Hello from South Glos

[dithering_idiot]

Hello All,
Thanks for the add on the forum and apologies for long winded first post.
I've been thinking about converting my bike into an ebike for a good while now (hence the username), and thought it about time I asked for some advice from those that know.

A bit about myself. I'm male, about to hit 60. Not super fit but not totally knackered. I'm not a regular (weekly) cyclist but I do enjoy getting out on the bike mainly in the better weather i.e. not windy and not raining. The routes that I tend to ride are not too hilly but there are some long drawn out inclines and a couple of routes have get off and push hills. I would like to try some other routes but some of these have some very long steep hills which I hardly ever managed when I was a nipper and a non smoker, let alone now. When I do get out on the bike I tend to get a bit carried away and ignore the fact that I've got to pedal the same distance back and I do get back knackered. My thinking is that if I had some assistance I could go further and still be able to stand up when I get home. Routes are mostly tarmac but I do like the odd off road excursion as well.
A couple of examples of some of the local hills are;
1: 0.8 mile distance, avg slope 8%, max slope 28%.
2: 0.37 miles distance, avg slope 12.3%, max slope 43.7%.

The bike that I'm looking to convert is a 27.5" Raleigh MTB, 21speed. Rear cassette 7 speed 14/28, front chain ring 48/38/28. It has 160mm cable operated disc brakes though I do have a donor bike (Ladies Pegasus Premio sl, 700c wheels), which has hydraulic disc brakes (180mm dia) of which the rear caliper could be retrofitted to my Raleigh. Can't use the front brake as rear derailleur shifter is combined with front brake lever. It also has the Shimano Alfine 11 rear hub which I had hoped to make use of but reading the comments on here, the 11 speed might not be up to it. Plenty of room in the triangle for a battery.
I am leaning towards a mid drive (bafang) motor but I'm not sure what model. I would like to stay within the legal limit if possible but I'm uncertain if 250w would be enough.
Any advice would be most appreciated.
Cheers All.

 

[soundwave]

the 250w limit is for speeds up to 15.5mph when in realty under this speed the power is way more my bosch bike can pull over 800w when climbing or id never get up anything.

the 750w one turned up can give me a run for my money turned up in the software for max amps but that will mean less range and more speed but you can set it how you like it.

 

[dithering_idiot]

Thanks for reply.
I forgot to say in my post that speed is not a requirement for me, I like to bimble along.
The hills around here are what make it harder for me and I don't know if 250w will do it.

 

[soundwave]

when you go up in motor wattage the controller has more amps so if you got the 750w it will give you more room to play about with it setting wise.

there also easy to service just make sure you get one that has uart programming and not can bus.

 

[Woosh]

Thanks for reply.
I forgot to say in my post that speed is not a requirement for me, I like to bimble along.
The hills around here are what make it harder for me and I don't know if 250w will do it.

don't worry about if 250w will do it.
All it is, you will go up more slowly compared to a more powerful motor.
It's best to stay legal though, a) it's cheaper, b) it stresses less your bike and c) it's lighter.

 

[StuartsProjects]

I would like to stay within the legal limit if possible but I'm uncertain if 250w would be enough.

I converted a 26" Moutain bike to rear hub 250W Bafang motor, the rear gears were 8 speed, 11\28 and 42,32,22 on the front.

The motor was just fine, since I had the gears, I can get up 1:5 hills, not very fast granted, but why would you need to go fast up steep hills in the first place.

The 250W rear hub motor is enough, and is road legal.

You can get more powerful motors but remember your driving license is at risk if your caught.

 

[guerney]

The bike that I'm looking to convert is a 27.5" Raleigh MTB, 21speed. Rear cassette 7 speed 14/28, front chain ring 48/38/28.

I am leaning towards a mid drive (bafang) motor but I'm not sure what model. I would like to stay within the legal limit if possible but I'm uncertain if 250w would be enough.

The BBS01B on my small 20" wheeled folding bike has been towing heavy trailers and my now lighweight self up steep hills all summer (52T>32T). I think you'll find that a 250W BBS01B would be fine, if the bottom bracket is compatible. Some people seem to have had chain-line issues, but not me...

 

[dithering_idiot]

Thanks for your views folks, i'll keep considering my options.
My username says it all. My daughter reckons I might have made my mind up by next spring....

 

[soundwave]

there is a new ebike shop that opened this year that sells bosch branded bikes like cube ect if you wanted to try one of those out but they not cheap!

Gloucester
FIND US
The Electric Bike Shop Gloucester, Dobbies Garden Centre, Bath Road, Gloucester GL10 3DP

The Electric Bike Shop Stores

www.theelectricbikeshop.co.uk

 

[egroover]

A BBS01 250w mid drive will be fine, it'll get you up most hills paired with a front 42t chainwheel and something like a 12-34t rear cassette. A BBS01 250w will peak at over 500w at 15a or you can increase this to 18a which will increase max power to 630w or thereabouts. 80Nm of torque so can match most Bosch/Shimano offerings for grunt

 

[dithering_idiot]

Thanks again for your replies and suggestions folks.
I shall continue to dither and hopefully I will make my mind up hopefully
this year.

 

[dithering_idiot]

Hi Folks,
I'm still undecided as to what conversion to go for so a couple more questions.
With reference to the BBS01B motor, what are the pros and cons of 36v vs 48v motors?
Would one version of them be better for hilly work or would the difference be negligible?
Also, would I be correct in saying that the 48v versions cannot have the current altered
in the programming settings?

 

[Woosh]

what are the pros and cons of 36v vs 48v motors?

The 36V BBS01B is rock solid.
The 48V version gives you about 30% more torque thanks to higher voltage so more suitable if you are heavy (18+st) or have very steep hills.

 

[dithering_idiot]

The 36V BBS01B is rock solid.
The 48V version gives you about 30% more torque thanks to higher voltage so more suitable if you are heavy (18+st) or have very steep hills.

Thanks for the reply, this gives me another option to think about.
Would you know whether the 48v version is programmable?
Thanks.

 

[Woosh]

Thanks for the reply, this gives me another option to think about.
Would you know whether the 48v version is programmable?
Thanks.

You can program more or less any BBS01/02 but beware of the limitations and voiding of your guarantee. The original program that Bafang loaded into the motor is safe and very usable. You can change the number of assist levels through the normal setup screen without needing the programming lead.
Why do you want to reprogram it?

 

[dithering_idiot]

Ref the programming, it will be more to do with pas settings etc, if I was to find the preloaded settings were not to my liking.
I wouldn't be changing any parameters until I'd ridden it for a while to see what the factory settings were like.

 

[guerney]

There's not excessive wallet pain buying a new controller, if needed. I murdered mine (or was it controller-slaughter?) attempting to solder something on about a year ago, but a new one arrived £87 and two weeks later.

The 36V BBS01B is rock solid.

It sure is!

Would one version of them be better for hilly work or would the difference be negligible?

BBS01b: If you get a battery capable of supplying more than the usual 15A continuously, you can legally (I think) get more torque from the motor - I haven't needed to increase amps drawn by the controller, but for heavier bikes or heavier people, I can see how doing so could be useful.

 

[Woosh]

Keep in mind that heat kills the controller and what produces excessive heat is when the motor runs in inefficient conditions such as running the motor on maximum throttle made even worse if in a wrong gear. This is the area where a hub kit is advantageous.

 

[Woosh]

Also, would I be correct in saying that the 48v versions cannot have the current altered

the 48V is better for steep hills thanks to the 30% higher voltage.

Also, would I be correct in saying that the 48v versions cannot have the current altered

You should be very careful with reprogramming if you choose to alter the original program. The BBS01 has less strong magnets compared to the BBS02 and BBSHD. When the magnets are saturated, like when you use the motor at maximum throttle, the excess input current has nowhere else to go than to produce eddie currents in the armature. You litterally turn your motor into an induction hot plate, frying the insulation and the electronics. That is why my 48V BBS01 is limited to 14A. If you have special needs, talk to us, we can reprogram the controller for you.

 

[dithering_idiot]

Thanks for your responses folks, much appreciated.
Will continue to consider the options.