FAQ - front or rear hub motor?

[LewTwo]

Why not, if the axle is long enough and you don't need disc brake nor to pedal.

OK --- my stupid question: Why not a disk brake ?
While at it .. pull the crank and install foot pegs to rest ones feet on.

 

[rosskernick]

I've just converted my Mountain bike using a Dillinger 1000w rear hub, heres what I found

Torque Arms on the back are needed, initially my back wheel was jumping out of the dropouts
I managed to find a 10 speed freewheel from sunrace as my current cassette was 10speed, this allowed me to keep all exisitng gear http://www.sjscycles.co.uk/sunrace-10-speed-freewheel-11-36t-prod39733/
Bike now goes very well, although its really heavy, hub has significant friction so without power it's harder to pedal
Range with me on a fairly hilly 10mile commute to and from work is about 20miles. As I get fitter and lighter (currently 280lbs) the range im sure will improve.

 

[alsmith]

I've got a front wheel direct drive motor (crystalyte 5303) and can no longer pedal the thing because of the permanent drag (I've got spondylosis). It's a bugger when it breaks down or the battery is flat but I'm not sure how I'd manage a geared motor. I'd need a similarly powerful geared motor to get up hills without pedal assistance when needed. I think the next bike I build will be rear wheel too- I've had no issues with front wheel drive but most bikes seem to go for rear wheel drive.

 

[d8veh]

I've got a front wheel direct drive motor (crystalyte 5303) and can no longer pedal the thing because of the permanent drag (I've got spondylosis). It's a bugger when it breaks down or the battery is flat but I'm not sure how I'd manage a geared motor. I'd need a similarly powerful geared motor to get up hills without pedal assistance when needed. I think the next bike I build will be rear wheel too- I've had no issues with front wheel drive but most bikes seem to go for rear wheel drive.

A Bafang BPM or CST at 48v would blitz that Crystalyte motor in a hill-climb race and they're totally free-wheeling, so easy to pedal with a flat battery.

 

[alsmith]

I've got a front wheel direct drive motor (crystalyte 5303) and can no longer pedal the thing because of the permanent drag (I've got spondylosis). It's a bugger when it breaks down or the battery is flat but I'm not sure how I'd manage a geared motor. I'd need a similarly powerful geared motor to get up hills without pedal assistance when needed. I think the next bike I build will be rear wheel too- I've had no issues with front wheel drive but most bikes seem to go for rear wheel drive.

A Bafang BPM or CST at 48v would blitz that Crystalyte motor in a hill-climb race and they're totally free-wheeling, so easy to pedal with a flat battery.

OK, I'll start saving my pennies! ThaNKS

 

[heavymetalthunder]

One you minimize by the way you ride.

You're right about that Dan. Most of the new E-bike riders get in trouble because they think they are still riding a bicycle and don't realize they are going 25 MPH or more. A fall from 25MPH can really hurt. The helmet I use is a old Bell Magnum with a high impact face shield and visor. Reasonably light but made before the Snell ratings came out. Granted not as good as my full face snell 2005 motorcycle helmet, but sure beats the heck out of bicycle helmet.

 

[dancliff]

I wonder if a front hub motor is less prone to flats than a rear hub motor setup?

 

[ddk]

I wonder if a front hub motor is less prone to flats than a rear hub motor setup?

nope, but it sure is easier to fix!

 

[dogman dan]

My experience in general is that the rear tire does flat more often than the front. But just about as hard to change a non motor rear tube as a motor rear tube.

Oh sure,, you might have a torque arm and actual nuts, vs a QR axle. But nothing that slows me down enough to care.

What happens is nails and screws lie on the road. Front tire hits them, but no puncture. But after the front tire flips it into the air, the back tire now hits it with the point of the screw pointing up sometimes, and into the rear tire it goes. This is how you get those nails jammed in the sidewall as well as through the tread.

I've toyed with some goofy ideas, like having a wedge shaped nail catcher in front of the rear wheel. The idea would be to bounce the spinning nail to the side before it gets to the rear tire. Also thought about a small broom just ahead of the rear wheel. Like made from a large paintbrush or something.

I go out and actually sweep about 6 miles of bike lane near my house, the loop I ride to the flea market, dollar store, carniceria. I do it by hand on the worst parts, or sometimes just drag the broom behind my bike to clear the junk off the bike lane when it gets crazy full of rocks and glass.

Riding in the dirt is different. Thorns everywhere, and the front tire tends to pick up the majority of them, and flat more often than the rear.

 

[cycleops612]

all this stuff about "needs to be installed by a pro etc"

where does that leave ease of front wheel removal?

if its hard, thats a big deal for me.

for example, removal makes car transport easier.

 

[docw009]

all this stuff about "needs to be installed by a pro etc" Where does that leave ease of front wheel removal? if its hard, thats a big deal for me.

If you install a kit, expect it to be hands on. A well designed front hub build would have one-piece torque arms that bolt to mounts on the fork. No messing around with questionable two or three piece units and hose clamps. You would still need to carry a sturdy wrenches. I packed two spares and a pump as contingency for a long ride, away from home, on Sunday. The axle on my wife's bike uses 18 mm nuts. Mine is 19mm. Dang. Two big wrenches to pack. No flats, by the way.

Now I plan to get some of those Gaadi inner tubes which are C-shaped as a field fix. Just need a sharp blade to cut the old tube out. No need to carry various wrenches to undo the axle nuts or worry about disconnecting an unfriendly power harness.

 

[dogman dan]

It's not ever going to be removable so easy you'd do it to carry your bike in a car, to ride it. Maybe to move, but not to go out and ride.

You'll need to get a hitch mount, and a hitch mount bike carrier, the kind that carries the bike by the wheels.

But if you get a REAR MOTOR, then your front wheel can pop off with a quick release just like it always did. THEN you can carry it in your car easy, all the time.

Just one of the many reasons to choose a rear motor. There is only one reason to choose a front. Your bike type makes using a rear motor flat out impossible. Ok, maybe two,, you use a front motor if you want a bike with front and rear motors.

 

[cycleops612]

It's not ever going to be removable so easy you'd do it to carry your bike in a car, to ride it. Maybe to move, but not to go out and ride.

You'll need to get a hitch mount, and a hitch mount bike carrier, the kind that carries the bike by the wheels.

But if you get a REAR MOTOR, then your front wheel can pop off with a quick release just like it always did. THEN you can carry it in your car easy, all the time.

Just one of the many reasons to choose a rear motor. There is only one reason to choose a front. Your bike type makes using a rear motor flat out impossible. Ok, maybe two,, you use a front motor if you want a bike with front and rear motors.

thanks. That kinda stuff is important to me. (am also agonising over how heavy a lifepo4 battery to buy - 15ah 36v is 6 kgs - eeks)

what i said was ~my tool kit is the back seat of a cab. I was just thinking of getting home. But yeah, no way is an ebike that has motorbike dimensions any good to me - eg the rack u suggest.

The lesson I draw is keep front hubs, if u must, light as possible (which means geared, 2 speed would be lovely which is 3kg) and not too powerful.

Avoid stress and the need for a torque arm. Disconnecting the motor power cable and the wheel sound tolerable inconveniences.

(NB also, front pannier racks cause similar problems with car transport - any protrusion beyond the axle is lost car space)

You imply front forks are weaker than back. I cant see it (certainly not so for (longer) axles), tho fronts do cop more bump shock (lower front tyre pressure has its good points). Suspension forks seem over strong/heavy if anything. Yeah, its about the axle mount point, but a 100kg rider surely must put more stress on it than my 70kg, a 3kg hub motor & 250/350 watts of power. u could argue its the best cushioned point on the bike, given suspension.

So I hear you, but ebikes are a bit like eisenhower's "2 nations divided by the same language" quote. You americans have 700watts to play with legally, we EU rules folks (most 1st world bikers, & 3rd world bikers are minimalists for pecuniary reasons - I am in Sydney Oz) have to credibly appear to have 200w (or 250w if no throttle). Cross borders and cross purposes

It makes a mid drive a no brainer if u sensibly want low profile here.

Briefly, i do fancy the idea of adding a second motor, front hub. After a lot of thought, its not as silly as it sounds. It would work v well with a mid drive. Let it do the lo speed, getting rolling stuff, and help with hills, no~ gears, but no chain & gear stress, and relaxed, smooth shifting on the move, always. At speed, use the mid-drive & the hub just freewheels. A bit like the prius etc. works with 2 motors.

BTW, i hear a 10mm 2 ended spanner works as an improv torque arm.