Which electric kit?

[airship17]

I could do with some recommendations: I'd like to convert my commuting bike (light 21spd mtb with slicks) to electric, to speed up my commute. I have been looking at the Currie kits but they look a bit previous generation - although available now and not too expensive. I don't want to buy a new bike (already have 2) so a kit would be best. Probably pedelec preferred but please advise.

My commute is around 12-14 miles depending on route, starting at about 120m altitude, descending to sea level and then climbing to 150m - so it's a good workout. I have plenty of cycling experience but not that fit at the moment.
Because of time limitations I currently drive half way then ride (non-electric) the rest, up a cycle track and some road. What I want is to get more speed (esp on the climbs) using electric assist so I can ride the whole way from home in a reasonable time (<60 mins). I can charge at work, so I only need to get there on a charge.
The bike needs to have enough grunt to maintain a decent speed up all the long hills, with me putting in "flat" levels of effort. There are some short nasty climbs (bottom gear) too which slow things right down because they leave you worn out for the following more modest grades. Assistance here would be welcome.

soooo Which motor/kit should I buy....? Or is that not the way to go?

 

[jimmyengland1000]

I used a retro-fit kit myself once but I wouldn't do it again and I wouldn't advise anyone to do it. I used a light 21 speed mountain bike. No matter how good the bike, or how good the kit, they look a bit ramshackle to me. The battery has to sit on a rack, often at one side, so the bike's centre of gravity is high and to one side. The total weight of the bike was a lot heavier than a ready-made electric bike and it was hard work pedalling on a flat battery. It wouldn't sit well on its side stand because of the weight being high and to one side.

Personally, I would never to it again and would always buy a good quality ready-made electric bike. Forget the kit idea, sell you other two bikes and spend about £1000 on a good electric bike, is what I'd say.... well, it's what I did.

 

[airship17]

Thanks for the reply. Surely some of the kits comprise a hub motor and a battery pack, so they don't look much different from a production e-bike? Take your point on the c of g but that's controllable with the format and positioning of the pack. Sadly I need the other bike for other things that I do, although I guess I could retire the commuter (not worth much so not worth selling, plus it's an old friend).
Anyway, if I did buy a production e-bike, which one should it be, given the requirements of my commute?

 

[johnl]

The Bionx Works for Me

My 250W Bionx kit works well. I rode with it on my recumbent bike untill mid December. I bought an old mtn bike for $25.00 at the Denver Police bicycle auction and moved the kit to this bike. We've had a lot of snow recently but I've ridden to work several times on this bike. I did put the battery on the rear rack. The high center of gravity is not a problem when riding the bike. It is a little more of a problem when walking the bike, but you get used to it. I could put the battery inside the main triangle by using the water bottle mount. I didn't do that because I wanted to fix up the rack for use next summer on the recumbent tandem--on the single recumbent I carried the battery in a seat back bag.

Anyway, the kit works well for my commute which starts at an elevation of 5600 ft and ends at an elevation of 6300 ft. I have 1000 ft of climbing and 300 ft of downhill in the ride to work over 6.6 miles. I use the Bionx in pedelec mode and usually only use the minimum assist level. I use the assist on the way in to work and the regeneration mode on the way home. I only use the assist on the big hills. I'm fairly fit and with this pattern of riding I have gone 350 miles without having to use the charger. The battery meter shows full at the end of the day's commute.

 

[Canadian Cadence]

My experience is totally opposite to JimmyEnglands. I find the kit I used better than the production bikes.
The Bionx kit is expensive but well worth it .
1.The console is amazing.
2.The bike handles with no friction and can be ridden with power off.
3. The battery is removed with a turn of the key and is dead centre and low.
4. The system is very light and powerful
5. The regenerative system helps out with braking and some charging.
6. It is rear hub that accommodates up to a 9 gear rear cassette.
7. 4 modes of pedelec assist, 4 modes of regeneration and a throttle.
8. Long distances possible with its energy management system.
9. Uses codes to change the various restrictions on the system.

It makes any bike better. You will not know it is there until you ask for some power . ( the bike handles the same)
This is a system I would recommend to any cyclist that loves the bike they have.
This system is also being used by some ebike producers to power their high end bikes.(Matra and OHM).
I guess you can tell I really like the Bionx system (PL350 watt)

 

[jimmyengland1000]

What does the BionX kit weigh? I used a Heinzmann kit which weighs about 10kg. That plus the weight of the bike put it much heavier than a top end electric bike and the range was nowhere near as good. Don't you think retro-fit kits look exactly that... ie a kit bolted on to a bike, rather than a piece of specialist engineering designed around the concept of it being electric powered?

I'm not sure re regenerative braking. From what I've read, I understood it to be pretty much non-contributory in normal use and not worth the hassle.

Do you have a link to the BionX kit you used? I'd love to have a look at it.

 

[jha07]

You should look into the Crystalyte kit. They are a lot cheaper than the BionX. You don't get as many fancy features like regenerative braking and different levels of assistance. But I find just having throttle control is pretty good.
I bought a Crystalyte 408 motor and a 20A controller. With 35 cell NiMh battery pack, I can reach speeds of 32km/h without pedalling. I don't know how steep the hills are on your commute, but I can maintain 26Km/h on 5% hills. If you want more speed, go with 48V battery, or a faster motor. That's that nice thing with getting individual parts. You can get exactly what you want.

 

[Jeremy]

I, too, think that the DIY option is likely to produce a better result for any given expenditure. It's quite straightforward to install a kit system that is discreet, adds little extra weight and outperforms some ready-made bikes that cost far more.

The key is picking the right kit for your bike and intended use and then taking the time to make the installation as neat as possible. I made a mistake with my first kit, it was both far too heavy and too powerful for my purposes. The second attempt is working out to be much neater, lighter and more discreet in it's appearance. Hopefully I should be able to post some pictures of it soon.

Jeremy

 

[jha07]

What does the BionX kit weigh? I used a Heinzmann kit which weighs about 10kg. That plus the weight of the bike put it much heavier than a top end electric bike and the range was nowhere near as good. Don't you think retro-fit kits look exactly that... ie a kit bolted on to a bike, rather than a piece of specialist engineering designed around the concept of it being electric powered?

I'm not sure re regenerative braking. From what I've read, I understood it to be pretty much non-contributory in normal use and not worth the hassle.

Do you have a link to the BionX kit you used? I'd love to have a look at it.

My bike with the Crystalyte conversion weighs about 55 lbs. I know the BionX has a lighter motor. Maybe 4-5 lbs. I don't think electric bikes can get much lighter than 50 lbs.
As for the look of retro-fit kits, I think my bike looks much better than the ebikes out there. I don't think most people even notice I'm riding an electric bike.

http://img.photobucket.com/albums/v630/jha07/DSC00340.jpg
http://img.photobucket.com/albums/v630/jha07/DSC00345.jpg

 

[johnl]

What does the BionX kit weigh? I used a Heinzmann kit which weighs about 10kg. That plus the weight of the bike put it much heavier than a top end electric bike and the range was nowhere near as good. Don't you think retro-fit kits look exactly that... ie a kit bolted on to a bike, rather than a piece of specialist engineering designed around the concept of it being electric powered?

I'm not sure re regenerative braking. From what I've read, I understood it to be pretty much non-contributory in normal use and not worth the hassle.

Do you have a link to the BionX kit you used? I'd love to have a look at it.

Vélo électrique, fabricant de vélos à assistance électrique, nos vélos électriques se démarquent des fabricants de vélos - BionX is the link to Bionx. The claimed motor weight is 7.7 lbs and the battery weight for the 250W Li-ion is 6.1 lbs. I have probably an extra pound of weight in the custom length long cables (needed to be long enough to support installation on our recumbent tandem). All in all it seems like the kit brought my 31 lb RANS V2 Formula up to 50 lbs. My weight measurement technique is somewhat inexact. I used a bathroom scale with me holding the bike in the air and then subtracted my weight without the bike.

Like someone else noted, once you have the kit on the bike, you hardly notice that it is there when you ride without it turned on. You can instantly cut the weight of the bike by 6 lbs by taking the battery off.

On the recumbent, the kit looks quite nice and unobtrusive. The battery is in my seat bag and most people do not know that the bike has an electronic assist. On the Mtn bike the battery is visible on the rear rack, but it does not look like it was cobbled together.

Here is a link to a picture of the Formula V2 with the Bionx:
'BentRider Online Forums - View Single Post - Electric Assist for Commuting

John

 

[airship17]

Thanks again, chaps. Jeremy, you didn't say which kit you liked?

BTW, what about the Currie kits - does anyone know how good they are? They're certainly reasonably priced, and if the only downside was slightly clunky looks, it wouldn't bother me. Unfortunately the bionx doesn't seem to have a dealer in the UK. Will check out the other options.

Looks like I should have about 350W, and the assistance level control sounds like a good thing. Right now I have the same uphill to work, downhill back profile, but if I start doing the whole thing it's U-shaped, up at both ends...

Rob

 

[Canadian Cadence]

To answer JimmyE my 350 with Li-ion has a combined weight of 15.6 pounds or about 7kg. (6.8lbs. battery and 8.8 for the motor) It is important to remember that you are not just adding this weight to the bike because you are removing the rear rim, bearings and axle. I think the total weight added is slightly over 6kg.
I like this link to the bionx system because it has some other link in it......check out the you tube section on the motor....The Bionx electric motor and battery electric bike conversion kit....Please note that all Canadians do not speak with this accent!!!lol
The regenerative braking does save the brakes and increases your braking power at high speeds.
I sometimes ride the bike in -1 or -2 regenerative mode when cycling with my son.....this way dad gets a work out. You do not get a lot of charging but it does work and is fun to challenge yourself to keep the battery at a certain level. You can coast down hills in -1,-2.-3 or -4 regneration and see the battery start to get more bars of charge....not much coasting at -4 level.
When the brakes are touched the system goes into -4 regeneration.
Most modern aluminum bikes are around 46 lbs with the 350w kit.
The interesting thing is that they say that at level 1 assist (25%) you have negated the weight of the bike (bike weighs nothing). Level 4 assist (300%) or using the throttle ....Hang on.

 

[giguana]

I have made a Crystalyte Kit with a top end mountain bike, 406 motor from ebikes.ca, it isn't as efficient or as beautiful as the bionx technology, 7kg hub +battery, but it can come with a console( the cycle analyst), it's very powerful, you can go up hills 3 times faster, so far so good, having great fun going around the bridleways at 30kph, through masses of mud and puddles and bumps, fantastic stability, just its importance to make a good engineering job with the batteries. if I had the money I would love a go with bionx, it's maybe 1/3rd+ extra. I have written a guide of my experiences with the motor last month.

 

[frank9755]

I, too, think that the DIY option is likely to produce a better result for any given expenditure. It's quite straightforward to install a kit system that is discreet, adds little extra weight and outperforms some ready-made bikes that cost far more.

The key is picking the right kit for your bike and intended use and then taking the time to make the installation as neat as possible. I made a mistake with my first kit, it was both far too heavy and too powerful for my purposes. The second attempt is working out to be much neater, lighter and more discreet in it's appearance. Hopefully I should be able to post some pictures of it soon.

Jeremy

I completely agree with both of Jeremy's points.

I'm also in the middle of installing a kit. After some thought and research, the motor I chose for my specific requirement is a Tongxin. These are very small, light and quiet motors with a good record on lower torque applications. With the kit installed my normal bike is far lighter than any electric I've seen and also looks more discreet.

I'd recommend a Tongxin for someone who has fairly flat terrain and is a reasonably strong cyclist. But your journey might be too demanding so I wouldn't recommend it for you, as users with higher torque needs have reported problems. If I were you the first one I'd consider would be the Suzhou Bafang, discussed in this thread, and used in the original Ezee Torq and Wisper 905se. Then crystalyte (Powerful but I think it may not have great range) and Bionix (good but expensive).

Good luck!

Frank

 

[jimmyengland1000]

The second attempt is working out to be much neater, lighter and more discreet in it's appearance. Hopefully I should be able to post some pictures of it soon.

Jeremy

What sort of kit is it and how much does it weigh?

 

[jimmyengland1000]

The problem with building your own using a kit is that, as one previous post says, one can make a mistake and this is expensive because one then goes back to the drawing board to some degree and this costs more in the end than buying a high-quality production bike in the first place...one with known performance, reliability and used by people who can give a report about it. I certainly found this out myself.

The person who initiated this thread hasn't had an electric bike before, right? And they aren't sure whether to build or buy ready-made? So, to chew over all the motors, kits, battery types, performance figures and opinions of everyone about what's best in kits really is quite a complicated learning curve and financially risky if the bike they make isn't what's required in terms of performance or looks less than ideal.

I personally wish I had not bothered building my own, using the Heinzmann kit. It didn't perform as expected, despite loads of research and talking to Heinzmann in the UK and Germany. Weight was a problem, as was the motor whine etc etc.

 

[frank9755]

Jimmy,

That's a good point however I would add that it is also important to get the right electric bike for your specific needs. They are all different, lots of people get the wrong one first time. At least there are fewer kits to choose from. Getting the wrong bike is a more expensive mistake than a kit. Although there is a better aftermarket in bikes than kits which woudl compensate to an extent.

Jeremy is also using a Tongxin. Motor weighs 2.5kg. Controller is tiny, plus a few wires and, obviously a battery. Starting with an average bike it is relatively easy to get something under 20kg all-in. However, more important than the absolute weight is how it feels. Comparing my Wisper to my 6 year old Marin hybrid that I have put the Tongxin in, the Marin feels so much nicer a bike to ride.

 

[jimmyengland1000]

Jimmy,

Comparing my Wisper to my 6 year old Marin hybrid that I have put the Tongxin in, it feels so much nicer a bike to ride.

Which one do you feel is nicer, Frank?

 

[Jeremy]

My case was rather specific, in that I already have a SWB recumbent bike, but have found that it's a bit of a struggle to ride up hills. I like riding the 'bent, as I find it doesn't give me any back or wrist problems, so wanted to keep it, rather than buy a conventional electric bike. My desire is to improve my fitness level, so I was looking for enough power assistance to solve the hill climb problem, but still have an efficient bike for use on the level. Due to the design of the 'bent, a front wheel drive hub motor was the most logical solution, a pedal drive kit would have been much more difficult to adapt.

My regular commute is quite short, less than a couple of miles each way, but has a couple of hills. I wasn't looking for long range, just enough to get me to work and back, with perhaps an extra journey home at lunch time on occasion. 8 to 10 miles range was probably enough for my purposes.

My first attempt was using a Crystalyte 405 hub motor fitted to the 20" front wheel, 35A controller and 48V battery. This added a lot of weight to the bike, particularly the hub motor, and adversely affected the feel of the bike when riding. The Crystalyte 405 fitted to a 20" rim weighs well over 6kg on it's own. It was also ridiculously powerful, spinning the front wheel was too easy and the top speed on the level was over 25mph, so this was far from being legal. It would climb pretty much any hill with ease though, albeit at the expense of a hefty current draw.

My current rebuild of the bike is with a Tongxin motor, which is a the same motor as the Nano. As Frank has said, this is much less than half the weight of the Crystalyte and uses a very small and light controller. It also uses less bulky cabling, making for a neater installation. I've made up a battery pack using six 12V nickel metal hydride electric model power packs, arranged with schottky diode combiners to give me 36V at 7.4Ah. This pack is also quite light, at under 4kg. It fits discreetly under the rear rack, in the gap between the rack and the rear wheel, as it's only 2" deep and the same width as the gap between the rack stays. I probably have more battery capacity than I need for my range requirements, but I needed to parallel up two strings of batteries to keep the maximum current discharge per cell down, in the hope that this will prolong the life of the pack. At a guess I probably have enough for at least 15 miles or so, may be a bit more.

Total cost for my latest kit has been around £250, with the batteries being the biggest single cost.

Hopefully I should be able to take some photo's soon (when the weather improves a bit!) to show how it's turned out.

Jeremy

 

[jha07]

I was also thinking about getting a recumbent bike. The regular diamond frame bikes are just too painful to ride in my opinion. I ended up getting a Rans "crank forward" bike, which I highly recommend by the way. Not as comfortable as a recumbent, but pretty close. The reason I choose it over a recumbent is because it offered the comfort close to a recumbent without the drawbacks, like being difficult to get started, or going up hills. It also felt much more stable at low speeds.
Anyhow, being as picky as I am on finding the right bike, there really wouldn't have been a prebuilt electric bike that would have satisfied me.