This question comes up nearly as much as what sprocket size to run. And the answer is not always easy so let’s dive into some pros and cons of each.

The 4.25” rear rim will fit ALL bikes. You do not have to worry about this size fitting your bike and it is the most commonly run rear rim size on Supermoto conversions. The 4.25” will install without much hassle and will keep the chain in line much better than a wider 5”. It is also considered to have a better “feel” and handling when cornering and riding through those fun and curvy canyons. If leaning into corners and really “feeling” the road is your thing, stick with a 4.25”. The commonly run tire size on a 4.25” is a 150/60 although you can run a wider 160/60 It will “balloon” around the rim more than the 150/60. PROS: Easy to install. Fits all bikes without rubbing issues. Best for cornering and leaning into. CONS: The narrower size may reduce contact patch and have a “narrow” or small look on larger machines.

The wider 5.00” is just that, wider. It will give you more contact patch with a wider 160/60 tire but is too wide for several models and harder to install and others that it does “fit” on. We’ve found that most people that want a 5” just like the look of the widest wheel possible. And, while we agree it can look great, it may not be the best choice for overall riding, and it may be a headache to install. Some bikes are known to fit the 5” without issues and customer feedback has shown they enjoy the larger rear on these bikes. They include KTM 500EXC and 690 Enduro; Husqvarna FE501 and 701 Enduro; WR450F’s and CRF450R’s. Other models we get conflicting reviews of fitting with ease and being a real pain in the @$$ to install! Models that the 5” is known to not fit and we will not sell a 5” rim for are: all XR models, CRF250L/300L, DRZ400’s, RMZ’s, DR650, KLR650, all KX/KX-F’s, and WR250R/WR250X. PROS: Larger contact patch with the asphalt, best for larger displacement models. CONS: Difficult to install, may rub with certain tires.

In conclusion, the 4.25” will fit your bike no matter the model. It will be easier to install, more readily available, and is still quite wide when you consider the average dirt bike rear rim is just 2.15” wide! The 5” can look really nice—especially on larger displacement bikes—and adds some contact patch area. The choice is ultimately yours! We want to offer you options but also insights into those options so you can make the best choice possible for your new wheels. We love to ride and want you to love your ride with your new wheels!