Donor Bike for a new e-bike Conversion

[Tubamanandy]

Looking for a sensibly priced strong and light mountain bike style frame for a new e-bike project (front hub motor 36V).

What make should I be looking at that are relatively cheap, strong and relatively light that could be converted into an e-bike ? It will only ever be used on road so not really interested in front shocks etc.

 

[jerrysimon]

Would you not be better with a hybrid ?

I have recently been considering a town bike and as I we live in Cambridge, looking at 3 speed internal hub equipped bikes.

So far I am interested in these

1. Raleigh Pioneer 3. I like it comes fully fitted with guards and rear rack.

2. A Creme Cafe Racer Solo which is a little retro

Then again I might look at an old frame to build up.

Jerry

 

[Deleted member 4366]

Any bike will do, but avoid ones with twist-grip gears. Also, look for a gap of at least 8mm between the pedal crank or chain-wheel and the bottom bracket so that you can fit a pedal sensor.

Suspension makes a bike much more comfortable on the road, and many non-suspension forks don't have much meat on them to be strong enough for a motor.

Disc brakes are better than rim brakes.

Something like a Carrera Vengeance is good, or the Kraken if you want a bit more.

The very cheap ones are also OK, but the suspension is not so good; however, they often have steel forks for strong motor installation.

 

[jerrysimon]

Disc brake wise, I am not sure you gain a lot over rim brakes unless they are hydraulically operated. Many of the cheaper disc brake bikes are cable operated.

Jerry

 

[Alan Quay]

Disc brake wise, I am not sure you gain a lot over rim brakes unless they are hydraulically operated. Many of the cheaper disc brake bikes are cable operated.

Jerry

I agree. I have had several mech disk, and rim brakes. Good rim brakes (linear aka V brakes) are just as good as mech disks for road use. In fact, I would say that my rim brakes require a lot less fiddling than my disks.

Hydraulics are a different story from what I hear....

 

[jerrysimon]

I like this Globe Works 3, but the cost is creeping up. Of course probably because it has a 7 speed hub on it.

Jerry

 

[trex]

Jerry, do you know any good motor that would fit the front fork of this this Globe Works 3?

 

[jerrysimon]

Well if I get one I would be thinking about either a Tongxin or Keyde motor but then as everyone knows I am biaise about these motors and my commute/rides are in and around flat Cambridge.

I guess any 100mm spaced motor would fit those front forks, though depending on if they are steel I would probably limit it to 250W.

Problem is all my motors are 260RPM which will be way too fast lol

I am pretty sure there is one in a shop near me so I may go take a look. Twist grip shifter would be problematic to fit a throttle on the right side.

Ps Full details of the bike here.

Jerry

 

[RobF]

Hydraulics are a different story from what I hear....

Good hydraulics require no adjustment or maintenance, which is about as good as a bicycle brake can get.

The other thing that occurs to me about rim brakes and a hub motor is changing the wheel is more complex when the rim wears out.

 

[Jonah]

Concerning hybrid bikes, when I was testing a few a couple of years ago I particularly liked Marin bikes (Larkspur was my favourite) and of course they do loads of mountain bikes too. Globe (Specialised) bikes are generally a bit cheaper (which is why I bought one but I was always a bit disappointed in it in comparison to the feel of the Marin). When it comes to brakes, I have to say the best I have experienced are Magura HS11 Pure hydraulic rim brakes. Long lasting, self-adjusting, zero maintenance and stop great even in the wet. Much better than the Shimano hydraulic disk brakes on my Scott SUB.

 

[Alan Quay]

....The other thing that occurs to me about rim brakes and a hub motor is changing the wheel is more complex when the rim wears out.

Don't know how far a rim is expected to last with rim brakes, but mine has lasted more than 1500 miles so far. Even if it needs changing, a new high quality rim is £20-30, and it took me a couple of hours to change and true after I destroyed a rim a few weeks back (pothole). I guess a good bike mech could do it in an hour or less.

 

[jerrysimon]

Not sure about larger rims, but I have 5000 miles on one of my Brompton rims and its still going. I am told that smaller rims wear faster.

I keep meaning to check out some Marin bikes.

Jerry

 

[Artstu]

When it comes to brakes, I have to say the best I have experienced are Magura HS11 Pure hydraulic rim brakes. Long lasting, self-adjusting, zero maintenance and stop great even in the wet.

I can't agree with that, sure for rim brakes they are good, but they're not self adjusting and they're not very good in wet weather, and not that long lasting either.

 

[falmouthtony]

If you are only going to use the bike on tarmac I would suggest you get as good a spec hybrid as you can afford. My Specialized Globe Pro ( well looked after but 7 years old before conversion ) with an Ezee kit is amazing. The 700c wheels with road tyres roll along easily and the 27 gears combined with the grunt of the Ezee motor make steep hills a doddle. If I was doing your project I would spend time hunting for a really good value well specced previously owned donor bike, leaving yourself a bit more cash to spare for a top end kit. More than happy with my V brakes.

 

[Jonah]

I can't agree with that, sure for rim brakes they are good, but they're not self adjusting and they're not very good in wet weather, and not that long lasting either.

Well I can only go on my experience. Used pretty much daily for over a year, come rain or shine - over 2500 miles - up and down many 20% gradient hills and they still work great without any adjustment.

 

[bmc]

Well if I get one I would be thinking about either a Tongxin or Keyde motor but then as everyone knows I am biaise about these motors and my commute/rides are in and around flat Cambridge.

I guess any 100mm spaced motor would fit those front forks, though depending on if they are steel I would probably limit it to 250W.

Problem is all my motors are 260RPM which will be way too fast lol

I am pretty sure there is one in a shop near me so I may go take a look. Twist grip shifter would be problematic to fit a throttle on the right side.

Ps Full details of the bike here.

Jerry

Hi Jerry

I'm considering buying a Keyde 36v 250w rear hub motor to fit in a 700c wheel.
Could you advise me as to the best RPM to go for ?

Thanks
Bill

 

[jerrysimon]

Well anything lower than 260RPM given that is what I use in my 16/20" rims.

I think a lot of people use 160-220RPM but as I have yet to dabble in those sized rims probably other's here can better advise. There is a formula somewhere for calculating the correct size dependent on speed you want and if you are ok with going over legal limit of 15-16 mph of assist specified.

Re donor bikes I managed to try the Globe and the Pioneer above. The Globe was the better of the two but why are aluminum frames so uncomfortable ? I swear the ride is better on my steel/ti Brompton than either of these full sized bikes.

Jerry

 

[jerrysimon]

The Globe was the better of the two but why are aluminum frames so uncomfortable ?
______________
Fut Coins

Exactly why are they ?

I ride a steel Brompton and it is way more comfortable than either of these two bikes. I am told steel framed bikes are generally more comfortable to ride.

I am now considering getting a s/h 531 frame in my size and building up a bike with a hub gear myself

Jerry

 

[jerrysimon]

Another contender the Dawes Urban Express 7. They also do a three speed version

As I said I have been scouring ebay for a older 531 frame which I could build up.

Jerry