Lightweight mid-drive kit for short commute

acidic

Just Joined
Jun 17, 2019
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I'm very new to this, still studying. I took a ride on one of the new Uber Jump bikes on Saturday and couldn't stop grinning. It confirmed my idea of converting my hybrid, a Ridgeback Velocity. Gears are 21 speed Shamano Altus, brakes are v-brakes.

It seems to me that I'd be well-suited to a mid-drive kit - it looks simpler to learn about and install, and my use is fairly light - a 3 mile commute 3/w with a single hill. I'm 6'4" and about 78kg.

I have to lug the bike up a flight of steps so I want the lightest possible setup - I imagine that means a fairly small (bottle?) battery with short range which is fine - but are there any lightweight crank conversion kits?

TIA!
 

Woosh

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May 19, 2012
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vfr400

Esteemed Pedelecer
Jun 12, 2011
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You can build a much lighter bike of around 14kg if you start with a light weight road bike. You can get a reasonable one for around £200, then fit a Q100 rear hub motor from BMSbattery, a 15 amp controller from PSWPower and a 20 cell bottle battery from Aliexpress. Change the handlebars to straight ones if you want and get some trigger shifters. The whole lot would cost about £650.
 

acidic

Just Joined
Jun 17, 2019
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acidic

Just Joined
Jun 17, 2019
3
0
You can build a much lighter bike of around 14kg if you start with a light weight road bike. You can get a reasonable one for around £200, then fit a Q100 rear hub motor from BMSbattery, a 15 amp controller from PSWPower and a 20 cell bottle battery from Aliexpress. Change the handlebars to straight ones if you want and get some trigger shifters. The whole lot would cost about £650.
Thanks. Yes I appreciate I could go that way, but I'm looking for a simple intro and it looks like it would involve more decisions that I would have to figure out.
 

Woosh

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May 19, 2012
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How's the reliability on the Gospade, compared to more mature units?
I don't know. I only have it for a few months. It is a new model (the first model is about 2 year old) and needs another 2 years for people to report problems.
The Bafang BBS01B and Tongsheng TSDZ2 (3.9kgs) are very reliable. Both have clocked up tens of thousands users, BBS01 hundreds of thousands.
 

Woosh

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May 19, 2012
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How much is the Gospade going to cost and when will it be on sale from?
the Gospade costs the same as the 48V TSDZ2, from woosh, £339. They were originally booked for July but the Pound is so weak at the moment, it's been postponed to September. You can get one from Aliexpress if you want to try.
 

Forty45

Finding my (electric) wheels
May 1, 2019
17
4
Hampshire
Thanks. Not on AliExpress, but are on Alibaba
the Gospade costs the same as the 48V TSDZ2, from woosh, £339. They were originally booked for July but the Pound is so weak at the moment, it's been postponed to September. You can get one from Aliexpress if you want to try.
Thanks. I'll wait for you to have them. I prefer your reputation for support if needed.
Will you have the full kit and battery range as on Gospade's site?
 

Woosh

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May 19, 2012
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Thanks. Not on AliExpress, but are on Alibaba


Thanks. I'll wait for you to have them. I prefer your reputation for support if needed.
Will you have the full kit and battery range as on Gospade's site?
You can use any 36V battery with the gospade. Their small bottle battery (YLBA-03) is only 36V 10AH and quite expensive.
For the same money, you can have the 36V 13AH small frog or HL battery.
http://wooshbikes.co.uk/2019/battery/smallfrog.jpg
http://wooshbikes.co.uk/2019/battery/smallfrog2.jpg
The motor Gospade makes for me has higher torque setting than their advertised model.
 

Nealh

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Aug 7, 2014
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Any updates Tony on the Gospade availability ?
 

Woosh

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the success of the TSDZ2 is the cause of the delay.
 

Forty45

Finding my (electric) wheels
May 1, 2019
17
4
Hampshire
Tony, any ideas what the price might be? I made an enquiry on Alibaba and got this;
"The Unit price (250W) : USD285/unit FOB Shenzhen, China The price includes the mid emotor, internal controller, crank arms, display, 44T chainwheel, extention wire, sensors, cable to conenct battery and instllation spanner. For 10ah Samsung cell battery,the price is USD265/pc. And the shipping cost to UK. is USD130 including duty. Currently we offer 5% discount for Alibaba Expo if the order is made in Sept. Pls send me your bike picture so as to check if our motor can be installed on your bike"

I assume this the 80 Nm, not 100 you will supply. Also the electronic gear shift shown in pictures is not listed (but I assume you need an electronic derailleur for that anyway).
So $285+130 = $415=£338 less 5%.
Don't know if the battery quoted for is a bottle, but $265 = £216 less 5%.
 

Woosh

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May 19, 2012
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I assume this the 80 Nm, not 100 you will supply.
you can always ask them if they can sell you their high torque version.
 

Woosh

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May 19, 2012
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Also the electronic gear shift shown in pictures is not listed
the magnet disc has 120 points, it's very quick to start and stop.
You don't really need a gearshift sensor and the kit does not have a socket for it anyway.
Wiring is very simple, just connect the battery and LCD.
 

Forty45

Finding my (electric) wheels
May 1, 2019
17
4
Hampshire
you can always ask them if they can sell you their high torque version.
Right, I've asked and it's gone quiet.....

I do like the look of a bottle battery as opposed to the Little Frog on the seat post, so if a good battery isn't available at this time I probably wait before buying.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
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Mid motors are hard on batteries, you need one that can provide lots of current very quickly. That limits your choices.

I agree with vfr400, if you want a light weight system hub motor is the way to go. Unfortunately all the major road bike manufacturers agree too...
 

kiersy

Finding my (electric) wheels
Oct 18, 2019
8
0
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.
 

kiersy

Finding my (electric) wheels
Oct 18, 2019
8
0
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.
 

Woosh

Trade Member
May 19, 2012
19,406
16,387
Southend on Sea
wooshbikes.co.uk
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 lightest crank drive kits I tested is the Gospade: 2.64kgs.

You can buy it on aliexpress.