serious Commute -is it even possible

Jimmeee

Finding my (electric) wheels
Sep 14, 2018
8
0
63
Traditional advice is to try and split the commute over 2 days. Take the bike to work in the car then ride home, do the opposite the next day.
:) I had considered this but what I think I'm going to do is drive part of the way, park up and cycle the rest of the way. Then reverse it.
The motorcycle/scooter suggestion was tempting too but i do love to cycle and although it would save costs on fuel, buying a motorcycle would wipe out any financial benefits
 

dwvl

Pedelecer
Aug 24, 2018
66
20
54
Essex, UK
Depending on the actual gradient of the hills, you could very well manage to keep around 15mph uphill with something like a Bosch CX
I'm an e-bike newbie, and I don't understand statements like this - could you explain to me please?

The implication is that a crank-drive motor is better than a hub motor at 15mph uphill on-road riding. But both are legally limited to 250W of power. Are you saying that the hub motor wouldn't be delivering 250W at 15mph uphill? Or that the crank motor would be delivering more than 250W at 15mph uphill? Or that the hub motor is somehow less efficient at 15mph (despite it not being affected by any drivetrain losses)?

I'm genuinely interested where you're coming from...
 

Woosh

Trade Member
May 19, 2012
19,407
16,387
Southend on Sea
wooshbikes.co.uk
But both are legally limited to 250W of power.
that figure is nominal, the guaranteed power that the motor won't overheat.
If you ride on a flat road at 15mph without much headwind, the energy required is about 200W, if you pedal a bit, say you contribute 70W through pedaling, the motor would supply about 130W. There is no way you would need all that 250W on a flat road without headwind.
The 15.5mph speed limit for assistance is on the other hand a permanent legal requirement. That's one key aspect where there is no fudging. That does not mean you cannot exceed it, going downhill for example, but that's where the motor will cut out. With a lightweight bike and fast rolling tyres, you can easily hit 30mph on a slightly downhill road.
E-bikes are allowed to exceed 250W when climbing hills or going against headwind. Typically, they can reach 500W-800W without breaking any law because it is limited to those bits of difficult roads. So heavy people need more help than lightweight people and that's allowed.
The reason that manufacturers choose different high power limit (500W-800W) is because more power needs bigger and heavier motors and batteries. So if you weigh 13st, you only need a about 500W top whereas someone weighing 25st will need something like 800W power on hills. The maximum power is usually indicated by the Amp rating of the controller, 15A for up to 14st, 17A for up to 20st and 20A for 20-25st.
 

Woosh

Trade Member
May 19, 2012
19,407
16,387
Southend on Sea
wooshbikes.co.uk
The implication is that a crank-drive motor is better than a hub motor at 15mph uphill on-road riding.
I think the forum is evenly divided on which is better.
Crank drive is like an engine fitted with a manual gearbox, you can select the best gear to suit so eke out a little more performance. Overall battery consumption is much more a factor of speed than the type of motor.
 
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Nefarious

Pedelecer
Jul 27, 2016
189
100
South Yorkshire; S11
The implication is that a crank-drive motor is better than a hub motor at 15mph uphill on-road riding.
In my experience, the higher torque MTB crank motors, such as from Bosch and Shimano, are more capable at getting you quickly to 15mph on a steep incline. So your ability to average that speed on the uphill sections is greater if you get there sooner... I have seen riders of other E-bikes show surprise at being able to climb at 15mph
 
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dwvl

Pedelecer
Aug 24, 2018
66
20
54
Essex, UK
E-bikes are allowed to exceed 250W when climbing hills or going against headwind..... The maximum power is usually indicated by the Amp rating of the controller
Thanks for taking the trouble to explain - that is very clear! I haven't bothered reading the legislation; perhaps I should do :eek:

So, I'm happy with the concept that the motor on a "higher-end" eBike may well develop more power transiently than a "low-end" one, while both are rated at "250W" nominal.
 
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Nev

Esteemed Pedelecer
May 1, 2018
1,507
2,520
North Wales
:) I had considered this but what I think I'm going to do is drive part of the way, park up and cycle the rest of the way. Then reverse it.
Seems like a very good idea to me, as you get used to the bike and your cycling fitness improves you could start to lengthen the distance covered on the bike and so reduce the mileage covered in the car.