Rear wheel selection

[Vintagesplash]

Ok, I'm building a CR/KDX hybrid and need to decide on a rear wheel.

What are the pros and cons of the 18" and 19" rear wheel setups?

Why do mx bikes come with 19" wheels over 18"?

Old fart needs to know!

 

[XRpredator]

I don't know why they went to 19" on the MX bikes, other than maybe the lower profile tire doesn't "wrinkle" (think top fuel dragster) under load like the 18" might. Of course, I'm talking out of my ass . . .

But, on the other hand, I'd imagine the 18" rim/tire combo would give you just that little bit more shock absorption and keep your rim from getting dinked. But that's just my imagination.

 

[Vintagesplash]

That sounds as plausible as any other explanation. I'll try to find a 18" wheel.

 

[Oldman125]

I don't know why they went to 19" on the MX bikes, other than maybe the lower profile tire doesn't "wrinkle" (think top fuel dragster) under load like the 18" might. Of course, I'm talking out of my ass . . .

But, on the other hand, I'd imagine the 18" rim/tire combo would give you just that little bit more shock absorption and keep your rim from getting dinked. But that's just my imagination.

You're on the right track (no pun!)
The 19" on modern MXers has less sidewall flex and a wider foot print, keeping the knobs in better contact with the ground and allowing less slide in modern MX/SX riding styles.
The 18" works well off road as it does have more bump absorption. They can ride through rocks or over roots better than the 19s with a narrower foot print.

Relate it to the 14 inch rims on a passenger car vs. 19s on a road racing style car.

 

[ebeck]

Hey, I built 2 KX/KDX Hybrids!
http://www.dirtrider.net/forums3/showpost.php?p=1285123&postcount=19


The increased sidewall reduces pinch flats and offers more absorbtion of rocks and what not. Offroad 18 MX 19.

 

[Vintagesplash]

So far all I have been able to find used are 19". If I find one cheap enough, I'll buy the 19 then lace up a 18.

Ebeck, I have ogled your builds. You and Lengendboy are my inspiration for this build.