electric road bike... or not worth it?

[cwah]

Hello all,

I discovered for the first time how cycling a proper road bike felt tonight with this new 10kg cboardman road bike:

It accelerate fast compared to ANY of my other bikes. The thin 700cc road tyres makes it fast and smooth on the road. I can cruise easily at 15mph.. or more. 20mph is not out of range (but I start to sweat).

I've always been wondering why all these human powered bike where so quick compared to my ebike.. now I (partially understand): Thin tyres + lightweight makes ALL the difference.

It was easy to do 7 miles to go home... With an unpowered ebike I would have been crying...


Of course, this bike doesn't have yet all the required equipment:
- Kryptonite lock : +2kg
- Light front/rear + gps holder : +0.5kg

And now... I'm wondering what I should do:
- Get a Keyde motor: +1.3kg (no torque arm required)
- Get a Q100H motor: +2kg (torque arm required)
- Mount my spare BBS02 750W: +4.5kg (no torque arm required). That would be a great bonus as I would be able to easily change tyre on flat and be able to use gears.

And add a 48V10AH battery: + 2.5 kg

So with the motor and wiring, it would add between 5 kg to 7.5kg to the bike, for a total of about 16 to 18kg. But somehow, I'm almost wondering if I shall just leave it as is.

10 kg bike is a breeze to pedal...


Any thoughts/inputs?

 

[Kinninvie]

Why not keep it as it is for the flat stuff and use your BBS bike for hilly/distance rides.
I have my BBS for hills and trails and my Dillenger for flatter stuff to the south of here and also a Raliegh standard MTB for when I feel fit enough to do some real pedal work(not very often yet!)..

 

[Geebee]

If you went with a BBS01 (3.7 kg) and a 5 ah 36v battery (1.2 kg) minus front derailleur, shifter and cable, front crank and BB (1 kg).
So 10 kg bike minus 1 kg plus 4.9 kg so just under 14 kg all up.
Would still be a very nice ride un-assisted but with pedalling and that weight 5 ah would give you a good range under power.
Hard decision

 

[trex]

the choice is down to average speed.
cwah, try the Woosh zephyr-B - that bike is made for riding around in London.

 

[cwah]

Most of my journeys are flat and not too long....

But sometime I'm really lazy to pedal, and sometime there are long slopes in london....


I'm heading toward the q100h for its weight..... 4.5kg more is half of the bike weight!

 

[trex]

the make and break thing about e-bike is handling. Putting the battery inside the frame solves that problem most elegantly. Until now, 3400mAH cells were very expensive. Not now, so you can pack 360WH inside the frame with ease. The rest is to do with the choice of tyres, crankset and derailleur. With e-bikes, you have the biggest choice of tyres because you are not limited to fast rolling tyres. You can choose puncture proof, safety and comfort. The crankset is often a compromise in any bike, the e-bike lets you use larger chainring. Try an e-bike with 62T, you'll see my point. Lastly, the derailleur is easy to upgrade, for that slick gear change that you get with quality bikes.

 

[Geebee]

Most of my journeys are flat and not too long....

But sometime I'm really lazy to pedal, and sometime there are long slopes in london....


I'm heading toward the q100h for its weight..... 4.5kg more is half of the bike weight!

After you take off the existing cranks etc. a BBS01 will be about 2.7 kg all up a Q100 will be 2kg plus controller so not a great difference, but the crank drive will climb better and go faster and handle a lot better.
Plus you can keep the light weight free spinning wheels with QRs etc.

 

[Kinninvie]

And you already have the BBS

 

[grldtnr]

to hell with all that! just keep it as it is and enjoy the experience of being at one with an ordinary cycle.

sometimes less is more!

 

[jerrysimon]

the make and break thing about e-bike is handling. Putting the battery inside the frame solves that problem most elegantly. Until now, 3400mAH cells were very expensive. Not now, so you can pack 360WH inside the frame with ease. The rest is to do with the choice of tyres, crankset and derailleur. With e-bikes, you have the biggest choice of tyres because you are not limited to fast rolling tyres. You can choose puncture proof, safety and comfort. The crankset is often a compromise in any bike, the e-bike lets you use larger chainring. Try an e-bike with 62T, you'll see my point. Lastly, the derailleur is easy to upgrade, for that slick gear change that you get with quality bikes.

So what are these 3400mAh cells ? I have been using 1500mAh Sony/Konion cells for my DIY small battery builds that dont require a BMS. I guess these would need a BMS

Jerry

 

[mfj197]

Ah, cwah, you have been enlightened! You're right - a road bike is a great deal of fun. I've been using a road bike unassisted for my commute for the last 5 years and it works very well - I do 19 miles per day with no problems, sometimes going the whole way of 44 miles per day. Incidentally you don't need narrow tyres - you need the right tyres. There's been some good research recently indicating wider tyres actually have less rolling resistance, all other things being equal, as they are deformed less when rolling (see Schwalbe's information here for example). Wider tyres do have more air resistance and take more effort to spin up as they are heavier, but put a pair of 37mm Vittoria Hypers on the bike and it will fly and be comfortable.

I'm in a very similar quandary. I'm looking to buy another bike, slightly more upright and which will take wider tyres than my roadie (which has 25mm - I could possibly squeeze 28 but no bigger) and convert it to electric so that I can do the 44 mile commute day in day out.

I'm not sure a Q100H motor is an option as I believe the forks are aluminium? You might have to go for the Q100CST rear, but then you are stuck with 201rpm (too slow) or 328rpm (too fast) on 36V and 700C wheels. You could overvolt the 201rpm one to 48V and I understand it works well. Or you can go for the BBS01 which is possibly the route I am looking at. Either would keep the feel of the fast bike you have, but yes, keeping weight down is important to maintain the nimble handling.

Michael

 

[cwah]

For clarification? I was considering the q100h 260rpm at 48v

I already have it on one of my bike and having tryied the bbs02, bpm, dd and q100h... the last one does deserve a trophy for its category.

Acceleration is similar to bpm at 48v20A.

It's near silent, cheap and I manage to carry someone on my bike with this motor.

My only fear is to have the clutch down after 3 months (happened to my bpm after 3 months at 2800w peak)

But q100h at 48v20a can easily compete against bpm and bbs02.

 

[mfj197]

As I understand it front hub drives aren't recommended for aluminium forks, even with torque arms. The front forks on the Boardman will be relatively lightweight ones so putting 960W into a Q100h would be rather risky.

Michael

 

[cwah]

No it wouls be a q100h rear 260rpm.

On the rear it would be solid and very stealthy

 

[cwah]

http://www.bmsbattery.com/hub-motor/631-250w350w-q-85100sx-motor-e-bike-kit.html

 

[mfj197]

Ah I see - so you'd lose the cassette rear gears and use a freewheel instead? How well does the indexing on the rear derailleur work if you do that, and where did you get the freewheel from?

 

[cwah]

Yes it works with freewheel and you can just use anyone. I have few spare from cellman and d8veh is also selling them.

I'll still undecided as q100h has benefits of being more stealthy, it has additional redundancy benefits (can work without chain, no need to worry about gears and with controller only add 2.5kg.

I have a spare bbs02 750 with the main benefit is to be able to use bike speeds, change wheels quickly, no torque arms and only 3.5kg if I just replace the bb and remove other things...........


Damn, i need help lol

 

[Geebee]

Thinking about it, if you are healthy and enjoying the bike as is, save yourself the headache and improve your health, leave it as is.

 

[neptune]

I think if a man uses bikes as a main form of transport, he can justify owning more than one bike. Keep the light road bike as it is, and enjoy it when the sun shines and you feel good. Have an electric bike for those other days. I am always looking for broken bikes to fix and pass on. I have five bikes of my own. Lots of room in the garage since the car went.

 

[Geebee]

I think if a man uses bikes as a main form of transport, he can justify owning more than one bike.

I think if a man or woman uses bikes, they can justify owning alot more than one bike.
Fixed it for you