Juicy bikes kit/Bafang 350/500 watt motor, faster than 250?

[Scottyf]

http://www.pedelecs.co.uk/forum/electric-bicycles/8240-bpm-kit-build-thread.html

Theres a link you may find interesting.
I did a similar thing by getting a 350w rear motor with a 20mph @ 36v nominal - increasing the controller size and then keepnig the same battery.

I'm probably pushing my 9amp hr battery. I then got board and took it all off and now ride without any electrics as I built up my strength. I also had to get used to the extra weight over the rear as it unsettled the balance of the bike (Previous motor was front wheel drive and also alot easier to fit).

Battery on rack and rear motor thats powerful makes for a flighty front end.

Then I made a rear back pack battery so I carried the weight of the battery and done away with the rear rack saving 1.5kg.

Now looking into RC Lipo to make a 5amp hr pack to make an ultra light build.

 

[BATFINK]

That's all useful info again from Frank, Scotty and NRG, appreciated. I cycled 26 miles today at full throttle helping me most of the time but I was also pedalling really hard most of the time and moved my average speed up to about 14/15mph( stopping at bridges, huge muddy areas negotiates slowly and slowing down when people were passing). It usually takes me around 2 hours 20 mins by pedal power alone and I am pretty fit having done martial arts since I was a small kid. Anyways I did the 26 miles in around 1hour 45/50 mins but I ran out of battery power at 22miles and had the steepest hill to climb at the end after the battery ran out (its all flat upto that point)and was hard with all the weight in the bike. Realistically I need to go a little faster and around 10 miles further.
Requirements of travel:
Minimum of 30 miles at an average speed of 18/20mph minimum
Reminder of current setup:
36volt 10amp(cut off is derestricted) with bafang 250watt motor
Having read your recommendations on how to go faster etc what do you as a more experienced rider recommend I actually do? Buy the 350 or a 500 watt motor? Upgrade my battery or buy a spare to carry based on my range. Are all the batteries in sale from different company's interchangeable?
Thanks a lot from a noob

 

[BATFINK]

Just about to read your BPM kit build thread too. Thanks.

 

[b0331e]

I went down this route. But you could just put a booster pack onto your original battery and keep the motor and controller. This will give more speed. Similar range and similar hill climbing ability.

Thanks Scottf
Can you supply some leads or where to research more information on booster packs or similar tweaks?

 

[JuicyBike]

Hey guys I just fitted my bike with a juicy bikes 250 watt kit, bafang front drive motor and 36volt 10amp battery. it is derestricted for off road use. I currently get around 15mph without pedalling. If I upgraded my motor to a 350 watt motor, would I get more speed derestricted and what would the implications be on my range. Anybody have any experience with this kit? Would I need a different controller for the 350 watt kit or could I just swap the motor and use my current controller and battery.

Hi Batfink
When did you buy your kit? Our latest kits are proving themselves very well and customers are very happy with speed and range.

 

[Scottyf]

to be honest when its come down to leads and things as I no longer drive I've had to source alot locally. Which isn't to bad given that I will in Birmingham city center and there is a Maplin's 20 min walk away. (Which is also opposite an evans cycle shop which is handy too).

I've ended up using 10amp guage wire with Anderson power pole connectors. Or torberry connectors for quick release connections.

You can make a booster pack by using another battery. However its wise to use diodes on connecting batteries in series (Which increases volts) using the same chemistry and "C" rating as well as similar amp hr capacity other wise you run the risk of draining one battery before the other and thus damaging cells.

Easiest way would be to buy a larger battery in all honesty. Espcially if your not very well versed with electrical connections etc... I'm fast learning since being on this forum as well as RC forums and endless sphere.

Problem is with increasing speed you will need more battery power. You need more volts to get to a higherr speed, you get more drag from wind etc... going faster will shorten your range.

Be a bit more sparce with your riding technique and you should be able to get a larger range. I only ever used mine on starts, uphills and if I felt like I needed a slight boost in speed and that way I was able to regularly hit 2amp hrs to complete a 9mile commute.


In your case though if you can't stop using the throttle i'd suggest a larger battery as the one you seem to have currently is not fulfilling your requirment. Maybe a 48v 15amp hr will be plenty and is quite a large battery, or have two independant batteries. who knows there's so much you can do but for your requirments that looks like the answer. That way you can keep the motor and increase the top speed with the volts and range with the increase in amp hrs. (You'd probably need a new controller due to the increase in volts with the low voltage cut off and high voltage cut outs).


Ps you can use any battery so long as it meets the controller requirements (Volts) but different manufactures will use different fittings. So long as you have a DC live and negative your on to a winner.

 

[BATFINK]

thanks Scotty, I did another blast today 26 miles and was pedalling like a maniac! Also spotted a plum tree on my road and blagged a few on the go. (i think they were plums coz they were similar to cherrys to be honest, when uve no water with you anything will do) Anyways the battery lasted as I did around the first 10 miles as fast as I could with 90% pedal power. But thanks for the recommendations. The bike I have converted is really a test bed to figure out all my highly issues before I am happy with my setup to put it on a decent bike. Bigger battery with more amps and controller will be my first purchase to see the difference then if needed il get a slight faster motor 350/500 watts.

 

[BATFINK]

juicy bikes - I called you the other day with a query about speed, I bought the kit second hand and it is performing perfectly so far, I've probably did around 150 miles on it already in only a few days and it is great it's just I need more range and more power. typical human being, although at least I'm not driving the car to work sometimes and doing a little bit to save the environment and have a clear conscience. I would highly recommend the 250watt juicy bike kit to 99% of users, it's just my needs are a little more than the average user with planning to commute 30 miles at an average speed of 18/20mph.

 

[BATFINK]

Oh and I read your thread back to front about ur build, great stuff. When I do my next build I will document it for any readers to help.

 

[Scottyf]

Please beaware electric bikes and kits are addictive. Annoyingly so. That's why I stopped for a little while!
If it's just speed your after I would seriously consider a higher wind motor. Maybe juicy bikes could offer you a faster rpm wind motor. Is one that's for a 16inch wheel. That way at least you would get to know the result without having to wait 6 weeks for it to arrive from china!

 

[JuicyBike]

juicy bikes - I called you the other day with a query about speed, I bought the kit second hand and it is performing perfectly so far, I've probably did around 150 miles on it already in only a few days and it is great it's just I need more range and more power. typical human being, although at least I'm not driving the car to work sometimes and doing a little bit to save the environment and have a clear conscience. I would highly recommend the 250watt juicy bike kit to 99% of users, it's just my needs are a little more than the average user with planning to commute 30 miles at an average speed of 18/20mph.

I think I know the kit - over 2 1/2 years old now. Great to hear it's still performing as it should. Maybe increasing the chain wheel size would have a decent improvement on speed and range, without too many pounds being spent. And you may notice an improvement in your own fitness level begin to kick-in soon, though as you say, you're keeping fit anyway. But some new muscles will be in use with increased cycling...

I can not suggest that a 36 Volt 20" motor laced into a 26" would solve the issues you have - it would not be within the law to ride such a bike on the road, I could not offer any warranty for such use and anyway, you could buy it from our website without explaining what you intended doing with it for a mere £105 (add an email note explaining you want the 20" motor).

 

[Scottyf]

You won't get much more of an honest and better offer as the above. Least not uk based.

Decisions yours though but that's going to be the fastest cheapest method to get more speed. You will loose torque but it would be a straight 5 min swap!
No connection swaps and if your not happy then you can start looking at higher amp contolleds and larger batteries.

 

[BATFINK]

Scott: will this really take only a few minutes, wouldn't I need bicycle mechanic to change all the spokes over?
At juicy: that motor may just be the ticket, just 2 small questions regarding install and brakes
1., would this have to be spoked into the wheel I have already or can I use it with any wheel? I.e. Get the spokes laced into it at a bike shop?
2. Is this compatible with disc brakes?
Thanks

 

[Scottyf]

Motor will be compatible with disks. Least all modern motors have the disk option built with them.

If you buy the motor only they yes you would need to get it spoked in. Unless it comes pre built. In which case it would be a 5 min job

 

[JuicyBike]

Hi BF
You would need to get it laced into your 26" wheel. The only 20" motors we sell that are pre-built, are laced into 20" wheels, though we do sell motors on their own, to use as you wish (warranted only when used as direct replacements for originals, of course). They are compatible with disks.

I still think it would be worth replacing the front chain wheel to see if that solves your problem for just a few pounds.

 

[BATFINK]

thanks Juicy I have ordered the item you suggested today. My names Alex so you will know which order. Also when you say changing the front chain wheel, what is the "front chain wheel" do you mean fit a larger wheel on my front sprocket? The one attached to the front pedals?

 

[mike killay]

I have to add that I am not too keen on e-bikes that can exceed the 15 mph limit.
Look what has happened in China.
I ride a lot on bike paths which also have pedestrians on them. If too many people start speeding on e-bikes, then the law will clamp down. At its simplest, it will be a ban on e-bikes using footpaths/trails etc because many are owned by County Councils, they can do what they like with them.

 

[BATFINK]

Hello Mike, I'm not being cheeky but they have built cars than can easily go 4 times the legal limit in built up areas for years, why? Nobody knows the answer I guess but nobody drives at that sort of speed all the time as you would need to be some sort of lunatic, it is the sensible use of speed that matters. used responsibly there is no problems. As a side note I have travelled more than 20 miles without passing a single soul when out on a deserted path and I always cut out power long before I get near anybody.

 

[JuicyBike]

Hi Alex - Yes, the pedal sprocket could be cheaply exchanged for a larger one to make use of your leg-power and increase speed that way. I hope you find the motor does its job. I'm sure we'll get to hear how it works out. Cheers, Bob

 

[BATFINK]

Cheers Bob, thanks again