Kits

[Steveu]

There seems to be relatively little on this site about the pros and cons of kits or reports of good/bad experiences with kits.

To most newbies, I think the style of electric bikes is generally pretty awful and, as most seem to come in one size only, the idea of converting an existing bike or a bike of one's choice to electric seems attractive.

A to B seems to indicate that the best kits are BionX and Nano (are these limited to small wheel bikes?) and Heinsmann if you're happy with older technology but want reliability.

Reports from those who have tried any of these kits would be very interesting.

Steve

 

[flecc]

Depends whether you have real hills to contend with Steve.

The Heinzmann is by far the most powerful, the Nano comes in various gearings, and if chosen for 15 mph in a 26" wheel, it has moderate power. Geared for higher speeds in larger wheels as Schwinn tried leaves it inadequate.

The UK BionX is 250 watts and rather weak, and it's definitely not a hill climber. Better to do as at least one member has done and buy from the USA, since you'll then get the better 350 watt original version. This is a particularly good time to buy from the States since the dollar is so weak. I just bought a charger from a Utah company which a few months ago would have cost me about £45 and now it only cost £28.
.

 

[JohnInStockie]

Hi Steve

I cant agree enough with what you say. For me, looking at ebikes and thinking, 'looks like a postman or a doctors bike', I didnt realise that I knew so little about bikes and bike design. I was really quite embarrased to consider riding one (if you look at some of my very early posts you will see how concerned I was).

One thing I have learned, bikes in the UK are generally very poor, and knowledge about bike design is very low. In my view, ebike design should differ from normal bike design in some ways, as most that use these bikes use them to pull a much heavier weight than the 'sports' riders do on normal bikes, and because of this, the bikes need to be designed slightly differently otherwise they would fail very quickly.

I for example carry a complete change of clothes, my charger, everything I could possibly need to change a puncture, a towel and full waterproofs with me on every commute, but then I am doing 10.5 miles each way, every single week day.

I think that many of these designs are designed specifically to do a task like this, which no 'normal' bike would be designed to do generally.

John

 

[Jeremy]

I've fitted a Crystalyte 405 hub motor and 48V battery to my recumbent. It works well, but did take a fair bit of work to make a battery box and the thumb throttle ergonomics aren't ideal.

The performance is frankly ridiculous though, so completely over the top that I'm going to take it off and re-think things. The bike will spin the front wheel easily, particularly when pulling off and when I tested the maximum speed on a flat lane I had to close the throttle at 30mph as it was clear that the unit as it stands is much too powerful for the clean aerodynamics of a recumbent.

The other issues with this setup are weight and drag. The hub motor is pretty heavy, particularly on such a light bike, and this does have an effect, even at speed (the front wheel gyroscopic forces are much greater). The drag is a really big disadvantage. With the power off, the motor drag is very noticeable.

Overall, if someone is looking for a conversion that provides a fair bit of power and is very quiet in use, then I'd say this kit is a good option. It does need some minor mechanical skill to fit, mainly associated with making something to hold the batteries, but is generally well engineered. Overall, the Crystalyte kit (less batteries) adds about 7kg to the bike's weight, easily exceeds the legal speed limit in the UK (!) and is relatively cheap at a total cost (less batteries, but including shipping and tax) of about £320 (I bought mine from www.ebikes.ca Homepage of the revolution, whom I would highly recommend).

This price included a complete new front wheel with the hub motor already fitted, a 48V, 35A controller and a thumb throttle. Over £50 of the total cost was shipping, and tax etc was another £45. The wheel and motor cost was just £128.

Jeremy

 

[HarryB]

The Heinzmann is by far the most powerful, the Nano comes in various gearings, and if chosen for 15 mph in a 26" wheel, it has moderate power. Geared for higher speeds in larger wheels as Schwinn tried leaves it inadequate.

To be fair to the Nano motor it is the controller on the Schwinn that is the problem rather than the motor. They put the 190 rpm in the 700c wheel and this would give a top speed of 17-18mph and then used the controller to limit the speed to 15 mph. Unlike the limiter in the Torq it simply doesn't work. Quite why they didn't use the 160rpm version is a mystery but I have heard from Tony Castles that there were issues about its reliability

 

[Jeremy]

As I understand it, the Nano motor is a re-branded TongXin motor from China (specs here: Hangzhou Zhejiang University Tongxin Electricity Company, useful data downloads here: http://www.tongxin.net.cn/en/download.htm).

The major advantages this motor seems to have is light weight, reasonable torque and apparently low drag when powered off. The clever bit is the way it uses a novel roller type planetary reduction drive, rather than noisy gears, although I suspect this hits overall efficiency a bit.

In many ways I wish I'd opted for this motor rather than the much heavier and much more powerful Crystalyte. The hub motor on it's own from TongXin is around £120 plus shipping and tax, I believe, so about the same price as the Crystalyte. You can easily get a suitable 36V controller on Ebay for about £25 (including shipping and tax), so this would be one way to build a lightweight assistance unit at a reasonable cost (it's the way I'm thinking of going after my experiment with the Crystalyte).

Jeremy

 

[flecc]

To be fair to the Nano motor it is the controller on the Schwinn that is the problem rather than the motor. They put the 190 rpm in the 700c wheel and this would give a top speed of 17-18mph and then used the controller to limit the speed to 15 mph. Unlike the limiter in the Torq it simply doesn't work. Quite why they didn't use the 160rpm version is a mystery but I have heard from Tony Castles that there were issues about its reliability

I agree in part, but I didn't want to go into too much detail, mainly wanting to draw attention to the fact that it's a medium power motor and not up to the Heinzmann in that respect.

I'm reluctant to give any praise to it due to it's obvious reliability issues, and I don't think the roller drive is a good idea for a long life. Using it in higher powers and/or torque provokes drive slipping, and if that happens a lot it can be a one way route to complete failure.

The Schwinns should never have been sent to the UK anyway, since they had already been withdrawn by the company in the USA as not being ready for market.
.

 

[Canadian Cadence]

Hi Steve

I have the Bionx 350 on a Marin Mountain bike.
This is a fantastic system that will truly let you ride the bike unassisted. When you add any one of the 4 levels of assist or the throttle(I call it the boost) you really feel the motor helping.
The motor is a large diameter hub that is on the rear wheel with no detectable drag. This helps two ways . First it allows the bike to handle like a regular bike and then it allows less of the assist offered by the rider to be lost as drag or friction.

I really feel that A to B magazine gave a poor report on the 250 a few years ago ( maybe they did not have the bike set up properly?) because the 250's I have used are very good (set up to 20 mph cut out)
The 350 is a much stronger system and really compliments any bike especially the 24 speeds.
I know of 2 manufacturers that are using this system on a premium style e-bike they are selling and it seems to be the system of choice for many of the multi speed folders.
I have used my bike off road in sand and mud with fantastic results. The only problem is tire choice as it is hard to find a tire that will perform on and off road. (I do most of my riding on road)

This is a great system that is installed very easily and has a very professional look and finish when installed. It also lets you keep a bike you like and retain all its riding characteristics......with the extra boost!

 

[Bradwell]

Hi Steve

I have the Bionx 350 on a Marin Mountain bike.
This is a fantastic system that will truly let you ride the bike unassisted. When you add any one of the 4 levels of assist or the throttle(I call it the boost) you really feel the motor helping.
The motor is a large diameter hub that is on the rear wheel with no detectable drag. This helps two ways . First it allows the bike to handle like a regular bike and then it allows less of the assist offered by the rider to be lost as drag or friction.

I really feel that A to B magazine gave a poor report on the 250 a few years ago ( maybe they did not have the bike set up properly?) because the 250's I have used are very good (set up to 20 mph cut out)
The 350 is a much stronger system and really compliments any bike especially the 24 speeds.
I know of 2 manufacturers that are using this system on a premium style e-bike they are selling and it seems to be the system of choice for many of the multi speed folders.
I have used my bike off road in sand and mud with fantastic results. The only problem is tire choice as it is hard to find a tire that will perform on and off road. (I do most of my riding on road)

This is a great system that is installed very easily and has a very professional look and finish when installed. It also lets you keep a bike you like and retain all its riding characteristics......with the extra boost!

Hi Canadian Cadence, any photos of your setup?
P.S. When I lived in St. Johns, Newfoudland, Canadian Tire was my favourite store.

Thanks

 

[flecc]

I really feel that A to B magazine gave a poor report on the 250 a few years ago ( maybe they did not have the bike set up properly?) because the 250's I have used are very good (set up to 20 mph cut out)

Not just A to B, and David Henshaw's many years of cycling experience means he can identify a poorly set up bike more easily than most people. The 250 watt one is a much weaker hill climber than the 350.

Much more recently Velovision cycle magazine tested it in company with two other electric bikes.

Of the BionX tested in a very light, slim tyred and free running Airnimal bike, they reported the 20 mph as you've done, but said lots of pedal effort was needed on steeper hills, though it coped with gentle ones ok.

As I remarked in the first post, much depends on what hills there are to tackle, and the 250 watt BionX wouldn't be on my list for a steep hill area.
.

 

[frank9755]

Interesting that this post came up now as I am about to order a kit today!

I've been doing research over the last few weeks and plan to put something together as none of the off-the-shelf bike options quite fit what I'm looking for. That is a fast, simple, light, visually uncluttered bike for commuting over a relatively flat but long route, where I am able and willing to give significant pedal input. Essentially I am looking for something similar to the T-bike created by Flecc, but equipped for commuting with mudguards and rack.

I've considered Heinzmann, Crystalite and Tongxin (aka Nano) kits. I ruled out Bionx mainly on price but also because I didn’t like the ‘fuel tank’ style battery.

I’m going to fit the kit to a 700c wheel on my existing Marin hybrid to give a bike capable of cruising at or slightly above 20mph, operating at 36v. Initially this will be powered by an SLA battery I have lying around in the garage but, if the concept works, I intend to replace it with a new NiMH. The SLA can be a handy back-up for very long trips, weekends away or emergencies.

From my research, I've come up with the following pros and cons:

Heinzmann
For – proven quality and reliability, powerful, good choice of UK suppliers
Against – heavy, noisier, brushed motor gives peakier torque curve hence may be less efficient so lower range, most expensive, daft-looking batteries (but could get alternative)

Crystalite (406 model)
For – powerful, good reports of quality, relatively inexpensive, good choice of motor options
Against – some rolling resistance (they do have a brushed model apparently has lower resistance but is noisier), range may not be great

Tongxin (36v 260 rpm)
For – very small, quiet and unobtrusive, low rolling resistance, good range, good choice of motor options, cheapest
Against – some reliability issues reported, especially in applications where high torque has been required (or in daft configurations, eg Schwinn). Moderate peak power output (360W, which is higher than my wife's powacycle but much less than the other kits) so would need to be geared for either speed or hill-climbing as motor unlikely to be up to both.

Obviously power and range are the opposite sides of the same coin – a more powerful motor will have a lower range for a given battery. I think the choice between these three comes down to the following:

• For someone who wants the most proven option and prefers the simplicity and back-up of a UK supplier, but doesn’t mind paying a bit more, Heinzmann seems to be the safe bet.
• However if you don’t mind ordering from overseas (ebikes.ca mentioned by Jeremy seems a good option) and are willing to sacrifice the German quality engineering, the (Chinese-made) Crystalite kits seem to offer pretty much everything that Heinzmann does, at a cheaper price and lighter weight.
• Tongxin is a slightlier riskier option given quality/reliability concerns but offers a lower power/longer range alternative for those who don’t mind doing more pedaling, and who value its low impact on the bike (small size, quiet, low rolling resistance).

I won’t say what I’m ordering yet as it may not work and I might have to change things, but I’ll post again when I have made some progress – which may take me a few weeks as things are busy at work right now.

Regards,

Frank

PS I wrote this this morning but not been able to get on the site for a few hours so couldn't post.
Jeremy - particularly interesting to read your experience with a high powered Crystalite and also your comments on Crystalite vs Tongxin, which chimes with what I have picked up elsewhere.

 

[Jeremy]

Frank,

My requirement was pretty narrow - I already have a recumbent, but a muscle injury has stopped me riding it because I can't generate enough "push" to deal with hills (recumbents are not particularly easy hill climbing machines).

I was looking for good hill climbing ability, so after looking around at lots of options (and not getting a reasonably quick response from ANY UK ebike dealers......) I decided on the Crystalyte. It's exactly the right choice if you want lots of power, but I seriously over-estimated just how much power these motors have. I also made the mistake of opting for a 48V battery, on the basis that this would give me better torque (and as a side effect, a higher speed) than a 36V system.

All told, I suspect that the TongXin/Nano may have been a better choice for me, as I am primarily looking for power assistance, as the aim is to get me back on the bike to get fit, not to zoom around at 30+ mph!

I've found ebikes.ca great to deal with and unlike some other sellers it seems that Justin really knows his stuff and has an excellent and supportive approach to dealing with his customers. I wouldn't hesitate to deal with him again. I particularly like their Cycle Analyst system, which plugs directly into the modified Crystalyte controllers they supply and gives a host of extremely useful information.

All told, the kit and aftermarket ebike world is a bit of a minefield. I will persevere with the Crystalyte motor for a while, most probably by looking at adding some form of intelligent control. The throttle input signal is just a 1V to 4V input, so it should be quite easy to make up a simple microcontroller that will look at cadence, road speed and "rider power assistance command" to allow just the level of assistance I need. This won't resolve the weight issue though, so I may find myself looking towards the little TongXin motor.

The Crystalyte "experience" has given me some other ideas though, including the idea of building an enclosed, electrically-assisted, velomobile. This 405 motor would be well suited to this, with it's high torque output.

To illustrate just how much torque these motors can deliver (all the "400" series motors have very similar initial torque curves, it seems) I have compared the torque that I can deliver at the back wheel with that which the motor will deliver. At a standstill, the motor delivers about 55 N-m when run on 48V, whereas in the very lowest gear I can deliver about 15 N-m at the wheel with 170mm cranks. At a more reasonable hill climbing speed, say 10 mph, then my torque will probably drop to about 10 N-m at the wheel (due to gear ratio change), and the motor torque will drop to about 40 N-m. It shouldn't have come as a surprise to me that the motor is as powerful as it is!

Jeremy

 

[Steveu]

thanks for the input

Good to hear all your views.

I live in Oxfordshire so not too many steep hills (and none on my commute to work). I just want to be able to get there reasonably quickly and in not too much of a sweat. But also use my bike on fairly rough and often muddy farm tracks.

Sounds like the choice might be between the BionX 350 and the Heinsmann - although not sure how these compare for power or for speed (electricbikesales also mentions a 500w and 900W (!) version of the heinsmann). They also do their own 250W kit - anyone tried one of these?

Frank - is there a reason why you haven't considered the BionX?

Steve

 

[flecc]

Sounds like the choice might be between the BionX 350 and the Heinsmann - although not sure how these compare for power or for speed (electricbikesales also mentions a 500w and 900W (!) version of the heinsmann).

For me in those circumstances it would be the BionX without doubt. Faster than most Heinzmann versions, longer range, very much quieter and more refined, and also well made. With moderate hills even the 250 watt would be ok, though the original 350 watt is better.

The higher power Heinzmanns can be very greedy, and I remember Kinetics some while ago describing the 900 watt version's range as being a short period of mad fun.

The only negative with the BionX is the high battery replacement price, but that said, it's one of the longest lived of it's type on evidence to date, which cancels out some of the high price.
.

 

[coops]

I've read on endless-sphere that the Bionx Lithium currently uses the 'Konion' (Sony?) make of Li-Mn, which appears to be capable of quite high discharge rate. I couldn't say if its the good quality battery, or good software power control, or both, which gives good longevity for the battery, but it seems as you've said lately that you do have to pay a high price for good quality Li batteries.

Stuart.

 

[frank9755]

Steve,

I didn't consider Bionx because of the poor reviews of the kit that I was aware of. It is also more expensive than other options and, as one of my criteria is that the bike should look unobtrusive, I don't care for the look of the 'fuel tank' battery case.

Why have you ruled out Crystalite? I'd have thought it could do more or less everything Heinzmann could at a lower price and weight.

Frank

 

[frank9755]

Jeremy,

Sounds like you have some interesting plans!

Good luck with your throttle modification ideas. Obviously the quick-fix to the excess speed is to take away one cell to give you 36v, but I am sure that you have thought of that!

In any case it won't do anything about the motor weight problem. To solve that, swapping in a Tongxin would be an obvious answer. However I understand that, where people have had problems with the Tongxin roller drive, it has been in higher torque applications.

Another question is how much lighter would the Tongxin be? Does your 7kg (or 6.61 as per the ebikes.ca site) include the wheel? That could be say 1.5kg of rim + spoke, giving about 5kg for the crystalite motor. Tongxin could save you 2.5kg over that, but the spokes, rim and tyres would still be as heavy, so its only perhaps a one third reduction, not 50%.

Anyway - good luck in your progress!

Regards,

Frank

 

[coops]

Hi Steveu

The 406 motor Jeremy has gives higher rpm than a 407, 408 etc. and run at 48V even in a 20" wheel gives high speed. At 36V in 20" wheel top speed would be more like 23-24mph for an upright, so possibly still rather high for a recumbent if air resistance is much lower.

For an idea of how different crystalyte motors perform with different wheelsizes, voltages, and throttle settings visit the ebikes motor simulator: once you've selected motor & battery type, etc. the red line on the resulting graph gives peak torque speed as its highest point, and the top speed of the motor will be where the red line is equal to the power needed at that speed e.g. very roughly, 15mph = 110-130W, 20mph = 250-300W 25mph = 400-500W 30mph = 600-700W+.

Crystalyte 4xx motors also seem very heavy to me - around 7-8kg each, excluding wheelbuild? Brushless 'geared' motors are much lighter (less than half the weight) and give much better torque at low speed though they seem to be both a bit pricier and less common in kit form - maybe because one can buy a ready-made bike (though probably lower spec, admittedly) for the same price .

Stuart.

 

[Jeremy]

Frank,

The wheel weight saving would be useful, I think, as it's mainly the gyro and inertial effect that I'd like to reduce. I've got a spare 406 rim (which weighs about 0.25kg) and I'd guess that a set of spokes would perhaps weigh around another 0.4kg. The Crystalyte wheel (with tyre) weighs 7kg, so I'd guess that the tyre and tube weighs about 0.4kg.

Switching to the TongXin motor would pretty much halve the wheel weight I reckon My best guess is that the weights would be 2.3kg for the hub, 0.4kg for the spokes, 0.25kg for the rim and 0.4kg for the tyre and tube, making around 3.35kg in total.

I may well reduce the battery voltage to 36V, but first of all I'd like to try and sort out the throttle response. At the moment it's a bit "on/off", which I think is part of the wheel-spin problem. I've no doubt that this wouldn't be a problem on a bigger diameter wheel.

Jeremy

PS: My motor is a 405, not a 406, so has an even higher rpm/volt. The ebike.ca simulator is really useful, but the battery capacity selected (which I think really sets battery internal resistance in the simulator) makes a significant difference to the results it gives, as does the choice between 20A or 35A controller.

 

[Tiberius]

Hi Jeremy,

Presumably the motor mass does not have a great effect on the gyro or the rotational inertia if its all concentrated at the hub. It still has an effect on the whole vehicle linear inertia though.

Nick