Monday, March 28, 2011

Pics

Original XR frame geometry

Slide the stock forks up in the clamps, and lower rear ride height

Swap out front end for GSXR front end

Show seat and gas tank

Add bodywork

Add tail section


Some concept pics. Created by tracing over a photo of the stock XR400 frame, then modifying in a drawing program.

2007 GSXR 600 Complete Front End

GSXR Front end I bought used. I also picked up a '93 Katana 600 rear wheel.

XR400 in the house

This past weekend, I traveled to my brother's house, and picked up my XR400 from him. We went for a nice ride in the woods near his house. I forgot just how stout the little XR400 powerplant is!

Pics to follow soon.

First Post - XR400GP

Hi, I'm Russ -- I live in Pittsburgh, USA.

The purpose of this blog is to chronicle the development of my dirtbike - turned - roadracer project, which I have dubbed the "XR400GP".

I've raced YSR-50's for about 7 or 8 years, and had a hiatus from racing for several years, but a recent trip to the Barber Motorsports Park for their annual Vintage Festival rekindled an interest in dragging a knee around a racetrack. I think it was the smell of high octane fuel and castor oil in the air that did it.

Anyway, after doing some soul-searching on whether to race my YSR again, or step up to something bigger, I decided to see how I could get on a larger bike without breaking the bank. We'll see how well that pans out. I remembered that I still own a 1996 XR400 that was being stored at my brother's house. After drawing some sketches, I convinced myself that by swithcing to 17" wheels and raising the forks up in the triple clamps a few inches, I could achieve roadracer geometry.

Some initial sketches here:
http://www.whiterose.net/~russ/xr400gp/index.html

A little more research brought me to realize I may need to simply swap out the front end altogether for a streetbike front end, so as not to have so much fork tube protruding from the triple clamps.

I spoke with Geoff Maloney of GPTech, LLC on the phone, and he was very helpful with information on setup for the Formula 450 class of bike. GPTech makes parts for YZ450 roadracer conversion, but Geoff seems very willing to help out do-it-yourself'ers also. 

I located a 17" katana rear wheel, and a 2007 GSXR complete front end, and now the journey begins...