Could anyone tell me the length of a xr650r fork from center of axle to top of fork tube?
I just measured mine at 37-1/16", topped out with the wheel off the ground.
My forks are not stock, they were done by Precision Concepts, springs/pistons/bottoming cones, dunno if they did anything to extend the forks.
Thanks a ton
I'm going to be altering length of the crf450r forks that came on my 650r and wanted to make sure of the height of the stock forks. Can anyone else verify the length of the stock fork from the top of the fork tube(not cap) to the center of the axle? Also, I could use the stock height for the fork tubes in the clamps. Basically how many mm are showing above the clamp.
5mm seems to be the best for all around dirt use. Going SM it would be different but, a good place to start. Race sag and rake (27 degrees 111mm tail) will play a huge part in your suspension setup along with a more aggressive rebound control for a good SM setup. You want a little slower rebound to slow the release during the apex of a turn or when you transfer from one turn to another in quick succession.
This one's easy, but commonly confused. Draw an imaginary line through the steering stem down to the ground. Measure the angle between it and another (imaginary) vertical line through the axle and you'll have the rake angle.
Sportbikes are generally around 24 degrees, while cruisers come in around 30-32 degrees and dirt bikes are close to 27 degrees. Typically, steeper rake makes for a quicker-steering and a less stable bike. At a maximum 90 degree rake with the forks parallel to the ground (0 degree castor), there would be no steering effort when you turned the bars (the wheel would just tilt to either side). Similarly, at 0 degrees rake, the steering effort would be instantaneous and impossible to control.
Point the steering straight ahead, and look at the bike side-on. The perpendicular distance between a line through the center of the steering stem and the wheel spindle is the fork offset. Altering offset allows chassis designers to tweak the trail and rake figures independently of the wheelbase, for example.
Simply put, this tells you how the bike's weight is split between the front and rear wheels. If you sat a 400-pound bike on two identical sets of scales, on perfectly flat ground, and both scales read 200-pounds, you'd have a 50/50 weight distribution. Sportbikes generally have more weight through the front tire than the rear, and cruisers are typically the opposite. Dirt changes as the rider adjusts but, usually very far back for whoops.
Trail is the distance between an imaginary line drawn through the steering stem down to the ground, and a vertical line from axle to ground. In general, larger trail makes for a more stable steering bike because the self-centering forces created by the castor of the wheel have more leverage to operate.
Problem I currently have is the stock shock on the bike has been shortened 1.5" for SM but I have crf450r forks that were put on the bike. The crf450r forks are stock length so I need to confirm the length of the xr650r forks one more time so I know whether I need to shorten the crf450r forks any. I just measured them at 35.75" which means I don't but I measure from the top of the fork tube(not cap) to the center axle.
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