My commute has become a pain. 6.5 miles with 700ft of climb and I have to be there for 7am for a 13 hour shift and I have to carry around 15lbs of stuff with me

So seems perfect for an ebike. I have bought and now fitted the sunstar so3 kit which is a bb mounted motor. Very impressed – pretty easy to fit, and works really well. Seems really well made and has a 2 year guarantee. Its the only retro fit kit with proper torque sensing which makes it intuitive to ride and also works well with the alfine hub I have ( other central kits need to have electricity cut outs for the brakes and gear shift) Its also lighter than many. Unfortunately it wouldn’t fit my genesis IOID as the motor unit clashed on the chainstays so I ended up putting it on a crap MTB frame I got from the bikes station for £20 while I decide what frame to put it on permanently, but I did use everything else from the Genesis in the build so its got nice forks and brakes and so on.

Finally got to try it today. Climbing up to town at 15 mph without much effort is fun. It really flies away from the lights. Its a bit odd when you hit 15 mph tho as its like someone put the brakes on and there is more drivetrain drag when pedalling over 15mph. Builds speed really quickly downhill ‘cos of the extra weight. Adds 18lb to the weight of the bike. only about 1/2 a mile of my commute is flat thos so this really won’t be an issue

Basically It feels like I am a full on Armstrong style doper up to 15 mph then an asthmatic 70 yr old over 15 mph on the flat

I didn’t buy a full bike ‘cos despite the fact you can get a cube with the bosch motor for £1700 its still cheapo components. I wanted to continue to use the alfine. It will also probably go on the tandem for a long ( 3-6 month) European tour so we can have a bit of help in the mountains as we will be carrying full comfy camping kit. BB mounted motors are better than hub motors at low speed which is another reason to go down this route as I have 20 traffic lights on my way to work with half of them being uphill starts

The sunstar kit is £1000 – £1300 depending on which options you pick.

Sounds spot on 🙂

Can’t get a camera to work. Broke my camera, phone thinks its light enough not to need a flash. I’ll try again later. Its on a really crappy frame as well 🙂 This is the kit http://www.sunstaribike.com/e-bike-mid-motor-s03/

I did try derestricting it ( easy to do – just remove the magnet from the wheel thats for speed sensing) I don’t have a speedo on the bike but got up to what I think was over 30 mph on the flat easily. However like the good law abiding citizen I am it will be used in road legal mode ( unless I am late for work 🙂 )

Love to know how you get on with it mounted to the tandem.
I really could see myself having some fun with one mounted up on ours.

Probably won’t do it for a while but I’ll post up when I do

Sorry but I reckon £1000-£1300 for a conversion kit is a bit salty. Half that would be reasonable. I’d have spent a bit more and got a Bosch equipped bike. Whatever the spec of the bike is isn’t really the issue, the longevity of the motor will pay off.

Peter – have you seen one of these kits? No? I thought not. Firstly is a 2 year warranty. Secondly its a very high spec well built kit with ten years of sales behind it. There are no reports on the web of them failing that I could find.

a £600 kit will be rubbish in comparison. The battery alone in this is £450 because it uses high quality cells with a big capacity and has a two year guarantee. Its not a cheap hub conversion – its of similar quality to the bosch

I fancy one for the trike. I don’t need one, but I’ve ridden a power-assisted ICE that PP may have worked on for a disabled rider I know. What a nice thing to ride! Would need derestricting, because I maintain 15 mph on the flat anyway. And 30 mph is about as fast as anyone would want to go on the trike. Above that and one feels like a passenger!

I think the price is justifiable. At £750, it would be good value. At £1000, you have to think more about the quality of the bike you are going to modify, compared with, say, a used Kalkhoff Agattu.

My reasons for using this kit rather than going for say a Bosch equipped cube for a few hundred more are as above – its more versatile, its greener as I recycle parts, I can use a alfine hub and discs which you don’t get without paying a big chunk more on a full bike and that it can go on other bikes including my tandem if I want in the future

Its not like the bafung BB kit – its significantly lighter,its much higher quality, it is the only retro fit with torque sensing and there are no plastic parts in the drivetrain and it has a full two year guarantee including the battery. I did my research and thought about it for a long time because it is expensive. Strong / light / cheap pick any two!

I wouldn’t use a derestricted ebike – I think folk in the UK doing so might well cause e bikes to be banned.

Half that would be reasonable

You can barely buy a decent battery for that.

Still not told me which cheap mid mount motor has non replacable bearings pp.

My nephew did something similar for the same commuting reasons. I would consider it as well. Think he killed his alfine using a bb mounted electric conversion though.

Andy – some of the mid mounts like the bafung do not cut as quickly when you ease off the pedals – so require a cut out switch in the gear cable and this is specific to the alfine without this you risk blowing the hub – another reason I used the sunstar. I hope it will be OK with the alfine. You can get full bike builds with the Bosch motor and alfines so I hope it will be OK – I have also raised the gearing by 50%

Photos – as I said its on an old frame temporarily so no criticism of that please ( some hope) and I need to get the cables a bit tidier – on disadvantage of a retroft kit is excess cabling
[url=https://flic.kr/p/Rjuz7Y]DSC_0127[/url] by TandemJeremy, on Flickr
[url=https://flic.kr/p/RjuJ6Q]DSC_0132[/url] by TandemJeremy, on Flickr
[url=https://flic.kr/p/RxYxav]DSC_0131[/url] by TandemJeremy, on Flickr

I have to say this looks pretty interesting. I’ve got 2 commuters – one with an alfine hub and one with derailleurs.

The Alfine bike is a Genesis Day One and it’s decked out for reliability rather than speed (and as such it’s a pig to haul uphill etc). Maybe converting it to an ebike might be a good idea?

I’m really keen to hear how you get on with it – it looks awesome!

Looks a lot neater than I was expecting.

I’m actually a bit disappointed in all the excess cabling I had to loop around the bike. But yes it is neat – motor unit, battery, speed sensor and switch thing are the only bits and one wiring connection between each which is all foolproof plug and play

You can barely buy a decent battery for that.

I know.
That doesn’t make a conversion kit worth over a grand. Sorry but I wouldn’t pay that for a conversion. If that’s all the money I had, I’d buy a used Bosch, Shimano or Yamaha powered ebike. I’m a big fan of ebikes but as yet I’ve not seen a conversion kit I’d pay my own money for, they’re all compromised somewhere and they all look a bit Heath Robinson no matter how carefully you install them.
I can’t quite tell, but that one looks fairly similar to the one I was replacing a motor on last week. 3000 miles or so and the bearings were shot. I rode it with the new motor on and it worked well. It was quiet and smooth. But it just hadn’t lasted. The Bosch stuff just doesn’t break, the backup is good, and there’s plenty dealers out there with the diagnostic kit who are trained to service them.

Could you not just singlespeed it and gear it for 15mph seeing as hills aren’t a problem (but destroying alfines might be)?

I have a singlespeed hipsterfixietwatbike but as going home is downhill I often hit 30 plus MPH which is real comedy on the aforementioned hipsterfixietwatbike ( it hads a freewheel)

the alfine should be fine – you can buy bosch motor bikes with alfines fitted

Peter – you need to acknowledge the limitations of your knowledge. this is nothing like the common bafung BB units. Its much higher quality.

Unless you have seen one of these then its really hard to see how you can pronounce on them. Its not compromised, its not heath robinson in any way. Its at least the quality of the bosch – in some ways better as it has no plastic gears inside.

Oh – and the ebike specialist I was at today had two broken bosch motors on the bench. He was impressed with the sunstar

Its a bit like saying – nexus hubs are poor so rohloffs must be as well. I have ridden a whole variety of ebikes and this one unit is as good as a bosch with the added advantage I can fit it to a different bike if I want.

Despite asking twice we still don’t have the name of this motor with unreplaceable bearings

Does have a warranty?

Bosch has 4-5 nylon gears inside but for good reason. All metal gears isn’t necessarily a good thing ESP where noise is concerned as they wear

Bosch biggest down side . Lack of spares sales to the customer.

The size and wear rate of their front sprockets being another .

Cost of compatible( and low capacity) batteries being a third .

They are not the messaih and they fail just like all the others

Have you any thoughts on how you would do the tandem installation? I understand it’s not such a straightforward installation, or at least much more of a compromise.

I’d be fitting a full guard on the front to reduce the hammering with water salt and crap. But looks a handy set up.

I have noticed the Relo kit in an SJS newsletter a week ago, looks neater than other mid-drives. More expensive and less powerful than the usual suspects, though.

Genesis core – 2 year warrenty

Dr T

Looks fairly straightforward

It would have to go in the rear BB as it does not have enough clearance for the ebb at the front. its square taper cranks so simply replace the left crank with a tandem left crank. I think this will work but not tried it yet obviously. Looks like it would

Parksie – good point. I really should do that

you need to acknowledge the limitations of your knowledge

I can’t be the only one who finds tj posting that rather amusing. Very good to have you back on the forum though and from my one ride on an ebike I have to say the doped superman to asthmatic geriatric analogy is spot on.

Its a lesson I have tried to learn addave. Hopefully you will have seen this in my new incarnation

I have tj, the forum is better for your presence and in my own opinion always was.

First proper ride on it today – I have had trouble setting up the chain so it didn’t slip. Very impressed with it. Its clearly going to eat the battery using it on turbo nutter barsteward mode up steep hills – good job I got the big battery. Very intuitive to ride, gearshifts with the alfine remain nice and smooth. Easy to hit 15mph on anything but the steepest hill. Even raising the gearing 30% as I have done I am still only going as low as 3rd on hills I would have been in 1st or 2nd without it. It really shoots away from lights as well which hopefully will mean keeping ahead of traffic.

Whats not to like about that 🙂

first commute yesterday – my commute used to be 37 mins in and 24 home. ( hills ain’t it) took me 26 mins to get to work. 11 mins saved was more than I expected. Its weird on the flat tho – accelerate easily to 15 mph then hard work to go any faster – and you get this odd surging effect as you go on an off electric assist.

Good bit of time saving that!

Well a month in I thought I would give a wee update just in case anyone is interested.

I am glad I set it up with a “euro commuter” type riding position as it helps hold me back from riding it like an utter bellend. I tend to ride a bit “crazy courier” style at the best of times and the speed from a start makes this very tempting to ride like a bellend

When I can hold this back I think its safer as I can accelerate away from lights quicker than cars thus get into a good road position easily and also up hill thru roadworks where its narrow I don’t hold up and frustrate cars as much as I would without the electric boost.

Range is slightly disappointing in that it does two commutes on charge easily but if I try to get a third commute the battery runs out on the way home and it tuns into a right slow heavy lump. Thats around a 25 – 30 mile range but half that is downhill. I can’t resist riding it on high boost all the time tho. Low boost should give twice the range

From the few little bits I have done on it proper offroad would be rubbish – the weight makes jumping really horrid altho I am not much good even on a non e bike

The torque sensing really works very well indeed and makes it very easy to ride. Gear shifts are slow tho ( alfine hub) as the motor takes a moment to cut when you stop pedalling. This would be no issue with a deraillier

tows a trailer well as well – makes getting the shopping in much easier

I am not taking it any easier getting to work- it just takes less time. Still get out of breath so am getting my exercise

Pedalling hard at high cadence you can get a slightly odd feeling as obviously the pedals speed and slow a little as you turn them but the motor goes at a steady speed and thus you get a momentary feeling of no resistance in the pedals at a 1 o’clock position. Only happens in an extreme situation both spinning fast and putting a lot of effort in tho and I guess an oval ring would sort that.

No issues with it at all bar the battery rattles over bumpy cobbles ( an issue with every e bike I have ridden) and easily cured by a strap around the battery

Its pointless on the flat – you would be better without one as you soon run off boost at 15 mph.

Only real issue – I have a new job with a 1 mile flat commute so I no longer need it!

Range is slightly disappointing….around a 25 – 30 mile range but half that is downhill.

Always wondered what would happen if you added a hub dynamo to charge the batt. Between your pedal input and the downhill sections you might be able to extend the range to three commutes 🙂

Just thinking on those cables tj
With it being a cheapish frame do you not fancy a go at some internal routing with the old drill in low stress areas ?

Not in the same league. Battery is 36v 9amp/hr. Hub dynamos are something like 6v at 1/2 amp.
Some hub motor ebikes do have regenerative breaking which puts a bit of power back in but you need alpine descents to get anything worthwhile