Front hub motor 250W | Torque Arm | Rear 350W hub motor

[loloTheman]

Hey guys,

1. Can this fork handle a 250W front hub motor? Will the dropouts most likely break?
2. If they break, will normally the wheel get locked or I can safely slow down?
3. Can I install the torque arm just like in the picture? (without the long part, but using only the other hole beside)
4. What is safer and gives more riding stability/control?
   front 250W 36V or rear 350W 36V? (For urban rides only, normally without downs or ups on the road)
5. Can I install both front 250W and rear 350W motors?

thanks

 

[indianajo]

Take a magnet to the front fork. If it sticks, it should be fine. Lots of material there. If it is steel should not be a problem. I think I see a little rust, but pictures can fool one. I made my torque arms out of bed frame rails, but amazon ones might work, although a little shorter than the 3 1/2" ones I made. Don't rely on worm hose clamps for torque resistance, use solid steel. Made my clamps out of box fan shell. that extended washer to the fender screw hole in the lower picture looks way too short to me.
Edit, that is comfort fork. Suspensions and front hub motors don't mix.
I've put a 1300 W & a 500 W front geared hub motors on the bike shown left. $221 1300 watt one wore out at 4500 miles, replaced in 2 afternoons with a $720 Mac12 that I hope lasts longer. I carry groceries or ag supplies on the back, so having the motor & battery on the front balances the bike better. I had a rear 1000 W dd hub motor on it, didn't like it. Mainly because the rear motor required a 7 speed freewheel, and the unpowered bike came with an 8 speed sprocket cluster that was much nicer. 11-32 ratios, which I could never find available in 7 speed freewheels (they exist in the catalog).
Only downfall to front hub motor, IMHO, is possible loss of traction on wet rocks, slick steel plates, wet or muddy wood bridge planks. Don't use the motor in those situations. I don't, & I haven't fallen off this bike in ~6000 miles so far. Upside to front hub motor, easy to change tube if you get a flat. I turn the bike over, don't even unplug the motor cables. When I had a display I mounted it on standoffs closer to me that would rotate when loosened if I wanted to turn the bike upside down. But the display leaked in the rain & fogged, so I just deleted it. No downside now to flipping the bike over on handgrips & seat.
Biggest downfall to that bike is rim brakes, IMHO. Rim brakes don't work in the rain. Coaster brakes & disk brakes do. Might be worth a new bike to get disk brakes, if you ever ride in the rain. I do, it rains 200+ days a year here. These days people say you don't save a lot on a stripper bike versus a conversion. I saved about $1500, but stretch frame cargo bikes are a category where electrified models have a high markup. Only 1 brand of 26" wheel bike fit 28" leg me in 2017, yubabike drop frame bodaboda, but now there is blix packa with 24" wheels. Not many other bikes have bosses in the frame to mount the battery to the front without swinging it around with the handlebars.

 

[Stefan Mikes]

You don't think Lolo that would be more reasonable to just buy an e-bike designed as e-bike from the very start? I was lucky to change my mind and bought an e-bike instead converting my traditional bike... The only reason to convert is to keep the matters inexpensive.

 

[ElevenAD]

i would not put a Hub motor on that fork.

 

[harryS]

The torque arm has to line up with the flats in the fork. It's unlikely that the hole in the fork, shown in your picture, will align with your torque arm. A custom torque plate might work better. You may also have to carefully file the slot in the fork 1-2mm deeper to center the hub motor axle in the dropout, as most motor axles are 10mm x 12mm.

All in all, it's a install that involves some risk and I would try to avoid it. You might have a steel suspension fork. There's a few around. I took one off a Schwinn RC2000 a few years ago.

I did install a 250W motor on a non suspension alloy fork a while back. I used two torque arms. RIding a different bike, I took a fall on ice earlier this month, falling with my face hitting pavement. While I was only scratched up, I looked like a mess. It's changed my outlook on falling, I'm pulling off that motor for a rear. I may use the front motor again, but only on a steel fork.

Pics of torque plates.

 

[indianajo]

I did install a 250W motor on a non suspension alloy fork a while back. I used two torque arms. RIding a different bike, I took a fall on ice earlier this month, falling with my face hitting pavement. While I was only scratched up, I looked like a mess. It's changed my outlook on falling, I'm pulling off that motor for a rear. I may use the front motor again, but only on a steel fork.

I don't use power on ice. In fact I take the battery off & store it in a garage under a heat pad 12/15 to 3/7.
Problem is using power on ice, not front hub motor. My motor rides around unpowered ~20 miles a week in winter. If there is glare ice, melted & refrozen puddles, or black ice, I don't ride bicycle at all. I walk or ride the bus. I can make do with groceries from Save-a-Lot 3 blocks away for a week or two if I have to.

 

[legsofbeer]

Don't rely on worm hose clamps for torque resistance, use solid steel.

So I take it you're not a fan of these (ebikeling front torque arms (2 arms) that go around the forks), instead of one arm that depends on a single m4 or m5 bolt. Not argueing with you, just have been considering adding the front ebikelings to my rear hub drive bike because some of my descents hit 30+ mph and I really don't like the idea of losing my front wheel at that speed. https://ebikeling.com/pages/torque-arm-installation-ebikeling-e-bike-conversion-kit

 

[indianajo]

That torque arm is long enough but the hose clamp can be stripped with a screwdriver with my weak hands. The weak point is the little strips of metal the worm engages. Great for rubber hoses, not for higher tension loads. You'll note diesel 40 ton trucks do not use worm clamps on the hoses.
A torque arm with a hole in the end for a 5 mm or #10 machine screw would be better. I use 10-32 x 1 1/2" screws in mine, with elastic stop nuts. I did have the front axle come loose once. The clicking warned me something was wrong with the torque arm holding everything in place.
Note a 10-24 screw is about 3/4 as strong as a 10-32 because of the depth of the thread. When I had an unpowered front axle, I replaced the easy-steal front axle with a 10-32" 4 1/2" screw. Was mcmaster.com taiwan sourced stainless steel, not ****ese scrap metal. But I only weighed 185 then, down 10 lb now. 10-32 axle might not be enought for 250 lb people, nor for jumping curbs.