I think we should start ending Saturday with a mini moto double header. Open class with entry granted to XR/CRF100 Motards & Grom
Of course if you already have a smaller bike and want to run it that would be ok, two 6 lap races of the entire track. Put in a couple of extra corners with cones and blammo good cheap fun, probably $50 to do two races?
2003 Honda XR100R Budget Build Sheet By: Jim Linton
Below is a build list for an xr100 built to UMRA spec Thunder class. The benefits of this build are the reliability that comes with the xr100 and how inexpensive it is to build a competitive bike for the stock class. I have compiled this list of information after spending weeks researching the best set up for the xr100 while keeping it cheap and reliable. The list is short, but it is all that can be changed while still following the rules.
The suspension modification is very limited for this class, so the best we can do is add the stiffer BBR springs for the forks with 15w fork oil along with a BBR spring for the rear shock. (Part numbers below)
BBR fork springs: 650-HXR-1005
BBR rear shock spring: 660-HXR-1005
For the stock class, the only wheel option is an xr80r 16” front wheel newer than 1985. If you are lucky, you can pick one up on ebay for around $60-$75. If not, the rim and spokes would run you around $140.00 and getting it laced to the xr100 hub shouldn’t be more than $75. The alternative is to buy a complete front wheel from Honda that runs about $285.
Honda XR80R complete front wheel: 42650-GN1-681
Honda XR80R rim ONLY: 44701-GN1-013
Spokes (36 total): 44610-GN1-405 (QTY 18)
44611-GN1-405 (QTY 18)
Unfortunately, using a 16” tire our options are limited. The best bang for your buck tires are the Bridgestone BT45s. My preference is a 100/90/16 on front and a 110/90/16 on the rear. When you order them, they will both be front scooter tires. Some people prefer to run 110/90/16 on both front and rear, but I found it transitions from side to side just a hair better with the 100 on front. A second popular option is the Pirelli Diablo, which is a bit cheaper although they do wear a bit quicker and have been reviewed as having less grip than the BT45s.
The xr100 front drum brakes do a horrible job at stopping, but with the stock class it is our only option. To help a little I recommend using EBC drum brake shoes.
More than likely, you will crash, so if it is in the budget, Acerbis hand guards with the metal brace should save you from spending money on hand controls.
The xr100 practically takes two hands to get to full throttle, so a T Bolt ¼ turn throttle is a very helpful upgrade.
¼ turn throttle: http://tboltusa.com/store/tb-14-billet- ... p-555.html