heavy rider spokeless integrated hub motor. Discuss?

[rborger73]

Which is why nearly every motorcycle on the planet since the 80s still uses spoke wheels... Oh... well... maybe not.. My only constant maintenance is normally checking spokes. Eventually ebikes will mostly have some new wheel be the norm. I doubt it will be wire spokes. A modular style wheel that fits different motor sizes will come out at some point. It just makes sense. If spokes were stronger than a cast wheel, you would still see most motorcycles have spoke wheels. A better setup will come out.

 

[amberwolf]

One thing to keep in mind, as Chalo pointed out, is that cost is a major factor (usually the defining one) for manufacturing--not whether something is better, just whether it is cheaper to make.

Spoked wheels are more complex and take more time to build and setup initially, so manufacturers have to pay more labor costs (even with automated wheelbuilding).


As to what's better; it depends on what you want out of it, and what you're doing with it.

 

[rborger73]

I know I had a broken spoke I didn't catch, and then 4 other came loose enough my wheel almost blew apart on the way to work once. I don't see that happening with a solid wheel setup. I had just come down a hill that I do 30mph + the entire way down for a mile or more. I didn't feel it till I came to the stop sign at the bottom. It was bad enough I had to walk my bike a quarter mile down the road to a garage where I knew the owner, because I had forgotten to throw my vice grips or pliers in my bag that day. Spoke wasn't broken the day before and all the spokes were tight. So one spoke broke and in less than 17 miles the wheel almost self destructed. Once I got to work I had to put some zip ties on the bike to rough balance the wheel to get home.

Once Graphene and a few other newer 8) discoveries becomes easier to produce in mass, we'll certainly see new ebike wheel setups.

 

[ddk]

...if the motor's big enuff :wink:

 

[MadRhino]

Yep. No spokes required when there is no room for them anyway.

 

[FluxZoom]

Kind of a catch 22.

Tension keeps the nipples from turning, but if some of that tension is lost, then the nipples may be able to turn and thus will absolutely require maintenance. Basically a slightly beat up wheel, which is still likely otherwise road worthy, may fall into a cascading downward spiral as the wheel is ridden unless some other force is used to prevent the nipples from turning.

You don't lock the nipples because you need to turn them should the wheel get a few harsh knocks so the nipples don't unravel, but maybe the nipples unravel from there because the nipples aren't locked.

https://youtu.be/IKwWu2w1gGk?t=91 https://youtu.be/WPCfd4Zr6rE Some examples of the idea I have in mind that might help illustrate this idea.

I imagine a fully built wheel with lubricated spoke threads, stress relieved, no spoke windup and all that and then a genereous amount of flux is applied followed by a soldering the nipples. With the nipple at the top of the wheel, with the aid of gravity, the heat and flux might flush out the lube used and you'd end up with a decent solder job. It may be viable to use a liquid wicking oil tolerant thread locker after the wheel is built, but I am not familiar with every thread locker there is nor if any would prevent the nipples from turning well enough.

I never have any problems with spokes loosening

With average speeds of 20mph and a 6-7kg hub motor for the rear wheel using regenerative braking? I'd love to hear your rim/spoke/tension combo for this sort of application. There are naturally going to be massive variables here which is to say our situations are unique, but still. When you say never, what is your highest total distance ridden hub motor wheel? Ever hit a pothole going 30mph+ down hill?

Personally, if a wheel cannot be built for an electric bicycle that requires no spoke maintenance I cannot use it. The biggest concern, for myself, is offering a product to a customer. Spoked wheels seem like both a liability as well as a potential severe negative. If I offer a customer a product I'd love it to be as reliable and long lasting as can I can muster, even if there is a worse strength to weight ratio.

 

[Chalo]

Well, maybe you should use a stamped steel car wheel then. Since you don't have concerns about weight or repairability, there are lots of choices for you. Bolt a compact spare to the side cover of a hub motor and off you go.

 

[FluxZoom]

Well, maybe you should use a stamped steel car wheel then. Since you don't have concerns about weight or repairability, there are lots of choices for you. Bolt a compact spare to the side cover of a hub motor and off you go.

It's difficult to be unbiased and without emotion in a discussion when the idea involves your bread and butter. Whats a wheelbuilder to do about cast wheels but speak solely of the spoked wheels virtues?

With average speeds of 20mph and a 6-7kg hub motor for the rear wheel using regenerative braking? I'd love to hear your rim/spoke/tension combo for this sort of application. There are naturally going to be massive variables here which is to say our situations are unique, but still. When you say never, what is your highest total distance ridden hub motor wheel? Ever hit a pothole going 30mph+ down hill?

Didn't want to touch this one? When is the last time you rode an electric bicycle?

The discussion is already about cast wheels, which aren't "repairable" in the sense that you can spend some time (or money) maybe through replacing some spokes, the rim, or just re-truing the wheel. But really, either way there are options for repairs no matter the type of wheel. http://www.leafbike.com/products/e-bike-hub-motor/brushless-motor-parts/18-inch-casted-hub-with-magnet-976.html An example of an option to repair a cast wheel. Even replacing a bolt on rim is a repair. I am guessing there are other with this replaceable rim idea.

 

[Chalo]

I had cast aluminum wheels on my Suzuki GSX1100G. They required no maintenance other than occasional replacement wheel bearings. I hit a pothole, though, and I had to replace the front wheel in its entirety.

Did I mention that the bike weighed 750 pounds? That's what you get by following preschool engineering principles instead of being a technological grownup.

Even that 750 pound bike required maintenance and lacked both cup holders and dual zone climate control. So it probably didn't weigh enough.

 

[DRMousseau]

Can't help but to chuckle quietly while reading the TONS of posts in this matter.

The "wheel" has been around a long time,... their application design is not without a long and proven history. And the technology of new materials isn't without the same! The "typical" spoke bicycle has evolved in the same way,... designed for typical bicycles, typical speed, weight, power, materials, etc.. Motorcycle wheels,... same! Automobiles,.. no different. But if you vary from the "typical" standards,... then you'll need an atypical design! AND, e-bikes are unique! They are also as varied in design and application as are bicycles, motorcycles, and automobiles!!! Ya ain't gonna drop a hot 350 in a Model A street rod without considering something other than stock spoke wheels or a LOT of problems and trouble!!! And you'll find a bunch of unsuitable cast wheels that jus won't meet your needs either.

And you're NOT gonna drive a typical bicycle rim on a 3000W 200lb bicycle at 40mph without some serious issues!!! And I won't mention issues with disk brakes on such wheels. There's good reason that those short spokes on big hub-motor assemblies are 12ga,... too bad that some are laced to unsuitable rims. And there's also a good reason that small diameter, big-hub driven wheels are cast! And who hasn't found "typical" bicycle tires to be TOTALLY unsuitable for e-bike use???

Typical bicycles today, are well suited to a 250W assisted conversion,... typical power, within typical weight, speed and braking designs. A "typical" bicycle of the '50s is well suited to a good bit more,... but "typical" then, was a lot different! Heavy gage welded steel frames, hub brakes, big tough tires, heavy steel rims AND 4doz spokes, and believe me,... they took a LOT more power to get movin'!!!

Nothing wrong with considering "brutally" strong rims,... cast ones are maintenance-free, but you WILL want to able to adjust and/or replace spokes as needed or necessary. Spoke wheels have NEVER been maintenance free! And if considering "mag spoked" wheels, make sure they're engineered and designed for something more than "typical bicycle" grade. Heck,... it's for an e-bike, NOT a bicycle! And ya better give a lot of thought to suitable tires too.

 

[Chalo]

MX bikes are more powerful, faster, and take more punishment than any e-bike. What do they use?

Hmm... Not a single cast wheel among the lot.

They probably need to be heavier and weaker too.

 

[liveforphysics]

I have had a decade of experience destroying wheels.

For a bicycle rim, you don't want to go bigger than 14awg, some of my best wheels (with respect to staying true and handling abuse) were 15-16-15 butted spokes.

For a motorcycle rim, thicker spokes can be OK if your motor spoke flanges and rim are strong enough to stretch the shanks on thicker spokes.

If you can't get the spokes under meaningful stretch in the wheel assembly, it will not share loading between spokes well and it will rapidly fail.

If you use cheap spokes or cheap rims it also will rapidly fail, but spokes tending to be more critical than the rim.

 

[rborger73]

I think we'll be seeing carbon fiber / graphene composite wheels on ebikes in 5 years or less. Wouldn't it make sense for a rim built of a strong composite, then like the Leaf rim someone linked to above. Picture that without the magnets but a bolt on motor system for the rim. You could have adapter plates so you could fit different motor sizes. It is hard to get spoke rims built for most people. Most bike shops don't want to attempt it, and most never have to lace in a motor for someone. Motorcycle shops sometimes build rims, but also they normally haven't done ebike motors. A composite rim would be pretty hard to destroy.

Someone could probably have a nice biz just selling rims and adapter plates. You could probably use existing motors with small bolts through the spoke holes, but ideally having motor manufactures adapt to a new mounting system would be the way to go. A modular rim ebike motor setup makes sense. Would cut motor swap times dramatically. Would cut down on customer issues with buyers. And I'd think you have less loss of power due to rim flex. Not to mention you could get matching front and rear wheels. Rim manufacture could also sell just hub assemblies for front and rear as well. Seems like commonsense to me.

 

[MadRhino]

Cf and comosite rims are available but this is racing material. Damage does mean expansive replacemet. Out of racing teams, where cost is assumed by sponsors and a pro tech team is in charge of continuous tuning and maintenance, many components in the bike industry are making no sense.

Top quality bikes are all above 10 K $ already. You seem to be eager to see them beat the 20 K using graphene. Anyway, all manufacturers are capable to build bikes that are sub legal racing weight already, using actual common materials. I don't see graphene fibre in bicycle components anytime soon.

 

[rborger73]

Graphene will drop drastically in price within the next few years. Which is why I said 5 years or so. It's expense is in the production, they've just recently started really mass producing it. The materials to make it are some of the most plentiful on earth. Just like any new tech expensive in the beginning, then cheap later on. I used to sell 3,000.00 cell phones in a bag. Now they nearly give away phones with happy meals. :wink:

You'll see carbon fiber / graphene composites first. Then full graphene. It's rather inevitable at this point honestly.

 

[rborger73]

In fact, it's further than the last time I searched.


http://www.cyclingweekly.co.uk/news/product-news/dassi-graphene-frame-260002

http://www.popularmechanics.com/adventure/sports/how-to/a19851/graphene-bike-tires/

http://www.cyclist.co.uk/in-depth/302/is-graphene-the-next-carbon-fibre

http://www.bikeradar.com/us/gear/article/graphene-bicycles-the-potential-future-of-composites-43196/

http://www.bikebiz.com/news/read/graphene-born-in-manchester-and-taking-on-the-world/020131

 

[Chalo]

Many of us waited a painfully long time for better batteries that were characterized as just around the corner. Magic materials are like that. You keep waiting, but in the meantime you work with what you have and can afford.

Yes, unprecedented new materials might make mag wheels relevant for light EVs. But until then, prestressed wire wheels are unsurpassed, and they have the added benefit of repairability. Saying "but they need maintenance" is disingenuous, because mags need maintenance too, but can't have it. Maintaining a mag wheel = replacing it.

When unobtainium comes to market, I expect we can make spokes out of it, and outperform unobtainium mag wheels.

 

[rborger73]

Just to be clear, you realize "mag wheels" are made of magnesium.. right?

Anyways I've been watching Graphene diligently for 8 years or so now. Inevitably it will be one of the materials that changes the planet, and very soon. I know a whole lot of guys riding crotch rockets with solid rims, that never replaced them for the life of the bike. Graphene will further increase the strength. If you manage to break one of these rims, you're probably dead, or the bike is a total loss. You won't break one of these rims on a pothole, unless it's big enough for you to ride "into".

 

[Chalo]

Most mag wheels have always been aluminum. Magnesium gave them their name, but mags are any cast, rather than stamped, one-piece wheels. In the bicycle world they're most often glass filled nylon, on kids' bikes.

I barely took note of the impact that wasted the front wheel on my GSX1100G.

 

[rborger73]

You're thinking of "Alloy" wheels. Mag wheels have always been almost completely magnesium.

https://en.wikipedia.org/wiki/Magnesium_wheels

 

[rborger73]

And graphene rims would be ridiculously stronger than magnesium, and most alloys. Lighter by a large margin, and not prone to cracking or blowing apart.

You're comparing a 750lb motorcycle plus whatever you weighed at the time, to ebikes where most weigh 6 or 7 times less, where you broke an alloy or magnesium rim, and there is a good chance that happened more due to a manufacturing problem, than from a bump you barely felt. That was probably the last bump to a series of bumps that slowly revealed the defect, allowing it to break.

On an ebike you'd bust forks or crack frames before you broke a composite wheel with graphene.

 

[MadRhino]

Composite rims are nowhere near the theorical strength of the fiber itself. Fibers are in a resin, and resin is sensitive to repeated stress, let alone temperature. It is not for durability that wheels are made of CF, it is for weight and/or fashion.

 

[rborger73]

Well, you should read up on it more. It's inevitable. Expensive now, but will be the norm within 5 years. Graphene makes all the difference. In heat resistance, strength, durability, and weight. Graphene is 20 times stronger than carbon fiber. Carbon fiber is 10 times stronger than steel.. Production techniques will change and adapt and prices will drop. Graphene is made from the most plentiful substance on the planet. Inevitable.

 

[DRMousseau]

Ah yes,...

"We build wheels Light, Strong, and Cheap, for ANYTHING!
And you may have your choice of any two."

"If it's Light and Strong,... it won't be Cheap!
Ya want Strong and Cheap,... it won't be Light.
And our Cheap Light ones,... won't be strong.
Any more of one, MAY likely mean less of the other."

It's a compromise of all which we desire and/or are willing to accept.
YOUR standards of such, won't likely be the same as another's, nor that of the local or foreign business, or even that of big Corps.

BTW,... recently noticed a 5-passenger battery powered RAIL vehicle last year. Efficiency was most desired within a reasonable cost. Wheel of choice,... aluminum alloy that appears to have a steel "tire"!
http://newatlas.com/team-eximus-1-2016-delsbo-electric/43603/#p408023

 

[Chalo]

You're thinking of "Alloy" wheels. Mag wheels have always been almost completely magnesium.

https://en.wikipedia.org/wiki/Magnesium_wheels

Funny, but "mag wheel" entered into Wikipedia redirects to the article on alloy wheels, not the article on magnesium wheels. That kind of makes my point for me.

One-piece nylon bicycle wheels are not made of alloy, but they are mags. For two generations now, "mag wheel" refers to a form and not a specific material. See for yourself:

https://www.google.com/search?site=imghp&tbm=isch&source=hp&q=mag+wheels
These are almost exclusively aluminum wheels.

https://www.google.com/search?site=imghp&tbm=isch&source=hp&q=nylon+mag+wheels
And here are nylon wheels.

It's every bit as correct as someone saying "carbon fiber" or "graphene" when they're talking about a material that's primarily plastic resin. (You do that.)