Lightweight mid-drive kit for short commute

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
One thing to consider with mid-drive weight is that you're replacing the existing crankset... On folders they usually weigh about 1.5kg... so it's worth considering that the added weight = (weight of middrive - 1.5kg)*

Adding hub motors means adding weight of motor and possibly a heavier wheel too??

Could get lighter crankset with hub motor to remedy that but doesn't seem worth it imho, given added cost, extra wiring, and lack of portability if you want to move to bike with different wheelsize later on.

*Please correct me if I've got this wrong, I'm a newbie too so could be talking rubbish.
The 15 .kg probably doesn’t include the pedal arms, which are square taper. There aren't many light square taper pedal arms compared with Hollowtech type. I would have thought that the first thing aybody would do if they wanted a light ebike is to look at the crankset, seat, seatpost, tyres and stem.

Another consideration using your own argument is the weight of the hub and axle that's included with the hub motor.

The argument about heavy rims and spokes doesn't hold any water. You can use whatever you want with whichever hub motor you buy.

I've done many conversions with both crank and hub motors. For the same performance, hub motor systems always work out lighter, except when using the very high power crank motors, like the BBSHD, but then all the other crank motor disadvantages become a higher concern than the small weight difference.

I reserve judgement on the Gospade crank motor. I cannot believe that its going to be reliable at that weight and with the performance they claim. I can't see how it's going to shed its heat. Someone needs to give one a thorough testing. Maybe that someone is you.

The main point, anyway, is that cranks motors are just not as good as hub motors for commuting. They're less reliable, less dependable, less covenient and more unpleasant.

I keep saying, when people use the argument that a crank motor is easier to fit, why would you want to save an hour of work to condemn yourself to years of less pleasant cycling and give the time back and more when you have to replace all your chains, sprockets and derailleurs?
 
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Woosh

Trade Member
May 19, 2012
20,372
16,875
Southend on Sea
wooshbikes.co.uk
I'd rather buy from you on cyclescheme.co.uk ;) ;):)
you haven't read their 200 pages T&Cs!
on top of this, they charge 15% commission on their voucher.
So their voucher is worth £850 to us.
Green Commute Initiative takes 5% commission.
 

kiersy

Finding my (electric) wheels
Oct 18, 2019
8
0
> The argument about heavy rims and spokes doesn't hold any water. You can use whatever you want with the motor.

Not really, I'm not about to go about chopping up the spokes on carbon rims and insert the motor myself, I'm going to order a wheel and get no choice in the matter.

> Another consideration using your own argument is the weight of the hub and axle that's included with the hub motor.

I thought the weights given when ordering mid-drives included that... I stand corrected.

> I would have thought that the first thing aybody would do if they wanted a light ebike is to look at the crankset, seat, seatpost and stem.

Yeah that's what I was hinting at too... looks like the best thing to do is replace crankset with something lighter and get hub motor (especially if you already have heavy rims anyway).

> Maybe that someone is you.

I'm seriously considering it... It would make my Tern Link D8 bike only 1Kg heavier than it is now with the battery removed.

However, I'm thinking the nicest solution around at the moment for a dahon/tern/brompton is to get the Swytch system coming out in March... as it's only 1.5Kg hub, and super simple... just not that transferable.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,786
The European Union
The 15 .kg probably doesn’t include the pedal arms, which are square taper. There aren't many light square taper pedal arms compared with Hollowtech type. I would have thought that the first thing aybody would do if they wanted a light ebike is to look at the crankset, seat, seatpost, tyres and stem.

Another consideration using your own argument is the weight of the hub and axle that's included with the hub motor.

The argument about heavy rims and spokes doesn't hold any water. You can use whatever you want with whichever hub motor you buy.

I've done many conversions with both crank and hub motors. For the same performance, hub motor systems always work out lighter, except when using the very high power crank motors, like the BBSHD, but then all the other crank motor disadvantages become a higher concern than the small weight difference.

I reserve judgement on the Gospade crank motor. I cannot believe that its going to be reliable at that weight and with the performance they claim. I can't see how it's going to shed its heat. Someone needs to give one a thorough testing. Maybe that someone is you.

The main point, anyway, is that cranks motors are just not as good as hub motors for commuting. They're less reliable, less dependable, less covenient and more unpleasant.

I keep saying, when people use the argument that a crank motor is easier to fit, why would you want to save an hour of work to condemn yourself to years of less pleasant cycling and give the time back and more when you have to replace all your chains, sprockets and derailleurs?
If I was still living in a flat place I would agree with that.

My leisure bike has a hub motor but my commuter has a mid drive to tackle the really steep gradients between my home and everywhere else. There is no way my Mxus XF08 could handle pulling 50+kg trailer loads back from the garden center.

Yes I could replace it with a BFM or Xionda 2 speed but I would have to buy one of those and stick the Mxus back in the parts cupboard. I can only afford to use what I have on hand unfortunately. The Mxus works great on those same gradients in the trike but that isn't a commuter...