cNw yokes

Yeah but if I had such great weather and such great country when would I get my tinkering done ...?

When we finaly get our wet season lol.

Nigel, is that a Brembo PS12 Master cylinder?

Genuine or copy?

And do you know what the ratio is with that Brembo caliper?

Or the piston sizes, looks like they are different sizes for each pair though!

SteveA said:

Nigel, is that a Brembo PS12 Master cylinder?

Genuine or copy?

And do you know what the ratio is with that Brembo caliper?

Or the piston sizes, looks like they are different sizes for each pair though!

Click to expand...

Don't know if it helps but I have a similar brembo MC on my commando this is a 12mm unit it came off of a burnt out scooter I found in a river ,I think it was a gilera?
I use it with a 4 pot missin and a 320mm disc
It is a superb set-up plenty of feel and it stops the bike easily

SteveA said:

Nigel, is that a Brembo PS12 Master cylinder?

Genuine or copy?

And do you know what the ratio is with that Brembo caliper?

Or the piston sizes, looks like they are different sizes for each pair though!

Click to expand...

I’m like Manuel Steve... “I know nothing”...!

It’s the cNw kit, as far as I know the caliper and master cyl are genuine Brembo. The only thing I changed was to fit Brembo ‘track’ pads.

I just bought a PS12 of the older round reservoir style, to run with an AP Lockheed CP2696, gives a ratio of around 23 instead of the 17 I have with a 14mm master cylinder.

But I also need master cylinders for two other bikes with the same calipers. These are later bikes and can run with the style you have.

The AN 13mm Master runs with I think the original 44mm Lockheed caliper, again a ratio of about 23. Trying to understand how this works out for people in terms of feel.

I used to think the 17 ratio, with the 14mm was fine, but I am not stopping as quick as I want at the moment, at Gedinne I even used the rear!

The issue may be that I am going faster!, but I am inclined to think it has more to do with muscle loss at coming 65!

baz said:

Wonder why Norton went to all the expense of re designing the yokes for the 850 frame when the could have stuck with parelell yokes as you have done?

Click to expand...

Others might disagree, however I believe that increasing the trail with the 27 degree rake, increases self-steering in the correct direction when the bike is gassed when cranked over coming out of corners, and the general steering becomes quicker. If somebody can predict what will happen by changing their fork yokes, they are a better man than I am. The first Commandos had racer-type steering geometry which was specified by Peter Williams, they crashed a few inexperienced riders - so the geometry was changed in later models, to make it safer. Safer is not necessarily better. Most road bikes are set up with neutral steering, so they don't kill people. If you get it wrong, the crash can come from nowhere.

SteveA said:

I just bought a PS12 of the older round reservoir style, to run with an AP Lockheed CP2696, gives a ratio of around 23 instead of the 17 I have with a 14mm master cylinder.

But I also need master cylinders for two other bikes with the same calipers. These are later bikes and can run with the style you have.

The AN 13mm Master runs with I think the original 44mm Lockheed caliper, again a ratio of about 23. Trying to understand how this works out for people in terms of feel.

I used to think the 17 ratio, with the 14mm was fine, but I am not stopping as quick as I want at the moment, at Gedinne I even used the rear!

The issue may be that I am going faster!, but I am inclined to think it has more to do with muscle loss at coming 65!

Click to expand...

I use a Lockheed master cylinder which is normally used with one calliper, to operate two callipers. I can lock the front wheel with one finger and that is all I normally use to operate the front brake. For racing it has to be that way. It is OK as long as you stay in practice. For road use, I would want the front brake to be less sensitive.

Two fingers for the street.

This thing about fork yokes interests me. A while back there was a young guy at Winton Raceway with a 1980s superbike which he wants to race in a new '(Period 6) historic class. He returned to Melbourne and went on a forum claiming the Winton circuit is dangerous - because he was bouncing off the ripple strips, which are on the outside of most corners. If his steering geometry was right for the circuit, he would go nowhere near the outside of the corners. On a modern bike the geometry is adjustable by moving the fork yoke up and down the stanchions. However if the bike tightens it's line in corners, it becomes more likely to high-side. So a very powerful bike can be at a disadvantage on Winton Circuit where there are 12 corners and only 3 and a half straights..

acotrel said:

Others might disagree, however I believe that increasing the trail with the 27 degree rake, SNIP...

Click to expand...

Wrong! Reducing the rake DECREASES the trail. Now stop mucking up Nigel's thread with your voodoo stories...

Nice yokes Nigel BTW, I'd love to give your commando a ride side by side with my own to see how much they differ... although it might promote a spending spree on my part if the difference was great.

Let’s be clear here guys, for a given rake, increasing the offset reduces the trail.

The cNw yokes have standard Norton offset. Making them parallel is going to have a similar effect as increasing the offset though as it’s moving the wheel slightly further forward in relationship to the imaginary centre line taken through the head stock, which is therefore going to give slightly less trail.

Enough of the theory, I’ve at least ridden it now...

The effect is very small. Note that I also fitted narrower clip ons and a steering damper at the same time, both of which will effect how the bike feels.

Initial tip in seems slightly less nimble, requiring slightly more effort to tip in. Although this could easily be the effect of shorter clip ons and steering damper!

However, it definitely turns in more sharply once tipped in (ie slightly more oversteer), several times I had to correct this, so it’s definately there. This is a good thing I think, and I quickly go used to this and definitely thought the bike felt better around some known bends.

The forks themsleves (Maxton internals) are a definite improvement, although perhaps need backing off a tad for the road.

The steering damper has the desired comfort blanket effect over known fast bumpy bits too!

Overall, the effect of the yokes seems very small, but positive.

I won’t get to test them on the track until next year.