Rim brakes for hub drive conversion?

[tomjasz]

All failures are with aluminum forks or forks without or inadequate torque arms. Even aluminum forks can be failure proof with well engineered torque arms. The anecdotal failures do not reveal the facts. I tend to believe what I’ve seen and experienced first hand rather than anecdotal reports. There are mitigating circumstances.

 

[tomjasz]

Okay - good to know. Not something I had thought about. I think my options are narrowing to just buying a pre-made ebike.

Just use 2 quality torque arms. 350w motors with 2 are not a risk. Anyone saying otherwise is just spewing disingenuous information.

 

[Balsa61]

Not saying I'll get this, but it may be a possibility:

SmartBikeWheel

smartbikewheel.com

There's also a couple of Youtube videos by Electric Bike Report. Just search for, "Smart Bike Wheel". I don't know how to copy the video link on my phone to paste here.

Everything including the battery is self contained in the hub. The monitor, throttle and even the cadence sensor are optional extras. Everything is controlled via your smartphone. So at the minimum, there are no wires coming out of the hub.

Like I said, I'm intrigued but I may not jump at this one. I'm just passing on the information for any of you who may be interested.

 

[tomjasz]

Not saying I'll get this, but it may be a possibility:

SmartBikeWheel

smartbikewheel.com

There's also a couple of Youtube videos by Electric Bike Report. Just search for, "Smart Bike Wheel". I don't know how to copy the video link on my phone to paste here.

Everything including the battery is self contained in the hub. The monitor, throttle and even the cadence sensor are optional extras. Everything is controlled via your smartphone. So at the minimum, there are no wires coming out of the hub.

Like I said, I'm intrigued but I may not jump at this one. I'm just passing on the information for any of you who may be interested.

Run dont walk away from this kit!

 

[m@Robertson]

Hub motors do not power "though the axle". Axles are fixed, and you're in trouble if they aren't. This isn't true of both type hubs either "Therefore they are singlespeed.". That's out of context.

OK... I should have said "at the axle" which is dead on, but the point still stands. Hub motors have no use for the bicycles gearing.

Both hub types generally offer the ability to have a multi speed freewheel (6-8 speed most often I think, changed using a derailleur) attached to them to allow you to downshift when climbing a hills.

Yes but this has nothing to do with the motor. The gears are for the exclusive use of the rider's muscles. The chain can, in fact, be removed entirely and the hub motor will continue to work just fine on PAS. You can pedal the bike and it works just fine. So given that the motor has no bearing and no effect on the drivetrain, the drivetrain is not a part of the electrical drive system. What the drivetrain *can* do is reduce the stress that poor motor is undergoing by virtue of the rider busting their ass to help get up the hill. Again I don't count that in the 'e' part of ebike.

The fact that there is a known history of front fork falure w/ motors,that should be enough to give a reasonable person concern for their safety.
I personally (being a reasonable person ) would not feel safe knowing this front fork weakness. BTW it's not just the fork that fails , it's the weakness of the drop outs, so that the front wheel departs the rider leaving them to figure out how to ride on only the rear wheel.

I don't know about the 'reasonable' person standard. A thoughtful build can entirely eliminate any concern. Again, they all happen on high power motors, and on alloy or suspension forks. Low power hub motors on steel: Never. And its not a mystery as to why this is. Regardless, if you feel that way about it by all means don't do it. But the growing number of 2wd/awd bikes out there with a complete lack of front fork failure (never mind the zillions of front motor conversions) point to the fact that this can be done. Its the high power hot rod guys that have the problems.

500w/45Nm motor. Steel fork. Two Grin torque arms. Just crossed 2000 miles in a little over a year.

750w/80Nm motor. steel fork. Two torque arms. Just over 7000 miles across 3-4 years.

Same motor and dual torque arms as above. About 3000 miles on this one. This is actually a heavy duty alloy fork. I recently chickened out and swapped in a quality steel replacement.

 

[AHicks]

OK... I should have said "at the axle" which is dead on, but the point still stands. Hub motors have no use for the bicycles gearing.


Yes but this has nothing to do with the motor. The gears are for the exclusive use of the rider's muscles. The chain can, in fact, be removed entirely and the hub motor will continue to work just fine on PAS. You can pedal the bike and it works just fine. So given that the motor has no bearing and no effect on the drivetrain, the drivetrain is not a part of the electrical drive system. What the drivetrain *can* do is reduce the stress that poor motor is undergoing by virtue of the rider busting their ass to help get up the hill. Again I don't count that in the 'e' part of ebike.

On the bold, this is the new buyers struggle with no previous experience to base the call on. Do you think the hills in the area you ride most frequently might be "do-able" when supplied with some assist on your part, boosted with some more assist from an e-bikes motor? Or are these hills big/long enough where they are going to overwhelm you and a low powered motor to the point you're going to need some serious climbing power?

A geared hub and a light rider can climb pretty good on shorter climbs (1/2 mile or less?). Heavier loads and steeper/longer hills are mid drive country as they are way more capable.

All else being equal, a geared hub is brain dead simple to ride. A mid drive may prove to be more versatile as there won't be much worry about climbing hills.

As far as front hub conversions, they feel heavy. Not my thing. A rear conversion isn't that much more difficult, and I believe the difference in handling is worth whatever the increase in difficulty cost me 10 times over.....

2wd, if you can justify it somehow, a whole nother story. A situation like that would be the only way I would ever do a front drive.

 

[Balsa61]

Everyone - thank you for your contributions here. I was iffy about the rim brakes for an ebike which is why I posed the question here.

By the time I acquire a bike with disk brakes then order a kit and install it, it's just not worth the time and money for me. I'll probably order another Lectric XP Lite to match the one my wife has.

Don't get me wrong - the XP Lites are entry level bikes to us and if needed we'll get more advanced ebikes in the future. Building an ebike is still in the back of my mind just as hobby thing. Also my wife suggested that we sell our other three pedal bikes and put the money towards an eBike, thus freeing up room in our shed.

 

[AHicks]

Everyone - thank you for your contributions here. I was iffy about the rim brakes for an ebike which is why I posed the question here.

By the time I acquire a bike with disk brakes then order a kit and install it, it's just not worth the time and money for me. I'll probably order another Lectric XP Lite to match the one my wife has.

Don't get me wrong - the XP Lites are entry level bikes to us and if needed we'll get more advanced ebikes in the future. Building an ebike is still in the back of my mind just as hobby thing. Also my wife suggested that we sell our other three pedal bikes and put the money towards an eBike, thus freeing up room in our shed.

An excellent plan IMHO. The wife and I rode Treks for quite a while before the e-bike thing. We had a couple of pretty nice bikes that were like new. They started collecting dust and taking up space the day we first rode our e-bikes.

Just one more thought. When it comes to this 2nd bike, I THINK you'll find the extra money spent on a geared version of the bike will make your bike much more versatile.... That's me though. 6-7 years into it, and totally spoiled. -Al

 

[JES2020]

Not saying I'll get this, but it may be a possibility:

SmartBikeWheel

smartbikewheel.com

There's also a couple of Youtube videos by Electric Bike Report. Just search for, "Smart Bike Wheel". I don't know how to copy the video link on my phone to paste here.

Everything including the battery is self contained in the hub. The monitor, throttle and even the cadence sensor are optional extras. Everything is controlled via your smartphone. So at the minimum, there are no wires coming out of the hub.

Like I said, I'm intrigued but I may not jump at this one. I'm just passing on the information for any of you who may be interested.

That's a lot of weight and power to put on the front fork. If I look into my crystal ball I see many a law suits for this company !

 

[tomjasz]

“Che Guevera” has reported me to the moderator. Claiming i harass him. So i ended it with IGNORE. And yet the guy who has claimed I bully continues add his laughing icon. This is exactly the sort of internet expert that inspired me to give up my lucrative 3% of sales, to avoid. Its kinda sad. Add gerentaphobia for a commitment to move forward and not look back. Making me rethink my own posts and just go back to helping without judgement. Old dogs can learn new tricks and change behavior. As of this moment its a new day. Thanks to my good friends here. Different sttokes for different folks. I even helped a buyer of a dub par locally get back on the road. No sense in making him feel bad.

 

[tomjasz]

My apologies for the off tooic bullshit. “Show ignored content” is all the closer I’ll get.

Mea culpa to all i alienated and disappointed.

 

[m@Robertson]

On the bold, this is the new buyers struggle with no previous experience to base the call on. Do you think the hills in the area you ride most frequently might be "do-able" when supplied with some assist on your part, boosted with some more assist from an e-bikes motor? Or are these hills big/long enough where they are going to overwhelm you and a low powered motor to the point you're going to need some serious climbing power?

I'm looking at the topic from the lens of the ebike's capability, and where its out of its element. I know people who can make a Rad Wagon work in hills while hauling two kids on the back. Thats fine for them. But the inherent issue remains and its that issue I want to point out as always-present. Its why I try to never say stuff like "hub motors don't work if there are hills" and instead always try to say "hub motors are at an inherent disadvantage in hills" The former is not always true but the latter is. I want to ride the bike - or recommend to the new buyer - the bike with the fewest inherent disadvantages given the terrain and use case they have laid out in a given thread. If they tell us they live in Kansas where its all flat or similar I think you've seen me say a hub motor will be fine... hell I still have one of them in Flat-As-A-Table-Fresno and its great ... there.

Another way to put it is I want to recommend a bike that can do the whole job. Not the bike that can be made to work given X or Y external inputs. That lets the rider decide how much work they put in on any given day rather than the bike dictating that they must do it.

All else being equal, a geared hub is brain dead simple to ride. A mid drive may prove to be more versatile as there won't be much worry about climbing hills.

Yes if you are going to set up your mom to ride a bike around the neighborhood I think a hub drive is the easy choice there. You can just put her on it and she already knows everything to do and can't screw up. A mid requires a competence level and some learned behavior to get it right and keep it right. There's no getting around that but the learning curve can be flattened with a little instruction.

As far as front hub conversions, they feel heavy. Not my thing. A rear conversion isn't that much more difficult, and I believe the difference in handling is worth whatever the increase in difficulty cost me 10 times over.....

Before now I would have been right there with you on those absolutes, but as I mentioned last week I rented an ebike for a full day of riding the streets of Amsterdam in the middle of a work day with a *zillion* other impatient commuter/utility riders. I found the small front hub (and *gasp* rack battery) to be a huge asset. These little front hubs do not provide any noticeable weight increase or affect steering response (I use a similar one on my Bullitt here in the States). And as much as I *hate* to hear people say that a front hub motor allows a form of 2wd - with the human providing the second motor in back - I found it to be perfectly true. I really appreciated the boost off the front while I worked the back and was able to keep up with my much younger kids. Bear in mind this was a pedal-assist bike with no throttle and the display told me it was peaking right at the 300w mark (probably a 36v or perhaps even a 24v battery). And oddly, even though I was in the deepest, darkest Netherlands, the speedometer was in mph so I was able to see I was peaking in the 15mph range and it was *plenty* fast given the traffic, which usually kept me in the 10 mph range just to keep from smashing into the bicyclist ahead of me, or the pedestrians weaving in front of me or that rail tram that ain't gonna stop for nuthin'. I totally get now why 250w is not any limitation in that kind of urban environment.

So when @Balsa61 is telling us about what he wants to do, I'm thinking a simple front hub is right up his alley, and rim brakes are a non issue because what he wants to do is low power enough that he can't screw up any worse than he could with an analog bike, for which rim brakes have been working just fine for decades. He can just throw on a front wheel kit and fuggedaboudit.

 

[tomjasz]

Sadly the biggest detractors of front hubs have nothing more than anecdotal reports devoid of pertinent particulars. One the most creative custom parts designers here and rider/builder @JRA has long been a front drive user.