Purchasing the right size dirt bike is an important decision. It's common for people to see how large a dirt bike is and become intimidated, so they choose a bike that is too short for them. Hopefully, I can help you to avoid that problem with this post.
Some people erroneously think that the taller you are, the higher CC of engine you should get. This is not at all true. The cc measurement on the bike is merely a measure of the engine displacement--not the proper height. Some higher cc engines are put on shorter bikes to accommodate riders who are shorter but want more power. The opposite is also true.
In general, the best way to tell the proper seat height is to simply sit on the dirt bike. Both of your feet should touch the ground, but both feet should only touch with the ball of your foot and toes. The heel of your foot should be in the air. This is a properly sized dirt bike.
The photo at the top of this page shows the proper seat height for a rider with his feet bent. Adult riders should fit just like that as well.
For almost all new riders, this feels uncomfortably tall. Many new riders get a bike where they can stand flat footed on the bike, and this is a huge mistake because it puts the rider in a cramped position on the bike and increases the likelihood of foot injury. Remember, 65% of all broken bones on dirt bikes are bones below the waist
Matching Your Seat Height to Your Height
It's tough to say what seat height you should get matched off only your actual height. The problem is that some people have longer legs, and some people have taller upper bodies. However, the following chart should hopefully help you to estimate about what size of seat height you should get on a dirt bike. Keep in mind that these heights are approximations to help you get a general idea of what size bike you could ride. The only way to know for sure what fits you is to go sit on a bike and try it out.
- 6' (182cm) Tall and Taller - 37.5" or taller seat height
- 5'10" (178cm) Tall - 35 to 39" seat height
- 5'8" (172cm) Tall - 34 to 38" seat height
- 5' 6" (167cm) Tall - 34 to 37" seat height
- 5'4" (162cm) Tall - 33 to 36" seat height
- 5'2" (157cm) Tall - 31 to 35" seat height
- Kids 10 to 12 years old - 26 to 31" seat height
- Kids 8 to 9 years old - 24 to 28" seat height (Read our full article on dirt bikes for 8-year-olds)
- Kids 3 to 6 years-old - 50cc dirt bike
Don't obsess about the chart above. For example, I'm 5'10" and I can ride my wife's Yamaha TTR230 with a 34" seat height just fine. It's technically too small for me, but that's just for a perfect fit. I don't feel cramped at all on the bike, though I'd probably get something a little taller for myself.
Sizing a Dirt Bike for Kids
Getting the right size of dirt bike for kids is trickier, because you have two additional factors to consider: (1) Getting a bike where the kid feels comfortable and not overly intimidated, and (2) Getting a bike that allows the kid to grow a little without the need to replace their bike every year as they get taller.
You can alleviate both of these problems by making sure you get them a dirt bike where only the balls of their feet and toes touch on both sides. This way they can grow a bit and will just get to the point of being flat footed. If you start out flat footed, then next year the ride can be a real problem.
What helped me with my boys so they wouldn't be intimidated by a taller bike was teaching them the proper seat height at home before we went to the store to look at dirt bikes. Then, when we went to the store, they would sit on the bike and instantly know if it was a good fit or not. If I had waited until the store for this, they likely would have chosen a bike that was too short and been stubborn about it :-)
If you have an 8-year-old, then definitely check out this post on the best dirt bikes for 8-year-old kids
. If you'll be buying a 50cc dirt bike, then check out this post on the best 50cc dirt bikes
How to Change the Height of a Dirt Bike
Many dirt bike riders aren't aware that you can actually change the height of your dirt bike to suit you. There is not one simple adjustment switch, but there are a lot of different mods you can do to have the same effect. Getting a bike to fit you properly will significantly improve your technique and feeling of comfort on long enduro rides.
To lower the dirt bike
: The easiest way to change the seat height is to simply remove the foam from your seat pad and either cut it down, or drill holes in it so that it's softer and will sink more. Another option is to simply replace that foam with a much softer foam so that you sink down another inch or two. Another option is to set the sag on the rear suspension of your bike to the lowest setting you can, but keep in mind that this can compromise your steering.
To raise the dirt bike
: The easiest mod is to simply get a taller seat foam (like this one on Amazon)
which can give you an extra 2" without changing the steering dynamics of the bike. One thing that helps is to mount the handlebars rotated forward and get taller handlebars, which doesn't raise the seat height, but it does allow you more room to scoot forward on the seat so you aren't pushed back too far.
Common Dirt Bike Seat Heights
- KTM 50XS - 26.7" (68cm)
- Yamaha TTR50E - 21.9" (56cm)
- Kawasaki KX65 - 29.9" (76cm)
- Suzuki RM85 - 33.5" (85cm)
- Honda XR100 - 30.5" (78cm)
- Honda CRF110F - 26.3" (68cm)
- Kawasaki KLX 110L - 28.5" (70cm)
- Yamaha TTR110E - 26.4" (68cm)
- KTM 125 SX - 37.8" (96cm)
- Kawasaki KLX140 - 30.7" (81cm)
- Kawasaki KLX140G - 33.9" (86cm)
- Kawasaki KLX 140L - 31.5" (83cm)
- Yamaha TTR230 - 34.3" (87cm)
- KTM 250 XC-W - 37.8" (96cm)
- Yamaha TTR250 - 35.8" (91cm)
- Yamaha YZ250 - 39.1"(98cm)
- Yamaha YZ250Fx - 38" (96.5cm)
- Suzuki RM-Z250 - 37.6" (95cm)
- KTM 300 XC-W - 37.8" (96cm)
- Kawasaki KX450F - 37.4" (95cm)
- KTM 450 XS-F - 37.8" (96cm)
- KTM 500 EXC-F - 37.8" (96cm)