dangers of front wheel drive

[Michael1098]

I recently broke my shoulder and mangled my thumb ( on the opposite hand, of course) and I blame the front wheel drive of my ebike.

It is a very powerful motor with throttle and pedelec. It is supposed to be only a 200 watt but it goes 35 km/hr by throttle alone. When you peddle there is the inevitable 1.5 sec delay but then it kicks in full power which is a lot of fun in the dry.

In the wet it's a different story and it has thrown me twice with the most recent being the more serious. I was on a bike path through a park on a slight downhill and not peddling as I rounded a slight curve. Then, when it straightened out, I started peddling idly. A second and a half later the front wheel started spinning and I then made the disastrous decission to hit the brakes. Immediately the front wheel disappeared beneath me and I was sliding along on a straight piece of pavement that you would think was impossible to crash on. And with the aforementioned broken shoulder.

The doctor says I can't ride for 6 months but when I do I may switch to a rear wheel drive.

Anyone else with similar issues from front wheel drive?

 

[Berry78]

I'm sorry to hear about your accident. I dont have the experience you are looking for, but switching to a rear hub (or middrive) might be helpful. Also consider your tires and brakes.

Sometimes wet pavement is crazy slick no matter what you do...

Hope you heal up quick...

 

[Michael1098]

Ok thanks. Perhaps it is just that it was crazy slick as you say. I'm 58 yrs old so can't afford another accident so perhaps commuting to work by bicycle only on dry days would be the best bet.

 

[VLADIMIRO LONGO]

I recently broke my shoulder and mangled my thumb ( on the opposite hand, of course) and I blame the front wheel drive of my ebike.

It is a very powerful motor with throttle and pedelec. It is supposed to be only a 200 watt but it goes 35 km/hr by throttle alone. When you peddle there is the inevitable 1.5 sec delay but then it kicks in full power which is a lot of fun in the dry.

In the wet it's a different story and it has thrown me twice with the most recent being the more serious. I was on a bike path through a park on a slight downhill and not peddling as I rounded a slight curve. Then, when it straightened out, I started peddling idly. A second and a half later the front wheel started spinning and I then made the disastrous decission to hit the brakes. Immediately the front wheel disappeared beneath me and I was sliding along on a straight piece of pavement that you would think was impossible to crash on. And with the aforementioned broken shoulder.

The doctor says I can't ride for 6 months but when I do I may switch to a rear wheel drive.

Anyone else with similar issues from front wheel drive?

I had my first ebike with two motors ((Link Removed - No Longer Exists)). I immediately removed it before my first pedaling as a friend of mine went through the same experience as you did. Sorry man.....they should outlaw front wheel rotors.

 

[George S.]

I'm not really sure what happened. It sounds like the pedal assist kicked in and the bike started to get out of control, and hitting the brake was the wrong thing to do.

I own two front drive ebikes and a rear drive. I don't consider any of the three less safe than the others, after maybe 5,000 miles.

You have a lot of pieces to this puzzle. The pedal assist is going to supply power whether you really want it to apply power in certain situations or not. The brakes are going to cut off power and maybe lock the wheel(s). In slides you rarely want to lock the brakes.

Are ebikes just like bikes? You ride a bike for many years and really know how to ride a bike. So how qualified does that make you to ride an ebike? How different are front and rear hubs? I once lost a much heavier motorcycle in some lose material, trying to make a turn. I try really hard never to let that happen again, and I ride ebikes more like motorcycles, anyway. There's always loose stuff or rocks that can throw the bike. I don't ride much in wet stuff, and I run from ice.

My advice would be to get back on the horse and really try to understand what the bike, the motor, the throttle, and the pedal assist, plus the brake cut-offs, are doing. Teach yourself to ride really well and don't get into a situation where you suddenly realize you've done one too many things wrong.

The rear wheel is basically locked into the frame. The front wheel is designed to turn, and making the front wheel the power wheel means any turning can be magnified by the motor. In deep gravel, which is great practice, you can see and feel the wheel turning and coming over. You have to fix that. You are either (1) going straight, (2)in a controlled turn, or (3)in a turn where the wheel is going to get very unstable, sometimes very fast. You always want to be in number one or number two.

No one ever says anyone needs to train to ride an ebike. Is that realistic? The faster people go, the less realistic it is. I'm sorry you were injured, but I think you can analyze how you ride the bike and solve the problems. If it has happened several times, maybe you should go to a rear hub. I KNOW front hubs are less stable in some situations, but it seems manageable. Understand what it means to have the drive wheel powering the bike even when you have let the wheel get unstable.

I don't really trust pedal assist systems, which may supply power when it will create a problem. I really want to be in control of the bike at every point in the ride. People get pretty casual and people are taking very big risks. That's not for me. I'm an old guy and I ride like an old guy.

 

[harryS]

A broken shoulder sucks. Hope the pain fades soon, and good luck with the physical therapy. Just be careful on the slippery stuff. I believe you might have slid with a rear wheel set up. Last winter, I took my e-bike (rear motor) out a few times on sunny days on the bike path. Yikes, in the shade, there's always either unmelted snow, or worse, black ice.

Pedal assist systems can be pretty crude in their power delivery. On my rear motor ebike, PAS1 will accelerate me to 10-12 mph and then shut off. For low speed maneuvers, I either turn off the power or squeeze the rear brake lever lightly to kill the motor.

Haven't fallen off an ebike yet. Last week near dusk, a deer broke cover on the bike, loped alongside me for a few yards on my right, and then cut in front of me. Wish I had mounted my dash cam.

 

[vincent]

strongly agree, definitely some of the pas systems kick in at the wrong time and with way too much power
this is where hopefully i saw it coming and was using throttle or no power....

am also really fond of my fat bikes for the very reason i am a novice and running into deep gravel etc unexpectedly is mitigated a lot with the fat bike

and i am like george - am old and ride like i am old!!

so sorry you got hurt and so badly, that sucks
hope you heal soon!

 

[Ann M.]

So sorry to hear about the shoulder & hand injury, @Michael1098. I wouldn't rule out that front hub system just yet; however, George is right, a little practice when you're healed will help. Can you tell us a bit more about what ebike you have? Some more simple pedal assist systems that use a 6 magnet sensor on the crank tend to have a more aggressive feel compared to sensors with 12 magnets. The more magnets on that sensor, the more sensitive and natural engagement of the power. With that said, any motion of the crank arms will trigger those sensors, so it helps to keep a hand on a brake to prevent the motor from engaging. Hope you're up and riding soon!

 

[steve marino]

I know this is an old post, but this question comes up a lot, and it's on my mind because I have plans to convert my cruiser type bike to a front wheel drive setup.

Several things to keep in mind: Do you live in a place where it rains a lot like Portland or Seattle? If so, I would go to a rear wheel drive because of the points brought up above. I live in the desert, so wet streets are almost never an issue. Also, avoid the pedal assist kits because they will give power at unexpected times. Go w/ a conventional throttle setup.

If you can afford a geared hub motor it will reduce the weight, which is always a good thing if you have that weight hung out on the front of a bike. What type of bike you put front drive on makes a difference too. I might think twice about it on a mountain type bike, but my bike is a pedal forward design with a slightly stretched frame like a Townie, and on these the rider sits more rearward, giving a better balanced weight distribution.

 

[JRA]

I have thousands of miles on 1000w front hub systems set up on drop handlebar type bikes. I only use a throttle control with no PAS but do have a cruise control setting that I use and set to any watt I deem necessary according to desired speed over ground matched to my input through the drivetrain. I also have regen as my bikes are direct drive and use it all the time to great effect and saving of brake pads.

I have traveled on just about every type of terrain and condition from sea level to 9000’ and never once have I ever experienced loss of control due to the front hub. In fact it has saved my bacon more often than not. One thing for sure is that the front wheel drive in coordination with my input and the resulting AWD provides the best overall traction I have ever experienced on any two wheeled vehicle other than my old Rokon, which was a gas engine two wheel drive motorcycle.

My bikes are well balanced with the weight of the motor up front, my battery mounted centrally on the down tube and my weight biased towards the rear of the bike. I can navigate rough single track trails at a moderate pace and downhill pavement runs at speeds over 30 mph in complete confidence.

I can pedal my bikes unpowered without any noticeable drag from motor cogging due to using Statorade which also helps to manage heat issues although they still are heavier than normal bikes at 45lbs so are sluggish on uphills and against headwinds but the motors more than compensate in those conditions.

Oh, and this bike with 3000 miles on it has a carbon fiber fork that shows 0 signs of fatigue due to proper fitment of a torque arm and keeping the axle nuts torqued properly.




So as I reside in the PNW, with many miles traveled in the Portland area in all the weather conditions it experiences in conclusion I would have to disagree with your post Steve, but it is just due to my personal experience and not meant in any way to convince you or anyone to change their view or opinion.

 

[indianajo]

I've got a front geared hub motor conversion of a cruiser bike. I have the battery located over the front wheel. This balances the 15 lb basket set I have on the back wheel, which has tire tools & pump always, frequently also supplies. This is not the bike shown at left. I don't have stability problems, although I would never ride with black ice or frozen rain on the road.
That system has 6 magnet PAS, which I don't like. I always start off with the throttle, switching to PAS only on long stretches without stops. 1/3 crank after I start pedaling PAS accelerates at 500 W to 12 mph, which could be dangerous in the wet. Why most posters here complain about throttle annoys me, because the throttle is much gentler and in control than a cheap PAS controller. Without a suspension I'm not going to be riding above 12 mph even though the 1000 W motor could drive me to 25. I ride that bike mostly PAS 0. Good thing Indiana is not a nanny state about e-bikes with throttles.
The bike at left is the second conversion, where I bought a DD rear hub with throttle only. No PAS. Main disadvantage, on long high speed runs (12 mph) it hurts to hold the throttle that long with my thumb. A twist grip throttle conversion is in the future for that bike, as 50 miles trips at 12 mph were in the the initial plan. My unpowered speed was about 8 on that bike before conversion. With the DD motor dragging, 6 mph is more the usual now. A geared rear hub without PAS may be in the future, but after this trade war settles down. The DD hub is very heavy, my geared hub was much lighter. Gear hub of course doesn't drag when pedaled by me, which I intend to do on trips under 25 miles when the wind is not >12 mph in my face.

 

[Off road all day]

I ride an e-bike in Canadian winters, just like cars if power kicks in front wheel drive is better, more control. If you put the hub drive at the rear of the bike it acts like a pendulum and swings wildly, all the extra weight is there, mid drive is better, front drive would be best, simple physics if the motor kicks in.
I have 3 cardinal rules for driving in the winter when it's slick, steer straight, slow down and don't decelerate or accelerate on ice or in slick conditions. If you can't steer straight on a path slow down.
I broke 2 rules the other day, speed and steering, paid the price, now i'm sure i have 2 bad knees

 

[ebikemom]

On your bike does breaking serve to disconnect the power? That's an important safety feature to have. I'm not sure if it is a standard feature on ebikes or not, but it's a good one to look for. Then, just a little touch on the breaks serves to stop the motor instantly, even if you don't want to brake a lot.

Welcome to the forum, and I hope you heal well!

 

[Jelester]

I have a 500 watt front motor and two torque arms on it and I have ridden many miles with no problems. Fast riding on a ebike is where some of these problems happens. Keeping the correct tire pressure, make sure spokes are tight and check axle bolts and I do not believe you will have an trouble.

 

[Burton]

I recently broke my shoulder and mangled my thumb ( on the opposite hand, of course) and I blame the front wheel drive of my ebike.

It is a very powerful motor with throttle and pedelec. It is supposed to be only a 200 watt but it goes 35 km/hr by throttle alone. When you peddle there is the inevitable 1.5 sec delay but then it kicks in full power which is a lot of fun in the dry.

In the wet it's a different story and it has thrown me twice with the most recent being the more serious. I was on a bike path through a park on a slight downhill and not peddling as I rounded a slight curve. Then, when it straightened out, I started peddling idly. A second and a half later the front wheel started spinning and I then made the disastrous decission to hit the brakes. Immediately the front wheel disappeared beneath me and I was sliding along on a straight piece of pavement that you would think was impossible to crash on. And with the aforementioned broken shoulder.

The doctor says I can't ride for 6 months but when I do I may switch to a rear wheel drive.

Anyone else with similar issues from front wheel drive?

On your bike does breaking serve to disconnect the power? That's an important safety feature to have. I'm not sure if it is a standard feature on ebikes or not, but it's a good one to look for. Then, just a little touch on the breaks serves to stop the motor instantly, even if you don't want to brake a lot.

Welcome to the forum, and I hope you heal well!

Hi - I work as an e-bike tech and just want to mention that brake cut-off switches are a legal requirement for e-bikes. Which isn’t to say that every e-bike will have them.

After-market kits that add a hub motor to the front or rear of the bike rely on the tech to install a PAS system and / or brake cut-off switches. In some cases (particularly if the kit is purchased online and installed by the owner) .... they get left off.

However, in the case of a 250W motor - that’s not the cause of a crash. Using the front brake and locking up the front wheel was the actual cause of the crash. With or without a motor I’d suggest practicing useing the rear brake under those conditions.

I have personally confirmed (by disconnecting the cut-off switches) that standard V-brakes are more than enough to rapidly stop a 500W motor even under full throttle. However, brake cut-off switches are a safer bet.

Wish you a speedy recovery

 

[shiruba]

I recently broke my shoulder and mangled my thumb ( on the opposite hand, of course) and I blame the front wheel drive of my ebike.

Hi,
First of all, I am very sorry you got hurt. I can only imagine what that's like.

I have actually never seen a front or rear wheel drive bike because as far as I know, all bikes in Japan are middle assist. The motor just drives the chain, just the same as your peddling power.

It surprises me that there is a 1.5 second delay, as my bike has no noticable delay, but it surprises me even more that it goes straight to full power, as all bikes here by law can only put out a ratio of the power the rider puts in.

Do you think your accident was more because of the speed or front wheel drive, or more just because of the rain?

 

[Dal Venable]

really the way you describe your PAS acting you must not have connected the speed regulator wire, generally two blue wire with a male connect on one and female on the other, it will restrict your bikes speed but not the power. with the regulator wire connected the system won't go any faster than 15.5 mph using PAS and throttle. I find this is the best way to operate a front wheel drive bike. and to I never read where your kit had a LED or a LCD controller with various PAS levels. low level is fine for riding around on flats but some systems that only have basically an on and off switch if you don't have a controller on your handlebars when you start peddling the system cuts on full power (level 3 or 5 depending on system) with the controller you can meter your power output better to fit your riding style.
I find most problems with front wheel drive e bikes come from over power on the throttle or PAS. you really should try to equalize to motor drive power to your peddling power output this creates an all wheel drive effect that will handle most all road and trail conditions.
In fact, most e bike builders will tell you to use a lower power wheel on the front of a true ADW e bike, example: 350 watt hub on the back wheel and a 250 watt on the front or duel controllers to meter the difference in power output between the two systems. I build lots of front wheel e bike mainly trikes and beach cruisers. front wheel driver is idea for hard frames like those style bikes, not so much for mountain biking though.

 

[indianajo]

I've converted the bike left from rear wheel DD hub motor as in post 11 to front geared hub motor. 4000 miles, 2 1/4 years, no accidents. Got tired of pulling the DD motor around unpowered with my legs. I deleted the "suddenly on" 500W PAS, I view it as a positive danger. I use throttle only, but am looking for a torque sensor + controller. I won't ride on black ice, and am wary of wood deck bridges which are wet. Both promote skidding. Note I have the battery hung out over the front wheel for better traction, and less chance of a battery fire between my legs.

 

[Dal Venable]

The two beach cruisers in my post are both front wheel 500 watt geared hub bikes with the battery mounted on the handlebars. the new 36 volt 500 watt li-ion battery only ads 4.5 lbs to the bike total added weight comes to 15 lbs extra to the 30 lb bike. Very light and as you mentioned no drag when you peddle around in manual mode the geared hub has little to no drag compared to the direct drive systems front or back hub. Both also have an LED controller display that meter the PAS to better fit your riding style and the systems both have the regulator connected to keep the ground speed under 15.5 miles per hour but not the power of the 500 watt motor to climb hills. kind of like traction control.