Help! 36v 17mah rear wheel conversion

[Hipaul]

Hi, as a long time member I have read with interest the many posts on this forum. The time has arrived for me to convert my wifes and my hybrid mountain bikes. With guidance from this forum and Woosh Bikes I have settled on 36v xf08c rear hub drive with rack mounted 17mah battery. As I need to lift the bikes onto a rack on the car roof I've chosen the lighter 36v version and the rack battery because there's no room on my wife's down tube. We're thinking we only need pedal assistance, i.e no throttle or brake cut outs. I have also been recommended to fit the crank sensor on the left which requires a change of bottom bracket.
I would like to read any good or bad comments anyone has on my choice of kit and supplier. This is my first experience of electric bikes so hopefully I've done my homework correctly but I am keen to hear of anything I may have missed. We intend to use the bikes for light off roading and ultimately the goal of the Transpennine trail.
Thank you.

 

[sjpt]

We've been very happy with the XF07 on the front of our tandem, and the help from Woosh in choosing and fitting. Luckily no help needed since then.

I'd have brake sensors anyway even without throttle; can be awkward if you are doing a slow tricky manoeuvre and the motor kicks in. I'd definitely remove the battery before putting onto a roof rack.

Enjoy.

 

[Nealh]

I always opt for RH PAS mounting as I don't like the LH option.
Have to 100% agree with sjpt remove the battery/s from the bike for safety and to make it a bit lighter.

 

[Hipaul]

I always opt for RH PAS mounting as I don't like the LH option.
Have to 100% agree with sjpt remove the battery/s from the bike for safety and to make it a bit lighter.

As along time contributor to this forum I respect your views Nealh. The reason I chose to go for the left hand fitting pedal assist sensor was from advice given by Woosh. They said if fitted to the right and the chain came off the sensor would take the hit. I would be interested to read your views as it would save me extra work and cash!

 

[Nealh]

If you drop the chain inbound then either derailleur adjustment is wrong or the chain is worn/ damaged and needs replacing, like wise the chain ring is worn and also needs replacing. I bolt my disc either on top of the granny ring or remove it altogether, RHS is also protected from accidental damage and a neater install in my view.
I have no front derailleur or chain keep on my 700c town/commute bike and for the last six years had no issue, it has twin 36/42t chain rings.
End of the day it is down to personal choice though if you look at the majority of hub bikes the PAS is in general on the RHS.

 

[Hipaul]

Thank you for taking the time to respond. I appreciate your views. I agree 100% with removing the batteries before trying to lift the bikes onto the roof rack but I'm wondering if there is such a docking device that I could top the batteries up from the cars 12v system whilst travelling?

 

[Woosh]

you can use the normal charger with an in car inverter when travelling.
The normal 230V charger will draw about 100W from your car battery.

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[Laser Man]

I have bought two of the Woosh XF08C kits : one for my own bike and one for my wife's.
I cannot recommend the kit strongly enough : good quality parts, neat waterproof connectors, detailed instructions and an amazingly good pre- and after-sales service.

The LHS pedal sensor is very small and neat. It is all enclosed so nothing to knock or damage. Well worth the additional trouble of changing the bottom bracket.
My own bike has a RHS sensor (I didn't have any choice as my bike has external crank bearings) : it works fine, but took a lot of messing about to get it right - including laser-cutting special spacers for the magnet disc which isn't something everyone can do.

I strongly recommend fitting brake sensors as there are times that you need to pedal but don't want any motor power : e.g.
* When changing gears while slowing for a junction.
* When maneuvering very slowly round an obstacle.
In these situations taking the time to turn the assist off at the display is not a good option.

 

[Hipaul]

I have bought two of the Woosh XF08C kits : one for my own bike and one for my wife's.
I cannot recommend the kit strongly enough : good quality parts, neat waterproof connectors, detailed instructions and an amazingly good pre- and after-sales service.

The LHS pedal sensor is very small and neat. It is all enclosed so nothing to knock or damage. Well worth the additional trouble of changing the bottom bracket.
My own bike has a RHS sensor (I didn't have any choice as my bike has external crank bearings) : it works fine, but took a lot of messing about to get it right - including laser-cutting special spacers for the magnet disc which isn't something everyone can do.

I strongly recommend fitting brake sensors as there are times that you need to pedal but don't want any motor power : e.g.
* When changing gears while slowing for a junction.
* When maneuvering very slowly round an obstacle.
In these situations taking the time to turn the assist off at the display is not a good option.

I read with interest your choice of kit, Laser Man, and wondered if you went for the same voltage and 250w output as I've shortlisted? I'm assuming SJPT chose the 250w on his tandem as they tend to be mostly road bikes and if the motor handles the weight of two people I feel more assured I'm making the right choice. Please correct me SJPT if I'm wrong!
I now recognise the need for brake cut outs are a must which is no problem on my wifes cable brakes but my bike has hydraulic brakes and my research on these shows a rather clumsy looking set up. Please advise me if you've come across or created a nicer looking system.

 

[sjpt]

I read with interest your choice of kit, Laser Man, and wondered if you went for the same voltage and 250w output as I've shortlisted? I'm assuming SJPT chose the 250w on his tandem as they tend to be mostly road bikes and if the motor handles the weight of two people I feel more assured I'm making the right choice. Please correct me SJPT if I'm wrong!
I now recognise the need for brake cut outs are a must which is no problem on my wifes cable brakes but my bike has hydraulic brakes and my research on these shows a rather clumsy looking set up. Please advise me if you've come across or created a nicer looking system.

The XF07 was weaker than we would ideally have liked for the tandem (as Woosh warned us before we bought), but we couldn't find any stronger legal alternatives on a 700c wheel at the time.

We do need to put in quite a bit of work on steeper hills and still need all our low gears; by the time you have slowed to somewhere around 6mph the power output is quite a bit down.

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Still, suits us really well, and would be really good on a solo (I'm always surprised when I go for a quick ride on it by myself). Almost all on road, some tracks and bridleways,

 

[Laser Man]

Yes - my kits are 250W with 36V 17AH batteries, just like you have been looking at.
At low levels of assist (1 or 2) the 17AH battery is good for 60 miles or more. If you start using assist levels 3 and 4 regularly, this will go down to 30 or 40 miles.

The hydraulic brake sensor kits from Woosh come complete with magnets, but unless you are lucky these are only good for an untidy temporary lash-up to get you going.
I bought tiny high power magnets (ebay) and fixed them to the brake levers with Sugru (mouldable silicon glue stuff) which makes a much neater permanent job.

I have photos of my brake setups on another computer - I will try to find them and post them tomorrow.

PS There is a short write-up of the conversion of my wife's bike here :

Another white bike Wooshed!

Last year I electrifried my old Saracen bike with a Woosh XF08-CST kit. It was a great success, but the bike had always been a bit big for me and with a dodgy knee it was becoming a problem. In the autumn I transferred the kit over to a new white Forme Stag mountain bike and that has been really...

www.pedelecs.co.uk

 

[Hipaul]

I would like to thank everyone who took the time to share with me and the forum their experience and knowledge. I am now in a much more informed position to purchase the right kits for our needs. I just need the supplier to come up with the goods at the right price!
I think without spending a lot of money on the hydraulic brake lever cut outs its a case of adapting suggestions made here to suit my bike. Wish me luck!!

 

[Hipaul]

I am finally in an informed and educated position to buy ebike conversion kits for my wifes and my bikes. The problem now is nobody has stock. The media seems to be suggesting that technology is moving faster than manufacturing meaning when the kits arrive they're already out of date. My question is does anyone know if the Chinese manufacturers supply the complete kits or is the job of creating these kits down to the bike shops including lacing the hub motors into the rims? The latter would be a nightmare for these shops but they would have a huge variety of stock!!

 

[sjpt]

The media seems to be suggesting that technology is moving faster than manufacturing meaning when the kits arrive they're already out of date.

I think that's an exaggeration. There have been advances over the last few years, with motors being smaller and lighter than before for the same power, but not change at that rate. If you look at the likes of Woosh and Yosepower you will see that many of the things they are selling now (if they've got stock) are the same as a couple of years ago.

 

[Hipaul]

I think that's an exaggeration. There have been advances over the last few years, with motors being smaller and lighter than before for the same power, but not change at that rate. If you look at the likes of Woosh and Yosepower you will see that many of the things they are selling now (if they've got stock) are the same as a couple of years ago.

I'm so pleased to hear that as I realise the media can be a little elaborate with the facts!

 

[Nealh]

Mid drives like Bosch,Yamaha etc, have much stayed the same size as has the diy ones some are a bit lighter, more Nm is being claimed but so is the released wattage to allow this but this isn't noted in the specs. The technololy for hub motor' s is moving forward smaller diameter hubs with HT & equal Nm to the larger hubs are appearing, Bafang and Aikema both producing small more powerful hubs, Keyda have a small rear cst hub with internal controller.

It is the design side that is moving forward faster with more integrated components, hidden motors and batteries etc,etc.

 

[sjpt]

It is the design side that is moving forward faster with more integrated components, hidden motors and batteries etc,etc.

Yes. with much greater risks of very high repair costs and very specific batteries that are expensive now and may well be unavailable in a few years time (*). The smallest replaceable unit will soon be the bicycle.

(*) see recent Gtech threads.

 

[RossG]

I came across a web site a while back that did some tests with bike motors using proper lab equipment.
The idea was to check claims manufacturers made for their power output in Nm.
None of the motors actually delivered the power the makers claimed, Bafang - Bosch - Yamaha none of them,
neither did any have the same rpm as claimed and usually it was slower, 45 Nm was often 35Nm & 70 was more like 60.
Manufactures call it tolerance which of course is true of everything, e-bike motors are man-made mass produced objects after all and like us they're not perfect.

 

[Woosh]

torque goes up when the RPM goes down, when the motor stalls, torque is highest but of course, a stalling motor is not useful.
The way that crank motors' torque is measured is also different from hub motors' torque. One RPM at the cranks can correspond between 1.5-4.5 wheels' RPM depending on your gearing.
Therefore, you are justified if you take published torque with a dose scepticism when the manufacturers do not specify at what RPM it was measured.
What is an accurate measurement is the torque at maximum power point (Max-Pout) where you get the voltage, current, RPM and torque on the motor performance chart like this one:

 

[RossG]

Good chart Woosh, I'll hang on to that. I used the term "tolerance" but I suppose a more popular description of difference is "product variation".

In my own game of Photography camera buyers in the US when purchasing an expensive bit of kit buy two, test them both then keep the best performing model, luckily for UK retailers that kind of practice it not seen so much over here. Our consumer rights are very powerful unlike the USA where they can, and do repackage a returned item and sell it as new, not so easy here.