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Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Tue Feb 17, 2026 8:50 pm
by ml83136
I've been working on a new-to-me narrowcase 250 Monza that has aftermarket handlebar levers & perches. The clutch pull is very stiff. The perches' fulcrum distances (center of pivot to center of cable end) are about 1.5 inches or 38mm. I am accustomed to British bikes which tend to be either 7/8" or 1-1/16" (22 or 27mm). Can anybody tell me what this distance would have been on the original levers? And can I assume the brake and clutch distances should both be the same?
Thanks in advance!
Re: Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Wed Feb 18, 2026 1:54 am
by graeme
450 Scrambler is 28 -29mm
Sorry I can't help with earlier models
Graeme
Re: Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Wed Feb 18, 2026 4:50 am
by Roland
For the 350 scrambler it is 27 mm or less, depending on year i think.
38mm appears to me to be too much.
Re: Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Wed Feb 18, 2026 9:45 am
by blethermaskite
Are you using a nylon lined clutch cable?
Cheers George
Re: Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Wed Feb 18, 2026 11:01 am
by Bevel bob
I had the same issue with some cheap scrambles levers with 30 mm cc ,as an experiment i re drilled the pivot to give about 20 mm centers !. It worked well ,so its still in use . The clutch has the Lacey plates ( thicker and fewer than std ) and was carefully set up to spin without wobble when lifted springs slightly packed if needed. I am probably a bit too near to clutch drag although i have ridden it like this for many years including 50 days of holliday in the IOM . try 22mm
Re: Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Wed Feb 18, 2026 3:53 pm
by ranton_rambler
My NC 175 has Tomaselli levers which are 25mm as best as I can measure. It has the heaviest clutch action of my various bikes, and that's with one pair of plates removed so the springs are operating at a lower load. The same clutch is suitable for a 250 and I have never experienced any slip. With all of the plates in, my poor little hand could barely pull the lever.
I am told that some NC bikes have been modified to use the longer lever at the gearbox end of the clutch cable.
Re: Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Wed Feb 18, 2026 4:04 pm
by nalimugmug
Hi,
Attached are a few pics
Various levers which i have aquired over the years in my quest to restore a Mach1, so its my assumption that these levers are for the 250 models.
The Mach 1 levers I removed from Mach 1 clip ons to take the pic.
Hope this helps
Bob
Re: Question Re. 250 Brake & Clutch Lever Ratios (Perch Fulcrum Distance)
Posted: Wed Feb 18, 2026 6:56 pm
by ml83136
I'm so glad I found this group! From what I'm seeing here, 38mm is way too high. George, I had replaced the cable with a nylon-lined version and also tried re-routing it around the side of the cylinder as I've seen a number of people do. Bob, thanks for the photos! I will try a 22mm set and hope it pulls enough cable.