Rated Ebike Weight Capacity

[6zfshdb]

Being a heavy rider, I've always been concerned about the weight carrying capacity of the bikes I've owned over the years. It was a major factor in choosing an ebike.

I understand that spoke gauge, number of spokes (usually 28, 32 or 36), spoke material, spoke angle & bracing if any, rim material & design and tire size are all contributing factors to the weight carrying capacity of a bicycle wheel. The total weight can't simply be divided by 2 since the rear wheel on most bikes carries more weight than the front. In addition to wheels, frame material & design are also major factors.

What I don't understand is how a cheap Chinese Walmart ebike with 32 - 14 gauge spokes can claim the same weight capacity as an expensive model with 36 - 12 gauge spokes. Yes, the Chinese could be (and probably are) over specking their bikes but I would think complaints and lawsuits due to failures would cause Walmart to remedy this situation. I suspect that most quality ebikes are under specked to a certain extent but not enough to account for this difference.

Walmart is just one of the weight rating discrepancies I've noticed when looking at ebikes. It also exists when comparing major brands. The weight ratings for most major manufacturers range from 250# to 375# yet the above mentioned specs are often quite similar. Some brands, like Pedego, offer mag wheel options which increase the capacity to 400#. That would indicate the weak link is the wheel.

Am I missing something here? Why is there such a big discrepancy in ebike weight capacity?

 

[Off road all day]

I way over rated a wall-mart bike for a year, me, gear etc, then i threw a 450 watt motor on it for a year, still going 12 months every year in Canada. Just sayin'
The difference is not price, it's maintenance! keep it clean and regularly lubed

 

[indianajo]

If you sue a vendor for injury from a device made overseas, and win, you get the copy machine and phone from the US office. And the copy machine was probably leased. So you get the contents of the office supplies closet. If you sue a vendor of a US made item, you get some portion of the factory. So their is no incentive for vendors from ***** to tell the truth. I have to say, ****ese steel is a big joke. Harbor freight tools shattered all the time when my co-worker used them. Or tore up the fastener we were trying to remove.
When niagara actually sold bike parts, you could get swiss brand spokes which were made in USA. With 175 lb me , 40 lb of baskets and 60 lb of supplies in the baskets, I never broke a swiss brand 14 gauge spoke. Only one spoke broke on all of my US made bikes over the years. But, I don't jump 50' in the air and land on my bike wheel, either.
I think the current craze for 12 ga spokes has to do with where all the parts come from. The shiny grey metal certain countries make spokes out of is 2% zinc lead or copper, which makes for *****y performance. Yeah, a pencil diameter spoke made of lead would possibly work, but it is a *****y way to make a product when real steel can easily be 80000 psi rated in tension. Even steel from the supply house, the blacksmith/spring maker at Biltmore mansion tells me he can't buy consistent product anymore. What Americans all want is more garbage from overseas.
Some QA departments can get good product out of *****. My african named yuba cargo bike was actually made there, and in 13 months of cargo hauling I haven't broken anything. I think it is rated 200 kg rider, 100 kg cargo, only 40 kg cargo allowed behind the rear axle. They were serious about it, I've put a pickup tire on the rack and not broken anything. Also two 42 lb keyboards in the panniers.

 

[6zfshdb]

Sorry if I got it wrong, but just by reading your post it sounds like you almost think that weight capacity rating is solely determined by the spokes.

Pedego Interceptor and Pedego Stretch for example, both have 12g spikes but one has much beefier frame. So one is rated at 250 lbs and the other one is 400 lbs.

I'm not an engineer and this is my completely amateur guess, but I don't think spokes are the only factor.

Even the design of frame will dramatically change the weight capacity. (diamond frame is more rigid than step thru)

I suppose I rambled a bit and the question I asked wasn't very clear. Yes, there are many factors used to determine weight capacity. I used spokes as one example. Put more simply, my question is, why do two ebikes, with very similar specs in all areas (including spoke gauge) have such a big difference in weight carrying capacity? The numbers seem almost arbitrary. Are these bikes tested until they fail? How is the weight capacity calculated?

BTW, the Pedego Interceptor 400# model you mentioned has mag wheels with no spokes.