my front disc brake which has a Norvil conversion feels like wood when applied!
since I am now in the process of changing to flatter handlebars ( from the existing trials type) I find the standard master cylinder fouls the front fork and will not fit, it seems like the opportune time to change the master cylinder. Any experience of improved braking using the Honda k4 master cylinder? Is it shorter in length than the standard?
Would you please be more specific about what you mean by 'a Norvil conversion?'
'Norvil' branded brakes have been sold by more than one supplier, to various specifications.
Some more details may help you to get more useful responses.
I have 73 Commando and a 73 CB750.
The brakes on the Honda are no better than the Commando
I am interested in this thread as having recently bought my commando(my first older than me bike!) i have found the master very limiting as to how i can adjust the bars and levers for same reason. When i got it it was rideable but lever definately slightly upwards.I have jiggled it about a bit but very little can be done position wise with standard one. Although the brakes are rubbish compared to most things i have ridden i am getting used to that and think i am probably happy to accept that as part of the "character" of an older bike?!
But i wouldn't mind changing for a period master cylinder that looks kind of right(ie only real norton commando expert knows its not original) but comes out straight if there is such a thing?
im afraid I cannot really be more specific Allan as I have no experience of the standard set up, all I can say is the disc is bigger, the caliper is some racing type and the mounting plate says Norvil on it.
my issue really is about fitting a shorter master cylinder as the standard one will not fit between the throttle body and the fork after a handlebar change. Is a Honda K4 cylinder shorter ?
have a look at RGM Grimeca one. Longer bars too?
The really important question is what the bore diameters of the two master cylinders are. The standard Commando master cylinder has a large bore. You can get a conversion kit which reduces this diameter, resulting in a much better front brake. If you fit a Honda K4 master cylinder, and it has a similarly large bore size, you will still have a wooden front brake.
For brakes with feel I found fitting EBC sintered pads made the difference but they do wear the disc.
I just fitted an RGM master cylinder sleeve to my 1974 Commando 850 and it gave me approx 15% better brake efficiency and as good a feel as some of my modern bikes (T120 2016).
The job took a little engineering knowledge as you have to effectively ream the original cylinder bore to accept a sleeve (to 16.5mm). Plus, the adjustment took some trial and error but I now have an original master cylinder that actually works (no more wooden feel). Love it.
PS RGM will do the work for you. And, Andover Norton sell one that has been done.
I should have added that this requires buying or making a pair of risers (visible in the photos if one is looking for them).
Thanks for all the info and the pics Julian, most helpful and it does give me something to work on.
i must say I hadn’t even thought of risers but is just what my set up requires
Glad to help, Dave.
This set-up does of course require one to be a Peter Williams-type enthusiast for really narrow bars.
the shorter bars are now fitted and as I discussed in an earlier message the original master cylinder wouldn’t fit( it was fouling the forks) so I have bitten the bullet and fitted the grimeca master cylinder which is quite a bit shorter so fits very well. The master cylinder is 14mm and handlebar clamp for the 7/8 inch bars. I roadtested this arrangement today and the front brake is completely transformed, it’s got feel now and is much more powerful than before.
Glad to hear that you've found a set-up that works for you!