Miles' Project 1 [eMoulton]

[Dee Jay]

Big Up to Miles!

Good to see that there are people on ES who care about elegance and class.

J

[Miles]

Hi Matt,

It's just a standard one-way clutch bearing, used as a freewheel substitute. I only made the housing/adapter for it - I'm not as prolific as you

The cranks are freewheeling, using a White Industries ENO 22t freewheel on trials cranks. I had a chainring made especially for it but others have made adapters to standard chainrings. The 22t ENO has handy circumferentially milled weight saving slots that one can use for fixing.... not that it's a problem to drill the fixing holes, with a suitable drill.

So, the one-way bearing isolates the motor drive so that you can pedal as a normal bike, without any extra drag, and the freewheeling cranks decouple the pedals when you use the motor without pedalling. For normal freewheeling, the original freewheel in the hub gear kicks in, of course.

[Miles]

Thanks J!

What we need is a bit more consistency of style...

There are 2 excellent books, for those that care about these things: "The Nature & Aesthetics of Design" and "The Nature & Art of Workmanship", by the artist/industrial designer David Pye.

[recumpence]

Miles,

You have class. Man, I love the superb simplicity and elegence of this design.

Oops, I need to clean the drool off my keyboard! No, wait, that is not drool, it is a tear.

You moved me, Man.

Matt

[Malcolm]

"The Nature & Aesthetics of Design" and "The Nature & Art of Workmanship", by the artist/industrial designer David Pye.

On my holiday reading list!
Cheers
Malcolm

[Miles]

Steady on, Matt

I appreciate the sentiment, coming from you....

Here's one for your reading list:

"The Dancing Chain, History and Development of the Derailleur Bicycle" - Frank Berto. My favourite book on bicycles (despite the title, it covers the development of all bicycle gearing systems and more..).

http://www.thedancingchain.com/

[Tito Tuerca]

One of the cleanest bikes ever. Congrats on your build.

[Miles]

Thanks Tito,

Not having to accommodate the batteries in the frame helps, of course

[HAL9000v2.0]

WOW, great bike, love the drive train....great work Miles...
How this belt sounds on small pulley? Do you hear that high pitch sound?

[Miles]

Thanks Hal,

Very little sound from the drive-train or the motor. If I approach walkers in the park from behind, they never hear me...

The next step is to go for a 10:1 reduction ratio (still single step) with a much lighter motor.

[HAL9000v2.0]

How about to put plastic planetary gearbox inside rear pulley?

[Miles]

How about to put plastic planetary gearbox inside rear pulley?

It's an idea - lot of work, though, and lose another 4% efficiency.... I've already got 0.734 reduction and 1.362 increase in the hub gear.

If I change to 5M belt, I can use 18t to 180t - or, if I keep the power down, 16t to 180t.

[recumpence]

Miles, I pull 6,000 watts though my 5mm pitch belt and it survives fine. However, alot of tension is required to achieve that.

I would say your power output would be fine with 5mm pitch even with only 9mm width. Your efficiency would go up quite a bit that way.

Matt

[Miles]

Hi Matt,

It looks like you have 16t (with 9 or 10 teeth engaged) to 58t for the first stage - is that right?

By my calculations on the above, using the half of no-load speed of your motor at 48V, you are putting over 3 times the torque through that part of the drive than the nominal rating

It seems I can give myself a reasonable safety margin and keep belt the tension as low as possible. Your experience is reassuring to me

[recumpence]

Actually my torque is higher than that. My secondary pulley is 48 tooth.

Matt

[Miles]

Actually my torque is higher than that. My secondary pulley is 48 tooth.

It seems I can't count up to 48 without losing track

[recumpence]

Hmm, 1,2,3,4,5,6,7,8,9,10,11,12,13,14,17,19,24,88

Wow, I lose track at 14!

Matt

[Miles]

Just received my new battery packs - still waiting for the charger....

[recumpence]

No fair, you bought "Racing" packs. Oh, man, now you are going to blow us all away.

Matt

[Miles]

Only if I was to run this motor at 5000 rpm

[recumpence]

OK, now we are talking.

Hmm, that belt will handle over 10,000 RPM...............

Matt

[Miles]

But the maximum speed rating for the motor is 4000 rpm

[recumpence]

But the maximum speed rating for the motor is 4000 rpm

That never stopped me!

Matt

[Miles]

.
.
Just received my charger and power supply from AstroFlight
.
.

[recumpence]

Hmm, looks familiar.

I have that charger and power supply. I use a Hyperion charger for my 12S lipo packs, though.

Man, you and I have too much in common.

Matt