Update 8/10/2011

Well folks, the bike took quite a pounding while at Pikes Peak. Spinning out 3 times was the least of our worries, with the violent headshake under decel being the real problem. The machine started doing this same thing seemingly out of nowhere last Sept. After the problem got worse, we determined the front end geometry was out of spec and made an adjustment. By adjustment I mean cutting the front suspension in half and putting it back together, not turning some knobs. Obviously this is a permanent adjustment and there’s no need to look back… until it inexplicably happens again while at Pikes Peak. We re-measured everything and found vaguely what we found last time. This is, things we not perfect but were close enough to not bring out the torch and band saw.

Well for sure the violent headshake is serious enough that SOMETHING needed to be done, so this weekend we will be cutting the front suspension in half yet again, and puttingthe numbers EXACTLY in spec. It’s really the only thing we can do. Our next race in September is fast approaching and features many of the medium-speed turns that Pikes Peak offers, but there are more heavy braking zones (where the headshake shows itself). For my non-riding readers, headshake is a violent instability in the front of the bike that waggles the handlebars back-and-forth in increasingly violent arcs. It looks like the 1:10 and 1:40 mark of this video:

http://www.youtube.com/watch?v=muqWIhoStwk

Obviously it makes it hard to steer, see, concentrate, and slow down; all things you need to do while approaching a corner. This is just as dangerous on a closed course like the one we are heading to next, as speeds are higher and you push the bike closer to the limits. We are hoping the new steering geometry will make the bike steer slower and heavier, reducing the impact of bumps while braking. The heavier steering will be less likely to be upset by bumps or accidental inputs into the bars.

Labor Day weekend will put Gina and I back on the bike for the first time since May, on the most challenging course of our season together, the East Course at Miller Motorsports Park in Tooele, UT. Racing with vintage-series AHRMA, we always get a big grid, good racing, great fun, and the VIP treatment with the GP garage spaces at the track. This track is the site for World Superbike when they come to the US, so the amenities are quite nice compared to what we usually have. Stay tuned to see how things go, and cheer us on.

-Johnny

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.