E bike conversion

Electrically assisted bikes, trikes, etc.
densmall
Posts: 20
Joined: 29 Jan 2015, 10:20am

E bike conversion

Postby densmall » 4 Feb 2020, 8:11am

I am going to fit a motor to my bike,can anyone give me there opinion on front versus rear wheel motor,I will be cycling in a very hilly area.Any advice is appreciated.

kwackers
Posts: 14586
Joined: 4 Jun 2008, 9:29pm
Location: Warrington

Re: E bike conversion

Postby kwackers » 4 Feb 2020, 8:35am

If it's "very" hilly, why not mid-drive?
With mid drive you have a full range of gears so hill + wind isn't a problem.

reohn2
Posts: 39293
Joined: 26 Jun 2009, 8:21pm

Re: E bike conversion

Postby reohn2 » 4 Feb 2020, 8:36am

Neither,I'd go for a Bafang mid drive system that replaces the BB,from everything I've read they're better than a hub drive and very reliable.
That said if it has to be a hub drive it'd be a rear wheel hub,if the hills are steep all the weight is on the rear whereas a FWD you could suffer wheel spin on sketchy,wet or gravelly sections,also a FWD is more inclined lose traction on wet roads exiting bends with the bike leaned over on the same kind of sketchy road surfaces.
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I cycle therefore I am.

stodd
Posts: 279
Joined: 6 Jun 2018, 10:24am

Re: E bike conversion

Postby stodd » 4 Feb 2020, 8:48am

Front hub risks losing traction on steep hills, especially if there is anything like loose grit on the surface.
Front hub has the advantage with slipping that the motor is driving one wheel and you are driving the other.
On our tandem there is more weight on the front, so that second point wins out.

Rear hub can limit choice of gears; make sure you get one that is correct freehub or screw-on, or be prepared for a new set of cogs.
Even though most rear hubs are now freehub, a lot of electric rear hubs are still screw-on.
Rear hub puts more stress on the spokes, and is often more awkward to get out with puncture or spoke issues.

Crank drive is a good option for hills as the motor can take advantage of the gearing.
It puts more strain on the drive train though, and can be limited to choice of front chainrings.
Woosh (see below) reckons crank drive is actually the easiest to fit.

Another important decision is cadence sensor (typically with front/rear hubs) or torque sensor (typical with crank drive).
Torque sensor multiplies your effort to give a more natural feel; and is more expensive. Kicks in quicker for hill starts.
Cadence sensor (actually just on/off are you pedalling) allows you to ghost pedal when you are tired,
just keep pedalling but no effort, and the motor still works. Often takes 1/2 pedal turn or more to kick in for hill starts.

Whatever you do, don't go for a cheap powerful direct drive motor; they are very inefficient, very heavy, and chew through battery.

Woosh sell excellent kits and give good pre and after sales support. https://wooshbikes.co.uk/
Give them a ring or an email with your details (weight, fitness, exactly how hilly, expected riding style) and they will give good advice.
A kit from there may be a tad more expensive than buying each part separately but you will know it all works well together,
and that you will have support for any issues. Especially important for a first conversion.

I suggest you post your details (weight, fitness, exactly how hilly, expected riding style) here as well so we can give better advice.
Also try posting at https://www.pedelecs.co.uk/forum/forums ... ussion.42/
which is much more active than here. (some noise from silly posters, but easy enough to filter out).

hemo
Posts: 768
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: E bike conversion

Postby hemo » 4 Feb 2020, 1:50pm

In the main I'm biased towards rear hub as never had any big issued with the ones I own and maintenance is easy to perform if you have to open them for greasing or change a sealed bearing.
I have a BBS01 and it has let me down twice with failed controllers, as Stodd has mentioned there are other after market mid drives.
The Tdsz is believed to be a better option being torque drive like the, (Bosch mid drive, not very reliable as they don't like the wet).
Aikema also make a BBS type copy which has nearly double the internal gearing ratio, so theoretically should be easier to ride unassisted if needed to.

Front hub can cause will slip/spin on wet loose terrain also steering can suffer from torque and feel a bit uncomfy.
Not advisable to fit to ali forks unless they have meaty drops outs, I have fitted one to Rockshok forks and the D/O's cracked /snapped (approx. 1k miles) even with torque arms fitted and others have also had this happen.
The cheaper Suntour 63mm forks were perfect for a front hub with meaty D/O's.
Easier to remove wheel for puncture repair then rear, using Gaadi tubes or one could go TL makes life easier for punctures.

Rear drives better and chain wear is kinder then mid drive, removing a wheel can be a bit more awkward.
Rim often needs dishing for centre alignment, drop outs invariably need some filing to allow the 12 x10 hub axle to sit deep enough to allow the use of the anti rotation washers supplied. Again a torque arm is needed as well to be fitted often the RHS is easiest.
A badly built wheel suffers from broken spokes, 14g are better to use then 13g often used.
Rear hub a little more disguised with cassette and on a lot of bikes a brake rotor.
Rear hub spacing/lining up not to bad to achieve with disc equipped bikes, sort out the spacing/washers on the RHS first then finish with LHS.

Bonzo Banana
Posts: 37
Joined: 5 Feb 2017, 11:58am

Re: E bike conversion

Postby Bonzo Banana » 5 Feb 2020, 12:25pm

I agree with a lot of the points here but feel the direct drive motor hub and front hub option hasn't been fully explained.

Direct drive hub motors are the simplest and strongest, often they have the highest weight capacities and provide the maximum lifespan often 10s of thousands of miles without attention. The front hub option is great for heavier riders as they provide sufficient downward weight to make them perform very well and also as much of the weight is on the rear is a better option. Lastly by fitting the motor hub on the front you can still use a high quality freehub based rear wheel with better gearing on the rear as many entry level motor hubs rely on low quality freewheels rather than use a freehub. This means more limited gearing as freewheels often start at 14T rather than 11T so you have inferior and slower high gearing.

Geared motor hubs can fail quickly with heavier riders as the nylon planetary gears wear out quickly and mid-drive motors are even worse which offer much greater complexity again. However I feel the criticisms are fair in the other comments but they haven't expressed the positives. It's a good option for people who want a more durable ebike even if less efficient especially for heavier riders.

Oldjohnw
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Joined: 16 Oct 2018, 4:23am
Location: Northumberland

Re: E bike conversion

Postby Oldjohnw » 5 Feb 2020, 2:05pm

I am making no recommendation here as I don't have technical knowledge or wider experience.

I added a front hub motor to my hybrid and have done many 1000s of km, including several camping trips in hilly country: Perthshire, Yorkshire, Hadrian's Cycleway. As I have a front suspension fork all my kit is on the back (including battery).

On a couple of occasions when fully loaded and on a gravel surface and a 20% incline I have had wheelspin. Once I fell off. Thereafter I dismounted on such a hill.

Original chain, drive and cassette. I expect I will renew some of these this year.
John

hemo
Posts: 768
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: E bike conversion

Postby hemo » 5 Feb 2020, 4:45pm

Not all geared hubs are freewheel there are many cassette versions.
As to stripping planet gears this is more in the domain of over volting or supplying far to much current, I have yet to damage planet gears with correct use of gearing.
D/D hubs are another game and all illegal as most are 1kw or more, they are wound for continuous faster speeds and not really suite for commute of slow leisure riding, they do have other draw backs like gutless at low speed and hill climbing unless one supplies 30+amps and more then 48v. Unlike a geared hub pretty unbearable to ride unassisted as they have no in built freewheel.

Front hub or mid drive is an option for users who like to use hub gears.
My Bafang CST is currently 5 years old and in excess of 7k miles, no stripped planet gears, though I have replaced a face plate bearing that started to feel rough on rotation.

Bonzo Banana
Posts: 37
Joined: 5 Feb 2017, 11:58am

Re: E bike conversion

Postby Bonzo Banana » 5 Feb 2020, 7:03pm

hemo wrote:Not all geared hubs are freewheel there are many cassette versions.
As to stripping planet gears this is more in the domain of over volting or supplying far to much current, I have yet to damage planet gears with correct use of gearing.
D/D hubs are another game and all illegal as most are 1kw or more, they are wound for continuous faster speeds and not really suite for commute of slow leisure riding, they do have other draw backs like gutless at low speed and hill climbing unless one supplies 30+amps and more then 48v. Unlike a geared hub pretty unbearable to ride unassisted as they have no in built freewheel.

Front hub or mid drive is an option for users who like to use hub gears.
My Bafang CST is currently 5 years old and in excess of 7k miles, no stripped planet gears, though I have replaced a face plate bearing that started to feel rough on rotation.


My point is the entry level products are mainly freewheel based which is a low grade option, often freewheels wobble, they have a weak pawl mechanism compared to freehubs and for heavier riders they are not a great option. For me a freewheel based hub is not a satisfactory engineering quality. The issue with stripping gears is more about heavy riders going up hill. D/D motor hubs can have a 250W option as ever with any ebike system its more about the controller just about any type of motor can take more current be it mid-drive or geared hub it is the controller that governs the power. Yes I'm sure the d/d hub being the largest heaviest type of motor has the capacity to take the most current because geared and mid-drive motors are much smaller more delicate motors but ultimately its the controller that governs how much current the motor gets and many controllers of D/D motor hubs have a 250W mode. As I said previously direct drive hub motors on the front make a lot of sense for heavier riders for reliability and strength and the fact you can use a high quality freehub based drivetrain.

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philg
Posts: 502
Joined: 7 May 2009, 12:13pm
Location: Porlock, Somerset

Re: E bike conversion

Postby philg » 6 Feb 2020, 10:45am

Bonzo Banana wrote:My point is the entry level products are mainly freewheel based which is a low grade option,

I have this on my MTB (with cassette) and despite the low price has behaved faultlessly, there is a similar 700c option.
https://www.yosepower.com/en/product/Hu ... e-110.html
I'm sure there are others but, as I reported in a previous post, the service from this supplier (on another product) has been excellent so I wouldn't look elsewhere personally.

And to answer the OP - I also live in a (very) hilly area (Exmoor) and would advise RWD.

I have a FWD system (Swytchbike) on my Spa Tourer and the loss of traction on the steepest (20%+) sections, especially in wet & leafy winter, causes an almost immediate stop and dismount, sometimes less than gracefull.
Standing on the pedals and leaning over the front causes loss of traction at the back, so that doesn't work either.

For fitter riders able to put more leg power in of course this may not be a problem, it is for me hence RWD for the MTB.

YMMV

Greenbuilder
Posts: 126
Joined: 17 Nov 2012, 6:24pm
Location: Tamar Valley

Re: E bike conversion

Postby Greenbuilder » 7 Feb 2020, 1:32pm

To echo the previous post, go for a rear drive cassette hub. Yosepower are really good suppliers, I have fitted several, all being used in a very hilly part of Cornwall

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SimonCelsa
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Joined: 6 Apr 2011, 10:19pm

Re: E bike conversion

Postby SimonCelsa » 8 Feb 2020, 6:32am

My only experience is with a front hub motor on a tandem. Conversion kit provided from 'Woosh' (cannot fault - excellent service)

Around 1200 miles and 18 months so far without any problems. I occasionally ascend a short, steep, damp, leaf strewn pathway close to home and as yet have not suffered any loss of traction (marathon plus tyres) - oops, that's blown it!

Fitted with pedal assist sensors & throttle, although I never use the 'throttle only' mode except to test it is still functional every few weeks or so.

No regrets with the purchase, as mentioned upstream it has transformed my tandem into an 'all wheel drive' machine.

hemo
Posts: 768
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: E bike conversion

Postby hemo » 8 Feb 2020, 12:39pm

Yose kits are cheap and use KT (Kuenteng) controller kits, the kits are custom kits but look basically the same as other vendors.
The hub I'm 100% sure whether it is a custom Bafang hub or another hub copy.

The kit's from Yose have had some issues in use and can only think it is the KT side of the kit having issues.
I have the hub in bike working faultless using KT stuff from a different supplier with out issue.

The advantage of buying from Woosh is they are UK based and know their kits inside out and dealing with them is very good, that said Yose don't appear t ignore their customers but the toing and froing with them takes a bit longer.

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philg
Posts: 502
Joined: 7 May 2009, 12:13pm
Location: Porlock, Somerset

Re: E bike conversion

Postby philg » 11 Feb 2020, 8:32am

hemo wrote:Yose kits are cheap and use KT (Kuenteng) controller kits,

Mine are certainly KT kit but looking at their latest products they now seem to be supplying Lishui - is this an up or down-grade?
The display looks like an improvement over the previous KT-LCD3

reohn2
Posts: 39293
Joined: 26 Jun 2009, 8:21pm

Re: E bike conversion

Postby reohn2 » 11 Feb 2020, 8:49am

I know nothing about the Yosepower kit but in their specs linked to by Philig they claim 30Nm torque,whilst Bafang mid drive claim 80Nm, Bosch and other big names are all claiming 70Nm+
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I cycle therefore I am.