive concept might be coming into its time for this reason, notwithstanding previous experience. Certainly worth reading the thread if you care to and within it is all the reasoning too - for example the use of friction applied to the tyre for drive instead of the seemingly better idea of cog-drive. Incidentally, in terms of tyre wear Keplers test bike has over 5000km of use without anything excessive it seems.
Again, the thread explains far better than I. Amongst other things I really like the light & stealthy look & methods applied.

.. the light and stealthy look ... Lovely .. efficiency and tyre wear ... Not so lovely. There is in any event friction drive on all bikes .... Between the tyre and the road.

 

[flecc]

There is in any event friction drive on all bikes .... Between the tyre and the road.

There's always the exceptions.

Video link
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[Recy]

Danadl, please explain how 5000km + (and still going) is somehow unacceptable tyre wear?

And since when is it a crazy 'room 101' idea for a group of guys to put together a system that clearly works so well for them in their locality?
It's not wet everywhere in the World fellas - even though it's just another wet Tuesday here in the UK.

Like I said in my opening message 'not for everyone' - why has it become so personal to you guys? Such seriousness and 'nay saying' about so little, can't be healthy.
No ones trying to change the World (or even discount your collective experiences) - it's just an interesting (if obscure) little thread about a fun activity that enthusiasts of pedelecs, battery's & little electric motors etc may enjoy reading.
No biggy guys - lighten up perhaps?
Or not.

Ps he also does his 80km rides on it wearing flip-flops - cool. (Literally)

Cue: 'We can't wear flip flops...it's all wrong!' comments next....

 

[flecc]

Cue: 'We can't wear flip flops...it's all wrong!' comments next....

I'm all for that, I've only ever ridden in normal street clothes all my life, so flip-flops are fine. Some don't bother with clothes:

 

[Danidl]

I'm all for that, I've only ever ridden in normal street clothes all my life, so flip-flops are fine. Some don't bother with clothes:

... You really like showing that picture!

 

[flecc]

... You really like showing that picture!

Actually no, it's a different one, but of the same person!

Recy did ask us to lighten up!
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[Danidl]

Danadl, please explain how 5000km + (and still going) is somehow unacceptable tyre wear?

And since when is it a crazy 'room 101' idea for a group of guys to put together a system that clearly works so well for them in their locality?
It's not wet everywhere in the World fellas - even though it's just another wet Tuesday here in the UK.

Like I said in my opening message 'not for everyone' - why has it become so personal to you guys? Such seriousness and 'nay saying' about so little, can't be healthy.
No ones trying to change the World (or even discount your collective experiences) - it's just an interesting (if obscure) little thread about a fun activity that enthusiasts of pedelecs, battery's & little electric motors etc may enjoy reading.
No biggy guys - lighten up perhaps?
Or not.

Ps he also does his 80km rides on it wearing flip-flops - cool. (Literally)

Cue: 'We can't wear flip flops...it's all wrong!' comments next....

... Flip flops are cool I wear sandals all year except in snow.
. A lifetime of 5000km on a single tyre subject to 250w friction drive would be excellent, but is that what is being claimed.? The Kepler post you referred us to does not make that claim. The subsequent posting in italics does but that is unattributed.
One might expect a minimum of half a lifetime on the tyre as it is being required to rub against two surfaces per revolution ... The ground and the friction drive wheel.
Unless the friction drive wheel surface is faster than the tyre surface in contact with it , it cannot impart energy to it. If it does it creates wear. As the tyre comes up to the drive wheel it has to become compressed eg work is done on it, which ultimately becomes heat and lost energy.
Again I make the comment that the motor looks really neat.

 

[Recy]

Post by Kepler from the thread (as stated) - posted previously by Anotherkiwi - dated Thu Dec 08, 2016 3:10 pm on ES:
"In regards to tire wear, this also has been discussed in detail. My current test bike has hit 5000km on the original road tire."
Seems attributed enough to me.

Hope everyone here read the ES thread by the way. Maybe someone could join in to tell them all it isn't working and can't possibly do so in any efficient way....
...as Kepler sails by virtually silently at 30kph from a 50k run in the baking sun on the way to another 5000 test kilometers.
(Yes, we all know it rains here etc)

That's me on this thread for now folks. Got a long train journey tomorrow and then a flight...both of which were once said to be nonsensical, fanciful impractical ideas at one time....by people who didn't get them to work right.

 

[anotherkiwi]

Please use the whole quote...

"In regards to tire wear, this also has been discussed in detail. My current test bike has hit 5000km on the original road tire. This is due to using a smooth metal roller that works perfectly in dry conditions but doesn't work at all in wet conditions."
My underlining.

His drive will work here where it is often wet, you just need to glue 30 grit sandpaper onto the motor from time to time. Don't expect 5000 km from your tyre in that case. The engineering is very good, but the idea has been visited and outside of Melbourne or maybe even Perth it depends too much on the weather. A definite no-no in Brisbane or Darwin especially during monsoon season...

I can now ride barefoot in the summer thanks to my ergon pedals. I find that even with the ergon pedals I kept losing my jandals (sorry I'm from NZ, that is what they are called there) so barefoot is more comfortable. The shoe doesn't slip on the pedal but the foot slips from the shoe.

 

[Woosh]

I am much more impressed by the ultra light kit by gng-electric.

http://www.gngebike.com/ultralight-300w-kit

Incremental progress on well proven technologies.

 

[Deleted member 4366]

I think you're all misjudging this drive unit. You're trying to put in into the context of your own riding, for which it's probably not suitable, but for a light bike and rider in dry conditions, I think it would be a pretty handy tool. If he makes a kit, I'll buy one.

 

[flecc]

for a light bike and rider in dry conditions, I think it would be a pretty handy tool.

I'd agree with that, very much the same application as the Cytronex bikes, but like those, suiting very few.

I still think there's an issue with power and efficiency though, either low power and lowish pressure on the tyre or much higher pressure on the tyre for more normal powers with consequent inefficiency.

Power/pressure/slip has been an efficiency issue even with carborundum rollers, so bound to be much worse with a smooth steel roller.
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[anotherkiwi]

I think you're all misjudging this drive unit. You're trying to put in into the context of your own riding, for which it's probably not suitable, but for a light bike and rider in dry conditions, I think it would be a pretty handy tool. If he makes a kit, I'll buy one.

I think it is a great unit. Good solid design. I did say "niche market" in one of my posts. My argument is against the generalist comment: "at last ALL the problems of x, y or z have been solved" without the "for those situations where it is adapted" qualifier. I would like a bracket that adapts to a trike frame to make it into a reverse gear for trikes and vélomobiles. The hills and weather around here make it useless as is.

 

[Deleted member 4366]

I'd agree with that, very much the same application as the Cytronex bikes, but like those, suiting very few.

I still think there's an issue with power and efficiency though, either low power and lowish pressure on the tyre or much higher pressure on the tyre for more normal powers with consequent inefficiency.

Power/pressure/slip has been an efficiency issue even with carborundum rollers, so bound to be much worse with a smooth steel roller.
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Although the system might not be particularly efficient when it's running, there's a saving when it's not, which would be most of the time. The lighter weight and total lack of resistance when not engaged would be a noticeable advantage. I see it as a device that would help me up the 5 mile climb that I have to do at the end of every ride-out.

 

[flecc]

Although the system might not be particularly efficient when it's running, there's a saving when it's not, which would be most of the time. The lighter weight and total lack of resistance when not engaged would be a noticeable advantage. I see it as a device that would help me up the 5 mile climb that I have to do at the end of every ride-out.

Indeed, that's why I likened it to the Cytronex which is also really a part time system due to it's tiny battery.

In my case almost all rides start with a 4.9 mile climb up the North Downs, which doesn't give me a chance to warm up before climbing.
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[Nealh]

Just read the10 page Kepler thread on ES, a very interesting read and one not to be poo-pooed. He has thought this out as a light weight assist option for a super light bike with a fairly fit rider on board, as he say's his motivation for doing so is out of his love for riding high spec carbon road bikes. A total all up kit weighing less then 2kg inc small battery giving approx 350w of assist power when needed for a sub 9kg bike, enough power from a 7s 2p or 3p pack to give light assist for 50/60miles in dry Melbourne conditions.
Currently no all-in-one kit available just the bb mounting mechanism to fit the small out rc out runner motor on.