Can a MH90-21-56H wheel be used on a 21x3" rim? If so how safe is it to do so? What would be the best tire size to use with this size rim?

 

No.MH 90 is for a rim width of 2.15. A 120 -70-21 would work on a 21x3

 

Thank you. I just purchased a nice used DNA wheel with this size wheel on it. Is safe to use this wheel for now?

 

Let me step back a little on my original statement. It is "not recommended" to run a mh 90 on a 21x3 rim.Some shops won't even mount that size tire on a 3" wheel(saftey reasons).If they do they may make you sign a waiver . But many people have stretched a MH 90 on to a 21x3 w/o any problems.Some have even put it on a 21 x 3.50 rim but that is REALLY stretching your luck IMHO.I'm sure it will be fine.But that is something you have to feel comfortable with.I would not do it .But maybe I'm just a pus . Like I said many have done it on here with 0 problems.I would just keep a watchful eye on it,and make sure it is always properly inflated.

 

Thank you Malingerer. The guy I bought wheel from said he put about 1k miles on it with no problem. On the tire it says max 40 psi cold, does that mean I should always keep at 40 psi?

 

If you check some brands on line they say up to 2 3/4 wide. From a general rule going to a wider rim within the tolerance of the width is safer then going to a smaller width rim. I would look up the 1-800 number of the manufacturer and ask him the tolerance for the rim width. I assume there is a tube in it. If the manufacturing said no I would listen to him. I am sure it would be OK for normal driving but who knows when you may need the safety tolerance.