I got this off of Airtech's Website:
CR7504
Front Fender
This is the front blade that replaces the steel front fender. Honda engineers designed the front forks on your motorcycle to work with that heavy steel brace on the front. Do not run your front forks without the steel brace, severe wobbling will occur. Simply take your stock fender and drill the rivets out to remove the steel fender from the fork brace and the front and rear hoops and reattach this fender onto your steel hardware. This lightweight fiberglass piece actually takes a lot of weight off your front fork assembly and helps the suspension reaction and makes your bike handle better.
Any idea how accurate that statement in red is?
I've seen a lot of people not use a fender at all and many with modified fenders so I'm curious. I'd at least like to know before I go chopping up the original one or swapping it out.
The statement is true: here's the 'rest of the story'...
The CB750K0-K3 had hard-mounted front fenders, which act as their [important] fender brace. The handling improvement with these is immediately noticeable when they are compared to those without.
Beginning in the K4, the front brace became rubber-mounted to try to make the front wheel appear to be centered better in the fender (as it was offset 3mm to the brake side, in production). The loss in handling was immediately apparent: even Cycle magazine commented about the K4-K5 handling issues in those road tests.
The 'secret' is exposed in my book, in the Suspension chapter: in order to go racing at Daytona in 1970, Honda had to meet U.S. "production racing" rules of the day. This meant that any parts on the bike had to be available to the average customer who walked into a Honda shop, and the bike's frame in particular had to be essentially stock. Honda wanted to run dual discs at Daytona, but the stock front hub of the sandcast K0 bikes did not mount the right-side disc. So, a new hub was created with a shoulder for the new disc. But, this new hub shifted the centerline to the brake side, about 1/8" (3mm). This new part became the defacto front hub by 2/1970 in production.
Those of us who worked on the bikes thought the new ones had misaligned fenders, and we spent a lot of time trying to make them 'straight', to no avail. Dealers disliked the appearance of the offset front wheel on the showrooms, too. So, in the K4, Honda simply added grommets to the fender braces and main mount so they could be tweaked into position for appearance's sake.
When the rest of this story became apparent, the solution became simple: just adjust the spokes to move the wheel to the right 1/8". This significantly improves the handling on these bikes.
In the meantime, replace those rubber-grommeted fender braces with some bushings instead of rubber: you will thank yourself for this effort next Spring.
