Help me plan my conversion

[munchie]

Hi everyone - I'm looking to build an e-bike conversion for commuting. I know I could buy one off the shelf, but where would be the fun in that? Also it's easier to hide a trickle of components from the wife than it is a one off purchase...

My commute is 10 miles each way, on flat roads. There's a fair bit of stop-start at traffic lights, and a few sections where you can get some speed although really 20mph is absolute tops (and it's not a long stretch). So I'm hoping the bike can do 10 miles there, maybe 2-4 miles during the day to get to meetings, and then another 10 miles home. And it would be nice to not have to worry about running out of power - ideally it would have about 50% charge at the end of the day. I weigh 95kg.

I've got a few bikes and want help choosing which one to convert, and with which kit.

Option 1 - Genesis Croix de Fer. Steel road bike with disc brakes, I've already converted it to flat bar and it has 11 speed 1x drivetrain and deep section carbon wheels for no practical reason whatsoever other than looking sweet. I could keep the wheels with a mid-drive, or lose them if I take the hub route.
a) Rear hub - what 700c wheel / battery combo will suit?
b) Mid drive - same?

Option 2 - Scott Racing Comp 26er from 2003. Aluminium frame that I've got steel road forks on and a 700c front wheel, would probably only go down the rear hub route with this one on a 26 inch. It will look a mess but not really bothered. So, what 26er wheel / battery would do the job?

Thanks for your suggestions!

 

[Woosh]

I'd convert the Genesis Croix de fer with XF08C kit:
http://wooshbikes.co.uk/cart/#/product/uid-177-xf08c-17ah/xf08c-rear-hub-kit-with-17ah-battery

The battery is good enough for about 60 miles, much less to worry about charging.
Alternatively, if you enjoy pedalling no matter the weather condition then TSDZ2. The battery is good for 50 miles.
http://wooshbikes.co.uk/cart/#/product/uid-207-tsdz2-12ah/tsdz2-cd-kit-48v-12ah

 

[munchie]

Thanks for the suggestion, looks good - would that also be the case if I got it in 26 inch wheel for the Scott?

 

[sjpt]

You may have difficulty finding a rear hub motor that will work with an 11 speed.
I highly recommend Woosh for kits. You can probably buy the various parts separately and save a little, but ..

• If any come from China direct you are not sure how much VAT/customs duty will be charged.
• If you are not fairly well versed there is a risk of getting bits that don't match in some way.
• The costs above battery+motor add up more than you might think by the time you have a good controller and display.
• You will get excellent support from Woosh both in pre sales suggestions and post sake if you have any issues.

They've got a couple of rear kits with big (17aH) batteries for just under £600, and several crank kits as well.

I see they got in before me to say pretty much the same ....

 

[Woosh]

Thanks for the suggestion, looks good - would that also be the case if I got it in 26 inch wheel for the Scott?

yes.

 

[munchie]

5 questions, Woosh:
- Is the rear rub kit compatible with an 11 speed cassette?
- Is the pedal assist sensor compatible with either Hollowtech II or Octalink?
- Do you include sensors to let me keep my hydraulic brakes?
- Would you recommend a downtube or rear-rack mounted battery if both are possible?
- Is a front hub simpler to convert - or does it give a performance tradeoff vs rear

thank you

 

[Woosh]

- Is the rear rub kit compatible with an 11 speed cassette?

yes.

- Is the pedal assist sensor compatible with either Hollowtech II or Octalink?

Those bottom brackets have external ballbearings, so must have a drilled magnet disc whose drilled hole is wider than the bearings. The sensor is mounted just behind the ballbearings' washers. On some bikes, you may need an extra washer. On some bikes, we supply the sensor mounted on a plastic carrier to be cabletied to the seatpost.
We'll ask you to send us some pictures of the bottom bracket area with the bike upside down to check which version is best suited.

- Do you include sensors to let me keep my hydraulic brakes?

you only need brake sensors if you fit the throttle. The brake sensors are there just in case the throttle gets jammed. We also offer hydraulic brake sensors:
http://wooshbikes.co.uk/cart/#/product/uid-196-hdbs-red/pair-of-hydraulic-brake-sensors-for-hub-kits

- Would you recommend a downtube or rear-rack mounted battery if both are possible?

Downtube solution gives better weight distribution and centre of gravity and is also cheaper, you don't pay for a rack.

- Is a front hub simpler to convert - or does it give a performance tradeoff vs rear

Yes, but there is not much difference in time taken.
You don't have to transfer the old cassette over with a front hub.
Rear hub gives better traction on gravel and wet surfaces.

 

[Benjahmin]

Having ridden front hub for years now I would say this:
If you are riding roads there is almost no issue with front hub. Very steep and mossy/greasy climbs can produce some scrubbing at the front but remedied by leaning over the bars. The occaisional gravel path can be fun.
Front or rear I would keep, if you can, at least one brake cutoff. Low speed manouvering can be a bit jerky say in tight spots, negotiating pedestrians or traffic. Also it's useful for changing down through the gears approaching junctions or traffic lights.

 

[munchie]

Thanks Ben, so really for commuting on flat roads, there's no difference between front and rear?

 

[KirstinS]

Thanks Ben, so really for commuting on flat roads, there's no difference between front and rear?

I commuted for years with a front hub on flat roads. No issues at all.

The biggest difference is in the feel of the bike. Front effectively gives 2wd, one via legs and one via motor

 

[munchie]

Which do you prefer?

 

[vfr400]

Which do you prefer?

Rear motor is a lot better than a front one in all respects. The only reason to fit a front one is that you can't fit a rear one because you have hub-gears or something like that.

It's a bit easier to fit a front motor, but it's also easier to get it dangerously wrong. There's plenty of advice on the forum if you go that route, so make sure that you get all the guidance before fitting. Front motors work with some forks better than others. Ideally, you want steel forks.

The main downside to rear motors is the issue of getting a motor that suits your gear system, and you might have to dish the wheel to suit your frame. Some of the suppliers supply the motor wheels pre-dished.

 

[Benjahmin]

I think that's what did it for me. There's no issues with dishing or disc alignment. I have aluminium suspension forks . Made sure that the motor axle was fully seated into the dropout (bit of filing required but it was easy 'cos it's aluminium), and also fitted a good torque bracket to prevent spinout. Not one of the kind with jubilee clips but one of these:

Torque Arm for e-bike Heavy-Duty 3mm Thick Stainless Steel,14x10mm,electric bike | eBay

EXTRA Heavy Duty version also available manufactured from5mm thick stainless steel.

www.ebay.co.uk

Generally fits to mudguard lugs.

 

[KirstinS]

Which do you prefer?

Rear for most uses. Snow the 2wd was better!

 

[munchie]

So I just rode a Lime E-Bike through London, which seems to have the same motor being suggested here - rear 250w. I actually really like the push from stationary and it seemed to have enough power. However, it quickly ran out of speed and I had to pedal hard beyond a fairly slow cruise.
Is it the bike that is limited, or the motor?
The Lime doesn't have any gears so it may be that adding them makes a big difference too

 

[Woosh]

Which do you prefer?

I ride the Woosh Faro.
It's very lightweight, purrs like a kitten, looks and feels exactly like a 'bike'.
I go to work with it at a small local charity's office 6 months now. Nobody noticed that I cheat!

http://wooshbikes.co.uk/?faro

 

[vfr400]

So I just rode a Lime E-Bike through London, which seems to have the same motor being suggested here - rear 250w. I actually really like the push from stationary and it seemed to have enough power. However, it quickly ran out of speed and I had to pedal hard beyond a fairly slow cruise.
Is it the bike that is limited, or the motor?
The Lime doesn't have any gears so it may be that adding them makes a big difference too

Motors might look the same, but they can be completely different regarding speed and power. Also, the power system (battery) and control system has a massive effect on how the bike behaves. They're all different. You can't go by looks or specifications.

 

[Woosh]

You can't go by looks or specifications.

specifications are a big help.
A direct drive motor does not cost as much as a geared hub or a middle motor.
A large capacity battery costs more than a smaller one, a battery built with Panasonic or Samsung cells cost more than one built with Chinese cells.
At the end of the day, for the same budget, you'll get a better deal if you have a bigger capacity battery and a better motor.

 

[munchie]

So I read that Lime bikes are limited to 15mph - woosh are your conversion kits limited in the same way?

 

[Woosh]

I do not condone breaking the law but legalities aside, the kits are not locked down. You can change settings via the LCD's buttons.
However, mid drive kits can overheat and die without you noticing that the motor is labouring, we void the guarantee if you derestrict a mid drive kit.
Hub kits don't have the same problem.