Technical Q and A for classic motorcycle maintenance and repair.
Editor’s note: If you’re having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith’s Garage, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with “Keith’s Garage” as your subject.
Q: I own a 1977 Honda CB750K with a single front disc brake. When the bike is pushed in a straight line, either forward or backward, it rolls fine. When the bike is pushed with the bars at full lock, the front brake drags and it becomes very difficult to maneuver. It seems to drag more when being pushed backward than forward. The brake line does not appear to get stretched or kinked with the bars at full lock and the fluid has been recently changed. Any ideas? - Jim Acklin/via email
A: My first suggestion would be to check the front wheel setup closely. What you’re describing usually happens when the front wheel is loosely held in the forks. This can be due to a couple of things. The first thing that comes to mind is worn wheel bearings. The second thing is incorrect assembly of the front wheel in the forks. With the bike on the centerstand, have a friend push down on the rear of the bike to raise the front wheel. Grasping the wheel rim where the fender is bolted to the forks, try to push the wheel sideways from one fork to the other. If you feel any movement you will have to find which of the above is the cause. Let’s make sure the front wheel is assembled correctly. First, check to see that the nut securing the front axle is tight. On the side with the pinch block holding the axle in place, slightly loosen the nuts that hold the pinch block. Make sure the speedometer drive is located correctly, then tighten the axle nut on the opposite side to the correct torque. Pump the forks up and down a couple of times to center everything, then tighten the pinch block nuts to the correct torque. If the brake drags after performing this repair, it is likely the front wheel bearings are bad and should be replaced. MC