36 or 48 volts?

[Hobble]

Have been considering a Bafang BBS01 or 02 and a suitable battery for a commuter bicycle.

Aside from the legal point which would mandate going for the BBS01-250 it's not clear to me whether I should go for a 36v or 48v setup when building from ground up without any existing parts.

The bike is a Boardman MX hybrid with 700c tyres. My commute would be around 25 miles return (13 miles each way actually) and my home is at approx. 90 meters higher elevation compared to the work. There are series of uphill and downhill sections in between depending on which route I choose to take. I used to cycle several times a week for a while a few years ago but gave up due to the distance imo. being too much on regular basis especially when it's windy. However, have been looking into the pedelec option for a few years now and I think it would help me to stick on the bike.

The initial thought was BBS02-500 or 750 with a 11.6Ah/48v bottle battery but would I be better off getting a 350 or 500W BBS01 and 15Ah/36V battery instead considering the distance I need to cover daily? I would probably want to put some input and pedal in semi enthusiastic manner. At the same time I would not be shy to use the assistance for headwind and hilly parts. What kind of range you think I could expect with the 48v vs. 36v option? I guess I could charge at work doubling my distance if I got a spare charger.

And, in general, is 48v the way to go on a new build with no legacy parts whatsoever? I'm a bit afraid that 750w motor would provide too much torque for the bike to handle and result in wear and tear so thinking that 500w would be a good compromise for a bit of a go vs. longevity not to mention the range.

 

[dbar]

Having both a 36v 500w and a 48v 750w I find the 36v one is more than adequate for most of the time. The 750w one only comes into it's own in difficult off-road situations.

 

[trex]

your commute is practically flat - even the legal BBS01 36V 15A 250W is enough to hit 23-24mph on 700C wheels. The BBS02 48V 25A 750W is overkill - unless you need 28mph.

 

[1boris]

Imo the new 750w bbs 48v with the new infenion controller is perfect.I would not go for anything less.You dont have too use all the power if you think it is to much.Thats much better than being dissapointed with the lack of power of the of the 250/350 w.The are very slow on hills imo

 

[Nealh]

I use Oxydrive on my Boardman CX with MX forks 250w 36v battery good for 45 miles, BBS01 350 36v on my mtb can do similar mileage with a mix of on and off road. Probably boils down to what speed you wan to achieve. If you want a legal kit that can be de - restricted at will to top 28mph then go for GSM from Woosh run it at 36 or 48v, I managed 29.4 on flat terrain with GSM on 26" wheeled knobbly mtb. 750w is imho overkill for road use hilly off road may be but if you want to still feel like your riding the bike for some exercise benefit then 250 or 350 BBS or go for a torque sensor bb with a hub drive.

 

[Hobble]

OK, thanks for the feedback all. 750w/48v sounds like it would be overkill then for my commute apart from a thumbs up from 1boris. I think I'll go for the 500w/36v just so that I have a bit more oomph for my amusement. Hopefully that combo will result in similar range to Nealh. 36v models have a less torque than 48 ones which should be good for the battery range, right, if lots of assistance is used.

My bike has a 48 tooth front ring so will need to order one of those. It's a SRAM Via Centro 20 speed so will be a 10 speed with a 12-36t cassette. As mentioned in the intro section I'll probably put on a few miles on my bike without motor to get a feel of it and will order the kit early 2016.

Thanks again.

 

[danielrlee]

OK, thanks for the feedback all. 750w/48v sounds like it would be overkill then for my commute apart from a thumbs up from 1boris. I think I'll go for the 500w/36v just so that I have a bit more oomph for my amusement. Hopefully that combo will result in similar range to Nealh. 36v models have a less torque than 48 ones which should be good for the battery range, right, if lots of assistance is used.

My bike has a 48 tooth front ring so will need to order one of those. It's a SRAM Via Centro 20 speed so will be a 10 speed with a 12-36t cassette. As mentioned in the intro section I'll probably put on a few miles on my bike without motor to get a feel of it and will order the kit early 2016.

Thanks again.

Not sure I get your logic here. If you aren't going the fully legal 250W route, why not go the whole hog and opt for 750W/48V? You can run it with the power dialed down, but you still have the option of more oomph when you really need it.

 

[Hobble]

I'm thinking that the increased torque from 750W motor might stress the drivetrain components a bit too much but what do I know.

Is there is any difference in expected range between the 36 and 48 volt models if you keep the average speed the same on a battery with the same number of cells? Will a quality 12Ah/48V bottle battery pack be able keep me going for 26 miles even on a windy day?

 

[Nealh]

The 750 can draw 25a and the 500 20a so range will be affected if the kit is used to its max, the 250 or 350 will still be better overall for range with the 15ah battery. 48v kit is built for v. high torque and speed if you max out the speed then the system will use more ah but should be good for 26 miles on the road.

 

[Cyclezee]

IMHO, if you are going for powerful kit it would better to go for a hub motor and have no worries about gearing.

Hmm, does that sound a bit like D8veh

 

[trex]

I suspect half of the members who have BBS02 bought them for speed. They are as capable as S-pedelecs without the price.

 

[1boris]

If you not go for legal 250wJust go for the 48v 750w.you Are not gonna regret it i belive.gearing is not a problem