Most of the bikes we race start out as street bikes and have to be modified to be good race bikes. It’s common to drill for safety wire, change the tires, up grade the suspension and replace the body work. But most people don’t mess with the geometry much because they don’t understand. They think that because the bike handles well on the street and track that the geometry is fine and are reluctant to change it much.
I’ve been fighting this battle all year. Here is the main point: The average street rider requires different geometry than a racer. The stock geometry on most sport bikes is set so the bike turns easy. When you go racing with the stock geometry and then add a larger rear tire you’r making the problem worse. But most racers can’t feel the problem and are happy with their times.
Fortunately for me most of my customers believe me enough to try the changes I suggest. This case started with some big changes to Jim’s R-1 at Miller for the WERA 6 Hour that gave him more stability, easier turn in and more drive grip.
Then at the last WSMC weekend at Willow Spring we made a change to his R-6 and he sent me this line in an e mail:
“BTW I turned my fastest laps at Willow on a 600 this weekend after dropping the forks.
Thanks for the help.
Jim”
No Jim, thank you.
I hope you are asking yourself this question:
“How can he make a bike turn in better AND be more stable?”
The answer is that everything is connected and most importantly you are connected to the bike. If I give you a more stable bike you will ride better and be able to put more energy into the bike, you will feel better, more confident and will be better able to keep the brakes on until after your turn in. When you are braking hard the forks compress between four and six inches, this gives you a steep steering head angle, very little trail and easy turn in.
What a good crew chief does is set the bike up to make the rider happy. Then the happy rider goes fast and makes the crew chief look good.