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 the subject.
Q: I have a 1975 Norton 850 Commando that I bought recently. It sat for many years, but runs very good, and it only has 7,700 miles on it. My problem is the clutch is so hard to operate that I can hardly ride it in stop-and-go traffic. In 15-20 minutes my hand is cramped up. It will also not go into neutral when running, but it goes right in when I stop the engine. I have lubed the cable and made sure it is routed with nice smooth bends.
A Norton specialist says nothing is wrong with the clutch, even though it seems it is the problem. I have had many different bikes over the last 40-odd years, but I’ve never had a clutch this hard to operate. Help! Thank you. — Thomas White/via email
A: There are several factors that can make the Norton diaphragm clutch hard to operate. You’ve dealt with one of the easiest, which is cable routing and lubrication. A major factor in how easy or hard it is to pull the clutch is the clutch stack height, the combined thickness of the metal plain plates and the composite friction plates in between them. It doesn’t take much friction plate wear to move the clutch from easy to hard to pull. How new are the friction plates? Also, Old Britts in Enumclaw, Washington, sells plain plates of varying thicknesses that you can use in combination with new friction plates to get to that sweet spot where the clutch is easy to pull, but doesn’t slip. If all else fails, Colorado Norton Works has a hydraulic conversion kit. It’s pricey at $459, but solves the problem permanently. Colorado Norton Works also has a less expensive clutch kit for $205 that keeps it mechanical, but claims to fix the hard pull. Good luck. MC