Miles' Project 1 [eMoulton]

[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

[recumpence]

Updates?

Man, I am dying to here how this thing runs!

Matt

[Miles]

Matt,

Had a brief test yesterday.

The new batteries are a huge improvement - much less voltage sag. Unfortunately, I had a bad puncture after 5 mins of fun So, nothing much in the way of data, yet. I'll add the eLogger for the next run. Still conditioning the batteries, though.

[recumpence]

How does it pull? How fast did it go?

Matt

[Miles]

It's designed for hill climbing, top speed is 22mph at this voltage (39V). It pulled up a long 20% gradient with ease. Consumption 12 Wh/mile, so far. Will get some proper data later in the week.

Have you rigged up the eLogger to yours yet, Matt?

[MitchJi]

Hi Miles

Wow that was so worth the wait!! has Randy seen it? hmm very nice indeed, how does it perform? what kind of top speed have you seen, I am guessing its a little less than Randys bike due to the wheel size, I bet its pretty quiet as well? love to see some video of it as well.

Thanks for posting the pictures they are superb and I think detail about the cleanest build on an upright bike that I have seen to date, it looks like an off the shelf bike.
Knoxie

Hi,

I disagree!

It looks much better than almost any off the shelf bike.

It looks much better than every off the shelf Ebike I've seen.

Nice work!