The holy grail for ebike wheels - 22 inch BMX rims = 18" motorcycle wheel diameter

neptronix

Administrator
Staff member
Joined
Jun 15, 2010
Messages
17,406
Location
Utah, USA
Recently when shopping for oddball wheel sizes for my recumbent, i stumbled upon 22 inch BMX rims, which recently came into fashion. As of writing, there are at least 4 manufacturers of these rims.

Here's some examples: https://www.modernbike.com/22-inch-rims

A few of these rims come in 457 ISO size; and 18" motorcycle wheels are also 457 ISO :mrgreen: ( note that motorcycle tire measurements and bike tire measurements are completely different. A 16" motorcycle wheel is a 20" bike wheel, for example )

An 18" motorcycle wheel with the right moto/scooter tire roughly comes out to 24" in bike size, so for bikes with 26" wheels, you can get away with using a single 18" moto rear, as it should only drop the rear about an inch.

This is great because normally an 18" motorcycle rim and spoke combination would be about 4-5lbs, whereas with a 22" BMX rim, we're looking at more like 1-1.5lbs.

IF you want moto rims on both wheels, then this plan doesn't work and you need to step up to 19", however there is no bike rim equivalent in that size, so you're stuck with extremely heavy wheels and a difficult wheel build overall.

Here is a damned good thread showing how 19" moto rims + tires can be within an inch of 26" bicycle size. ( therefore, 18" can be within 2 inches if 26" - resulting in a rear drop of just 1 inch )

https://endless-sphere.com/forums/viewtopic.php?t=55458

In my experience, going dual motorcycle wheel is completely unnecessary on an upright bike because around 70% of your body weight is on the rear, therefore the rear is most likely to puncture and also needs the most traction. The front wheel is doing a fraction of the work, so the main reason you'd want a moto tire up front is for traveling at highway speeds, or perhaps just aesthetics.
 
spinningmagnets said:

Isn't it amazing how cheap these motorcycle tires are compared to bike tires?

That would come out at a 24.8 inch outer diameter. Resulting rear drop on a 26er would be 0.6-0.8 inches. I imagine that the tire could contact the frame on some bikes.. perhaps 2.75" would fit a majority of bike frames and still be within that desirable ~1 inch rear drop max..

The most narrow 18" moto tire i've seen is 2.25" wide. 2.5" seems to be a common size.
 
Nice post!

Looks like a great option, 22BMX bicycle rim with motorcycle/scooter/moped tires.

Don't forget treadland.tv for a source of tires. Though they are quite expensive for shipment into Canada eh


More rims to choose from....
https://www.danscomp.com/bmx/Parts/Rims/
Nothing yet, at Chain Reaction Cycle
 
Article
The Rise Of 22″ Bikes
https://bmxunion.com/daily/the-rise-of-22-bikes-bmx/
The guys at Faction BMX were the first to start trying out this unique size that fit right between 20″ and 24″ bikes way back in 2002. It was a very small niche in the BMX industry that was geared toward riders that wanted something a little bigger than a traditional BMX bike, but didn’t want to go for an all out cruiser bike. It wasn’t a huge change, just slightly bigger wheels, fork and frames, really. This story of the rise of 22″ bikes originally started 15 years ago.
 
ppl I know that tried this almost died when their 18" moto tires came unseated from the 22" bike rims at speed.. so keep that in mind if you plan highway speeds on this setup.. its a loose fit and you need a wide rim.. (ask barn burner motoped builder if you need more evidence)
 
Maybe you can just use standard 18" moto rims instead of the BMX rims?

This way you can get angled spoke holes in the rim, which would make lacing up a hub motor easier.
 
efMX Trials Electric Freeride said:
ppl I know that tried this almost died when their 18" moto tires came unseated from the 22" bike rims at speed.. so keep that in mind if you plan highway speeds on this setup.. its a loose fit and you need a wide rim.. (ask barn burner motoped builder if you need more evidence)

I've never heard of such a thing. What sort of 22" rims were being used?
Were they using the older narrow 22" rims instead of the wide BMX ones i'm talking about?

I've put alot of miles on 20" bike rims with 16" motorcycle tires. The fitment has been excellent every time.

sleepy_tired said:
Maybe you can just use standard 18" moto rims instead of the BMX rims?

This way you can get angled spoke holes in the rim, which would make lacing up a hub motor easier.

You could, but the rim and spoke combination would be 4 times heavier. You also would need to drill spoke holes of the appropriate diameter into the hub itself, because motorcycle rims are designed to use 6-10 gauge spokes generally.

It is a lot easier just to deal with 13 to 14 gauge butted spokes, because any average bike shop could build your wheels for you. Whereas with using motorcycle parts, just finding someone to cut the spokes can be difficult.
 
Rix and I warned about this combo in the other thread ..

if the tires go on the rim easily then also can come off easily, especially from a flat or impact, pothole, etc.. if it requires heavy duty metal tire levels to mount the tire then it will not likely unseat without those same tools..

neptronix said:
efMX Trials Electric Freeride said:
ppl I know that tried this almost died when their 18" moto tires came unseated from the 22" bike rims at speed.. so keep that in mind if you plan highway speeds on this setup.. its a loose fit and you need a wide rim.. (ask barn burner motoped builder if you need more evidence)

I've never heard of such a thing. What sort of 22" rims were being used?
Were they using the older narrow 22" rims instead of the wide BMX ones i'm talking about?

I've put alot of miles on 20" bike rims with 16" motorcycle tires. The fitment has been excellent every time.



sleepy_tired said:
Maybe you can just use standard 18" moto rims instead of the BMX rims?

This way you can get angled spoke holes in the rim, which would make lacing up a hub motor easier.

You could, but the rim and spoke combination would be 4 times heavier. You also would need to drill spoke holes of the appropriate diameter into the hub itself, because motorcycle rims are designed to use 6-10 gauge spokes generally.

It is a lot easier just to deal with 13 to 14 gauge butted spokes, because any average bike shop could build your wheels for you. Whereas with using motorcycle parts, just finding someone to cut the spokes can be difficult.
 
efMX Trials Electric Freeride said:
Rix and I warned about this combo in the other thread ..

if the tires go on the rim easily then also can come off easily, especially from a flat or impact, pothole, etc.. if it requires heavy duty metal tire levels to mount the tire then it will not likely unseat without those same tools..

Yeah, if you can get it on by hand, that's a problem, right? i've never NOT had to bust out the 1lb ea. steel motorcycle tire levers out to fit my 16"s..

Maybe what you saw is someone using a 22" rim with a 440 ISO diameter. Because companies are selling those for bikes also. I imagine that a 18" motorcycle wheel ( 457 ISO ) in a 440 rim is a mechanical fail in the making, but possibly the difference in diameter wasn't enough to tip the guy off.

If you can point me at the other thread, i'd like to chip in and ask some questions. Because i haven't tried this idea out myself, and if i'm wrong about this idea, it'd be nice to get it sorted asap.
 
should be ok as long as the tire requires effort and tools to mount.. more effort more safety.. (only briefly mentioned prior due to possible loose fitment).. remember to also match tire and rim width.. a heavy bike cornering could result in tire burp without good rim width and tight fit.. interested to see your results..

https://endless-sphere.com/forums/viewtopic.php?t=55458&start=1325
 
Try looking for 19" BMX trials rims and tyres.
I found that a winner.
They are for people who hop up and down on the BMX balancing like a unicycle.
 
monster said:
Try looking for 19" BMX trials rims and tyres.
I found that a winner.
They are for people who hop up and down on the BMX balancing like a unicycle.

Interesting. I'd never heard of these for pedalbikes until now.
https://www.tartybikes.co.uk/19_inch_rims/c517.html

Those rims seem to have an ERD generally of 374mm, which doesn't have a motorcycle tire equivalent. If there was such a motorcycle tire, it'd be referred to as 14.5".

This is an interesting size for putting a really fat tire on something that came with 20" wheels but doesn't have the space to fit. I imagine that's why it exists in the trials world.
 
The We The People Logic 22" from Modern Bike has a 33mm rim width external,
"Also states "Extra thick sidewalls to resist denting" and "Hub Drilling: 36"
Which means that the internal width is lets say 30 or 31mm.
That would mean you could stuff a 3" tire in there if the frame allows.
I like it.
Match with Shinko SR241 2.75-18 Front/Rear Tire

If a classic fat bike 26 x 4.00 is ~29" overall diameter.
Then whats a 24 x 3 or 22 x 3 overall diameter, say what 25" and 27". Might be a good setup for more torque in a fat bike with its smaller wheel.



neptronix said:
 
You save about 2.5 lbs on the wheel, but still use a 9 lbs tire and that is a big efficiency loss. Let’s say you must really need it.

-For traction: nope, good bicycle tires have a better grip than motorcycle tires.
-For braking: nope, the weight of a motorcycle tire has a greater momentum, thus braking and acceleration performance loss.

So it is about puncture resistance, and saving money on the long term, at the cost of lesser efficiency and performance.
 
markz said:
The We The People Logic 22" from Modern Bike has a 33mm rim width external,
"Also states "Extra thick sidewalls to resist denting" and "Hub Drilling: 36"
Which means that the internal width is lets say 30 or 31mm.
That would mean you could stuff a 3" tire in there if the frame allows.
I like it.
Match with Shinko SR241 2.75-18 Front/Rear Tire

If a classic fat bike 26 x 4.00 is ~29" overall diameter.
Then whats a 24 x 3 or 22 x 3 overall diameter, say what 25" and 27". Might be a good setup for more torque in a fat bike with its smaller wheel.



neptronix said:


What is the real diameter of a wheel using a 20" rim with a 4 inch tire ?
 
A 20 inch bicycle tire that is 4 inch wide could make 22 inch OD when inflated hard. Yet the proper PSI for fat bike tires is pretty low, so it should make effective 21 inch.
 

Attachments

  • 2021-05-25 10_56_39-FIT BIKES 22 INCH ARC BLACK RIM 22_ BMX BIKE REVENGE S&M FACTION 36 WTP _ ...jpg
    2021-05-25 10_56_39-FIT BIKES 22 INCH ARC BLACK RIM 22_ BMX BIKE REVENGE S&M FACTION 36 WTP _ ...jpg
    117.1 KB · Views: 1,772
Well, same ERTO and we see the tire is properly fitted in the picture.. no reason to believe it won't work other than rim lip fitment, which has never been a prob for me with 16" moto tires on 4 different bike rims.

I've got a 22" rim on order now, so i'm signing up to be the test hamster for this one.
 
The fitbike rim is here and looks like a very nice rim.

Went to a few moto shops to look at 18"s. All of them were 3.0" or above and weighed a ton. The diameter seems to be a perfect match but there's no way a test fit would have been possible.
Sava B3 18 x 2.25 ordered from treatland.
 
The tire is a very good fit!!!! no wrangling with a tire iron etc needed! admittedly this Mitas B3 is the wimpiest of all 18" tires, but.. :)

okat9g5b.jpg

0auaujd1.jpg

Compared to a 24" wheel, this wheel is 1.25" less tal, so this 18 x 2.25 tire is more like a 22.75". Throw a 2.5" tire on and you're at a perfect mid-point between a 20" and 26" wheel.

So yes, if you want the benefit of a smaller wheel and more rubber on an upright bike, this is the way to get it. 8)
 
For what it's worth, the latest version of Rad Wagon uses 22 x 3.0" tires. If there's a drawback to that, it's that you can only get those tires from Rad Power at the moment.

RadWagon4_Orange_Sidewall_600x.jpg
 
Oh no, there's tons of 22" BMX tires and also 18" motorcycle tires ranging from 2.25" - 4.0".
There's something out there that will fit it for sure.

The bike would be quite posh with a front 20" suspension fork and front 20" wheel to balance out the geometry.. The front suspension will take some of the hits in the rear. Throw one of the lighter moto tires on the back and it's even better.

It's a good thing that 22" tired bikes are becoming more popular :)
 
neptronix said:
Oh no, there's tons of 22" BMX tires and also 18" motorcycle tires ranging from 2.25" - 4.0".
There's something out there that will fit it for sure.

I mean if you want to use 22 x 3.0 bicycle tires, there's just the one hookup at the moment. BMX tires don't get that fat yet, and motorcycle tires feel like they're filled with cheese singles instead of air.
 
Back
Top