Which Bafang, display & tooth choice?

[timneo]

I've been looking at the 250w or 500w kits on amazon/ebay - they seem to be the same price.

I have a Claude Butler Urban 100 which I'd like to convert. It currently has three gears, the largest being a 48T. The bike is completely unmodified and despite being about 10 years old, still has the little rubber bits on its first set of tyres. Ahem.

There's a lot of choices on these motors, mostly around the tooth and display. It also appears (at least to my eyes) that the 250w and 500w seem to be exactly the same price. Is this just one limited by software and actually it's 500w+?

I'm assuming 48w is better than 36w

Also a bit confused by all the battery choices. More amph = more distance but bigger battery - is there any point in going for a slightly smaller batteries? The longest distance I've ever done on my bike is about 20 miles. My main commute would be closer to 2m each way on a bridleway with only minor hills but I'm looking for low effort.

And it appears a lot of choices on the controller - does it make the blindest bit of difference which I chose?

 

[Gavin]

Hi Timneo, and welcome.

Battery size is the eternal debate. If you go big then you've got range to spare but they weigh more (sometimes a lot more). One thing to allow for is degradation of the battery. If you go for a small one, it might not have the range you need as it gets older.

Regarding 250w Vs 500w, the biggest difference is legality. If you're a "law-abiding citizen" then you need 250w

Good luck with your conversion


Gavin

 

[timneo]

does tooth size matter? I've seen comments of going for 42T for longevity? I'm usually on the mid range sprocket(?) for my peddling.

 

[Gavin]

I'm no Bafang expert so I'm sure someone with more experience will be along shortly.

In simplistic terms though, the smaller the chainwheel = the lower the gearing. And the lower the gearing = the less load on the motor (at the expense of top speed)

 

[timneo]

Not massively interested in a top speed, I find the large chainwheel is a bit too much for me (and feels like I'll bend the pedals off). I think I'll look at my gears and see what the middle gear is and that'd probably do.

Still completely confused about the display systems.

 

[Gavin]

I think I'll look at my gears and see what the middle gear is and that'd probably do.

I'm guessing you've come to the world of conversions because you're a tinkerer. If that's the case then buy a couple of different sized chainrings and maybe a new rear cassette/ freehub and play around until it works for you...

 

[timneo]

I found this, which seems to suggest 44T

 

[Tarka]

I have the DPC14 colour display, it's very easy to use and clear to read. I think I have the 46 tooth sprocket, but it's fine with a 7 speed derallier for both flat road and steep hills.

I would also suggest getting the special spanner as the nuts need to be very firm and the alloy outer nut is easily damaged.

 

[timneo]

C695 looks like it's just a B&W display - I'm assuming apart from being more attractive to thieves, the colour screen doesn't do an awful lot more or offer different functionality? I'm not massively interested in statistics but I've seen there are gear sensors etc? do they have a massive benefit?

 

[Jayfdee]

C695 looks like it's just a B&W display - I'm assuming apart from being more attractive to thieves, the colour screen doesn't do an awful lot more or offer different functionality? I'm not massively interested in statistics but I've seen there are gear sensors etc? do they have a massive benefit?

I have the colour display, it shows the wattage being used as well as all the usual data.
Gear sensor essential in my opinion, although you can soon get used to easing off the pedals,change gear and power up again.