Question please forum masters & apologies if this has been answered elsewhere.

 

I am currently looking into my first e-bike purchase & test rode a friends MTB this morning which has been modified with a 1500w rear hub motor with a 48w battery. It was fast to say the least.

 

The only major downside I experienced is that the bike was so fast you could not get any traction resistance whatsoever even when peddling in 'level 1' (the slowest/weakest) pedal assist mode. It was such a horrible feeling riding when there is no resistance at all on the pedals, I might as well have been riding a moped!

 

My question Is this a common issue when riding on these fast motors or do you think his bike was set up poorly? I am looking at a 500w Motor & i do want to be able to feel pedal resistance in PAS mode in order to get some exercise in!

 

Thanks in advance for any thoughts & responses you might have.

I find that with mine, once i am above about 12 mph i have very little resistance but then i commute daily on mine so want to arrive fresh to work so it suits me, you are probably better with a 350W motor and controller

Question please forum masters & apologies if this has been answered elsewhere.

 

I am currently looking into my first e-bike purchase & test rode a friends MTB this morning which has been modified with a 1500w rear hub motor with a 48w battery. It was fast to say the least.

 

The only major downside I experienced is that the bike was so fast you could not get any traction resistance whatsoever even when peddling in 'level 1' (the slowest/weakest) pedal assist mode. It was such a horrible feeling riding when there is no resistance at all on the pedals, I might as well have been riding a moped!

 

My question Is this a common issue when riding on these fast motors or do you think his bike was set up poorly? I am looking at a 500w Motor & i do want to be able to feel pedal resistance in PAS mode in order to get some exercise in!

 

Thanks in advance for any thoughts & responses you might have.

 

Many of these high power motors are direct drive rather than geared motors. Great for high speed but pedaling then is a pig as you are effectively driving a generator. Geared motors have a clutch type arrangement so they can be freely peddled (or vastly more freely any way )

You have to change the gearing, but that can be complicated with those motors. If it's a narrow one, you can use a 7 speed DNP freewheel with 11 teeth on top gear, then change the large chainwheel to at least 48 teeth.

 

11/48 will allow you to pedal just over 30 mph and 11/53 about 35 mph. Some MTB frames won't allow a big chainwheel because of the shape of the chainstay, so have a look and see how much clearance you have. For a 52 or 53 tooth chainwheel, look for road bike cranks.

 

If you want to pedal without power, a direct drive motor is no good. you should look for a geared one or a mid-drive of some sort. A 500W geared motor will give a lot more usable power than those cheap 500w direct drive ones.

every kit is a trade off. You should choose a kit according to:

 

- the donor bike: frame type, weight, tyres, gears, handlebars, suspension, crankset

- the person's weight

- is the area hilly?

- does the person hate changing gear?

- does the person like to spin the cranks reasonably fast? (over 60 RPM)

- maximum desired speed

There becomes a point at around 30mph where it is less efficient to pedal and you're better off tucking your legs in to minimise aero drag.

Edited July 17, 20196 yr by danielrlee

https://www.sheldonbrown.com/rinard/aero/formulas.html

 

On my way to work I peak at 42 km/h, I am not pedalling but concentrating on negotiating a -15% gradient with a corner at the bottom. I guess if I tucked in and lay down on the bars I could top 50 km/h but I'm scared my tie might get caught up in the front wheel... Not going to do an Isadora Duncan, sorry!