Which Bafang kit?

DBrown67

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Feb 26, 2017
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I bought a Carrera Crossfire bike from Cycle Republic last August and was disappointed when the battery cut out twice on me in the first fortnight of use. So I returned it and got a full refund (fair do's to CR they didn't quibble at all). I then bought a second hand nearly new standard bike (Giant Escape 01 model) and I'm quite happy with it for my relaxed commute.

However I'm now wanting to go further afield and rather than just buy a new bike and sell this I'd like to convert it with a Bafang kit. But which one? I'm considering the 500W kit which I know is not road legal. But the 250W kit wouldn't be strictly road legal as you can alter the max assist speed from 15mph to 25mph on the head unit and I just KNOW that I will do that. ;);)

But what advantages/disadvantages does the 500W motor offer? And is it worth it? Price difference doesn't seem too much. I understand it will put extra stress on the chain etc. but will it run the battery down much faster? I do intend to get the highest AH battery available in the kit. Also the brakes on my Giant Escape are standard rim brakes (not hydraulic) so will they be OK for the conversion?

For the record I was happy with the Crossfire save for the battery cutout which I believe a number of owners experienced. I'd have kept it otherwise but did wish it went a little faster before the assist stopped.
 
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LeighPing

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For the record I was happy with the Crossfire save for the battery cutout which I believe a number of owners experienced. I'd have kept it otherwise but did wish it went a little faster before the assist stopped.
In that case get the 250w kit that'll do the same speed as the 500w. 25 mph is fine on either bike. But when you turn the 250w speed down to street legal, you'll feel better for it being a legal 250w. Just my 2 cents of course. Enjoy. :)

I prefer disc brakes to rim brakes myself.
 

anotherkiwi

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I bought a Carrera Crossfire bike from Cycle Republic last August and was disappointed when the battery cut out twice on me in the first fortnight of use. So I returned it and got a full refund (fair do's to CR they didn't quibble at all). I then bought a second hand nearly new standard bike (Giant Escape 01 model) and I'm quite happy with it for my relaxed commute.

However I'm now wanting to go further afield and rather than just buy a new bike and sell this I'd like to convert it with a Bafang kit. But which one? I'm considering the 500W kit which I know is not road legal. But the 250W kit wouldn't be strictly road legal as you can alter the max assist speed from 15mph to 25mph on the head unit and I just KNOW that I will do that. ;);)

But what advantages/disadvantages does the 500W motor offer? And is it worth it? Price difference doesn't seem too much. I understand it will put extra stress on the chain etc. but will it run the battery down much faster? I do intend to get the highest AH battery available in the kit. Also the brakes on my Giant Escape are standard rim brakes (not hydraulic) so will they be OK for the conversion?

For the record I was happy with the Crossfire save for the battery cutout which I believe a number of owners experienced. I'd have kept it otherwise but did wish it went a little faster before the assist stopped.
BBS01 kit then. Are you heavy? Do you have long steep hills to climb?

It will stress the drive train so you will be changing cassettes and chains more often.

500W will use more Wh than 250W, mathematic...

Your front brake isn't up to the job get a Magura HS11 https://www.bike-discount.de/en/buy/magura-hs11-4-finger-brake-front-706490 I prefer the 2 finger lever but none on sale... Simple swap a 15 minute job.

Get a hidden wire brake sensor when you buy the kit and mount it on your cable rear brake.

Enjoy!
 

STEVEMANFA

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Hi
If you was happy with the power of the crossfire I'd stick with the 250w motor and like you said you can get 25mph out of it.
 
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DBrown67

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Feb 26, 2017
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Just to update... I ended up buying a Bafang a BPM rear hub kit for my Giant Escape. Fitted it today, The included PAS sensor wasn't suitable due to tapered crank shaft (which will be sorted) but that didn't stop me trying it out a couple of miles with throttle only.

Easily more powerful than any bike I test rode from shops. Hill climbing is more than I expected. Not what I'd call "ludicrous mode" but more than acceptable for a daily hack with a few gradients to climb. Gotta keep things sensible and a bit stealthy.
 
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DBrown67

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Feb 26, 2017
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Hi
What power did you go for in the end?
It's a 350W BPM motor. I suppose ebike kits are like cars or whatever. You get some power and always want a bit more. For now I'm quite happy to be able to get up normal road hills with little effort (not very steep off road inclines).

I think my bike will be much improved once I get the correct PAS then I can choose my assist level from the 5 available. Once I've picked that I probably won't change it. For now it climbs all the hills most road inclines fine with no pedalling at all at around 9/10 mph on level 1 assist. But this isn't efficient on the battery of course.

On the flat, no pedalling, with my 95kg weight it tops out around 19/20 mph which is fast enough for me. Changing assist level thru 1-5 makes no difference to top speed, just how fast it gets there I think. No sweat pedalling in suitable a suitable gear up road inclines will be around 12-15 mph I'm hoping once I get the PAS fitted.
 

Nealh

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Each assist level will have a different amp draw ( torque control) as noticed acceleration is noticeably different, it is on inclines and hills that these levels really come in to play.
For most flat/level riding assist level 2 will give the best range for the speed as level 1 can be underwhelming. I see/get 70% more range using level 2 over level 3 assist.
 
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DBrown67

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I'm thinking of swapping out my front derailleur for a single cog so I can just use 1-8 gears. Depends how it rides once I get my sensor fitted. If I'm using the top 4 gears of the middle front cog and the bottom 4 of the largest front cog then I'd look into it. Does this sort of thing occur much?
 

Woosh

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most people don't need triple chainring after the conversion.
I'd simply remove the front gear shifter and declutter the handlebars.
 

Woosh

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The motor assists a lot, when you are on assist, you probably spend most of your time on the highest gear, largest ring, smallest rear cog. If you hit a steep hill, push the throttle lever to flatten it. Much easier than changing gear!
 

anotherkiwi

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I'm thinking of swapping out my front derailleur for a single cog so I can just use 1-8 gears. Depends how it rides once I get my sensor fitted. If I'm using the top 4 gears of the middle front cog and the bottom 4 of the largest front cog then I'd look into it. Does this sort of thing occur much?
If you are in a flat area that works no problem at all. I am going to convert Number Two to a 38 tooth single chainwheel 7 speed 11-32 freewheel setup.

I will experiment with the trike running single 46 tooth front and 8 speed 11-40 rear but will probably need to go to a 10 speed 11-46 cassette in the long run. We have big hills and long climbs. For long distance, high speed I will have a double.
 

Charliefox

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Feb 11, 2015
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It's a 350W BPM motor. I suppose ebike kits are like cars or whatever. You get some power and always want a bit more. For now I'm quite happy to be able to get up normal road hills with little effort (not very steep off road inclines).

I think my bike will be much improved once I get the correct PAS then I can choose my assist level from the 5 available. Once I've picked that I probably won't change it. For now it climbs all the hills most road inclines fine with no pedalling at all at around 9/10 mph on level 1 assist. But this isn't efficient on the battery of course.

On the flat, no pedalling, with my 95kg weight it tops out around 19/20 mph which is fast enough for me. Changing assist level thru 1-5 makes no difference to top speed, just how fast it gets there I think. No sweat pedalling in suitable a suitable gear up road inclines will be around 12-15 mph I'm hoping once I get the PAS fitted.
Thats odd. I gave up on PAS and stuck to the throttle (full size) I can set 3 power levels (speeds really) approx 11mph, 15mph and 19mph. Only use it on hills and long, rough forest tracks. A proper throttle is not just Off/on like a thumb switch.
 

Charliefox

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Feb 11, 2015
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most people don't need triple chainring after the conversion.
I'd simply remove the front gear shifter and declutter the handlebars.
Glad I didn't remove mine when the battery started to fade (little warning with a LiPo4) cos I needed the granny ring to stagger the last mile home as the bike suddenly felt all it's 25kg!
 

DBrown67

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Feb 26, 2017
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I now have a fitted and working PAS and done around 100 miles so far. I've found I use assist level 3 nearly all of the time. I cannot even tell that 1 is working (I'm sure it is though) and I can just about feel level 2. Level 3 is a real boost though. I can really feel the push as I set off from a standstill. Because of this I never really use levels 4 or 5 and only use the throttle to flatten out a few really steep inclines I come across. There's a rough track near me that ends up at around 25% for the last 50 yards. That's the sort of thing I use throttle for so I don't have to drop off the large front cog at all. I won't remove the other cogs though as I'd need the small one if ever the battery dies due to the weight.

I quickly realised the freedom it gave me was making me go further afield and be a bit more adventurous. My current bike wasn't cutting it off road so I bought a new "Cube Aim Race" mountain bike and transferred all the kit over. I made sure to get one with 8 gears on the back as the kit has an 8 gear freewheel. That has helped a lot as the rear wheel was a straight swap and all the gears have remained indexed correctly as it left the shop. The 2.1 inch tyre fitted right across to the motor wheel as well. And this Cube bike didn't need any grinding out of the dropouts either. Motor wheel dropped right in snugly. (I really wanted the 2017 model as I loved that colour scheme but couldn't find it anywhere)

Hydraulic brakes on the new bike are miles better than the old rim brakes. I got the brake sensor switches out of the kit handles and fitted them to the new bike. Took me a while to get the switches perfectly positioned and for the whole thing to not look like a gaffer taped mess :p. But it all works seamlessly and looks almost factory. I did have to buy a 180mm rotor and Shimano adaptor for the back wheel as the caliper doesn't clear the motor body with 160mm rotor.

The result is the ride is so much more comfortable now. That rough track I spoke of earlier is very easy on the new bike. I had to really concentrate where I was pointing the wheel of the older bike and slowed down a lot as a result. Did a 20+ mile return trek down the canal towpath yesterday. Cruising at 10mph alI at level 3 was so effortless. Deffo need a bell fitting though as I realise people do use them a lot on the towpath and MTBs from shops don't supply one.
 
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Deere John

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I had a such before. It is great, loud sound and people react. That's the whole purpose :) but it is not good for bumpy roads, fastening clamp broke on mine.
 

Nealh

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When riding on level/flatish terrain assist 2 is very useful for conserving battery energy and extending range, very helpful for longer rides or a get you home tip. Less power but all the same power albeit at lower amp draw and speed sometimes.
 

anotherkiwi

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Level 1 provides just about enough Watts to move the kit you put on the bike, like riding the bike before you put a kit on. Level 2 things start to get serious on the flat.

Funny thing is as you get fitter you will feel the difference between levels more distinctly, at least that has been my experience.
 
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