Twin motor, 2 wheel drive

[amigafan2003]

That's good, it just needs the bike's weight added.

Duly noted! Cheers.

I might get a bulk lot made up and flog them on ebay

http://www.ebay.co.uk/itm/TROPHY-ENGRAVING-PLATES-NAME-PLAQUES-ENGRAVED-FREE-/180857936280?pt=UK_SportingGoods_OtherSports&var=&hash=item2a1bf91998#ht_4187wt_1043

 

[Tinker]

Does that mean that all kits are illegal? as I've never seen any labels included. However I recall buying a 750w cyclone years ago with a supply of 259w stickers!

 

[flecc]

And virtually all e-bikes Tinker. The e-bike plating regulation must be one of the most universally ignored laws since the one that required London taxi drivers to carry a bale of hay for their horse.

 

[Deleted member 4366]

Now that I've finished my bike I can give some comments.

Firstly, I think if you want to try two motors, you need to choose your motors carefully. The Cute Q100 has a free-wheel that completely disengages the motor when free-wheeling, so hardly any drag penalty when only using one. The weight of two Q100s is about the same as a BPM, and the two controllers are similar in size and weight as a suitable one for a single larger motor, (although you can get small high-powered controllers), so no disadvantage there.

The main disadvantage is the added complexity and slightly higher cost.

There's a few advantages;

• Less strain on the drop-outs, so you can use high quality forks and frames, which tend to be lighter and weaker in those areas.
• Better weight distibution for good handling and control - especially if you can get the battery in the middle.
• Better traction on slippery surfaces. If you've ridden a powerful ebike, you'll know how important this is.
• The lighter unsprung weight (than a single bigger motor) allows the suspension to work better.
• More controllable power. You don't get the fierceness of a large single motor and you get twice as much hill-climbing ability as a single small one.
• Not proven yet, but I'm reckoning on better efficiency because the motors can work with less throttle.
• Of couse the main advantage is that it makes a good talking point.

 

[Tinker]

Actually I so admire your current build I'm actually dreaming of doing one myself

 

[stesteste]

My bike's got a 250w 36v plate attached, with a "limited to 15.5mph" line for good measure

same here I have a label maker with silver sticker put on 250w /36v
other ebikes only have stickers

bike -alien aurora

 

[Old_Dave]

In preparation for the koshering part of my forthcoming project

I was just about to order some self adhesive silver vinyl stickers with suitable lines of writing.. but just for a laugh I thought I'd do a forum search first, not expecting any results as I didn't think that anyone else would of had a cunning plan.

Just shows how wrong I was

Thanks guys.

 

[cwah]

Today I was on my Brompton on a red light next to a moped. I wanted to start much faster than him.

I've put my throttle to the max to start and I started to wheelie, and when the front wheel came back to the ground it wasn't stable enough and I felt from my bike.

My Brompton front bag has been teared apart but my polycarbonate box protected the battery. I still have pain everywhere. I also have to buy a new jacket as it is completely scratched now.

Hopefully I felt on the right side (haven't been hit by car), I had my helmet and was at low speed.



I believe if I had a 2WD I wouldn't have this stability issue and gyroscopic force would have kept the front wheel straight. I'm also now thinking if it might be too dangerous to have 2 BPM lol

 

[flecc]

Sorry to hear this cwah, it's a problem with folders that the rider weight is much more to the rear than with larger bikes. That, together with the acceleration advantage with a small rear wheel means large wheelies occur very easily.

The moral? Don't take part in traffic light Grand Prix events!

 

[hech]

Cwah you are such a dick. This is exactly what everyone warned you about and what you promised not to do. Did you think you wernt attracting enough attention with your flashing lights and ridiculous umbrella. The cops will come and get you and after that they will look for others. Your looking at the wrong end of 20 years if you hit someone, the same if you burn your house down when your battery pack catches fire.

 

[hech]

Sorry mate, that was uncalled for, just look out for yourself that's all, we enjoy your posts too much.

 

[Old_Dave]

If your going to try it again, then remember to shift your weight over the front wheel lol



Sent from my iPhone using Tapatalk

 

[Scimitar]

Today I was on my Brompton on a red light next to a moped. I wanted to start much faster than him.

I've put my throttle to the max to start and I started to wheelie, and when the front wheel came back to the ground it wasn't stable enough and I felt from my bike.

To make it worse, I bet the scooter rider was laughing his nuts off as he rode away.

 

[cwah]

lol. If only I had a 2WD I'm sure I'd have beaten the scooter and some motorbike!!

But my Mac seems to make strange pinch noise with high RPM on 16" wheel. Will try a bit longer the mac to see if geared motor works fine with small wheels.

 

[hech]

cwah your such a dick, lol !

 

[Geebee]

Now that I've finished my bike I can give some comments.

Firstly, I think if you want to try two motors, you need to choose your motors carefully. The Cute Q100 has a free-wheel that completely disengages the motor when free-wheeling, so hardly any drag penalty when only using one. The weight of two Q100s is about the same as a BPM, and the two controllers are similar in size and weight as a suitable one for a single larger motor, (although you can get small high-powered controllers), so no disadvantage there.

The main disadvantage is the added complexity and slightly higher cost.

There's a few advantages;

• Less strain on the drop-outs, so you can use high quality forks and frames, which tend to be lighter and weaker in those areas.
• Better weight distibution for good handling and control - especially if you can get the battery in the middle.
• Better traction on slippery surfaces. If you've ridden a powerful ebike, you'll know how important this is.
• The lighter unsprung weight (than a single bigger motor) allows the suspension to work better.
• More controllable power. You don't get the fierceness of a large single motor and you get twice as much hill-climbing ability as a single small one.
• Not proven yet, but I'm reckoning on better efficiency because the motors can work with less throttle.
• Of couse the main advantage is that it makes a good talking point.

I suspect your efficiency will be slightly lower due to two lots of losses on motor efficiency, good fun though.

 

[Deleted member 4366]

I suspect your efficiency will be slightly lower due to two lots of losses on motor efficiency, good fun though.

It doesn't work out like that. I'm getting much better range with two motors than one.

Small motors spend a lot of time at full throttle under load, where their efficiency drops to 40 -50%, while two motors will run in the same circumstances at lower throttle under less load with an efficiency of between 60-80%. These gains out-weigh the losses by a significant amount, especially if it's hilly. I managed 40 miles with 8aH. Although that's nothing special, another time I did the same 15miles at the start of that journey, which is mainly flat and slight down-hill on the same bike with mainly only the rear motor and used about 3.5aH.

I think with a larger more powerful motor the difference would be much less - if anything

 

[mike killay]

Can we stop knocking CWAH?
He is a true experimenter and therefore comes across as eccentric, but we need people like this because it is their sort of thinking, and only their sort that leads to advances.

 

[Scimitar]

I'm all for experimentation, but with a modicum of safety in the approach to it. Flatmates, for example, are not expendable guinea pigs.

 

[flecc]

Flatmates, for example, are not expendable guinea pigs.

Many experienced flat sharers would not agree!