Recommend a kit/components

I'm based in the UK and looking to get a hub motor (and all the other bits that make it work) for my spare hardtail bike.

I live in a place where there's flat and hills but would still prefer a hub motor rather than BB due to simplicity of fitting and the greater stealth factor.

I'd like to be able to reach speeds of 30mph on the flats from a 26" wheel. I don't need to do 30 mph constantly but would like it for bursts of just a few minutes at a time. Torque is preferred over top speed.

Range needs to be around 30 miles to give me route options.

I'd like to use a thumb throttle but also have the option of PAS too for when in pedestrian town-centre type areas.

This is going to be a fun bike for me as I already have carbon racers and mountain bikes for exercise and hardcore activities. As it's a fun bike I don't want to be spending much on the parts (I have the bike already).

I've been looking at 48v 1000W motors like MXUS 1000W, Crystalyte HT3525, and some of the £160 kits from eBay. The problem is the brand names parts are hard or impossible to find in the UK for reasonable cost. The eBay kits are unbranded and I have no idea what I'm getting.

Does anyone have experience of the eBay kits?

Thanks in advance.

Electricbike Conversions sell complete kits on EBay, I have fitted a couple of their 500watt Hub motors and one 1000watt, - excellent value and good quality, really good after sales as well

www.electricbikeconversions.co.uk

Electricbike Conversions sell complete kits on EBay, I have fitted a couple of their 500watt Hub motors and one 1000watt, - excellent value and good quality, really good after sales as well

www.electricbikeconversions.co.uk

The above statement sounds good but you give no real world facts about the kits capabilities , how do they fair for climbing ability, what speeds are achievable on the flat and on hills. How well do they climb hills, type of hill gradient and range possible. How do they ride unassisted in case the battery runs low.

If you have good quality bikes for riding why would you want to put 6+ kg in your wheel "just for fun"?

A geared 250 W kit will be just as good on hills as a 500 W direct drive (maybe better?). And it will be easy to ride un-powered as Nealh says above. A geared 250 W rear hub motor with a 48 V controller and battery will give you the speed you want while weighing under 3 kg in the wheel.

most 250W motors have 4.5 to 1 reduction, the BPM has 5:1 reduction, the torque on them beat the 500W direct drive by a large factor.

At the same core RPM, same controller, 250W geared is 2.25 times torquier than a 500W DD.

The real benefit of DD motors is reliability. They can easily do 6-7,000 miles without maintenance.

You need 1000w of output power to reach 30 mph on a MTB type bike. You can comfortably sustain about 100w by pedalling. If you're reasonably fit, about 200W. That means that you'll need about 1200w of battery power, which is 30 amps at 36v or 25 amps at 48v. At those sort of currents, your battery will go down very quickly, so you need a big (read heavy) battery. If you're thinking about sustaining 30 mph, you need to look at the stuff from Em3ev.com

http://em3ev.com/store/index.php?route=product/product&product_id=138

If it's only short journeys you do, it should be OK, but think about 10 to 15 miles max from a frame mounted battery.

Cyclotricity do a 1000W kit that a couple of people on this forum reviewed.

You need to bear in mind that bicycles are not designed for 30 mph, except the light weigh ones. If you're going to use a 6kg motor and massive battery, you need wide tyres and hydraulic disc brakes.

Direct drive motors are good for sustaining high speeds, but their efficiency suffers if you do stop-start riding or use them at a speed below their optimum.

To be honest, I don't believe that you'll achieve your aims. An electric bike with a top speed (occasional, not sustained) of 25 mph is realistic. Above that, you need a lot of knowledge to get something that's suitable for every day use.

I don't get the bit about not wanted a crank-drive because you want stealth, then mentioning that you're thinking of a 1000w DD motor. A Bafang BBS02 will do what you describe, and it's a lot stealthier than one of those DD motors.

electricbikeconversion.co.uk told me they don't like the crank-drive motors. They do them when requested but 'wince' because of the many issue that arise eventually. "Too much power" going through there causes breakages and i can't remember the other cited issues.

That was in response to me saying if they (mid-drive motors) weren't so expensive, I'd want one because they're better. They seem to think the hub-wheel motors are better.

I have no personal experience or knowledge of either.

Hub motors are simple and legal ones are cheap. They will do the job for anyone at a low price.

Better hub motors have more complex things like internal gearing and can be more capable. As well as huge speed and hill climbing ability. But the cost rises. Both £ and how big a battery you need.

Mid motor uses the bike gears and a legal one won't eat the drive. But this has a higher £ upfront.

They can be much nicer. And can get good range.

The initial Panasonic crank drive was fantastic against the motors available in 2000's but hub drives have improved lots since then.

electricbikeconversion.co.uk told me they don't like the crank-drive motors. They do them when requested but 'wince' because of the many issue that arise eventually. "Too much power" going through there causes breakages and i can't remember the other cited issues.

That was in response to me saying if they (mid-drive motors) weren't so expensive, I'd want one because they're better. They seem to think the hub-wheel motors are better.

I have no personal experience or knowledge of either.

The problem is often the rider not the motor. If you use the gears correctly, as if you were riding a bicycle for example then you will have no problems. There are many of thousands of kits sold where people don't have problems. Hot-rodding or asking too much from the motor (being in the wrong gear) and you will have problems with heat and/or blowing the internal controllers as well as chewing trough chains and cassettes.

Mid-drives are easier to mount to aluminium frames and you have the advantage of having quick release on both wheels. You keep your rear wheel but can change your gearing to suit the extra power. Or you can go to a hub gearbox with a nice clean chain line. Cheap hubs don't like too much torque but Rohloff can go as high as 250 nm.

Thank you for the responses. It's been helpful to gain more knowledge about the variety of e-bike systems out there.

I don't know whether it's ok to ask here.

I am looking at an e-bike by electricconversions.co.uk - their Camaro 500W rear-hub bike, which from my reading here I understand to be a Direct Drive system. I wanted the extra power to be able to go beyond the limiting 15.5mph and with a 13Ah battery.

A 2nd hand Carrera Crossfire -E has now come up. I'm not sure whether it has a geared hub system, but in theory even at 250W that could serve just as well if not better, if I understood correctly. I'm in town and I am looking for the torque power to assist with the hills of N.London

Thanks again, in advance

The 250 watt motors will exceed 15.5 mph. The limit isn't power but rotation speed. You don't need to go illegal.

Most motors will peak at over 500 W. The north London hills are short and not many maintain 15% if any.

Unless you really want to stand out and beat the Lycra crew stupid, 250 watt is plenty. Even with that I out accelerate most fast bikers from the line and climb better. Then I'm still relaxed enough to cruse quickly.

Thanks D8ve,

I've only tried a couple 250W bikes and found the 15.5mph very restrictive. It felt like 1st gear and I was ready for the 2nd. I don't know who makes these laws but that's another conversation, but regular bicycles easily go faster than 15mph so...

One bike I tried was the Momentum and after the initial surge it not only took me up to it's limit it restricted me from going faster by my own additional efforts, so, my pedalling was merely to allow it to travel at its designed limit, which again, I think is set too low, imho, but it's what matters to me.

Now, up a steep hill 15 mph would be fair and reasonable and I'd be well served by a motor that could reliably haul me up hills at that speed. Highgate Hill? Haverstock Hill? Hampstead? I'd say there are lots of tough climbs in the areas I live and cycle.

Downhill is of course not an issue on any bike, but if on the flat and regulars I can take the bike beyond the 15mph through my own pedalling efforts then that would be fine indeed.

My journey began with looking for bests value on my limited budget with the range being a primary concern. In that respect, Cyclotricity offers a good bike with a 15Ah battery at £800 albeit with a 250 W motor.

I then discovered the above-mentioned company electriconversions.co.uk who did a 500W rear-hub for £700 and so that made sense, even with the compromise of a 13Ah battery, I figured that was overall a better deal.

Now, I see a 2nd hand Carera and in light of what I've read, if its a gear hub instead of Direct Drive it might still work for what I need; it certainly would be less expensive than buying new; I just don't want to falsely economise.

Convert a good bike is the way to go. I cruse on the flat at 17+

Down hill, silly speeds and 6% uphill still get my over 50,s lard up at near 15 mph. Add in quick off the lights and you start to scare the Lycra crew.

There was a cannon dale with rohloff went in London for under £700 on flebay yesterday with a mid drive that would be nice.

on eBay?

I've been searching here and on gumtree and ebay for 2nd hand deals.

The Carrera is on ebay for £600 and he's willing to take an offer. Might go this evening to view

on eBay?

I've been searching here and on gumtree and ebay for 2nd hand deals.

The Carrera is on ebay for £600 and he's willing to take an offer. Might go this evening to view

Test ride as many bikes as you can. You've done some so good and test ride with the power off. This lets you know how hard the the assist has to work as well. Easier the ride the better the range.

Thanks D8ve,

 

I've only tried a couple 250W bikes and found the 15.5mph very restrictive. It felt like 1st gear and I was ready for the 2nd. I don't know who makes these laws but that's another conversation, but regular bicycles easily go faster than 15mph so...

One bike I tried was the Momentum and after the initial surge it not only took me up to it's limit it restricted me from going faster by my own additional efforts, so, my pedalling was merely to allow it to travel at its designed limit, which again, I think is set too low, imho, but it's what matters to me.

A pedelec will go faster than 25 km/h too, if it is correctly geared! I thought about this a whole lot and gearing seems to be the number one issue with going past the cut out "dead spot".

Many bikes seem to be under geared either because they are aiming at "people of a certain age" who don't want to go much faster than legal cut off speed anyway. Or because the owner (me) didn't understand what having +250 W under foot means regarding gearing.

For a 250 W hub motor if you are a fit enough cyclist already I would suggest 50-38 chainwheel on the front and an 11-28 cassette on the back, 7 speed is plenty enough. I have what was given me on the front and the 48 is too low. On the back I bought a 14-34 freewheel thinking it would get me home in case of battery or motor failure. I have used the 34 tooth a couple of times in the mountains or for climbing ramps. d8veh told me I was making a mistake but at the time 11-28 screw on freewheels were as rare as hens teeth so I went ahead with what was available for little €.