What to try and buy?

[Simon Knight]

Hi,
I am trying to understand the options and merits of conversion kits and ride away ebikes. I'm in the UK and want to stay street legal and I have a Brompton Nano conversion and many years ago I had half a day on a KTM 29er fitted with a Bosch mid drive motor. The KTM was great fun but it needed power as the motor came with loads of drag. I did not buy one at the time because I read of problems with sealing and water ingress causing problems. Also after sales support was said to be lacking. The Nano has been a surprise and good fun to ride with two wheel drive proving useful on muddy tracks, it also seems quite capable at climbing hills but then I do live in North Lincolnshire where hills are quite rare.

I am torn between buying a complete bike with a mid-drive motor or converting an older 26inch mtb by adding a geared hub motor to the rear wheel. To me the ready built mid drive option is either expensive or very expensive and while they may be better climbers I have to ask if the manufacturers have solved any reliability options ? To be fair there are hints of problems mentioned in posts on this site but I have not found many recent descriptions . Although I can imagine there has to be greater wear of chains and cogs

Converting a normal bike to a hub drive seems to have some advantages two of which are its cheaper to start with and if everything stops working it is simple to restore normal push bike functions. I wonder if the small wheeled Brompton is a special case as I have read that smaller wheels make better climbers. Is this true and more importantly is it significant?

I look forward to your comments,

best wishes

Simon

 

[sjpt]

Converting a normal bike to a hub drive seems to have some advantages two of which are its cheaper to start with and if everything stops working it is simple to restore normal push bike functions.

Also easy to get cheapish replacement parts and fix it. You'll be pretty familiar with it if you've done the conversion.

Ease/cheapness of fixing is true of some ready to go bikes too, especially the cheaper ones.

 

[Benjahmin]

The 'ready built' mid-drive bikes see, to me, to all be over complicated and over priced. Because of comms between battery, controller and motor, it is impossible to do self repairs and dealers are limited to diagnostic software only. The bike or motor then has to be returned to the manufacturer for replacement. Also when the battery needs replacement you are stuck with a highly overpriced manufacturer only option. i.e.Bosch battery around £650, when good batteries can be had for £250-350.
As for mids being better hill climbers? I live in west Wales where hills are hills and lungs know about it. I have a front geared hub with around 9k miles on it. As a late 60's leisure cyclist believe me it would not have that mileage on it if it was crap at hills.

A rear self fitted hub has good traction, and you will know the machine well for garden shed repairs/mods. It'll be good for mild off road and,despite being 250w rated, will give you 6-700w of power (depending on the controller chosen). Bradley Wiggins would be happy with kind of oomph !
The trick is to select the motor rpm that suites your wheel size to give your modal speed. So 16-18mph no load speed. This would then be limited by the controller to 15.5mph. This is the sweet spot for efficiency as you would be riding, most of the time, at 50-80% modal speed, so making best use of battery capacity.

Here endeth the Saturday morning ramble

 

[Simon Knight]

Thanks for both your responses. The discussion may be moot as new bikes of any type are thin on the ground at present. Both of your comments and my own experience with the Nano Brompton are pushing me towards a hub motor, after all 9000 miles on one motor is impressive and I remember how hilly west Wales is.

I shall take a look at front geared hub motors as I know that two wheel drive can be helpful in some circumstances.


best wishes
Simon

 

[vfr400]

I shall take a look at front geared hub motors as I know that two wheel drive can be helpful in some circumstances.

You were doing well up to that point!

I did around 4000 miles with front hub-motors, and I can tell you that that's not a practical advantage that would sway me to use one again. I can remember going out in the snow, and I couldn't even get off my drive. The only sensible reason to fit a front hub-motor is that it's impossible to fit a rear one on the bike concerned.

Front motors work, so it's not a deal-breaker to have to fit one. let's say that if a rear motor gives you 100% good riding experience, then a front one would be 80% to 90% if properly fitted, and 0% if your drop-outs break. Ideally, you need steel forks.

 

[sjpt]

The 'ready built' mid-drive bikes see, to me, to all be over complicated and over priced.

On the whole I agree.
There are important exceptions though, eg https://wooshbikes.co.uk/?santana-cd (it even claims to be available). I'm pretty sure that is all standard parts.

That doesn't change the overall argument about crank vs rear (or front if necessary) motors; but does give a sensible choice if for some reason you do want CD.

 

[Simon Knight]

I've sent an email to Woosh asking what they have in stock.

I think that snow is a time for studded tyres and a trike so not getting off the drive could be viewed as a safety feature ;-).

"Ideally, you need steel forks." not a problem as all my bikes have them, I'm not a great fan of aluminium or plastic for reasons of strength and Mr. Hooke's law.