Catastrophic front fork failure / BMC front wheel drive

[Chalo]

Front wheel drive is so stupid, lol. Such a waste of time and parts, looks and handles poor.

That's two wheel drive, unless you're unable or unwilling to use the pedals. There are advantages to that, not least of which is having a proven bicycle wheel with decent flange spacing in the back where stresses are highest.

Chalo

 

[D-Man]

I would take the disc brake off, and mount the torque arm to the mounts. Then convert to rim brake.

 

[neptronix]

3rd try is a charm, man. :lol: That is an astounding lack of self-preservation instinct that does not compute to me!!

Front motors above 500w really shouldn't be sold, or should be sold with a caution to the buyer, IMHO.
Even if you have a steel fork, torque slip can be a problem, and steering a heavier motor is a bit odd.

It doesn't help that the controllers sold with BMC/MAC motors are typically set for 3:1 phase to battery amp ratios either. That creates a satisfying kick/shock of torque on the nudge of a throttle, but will tear up some inadequate torque arms / dropouts in short time!

I wish the manufacturers/sellers would get the hint, because us folks warning people on ES hasn't changed a damn thing.

Maybe it is time to consider getting another bike and switching to rear drive. Mounting something that powerful to something that is long and flexy ( a front fork ) is not good. I guarantee your life span will be extended

Stacking the odds in your favor instead of against you is a better plan. Doing the same thing twice, while expecting a different result, is not wise. 3 times.......
I figure the cost of one hospital visit is more than that of all the bikes one can imagine, and I have full, free medical. IIRC all the current wisdom boils down to 500W max for front wheel drive AND NO ALUMINUM FORKS, EVER. Why are we here?

 

[ions82]

Here is what I bought for one of my projects. It would be an affordable/adjustable option.

http://www.ebay.com/itm/TRIPLE-TREE-32-CHOPPER-BIKE-BICYCLE-Chrome-FORK-1-w-Disc-Tab-Black-/330774141736?pt=Cycling_Parts_Accessories&hash=item4d03acdb28

It's easy enough to just switch over to a threadless headset and stem. The triple clamps can be adjusted to whatever height/length you need. If it came down to it, you could even tack/weld fittings on them as needed. However, with a steel fork like that and properly installed torque arms, it should hold up to the hub (hopefully even with a 260-pound rider.)

 

[dogman dan]

Front hub is definitely not stupid, as pointed out, it's all wheel drive. Untill you get above 3000w and start drifting the front wheel, it corners great!

But front hub on shock forks is most definitely problematic. Cheaper forks tend to bind if the motor is pulling, and any kind of alloy fork requires a torque controll device that actually functions.

These ones that cracked failed because the connection between the arm and the fork tube, and the alignment of it was flaky, or the axle shoulder wedged em apart.

Thousands of happy miles on this one, and I've run it briefly at 1500w. Mostly though, at 1200w. Both sides of course. Getting everything fitting perfect can take hours. It's been ridden off more than a few curbs too btw.


But for the win, those dropout sleeves would be the way to go.

 

[cal3thousand]

too bad you have a 1" steerer requirement. These would work for 1-1/8". Steel, disc or v-brake suspension 26" and CHEAP

http://www.ebay.com/itm/OMNI-RST-191CL-SUSPENSION-MOUNTAIN-BICYCLE-FORK-BIKE-PARTS-571-/230728626965?pt=Cycling_Parts_Accessories&hash=item35b87f7315

 

[Thud]

here are some reasonably priced trike forks. (rake looks wonky for your bike & the stear'r tube looks long also)
http://www.niagaracycle.com/product_info.php?products_id=820534

& the bike they are replacment for:
http://www.bicycleman.com/recumbents/trikes/sun/sun-ez3-AX-recumbent-trikes.htm

prolly not worth the bother....the suspension fork above look worse than any ridged fork.....wall mart take off's may be better.