Newbie considering an e-conversion. But what.

[RichD1]

Being close to 70 and the old leg muscles on the decline I would like to convert my 2016 Cube Nature to electric. I've spent many an hour reading numerous reviews, websites and forums and I'm still a tad unsure what type of kit to go with. I'm 6'-1" tall and weigh 96kgs. My typical ride is mainly on cycle trails and towpaths and we also take our bikes in the motorhome when touring in Europe. I would like the ability to do about 30 mile round trips with a mix of flat and hilly roads.

My first question is rear hub or crank mounted drives.? I'm leaning toward crank mounted as I can retain my existing rear cassette and the reviews suggest it provides much superior power and smoothness.

Secondly cadence or torque sensing. This is probably my biggest concern. I understand the basics of both systems and like the way torque sensing works but what happens if I run out of steam before I finish my ride? Cadence will solve this problem but will it give me enough of a workout? Does using the lowest power level overcome this problem?

Lastly for the moment, 36v or 48v systems? What are the differences and what battery capacity will I need to suit my riding requirements.

All advice would be welcomed.

 

[vfr400]

I'm leaning toward crank mounted as I can retain my existing rear cassette and the reviews suggest it provides much superior power and smoothness.

That's not my experience at all, and I've ridden a lot of electic bikes.

Power is a product of battery voltage and the number of amps the motor conroller allows - nothing to do with the type of motor.

 

[Nealh]

48v rear hub is easier on the drive train and you can keep the cassette gears with cst/cassette hub. A mid drive will require your tired legs to drive the motor harder then a hub drive, combine the hub drive with the excellent KT torque simulation /current control system.

Or buy a 48v hub kit via Woosh bikes.co.uk.

 

[Nealh]

With a KT cadence control system you get 5 power/current level's, so one can work a bit or take it easy. PAS 1 13%, PAS 2 20%, PAS3 33%, PAS 4 50% & PAS 5 100%.
If you really want a work out ride unpowered, with a TS drive if you are weak or tired then you will struggle with the TS multiplier in use.

 

[RichD1]

So cadence sensing it is, so that's one question answered but what about the others?

Rear hub or mid-drive?

36v or 48v systems?

Battery size to cover my ride type?

 

[Nealh]

10 - 12 ah battery at 48v should comfortably do 30 miles.
I get 25 miles from 6ah battery @ 44v on flat terrain and 25 miles from 8.7ah @24v with 1000' ascent.
It all depends on terrain, wind and rider effort.

 

[Nealh]

Hub bike all day long for me.

 

[vidtek]

I'm 71 and 78kg, 5'11". My mid-drive Tsdz2 Tongsheng from Whoosh has seen sterling service for the last 2 years, but I suspect my motives are a bit different to yours. I settled on a mid-drive torque sensor for exactly the same reasons you describe. The way I use the motor is to keep the assist switched off with the display up showing speed etc., until I come to an incline or run into a stiff breeze. I need the exercise and just wanted to take the pain of hills and winds away.

I once lost a crank mid-ride and was able to use the throttle to get back home, but had to get off and push up a steep hill.

If you want to put in minimal effort then a rear hub cadence sensor kit with throttle is what you need, but you will get little health benefit. It depends on what YOU want, but you need to be brutally honest with yourself.......

 

[Nealh]

One can get a lot of exercise out of a hub motor e bike as one can a mid drive, you choose the appropriate controller system that enables one to do so. Like mid drive one can ride with no power and a live display reading.
Long term the hub bike will likely be more reliable then a mid drive.

 

[Deleted member 16246]

The disadvantage of hammering the chain and cassette with a mid drive system should not be overlooked. I know it was mentioned above, but its worth mentioning it again. I recently bought a Bafang, mid drive conversion, and I am enjoying it a lot, but some of the sounds that have come out of the transmission when I fluff a gear change while the motor is still hauling away on the chain, are not pleasant, if you have any mechanical sympathy at all. I am keeping the chain well oiled with gear oil, but I don't hold out a lot of hope of the chain lasting that long. I am very glad my motor is the 250 watt one and not one of the 500 r 750 watts that were on offer. They must magnify the problem of wrecking the transmission when you get it wrong.

I am puzzled that people I respect as very experienced e-bike mechanics, take opposite views on the question asked by the OP. Some, like the guy who made my conversion, who have converted and sold many hundreds of bikes, and had to service them when things went wrong, I suppose, shook his head when I suggested a hub drive, and gave the reasoning the OP did about climbing. Others, like the gurus on here take an opposite view. How do you decide as a beginner? I don't know when there is such division of opinion.

Maybe we need a definitive engineering analysis.......

 

[Woosh]

I too prefer hub kits.

 

[Nealh]

Hubs still climb steep hills, and like mid drive can get warm though the first thing to suffer is the controller with heat. When talking hills I'm not talking gut busting TDF inclines of many K's.
For road and inclines a hub is plenty capable for off road then a mid drive.
That said I now use in the main hubs for both as they are reliable. My first kit was BBS01 it covered 1600miles before the stock controller smoked about 23 miles from home, I was able to ride home unpowered so not an issue. The second controller I programmed and it did not fair as well and smoked before 1500 miles, so as I also had a hub bike I moved over to hubs with remote controllers for reliability.

I still have the BBS01 and one day will drag it out of the hiding place it is currently dumped in and try again with a KT remote controller to get it going again. I tried briefly about 3 years ago and wasn't able to get it to run smoothly or reliably but will spend some time again one day and get it to work as we know they work fine with KT stuff.

 

[vfr400]

96kg, health going gradually downhill and hills puts you on the limit of many of the common hub-drive kits. The Woosh 48v kits give a lot more torque than most, which should be enough to keep you going until you can't get your leg over.

 

[Deleted member 16246]

Hubs still climb steep hills, and like mid drive can get warm though the first thing to suffer is the controller with heat. When talking hills I'm not talking gut busting TDF inclines of many K's.
For road and inclines a hub is plenty capable for off road then a mid drive.
That said I now use in the main hubs for both as they are reliable. My first kit was BBS01 it covered 1600miles before the stock controller smoked about 23 miles from home, I was able to ride home unpowered so not an issue. The second controller I programmed and it did not fair as well and smoked before 1500 miles, so as I also had a hub bike I moved over to hubs with remote controllers for reliability.

I still have the BBS01 and one day will drag it out of the hiding place it is currently dumped in and try again with a KT remote controller to get it going again. I tried briefly about 3 years ago and wasn't able to get it to run smoothly or reliably but will spend some time again one day and get it to work as we know they work fine with KT stuff.

I'm interested in the issues you had with the BBS01. Were these the older style controllers before the mosfets were beefed up? I know they used to have a poor reputation when the older style controller was in use. Quite a lot did as yours did then.

Only an anecdote - so no substitute for proper analysis, but I have given mine a bit of stick up some horrible off road hills, pulling 15 amps in a low gear, and it did not even get above mildly warm. I had to get off mine last week when the hill became so steep I thought loss of traction in the tyre would cause me to fall off if I didn't. The motor and controller were just mildly warm. That said, I would not like to have tried to slug it up there in a higher gear.

 

[Woosh]

I'm interested in the issues you had with the BBS01. Were these the older style controllers before the mosfets were beefed up?

back in the old days, there was no dust barrier on the BBS's axle. Dirt and water got inside the motor case and corroded anything and everything. Since 2016(? I can't remember the date), Bafang fitted rubber seals to the axle and the number of blown controllers has vastly reduced. Later, Bafang made the 15A limit on the controller compulsory, reducing the small chance of controller overheating to even smaller.
Nowadays, the BBS01 is very stable and dependable.

 

[Jodel]

With respect to the torque available from some of the Woosh kits, I'd endorse what vfr400 has stated above.

I bought a Woosh DWG22C 48V hub kit to provide some assistance for our tandem. This was suggested by Woosh as their recommended option for something big / heavy. It has certainly not disappointed - it allows us to easily climb hills we would have previously avoided. The tandem and crew weighs in at around 165Kgs, yet we rarely use more than level one or two (of five) of the power settings. We also want some exercise, so the motor is used to augment our own efforts, not replace them. I just monitor my pulse rate (I'm happy if I stay between 140 - 160 bpm) and adjust our speed or the power level to stay within those parameters.

I recently converted one of my solo bikes with the same Woosh kit - overkill really for my 'pencil-neck' stature, but I wanted to retain parts commonality between the two bikes. I'm 5' 9" and about 70Kgs, so a lot smaller than the OP. The torque available from the Woosh kit for someone my size is more than adequate - on high power settings, the acceleration from rest is more akin to that available from a small motorcycle than a bicycle. Obviously the power is set to taper off at 15.5 mph, but getting to that speed is really quite brisk.

As you might expect, the hill climbing ability is also quite impressive. I've never needed more than power level one to climb any hill I've encountered thus far (I live in Edinburgh, so there's no shortage of steep hills). Again, I use the motor to assist my progress rather than replace it, so I do tend to put in a fair bit of my own effort too.

Clearly the best thing is to try all available options then decide what suits you best. That choice is not always available unfortunately. From my (limited) experience of hub-motors, you need have little fear of them running out of 'oomph' on the hills and you can still get a decent workout if you want. I have cadence sensing on my kits and am quite happy with that system, although I'd like to have torque sensing too for a more 'natural' riding feeling.

The bottom line, in my opinion, is that you'll enjoy any electrical assisted bike and will get out and ride more as a result of fitting a conversion kit!

 

[vidtek]

The disadvantage of hammering the chain and cassette with a mid drive system should not be overlooked. I know it was mentioned above, but its worth mentioning it again. I recently bought a Bafang, mid drive conversion, and I am enjoying it a lot, but some of the sounds that have come out of the transmission when I fluff a gear change while the motor is still hauling away on the chain, are not pleasant, if you have any mechanical sympathy at all. I am keeping the chain well oiled with gear oil, but I don't hold out a lot of hope of the chain lasting that long. I am very glad my motor is the 250 watt one and not one of the 500 r 750 watts that were on offer. They must magnify the problem of wrecking the transmission when you get it wrong.

I am puzzled that people I respect as very experienced e-bike mechanics, take opposite views on the question asked by the OP. Some, like the guy who made my conversion, who have converted and sold many hundreds of bikes, and had to service them when things went wrong, I suppose, shook his head when I suggested a hub drive, and gave the reasoning the OP did about climbing. Others, like the gurus on here take an opposite view. How do you decide as a beginner? I don't know when there is such division of opinion.

Maybe we need a definitive engineering analysis.......

I really think it's horses for courses.
@Tony1951 -- you are not seriously suggesting a mid-drive motor places more strain on the chain and cassette than a grown man standing up can do?
99% of riders at some time feel the need to stand up and pedal to give that little extra grunt up the hills on non-electric bikes. What you are suggesting stretches credulity.

 

[sjpt]

you are not seriously suggesting a mid-drive motor places more strain on the chain and cassette than a grown man standing up can do?

Probably not, but they may well put that strain on much more frequently.

 

[vfr400]

I really think it's horses for courses.
@Tony1951 -- you are not seriously suggesting a mid-drive motor places more strain on the chain and cassette than a grown man standing up can do?
99% of riders at some time feel the need to stand up and pedal to give that little extra grunt up the hills on non-electric bikes. What you are suggesting stretches credulity.

A 250w crank motor can multiply that force by about 4 times. Bicycle drive trains were never designed for those type of forces.

 

[vidtek]

A 250w crank motor can multiply that force by about 4 times. Bicycle drive trains were never designed for those type of forces.

@vfr400 Sorry, don't see it. There is no way a poxy little 250w motor can multiply the force a grown man standing on the pedals on the drive chain by a factor of 4. It's just nonsense.
@sjpt is much nearer the mark when he says it can consistently increase the load, that makes much more sense.