Can't Find A Single Speed Rear 20" Fat Tire Hub Motor

[stuxtruth]

I've looked everywhere and this is about all I can find:

http://www.ebay.com/itm/48V-1000W-20-Front-Wheel-Electric-Bicycle-Motor-Conversion-Kit-for-Fat-Tire/331971021303?_trksid=p2045573.c100507.m3226&_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D41375%26meid%3D17a22e8194014516b8e5e985865961ed%26pid%3D100507%26rk%3D1%26rkt%3D1%26

I'm building a custom bike that requires a 20" Fat Tire REAR hub motor wheel. Will I need to just buy a hub motor and wheel and spoke it myself?

 

[Chalo]

Why wouldn't you build it yourself, so you can have the motor, rim, and spokes exactly as you want? Pre-built hub motor wheels are usually unredeemable garbage anyway.

If you're not into learning the craft, it's worth it to have a pro do the job for you.

By the way, you'll probably need to use a multi-speed type hub with a multi-speed freewheel, but remove the sprockets you don't want. The sprocket of a traditional single speed hub is located such that the chain will rub on a 4 inch or larger tire.

 

[Drunkskunk]

A single speedhub would be too narrow. About the narrowest you can go with a 4" tire is a 135mm hub. Whats the spacing on your frame?

Some multi-speed freewheels were dismantleable like modern freehubs. You can take off the gears you don't need and add spacers to get the spacing you want.

 

[dogman dan]

Though its not on the website for click and buy, the place I work for ( E-bikekit) makes 20" rear fat tire wheels all the time. 500w geared motor. Just call them and ask nicely, for a rear 20" fat motor wheel with a ss freewheel and spacer.

But nothing wrong with build your own either. The real problem is just finding the rear motor with long axles for fat bike frames.

 

[Hillhater]

From the... "best bang for the buck". thread above..
http://www.leafbike.com/products/diy-bike-conversion-kit/20-inch-electric-hub-motor-kit/20-inch-48v-2000w-rear-hub-motor-beach-snow-fat-tire-bike-conversion-kit-1086.html

 

[stuxtruth]

Thanks for all the input guys! The only issue I have with lacing my own wheels is how hard it is to find wheels/tires/hubs for a 20x4 size rim. I'm fabricating my own frame and must have this size. "Hillhater" thats a good option I would just need to find a front wheel that would accept a disk brake. Does anyone know how long shipping is from leaf bike to USA?

 

[Chalo]

The only issue I have with lacing my own wheels is how hard it is to find wheels/tires/hubs for a 20x4 size rim.

It's easy and cheap, because of those crappy chopper bicycles from the early 2000s I was talking about.

https://www.niagaracycle.com/categories/sunlite-xl-cruiser-tires-20-x-4-1-4-black-black

https://www.niagaracycle.com/categories/weinmann-alloy-rim-20-x-4-1-4-36h-black

 

[stuxtruth]

But by the time you factor a front hub and discs in your better off just buying something like this for parts.

https://www.amazon.com/gp/aw/d/B00X6DDQBS/ref=mp_s_a_1_12?ie=UTF8&qid=1500495669&sr=8-12&pi=AC_SX236_SY340_QL65&keywords=mongoose+fat+tire

 

[DRMousseau]

It's easy and cheap, because of those crappy chopper bicycles from the early 2000s I was talking about.


https://www.niagaracycle.com/categories/weinmann-alloy-rim-20-x-4-1-4-36h-black

And "cheap" is probably what you'll get, because,... "You get what you pay for!"

Since I too am currently designing and constructing a new build that specifically requires a good quality 20" "fat bike" rim, I too have had the same difficulty! AND, the difficulty is made even greater by the rather unclear and/or deceptive (intentional or not!) practices of manufactures, distributors, dealers and sellers! Buyer BEWARE! Yes,... you can easily get "cheap" and "crappy chopper bicycle" rims (most notably, Schwinn OCC Chopper), and I've seen SOME cheap single-wall steel and alloy rims. But what of us who REALLY, want a good double-wall alloy rim, like anyone else!

I'm sure the site noted here is very reputable, but this particular item (linked above) lacks the important info and specs. that I need to know! It does NOT specifically state that it's double-wall, or that it's Weinmann's DHL-101 or any other specific Weinmann description. It states "4-1/4 inch",.... HA! Is that max Tire fitted? or actual rim width??? The Weinmann site specs the DLH-101 as " 20x3.0-4.1/4 " and accompanying cross-section dimensions overall width of the double-wall rim at " 100 ", (I HATE the mix of SAE and Metric, especially without denoting inch or mm!!! And I won't touch the issues of SAE vs Metric in this topic,... ARGH!!!) The illustration in the link above, does not have a Weinmann label as others on their site do, but I could find no matching illustration on the Weinmann site. Strange that I see listings for 26" DLH-101 that are more than TWICE the cost of that 20" Weinmann rim, so I'm left wondering if this is jus a "cheap and crappy" single-wall rim. The apparent drilled hole spacing and location is also important to me when considering a hub-motor.

From the... "best bang for the buck". thread above..
http://www.leafbike.com/products/diy-bike-conversion-kit/20-inch-electric-hub-motor-kit/20-inch-48v-2000w-rear-hub-motor-beach-snow-fat-tire-bike-conversion-kit-1086.html

I noted this on the thread above, as my choice of purchase,.... they spec the rim as "Rim: 20 × 3" double wall Alloy ( Fir for 20 × 4.00" tire )", Fir??? LoL!!!. Not exactly what I want,.... as I truly desire a 100mm or 4" overall width. I didn't find that Leafbike has yet made this particular hub-motor available separately, as I would indeed lace it to a desirable rim myself! Although this kit will limit me to the "minimum spec" of my design, a max tire size of 130/90-16,... I will still build to my desired rim and tubeless 160/80-16 tire, with hopes I'll eventually FIND available that good desirable rim.

Soooooo,.... WHERE can one REALLY get a good 20" double-wall 100mm rim??? or a 20" Weinmann DLH-101 rim?? Can you order from Weinmann direct??? And what of that rim listed? IS it a double-wall rim???

Other notes-
It was jus over a year ago that last ordered from Leafbike. Don't remember exactly how long it took, but I DO remember being VERY surprised at how quickly I had received my order.

And YES,.... a 160/80-16 tire IS about 6 1/2inches wide and also 26" in diameter. Note the motor above has an "install: spacing of 170mm or more", with "Freewheel / Cassette: space for 6 or 7 gears". I'm ALSO designing for a single speed and MAY need to be a little "creative" to accommodate chain-line.

 

[Chalo]

I don't think you'll ever find a double walled 20" fatbike rim. Even the single walled ones have a great surplus of strength for any normal use. I mean, look at what the MTB fatbike rim makers are doing-- blowing the things full of huge holes to save a little weight, but in the process gutting out whatever strength they have. And yet they still work for off-roading.

Given that 20" rims are stronger than 26", and non-cutout rims are stronger than ones that are skeletonized, and that the 26" skeletonized ones seem to be doing the job anyway, there just isn't much incentive to make a double walled version of the fat 20" rims that probably have a lot of unsold stock as it is.

Edit:
As for 20 x 4-1/4" tire quality, Kenda chopper tires are relatively good. They're also branded Sunlite. Vee Rubber and Schwinn branded tires are wretched.

The reason you see that size designation (20 x 4-1/4") is because that's what Pacific/Schwinn decided to call it when they invented it. The bead seat diameter is the same as 20" decimal sized tires (ISO 406), but there's no real intercompatibility due to width, therefore there's no reason to use a uniform designation.

100mm is the outside width of the rim. 4-1/4" is the nominal width of the tire, which of course varies with the rim, inflation pressure, and model of tire.

 

[DRMousseau]

Thanks guy! Ya kinda summed up the horrible issues of those us looking for 20" "fat rims" for hub-motors. Single-wall rims lose a lot of integrity with narrow spoke-hole offsets, drilled or not, steel or alloy. But the simple single-wall rim with wide offset gains alot from wide hub flanges for which they're intented.... but hub-motors are dang narrow!!!
Drilled rims, single or double wall, tend toward slightly wider offsets, while solid double-wall constructions are designed and engineered for a narrower offset,... with considerations of wide multispeed hubs that are becoming popular and commonly available in 24-26". The carefully designed cross-section of the extrusions used in the DLH-101 are VERY desirable to me for such purposes. Internal support structures, thick spoke ridges set more narrow than others, in a solid undrilled rim makes it much better suited for large hub motors, than many, many others... well, except for the nasty spoke angle that the short spokes will set at. And I can easily accommodate that. :wink:

I don't think you'll ever find a double walled 20" fatbike rim.

Weinmann lists and specs a 20" double-walled DLH-101 on their site.
But, jus WHERE can I purchase those 20" DLH-101s or something very closely equivalent?

The consumer market must drive manufactures insane!!!!

 

[Chalo]

When building hub motors on wide rims with lots of hole offset, I usually lace spokes to the opposite side of the rim for more bracing angle.

 

[DRMousseau]

When building hub motors on wide rims with lots of hole offset, I usually lace spokes to the opposite side of the rim for more bracing angle.

Increasingly wider rims typically have greater offset, and most notable in single wall rims. "Fat Rims" have INSANE offset!

But I'm thinkin even the lesser offset of the DLH-101 would benefit from lacing like that. The Leafbike assembly noted in previous posts, is on a 3" (80MM?) rim. It "appears" to be laced typically, but I wonder if it too might not benefit more from "opposite" lacing. I noticed that the illustrations depict spokes with elbows inside the flange, and somewhat appears to angle outward toward the rim rather than inward toward the rims center, due to offset of the nipple holes.

Jus how much does this lateral angle across rim and hub affect the wheel assembly??? and in what ways??? This lateral bracing angle IS important, as no angle makes for a parallel "frame" that offers no lateral support and would see parallel movement in line with axle and could never be "trued". But aside from rim support, is there any advantage to inward vs. outward spoke support on narrow flanges with strong rims???? Stress on hub flange maybe??? or other stresses??? CAN wide rims offer a benefit from outward support from the hubs??? And what will effect the short (+/-100mm) stocky spokes of small rims on big hub motors???

Had I ever laced hundreds of rims, I'd likely know,... but I'm limited to jus few dozen in my lifetime. And no great ventures into the unknown! Any experience or understanding of the dynamics here?

Big motors on small spoke Fat rims are a PAIN!!! lol