rims-n-tires

[450RACER1]

can anyone tell me the why i would want to switch to 18 inch rear tires and 20 inch fronts what is better about them and what is worse???:huh

[Scro]

Smaller tires are normally used for MX racing. The smaller tires lower the center of gravity, allowing better cornering. The smaller sidewalls also decrease the amount of flex in the sidewalls, which also allows better cornering.

The downfall is the fact that you lose ground clearance. But, most MX tracks, clearance is not an issue.

[Ty's400]

The smaller size is preferred in motocross for turning and lighter weight. They also have a stiffer sidewall for the impact of big jumps. Disadvantages would be lower ground clearance and not as heavy duty (puncture wise) of a tire, per say for trail/xc riding.

[81built2hill81]

To Take That Question Maybe One Step Further. Why Do You Run 8" Rims Instead Of 9" Or 10" Wouldnt They Have Even Less Sidewall Flex? Please Dont Flame Me I Would Just Like To Know.

[Scro]

If you ran a 9 inch rim with 18 inch tire, you will likely bend the wheel, since the sidewall will then be too thin.

[the 97]

If you are riding mx run 18s on 8in rims.......xc 10 inch rim 20s n up.....beadlocks are a good idea eather way.

[Flyin-Low]

18's on 9 in. rims are great because they have almost no sidewall flex, but most people run them on 8 in. rims because there is less of a chance of destroying the rim.


-Martin

[81built2hill81]

thats kinda what i figured but i figured i would just ask. I Know Aluminim Rims Bend But What About 9" Hypers On 18's. Do They Break?

[whiteboycustom]

its gonna take alot to break that hiper, its not just gonna bend like a aluminum rim, and i dropped to 18's and i rev out hella fast and lost top end, i want to change to a 13 tooth front sprocket and see what that does

[quad janern]

yeah that happend to me too.

how big front tires do you guys use in mx ? is it 20" or 21" ?
-j

[400exrider707]

Also there are not a large variety of 18" tires for 9" rims, unlike the 18"s for 8" rims. There are 19" tires for 9" rims, but again not many.

[whiteboycustom]

i have 21" razor 2 and they seem abit tall, 20's would be alot better for mx

[Ty's400]

20" front tires are the most standard for MX. Some run 19" fronts, but that isn't as common. For the woods 21" fronts with 20" rears are the most common.

[450RACER1]

do 20 fronts and 18 rears suck out n the trails will i get stuck alot?

[whiteboycustom]

might not get stuck but ur gonna hit alot more stuff like roots and big rocks, if theres deep ruts u might get stuck easier then bigger tires

[katch26]

that and the fact smaller tires (mx size) have less ply so youd probably just end up wth flats

[N300exJ]

I ride through woods and trails with 20's up front and 18's in the rear. Not a single problem at all.

Whiteboycustom with 18's in the back you need to go to a 15 tooth front sprocket to not rev out so fast and get your top speed back. not a 13 tooth.