I'm looking to replace the back tires on my Xpress and can't decide which way i should change my tire size either one inch larger or an inch smaller or stay the same any suggestion's. I'm looking at getting a set of Dirt Devils.

 

Going a size smaller will reduce your ground clearence. Going a size bigger will add weight and you will loose performance. Dirt devils are a heavy tire and a rough ride on the hardpack. Check out the maxxis surtracs, they kinda look like the spidertracs only they last much longer. I have them on my machine and they can take any punishment that I can dish out. Dirt Wheels magazine calls them a rubber triathelete. Hope this helps you out.

Keep on riding!!

 

They also change your overall gear ratio. Smaller tires will get you out of the hole faster but lose a bit of top end. Bigger tires will take longer to get wound up, and should have higher top end if they are not too heavy and the motor can pull them.

 

I have run everything from 25" to 22" tires on my Xpress. I currently have 22" Titan489XT's. I like the smaller tires myself. The larger tires have too much give in the side walls for my liking.

To answer your other question, I gained about 3-5 MPH with the 25" tires. It didn't really take much off my bottom end. It still pulled about the same.

Like I already said, I really like 22" Titan 489XT's.