Stu Summer
100 W
Luna says not to put a hub motor on a front suspension fork? Why? What goes wrong? Is it inherently dangerous or only if you hot rod it?
Hub motor on front suspension fork?
- Thread starter Stu Summer
- Start date
Small hub-motors are OK, but the bigger ones can break the drop-outs even when you use torque arms. Some forks have stronger drop-outs than others. There are somesteel suspension forks from Zoom that would be suitable for any motor.
MadRhino
100 GW
It makes no sense fitting a hub motor to a good suspension fork. Doing it on a cheap fork could be an option, especially if it is steel, but should be limited to a small hub fed low power.
A bike does ride much better with a rear motor anyway.
A bike does ride much better with a rear motor anyway.
nutnspecial
10 MW
I had a ebay front motor on an old 70's kmart huffy, and it was a blast in snow. Pedalling gave 2wd, and the power to the front kept the thing upright as it clawed and spun it's way around. Kinda like a fwd car I guess.
~1 steel forks for anything substantial- aluminum is a tricky fickle biznatch.
~1 steel forks for anything substantial- aluminum is a tricky fickle biznatch.
dogman dan
1 PW
The first thing that goes wrong is the motor will break the dropouts of the fork. This can also happen with steel forks, if the nut gets loose or the washers don't fit.
The washer never fits a suspension fork, so the first thing you need is called c washers. These go inside the little cup on the fork end, so the larger washers don't crack the fork on the first tighten. Then you need TWO good torque arms.
The second thing that goes wrong is the fork often binds. So you only have shocks when the motor is off. the rest of the time the motor pulls the fork hard enough to jam it, and it behaves like a rigid fork, unless you hit a huge bump. So you learn to get off the throttle crossing the rail road tracks, or dropping off a curb.
You can do it, but its not ideal. In some cases, the motor body itself simply wont fit between the tubes, so you have to find the right fork to begin with.
I'm not blowing this out my ass, I rode to work for 5 years, over 10,000 miles, with front motor and shock fork.
But for the last five years,, I don't run any front hub bikes. :wink: Rear just works better, if you have a choice. Particularly in dirt, where front hub simply sucks. (The exception to this rule is a 2 motor bike)
If you need to run front hub for whatever reason, like you have a rear IGH, then you might choose a bike with rigid steel fork, rather than try to make a full suspension MTB work like I did. If you need a better ride, get a long tail bike. When I went long, I stopped needing suspension as much. The frame rocks, acting like suspension, if your ass is not hanging over the rear wheel.
The washer never fits a suspension fork, so the first thing you need is called c washers. These go inside the little cup on the fork end, so the larger washers don't crack the fork on the first tighten. Then you need TWO good torque arms.
The second thing that goes wrong is the fork often binds. So you only have shocks when the motor is off. the rest of the time the motor pulls the fork hard enough to jam it, and it behaves like a rigid fork, unless you hit a huge bump. So you learn to get off the throttle crossing the rail road tracks, or dropping off a curb.
You can do it, but its not ideal. In some cases, the motor body itself simply wont fit between the tubes, so you have to find the right fork to begin with.
I'm not blowing this out my ass, I rode to work for 5 years, over 10,000 miles, with front motor and shock fork.
But for the last five years,, I don't run any front hub bikes. :wink: Rear just works better, if you have a choice. Particularly in dirt, where front hub simply sucks. (The exception to this rule is a 2 motor bike)
If you need to run front hub for whatever reason, like you have a rear IGH, then you might choose a bike with rigid steel fork, rather than try to make a full suspension MTB work like I did. If you need a better ride, get a long tail bike. When I went long, I stopped needing suspension as much. The frame rocks, acting like suspension, if your ass is not hanging over the rear wheel.
tomjasz
1 GW
wait the experts say....d8veh said:
My best riding flat street bike is a direct drive front hub. Soon to have a new front drive Mac running. Experts are getting old...
tomjasz
1 GW
Reminds me of the fella that was pissed when he couldn't get a Dolphin pack with 20Ah...
Great with a steel fork at bicycle speeds. Wouldn't trade mine for anything, but its steel and its a 20mph bike.
Great with a steel fork at bicycle speeds. Wouldn't trade mine for anything, but its steel and its a 20mph bike.
markz
100 TW
I had a rear hub motor break free while riding about 30kph and there wasnt much to it. It felt like I just dropped the seat about 8 inches. You do that on a front hub motor, you are going over the handlebars.
tomjasz
1 GW
Shit happens. 55 years of bike riding and no endovers yet. I'm far more fearful of the cages trying to run me down.
dogman dan
1 PW
I liked front hub enough to ride it for 5 years. I had my reasons. I wanted motor weight on the front wheel, because I had little choice but to carry battery on rear racks and panniers. The bikes were old school Y frame FS mtb's. I felt I needed full suspension because my back got ruined framing houses 30 years ago. and streets here are that bad with heat cracks.
But then I found the longtail, and now all my street rides are longtails. They easily carry everything in back without much affecting handling of the bike.
One thing you do lose with the front hub, is good response of suspension forks, and or the ability to easily lift the front wheel over a curb. And you definitely lose performance off road.
But make no mistake about it, if you dive into a corner at 30 mph on the street, It does feel real good having the front hub pull you through the corner, especially if you cant keep pedaling without strike. But, how many of us actually do that? Even a 20 mph corner is beyond at least 80% of riders wheelman skills.
I did find that above 30 mph in a corner, the front hub is not best. A power drift is extremely hard to control on the front wheel, while rear drift is easy.
But then I found the longtail, and now all my street rides are longtails. They easily carry everything in back without much affecting handling of the bike.
One thing you do lose with the front hub, is good response of suspension forks, and or the ability to easily lift the front wheel over a curb. And you definitely lose performance off road.
But make no mistake about it, if you dive into a corner at 30 mph on the street, It does feel real good having the front hub pull you through the corner, especially if you cant keep pedaling without strike. But, how many of us actually do that? Even a 20 mph corner is beyond at least 80% of riders wheelman skills.
I did find that above 30 mph in a corner, the front hub is not best. A power drift is extremely hard to control on the front wheel, while rear drift is easy.
MikeSSS
1 kW
Interesting thread and very helpful to those who are considering what to do next.
Thanks to all who posted.
Thanks to all who posted.
