19" Motorcycle Wheels vs 26" Bicycle Wheels (rim and tires)

[ohzee]

roadrash just recently built one of those for myself with a 19 from wheel with a 20mm axle. It looks choice.

What size wheel are you going with ? I will go out and measure mine in a moment and reply.

 

[Rix]

I'm getting a wheel built by roadrash to mount on a dnm usd-8 dual crown fork with 20mm thru axle. The Shinko 241 2.75x19 (what I want to use) is actually 3 inches when inflated. Does anyone know if it will fit in between the stanchions. If no one knows I should be getting the fork on Friday and will post the answer here.

Yah, it should fit just fine. here is a pic of my old Bomber with the 2.75-19 Sr241 on the front with Marzocchi 888 forks. Have about 1/4 inch between the tire and the fork leg. Clears just fine.

 

[ohzee]

my 19" front is 81.5mm at the widest point with that tire and the rear 17" is 82.6mm

also has about a quarter inch on each side front.

 

[100volts+]

roadrash just recently built one of those for myself with a 19 from wheel with a 20mm axle. It looks choice.

What size wheel are you going with ? I will go out and measure mine in a moment and reply.

Either prowheel 19x1.4 but roadrash is also looking at yamaha playbike motocross 19x1.4 which is what is have in back and Shinko 241 19x2.75 tires

 

[GiantEV]

I'm getting a wheel built by roadrash to mount on a dnm usd-8 dual crown fork with 20mm thru axle. The Shinko 241 2.75x19 (what I want to use) is actually 3 inches when inflated. Does anyone know if it will fit in between the stanchions. If no one knows I should be getting the fork on Friday and will post the answer here.

It'll fit. This is the same fork and tire combo I'll be going with as well.

Here are the dimensions from DNM's site:

 

[richdeloup]

Just for reference, the Shinko 241 2.75x18's will fit quite a few standard (non UD) forks, as the height is just below where the brace starts to taper in. 3.0's prob won't...

 

[Kent]

For those who have finished and mounted their wheel/tires, Roadrash has started a thread for everyone to share their stuff

http://endless-sphere.com/forums/viewtopic.php?f=6&t=65293

Be sure to make detailed photos and a build link so we can check out your build!

 

[Rix]

For those who have finished and mounted their wheel/tires, Roadrash has started a thread for everyone to share their stuff

http://endless-sphere.com/forums/viewtopic.php?f=6&t=65293

Be sure to make detailed photos and a build link so we can check out your build!

Yah Kent, I posted up a few of the Fighter and Bomber. That thread road rash started up is neat, its not a tech thread, but more like a photo thread. If wen can get the workd out, maybe build it up to a couple of thousand pics over the next couple of years or so.

 

[richdeloup]

Could anyone give me the low down or link me to a thread about wheel sizing. I've noticed that lots of people are running really small back wheels and larger front, is this for torque purposes? I'm trying to equate it all to motorcycle world, where smaller wheels are more common all round?

 

[John Bozi]

There isn't really much to say that you don't guess.

If you have hills the smaller the better. If you have to ride slower where your motor is spending time out of its sweet rpm smaller is better. If you realise you are doing lots of starts and stops smaller is better.

you are giving up ground clearance, original geometry of the bike to the ground, normality of what a bicycle looks like.

ground clearance would mean then you are losing out on the torque of longer cranks, the possibility to pedal at high speeds with a large chain ring.

If you want to follow someone who preaches smaller is better than anything else you can do such as change winds - follow John CR.

As for me 20"/26"x100 = 77% 100-77= 23% increase in torque and being in the right rpm = 23% increase in better heat handling. Then add venting, I reckon overall more than double my ability to climb mountains off road.

If your just riding flat normal (what the motor was designed for) speeds don't bother.

 

[richdeloup]

Thanks John, makes sense.

I suppose modern motorcycles dont have to factor in torque vs speed as much as vintage ones needed to, in order to make up for lower HP.

Sort of guessed it but good to know for sure.

 

[madin88]

smaller wheel = less torque needed for the same forward thrust = less amps needed = less heat in the motor
higher battery voltage or motors with higher kV will give you same top speed while still being more efficient under high load.
aside from ground clearance another bad thing about small wheels is the handling of the big unsprung motor mass. bigger wheels are definitely more comfortable. I think 17" moped wheels are a good balance.

 

[John Bozi]

smaller wheel = less torque needed for the same forward thrust = less amps needed = less heat in the motor
higher battery voltage or motors with higher kV will give you same top speed while still being more efficient under high load.
aside from ground clearance another bad thing about small wheels is the handling of the big unsprung motor mass. bigger wheels are definitely more comfortable. I think 17" moped wheels are a good balance.

ah yes I knew I forgot something, longer spokes more suspension, and going small enough might mean radial lacing and worse transfer of power to the ground.

Having said that if you come from riding a hard tail 26" normal stock light tyres for example and then ride my 19" rim radial laced on full suspension and soft fat 2.5" tyres you'll still feel like your riding in the clouds. Touch wood no spoke breaks yet.

 

[Offroader]

Smaller rim allows for fatter tire. The 17" 3.00 tire is much fatter then the 19" 2.75. Fatter tire has much better ride because it cushions that heavy hub motor.

bigger rims are not always better, bigger tires are. That is why 19" tires are crap because they are designed for front tires and are not fat.

Ground clearane and small tires are not an issue with properly designed bikes like the raptor which allows for adjustable suspension.

Smaller diameter tire is hands down better, I would never use a 19" tire again. Sweet spot is 17" 3.00 tire.

 

[John Bozi]

Smaller rim allows for fatter tire. The 17" 3.00 tire is much fatter then the 19" 2.75. Fatter tire has much better ride because it cushions that heavy hub motor.

bigger rims are not always better, bigger tires are. That is why 19" tires are crap because they are designed for front tires and are not fat.

Ground clearane and small tires are not an issue with properly designed bikes like the raptor which allows for adjustable suspension.

Smaller diameter tire is hands down better, I would never use a 19" tire again. Sweet spot is 17" 3.00 tire.

3" would be dam sweet, but motorcycle wheel just adds to the problem of a snake eating its tail of unsprung weight.

My 19" rim is still running bicycle dx32 and kreepy crawler tyre. sure I'd love your wheel for longevity though but not for more weight again...

EDIT: I searched for a long time for the shinko but the weight makes shipping ridiculous to Australia
I can easily replace my bicycle tyrre for half to a third the cost.

Edit 2: easier in more ways than one: https://www.facebook.com/video.php?v=586186431515432&set=vb.250864551714290&type=2&theater

 

[Offroader]

The shinko 241s are designed to be light weight. The 3" tires have deep knobs also.

Running the 3" with about 14psi offers a very nice ride and you feel the heavy rear a lot less.

It is honestly worlds above the 2.75" tires and improved my riding ability drastically. Yet everybody is stuck on the crappy 19" 2.75.

 

[adriftatsea]

This thread is full of great info - but the data on tire width is all over the place. The first post mentions the 2.75" Shinkos are really '2.95 inch' - but it's clear from other posts that this isn't the case. Additionally, it seems there is no info on tire combo widths for the 19x1.6 that Holmes Hobbies and Roadrash are selling :/.

I have ran Shinko SR241 17x2.75, 18x2.75, and 19x2.75 on ebikes for a while. Every one of these tires is at least 3.2 inches wide or wider, and that's a on a narrow 1.4 wide rim. Shinko lists them as 2.95" wide on their website. As I learned from Zombies build, the 2.75x19 he is running on 2.14" wide rims is over 3.3 inches wide
...You can't always trust the manufacture listed data.

source

Can someone confirm the actual width of these tires? I'm seeing 2.95" and 3.3" in this thread for the width of the Shinko 19x2.75" tires. Preferably pictures with calipers at the thickest part of the tire!

I went back and collected what I could find from the past 30 pages in hopes we can keep a running table of motorcycle rim/tire combos.


|-----------+---------------+-------------+------------------|
|  rim      |   tire          |  width     |  source           |
|-----------+---------------+-------------+------------------|
| 19x1.40 | SR241 2.75 | 3.1"         | Rix                |
| 19x2.00 | CST    2.00 | 2.04"       | giantev          |
| 19x2.14 | SR244 2.75 | 3.3"         | zombiess       |
|-----------+---------------+-------------+------------------|
| 20 bmx  | 19x2.75     | 2.96"        | richdeloup     |
|-----------+--------------+--------------+------------------|
| 21x ??    | ???             | 3.57"        | 2007blueprius|
|-----------+---------------+-------------+------------------|

 

[amberwolf]

Some other related info:

http://www.endless-sphere.com/forums/viewtopic.php?f=5&t=16834

http://www.endless-sphere.com/forums/viewtopic.php?f=11&t=20282

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=16908

 

[richdeloup]

20 bmx | 19x2.75 | 2.96" | richdeloup |

I think this should be 22 bmx 18x2.75 Tyre is Continental contigo, if we on the same post?

 

[richdeloup]

double posted?

 

[richdeloup]

Can someone confirm the actual width of these tires? I'm seeing 2.95" and 3.3" in this thread for the width of the Shinko 19x2.75" tires. Preferably pictures with calipers at the thickest part of the tire

I think that this can vary a bit depending upon the width of rim the tyre is being squeezed (or no) onto.

Narrower rim may pull the width in slightly and make it slightly taller and vise versa?

Warrah and myself couldn't figure out why we had pretty much the same ride height with him running 19's and me on 18's, we think it was rim width.

 

[adriftatsea]

I think that this can vary a bit depending upon the width of rim the tyre is being squeezed (or no) onto.

Agreed. That's why I'm trying to keep track of rim+tire combinations since it varies with rim width.

20 bmx | 19x2.75 | 2.96" | richdeloup |

I think this should be 22 bmx 18x2.75 Tyre is Continental contigo, if we on the same post?

Thanks Rich! I updated the chart.

|-----------+----------------+-------------+------------------|
|  rim      |   tire          |  width     |  source           |
|-----------+----------------+-------------+------------------|
| 19x1.40 | SR241 2.75  | 3.1"         | Rix                |
| 19x2.00 | CST    2.00  | 2.04"       | giantev          |
| 19x2.14 | SR244 2.75  | 3.3"         | zombiess       |
|-----------+----------------+-------------+------------------|
| 22 bmx  | 18x2.75      | 2.96"        | richdeloup     |
|              |Contintental|               |                      |
|              | Contigo      |               |                      |
|-----------+---------------+--------------+------------------|
| 21x ??    | ???              | 3.57"        | 2007blueprius|
|-----------+---------------+-------------+-------------------|

 

[richdeloup]

Agreed. That's why I'm trying to keep track of rim+tire combinations since it varies with rim width.

Yep sorry,just realised that

Not sure if ride height has been factored in before, It probably has?

 

[richdeloup]

rim size 19x2.14

Do you know if the manufacturers rim width is usually internal or external, guessing external? ill get my measuring stick out and get a list up of the various combos that I have laying around....

Maybe a ride height box and total combo weight (front wheel, no motor) would also be in order for quick reference? edit: hmm then front hub, spokes and tube need to be accounted for, maybe just the weight of bare rim and tyre if possible?

 

[johnrobholmes]

moto rims are measured by the internal width of bead seat. Bicycle rims are measured by the external width.