I suspect you are right about the 16mm Lockheed master being the problem Bill. Really, my lack of stopping power started when I swapped to that, and I then swapped front pads in a attempt to improve the situation.

The rebuilt rear vintage Lockheed caliper has Ferodo FDB342P Platinum pads, and it stops fine with an 11mm Brembo master. The Grimeca also worked well.

The pads in the new AP front replicas are what was provided by AP, and they worked fine with the 14mm Brembo, but most riding was of the careful kind that a newly-built bike demands, and careful trips down the road looking out for the police. Only after I changed to the AP master did I loose friction up front. I remember taking the original pads out and flat-sanding them, and cleaning the discs again, but it did not help. Replacing them with the same FDB342P pads did not work well on the front rotors either, which are same as the rear. So, the modern-but-used (I have forgotten its history, but it seemed good) M/C is likely the culprit.

I see that AP now has a replica of the early front master with a solid body and cap; that was not available back in 2011-2012 when I was looking, and the few used ones I saw for sale looked well-worn. I suppose that one of these could be the answer, and more period-correct.

I really think I will come back to this problem in the spring, and maybe one day at the track with it would be fun.

Thanks, MikeV

At the risk of beating this issue to death, one more comment.....the AP website shows that their classic master cylinders came in two sizes. 5/8" (16mm) bore or .70" bore. Should your existing Lockheed master somehow be the .70" bore size, you would definitely experience a more wooden / firm braking feel. They say the 5/8" bore size master is "identified by a single groove", and the .70" bore size master is "identified by 2 grooves".
Bill
http://www.apracing.com/products/motorcycle/classic_range/spares_for_classic_equipment.aspx

Now another page from the AP catalog, with more front masters listed! When I looked yesterday only two showed up, vintage and very modern.

You have this figured out Bill. The lever has a 16 scribed onto it, and I was told that is what it is. But I have always wondered what the TWO LINES scribed on the master near the banjo bolt meant. I guess I have the BIG version! Maybe the lever was replaced? A really good example of what "wooden" feeling means; it clamps, but just goes dead, and the bikes does not stop!

Bill, do you have any recommendations for someone in the US who sells the AP stuff. Their website did not even list the USA as having a distributor or seller---it was not one of the choices. I see no reason why you cannot recommend someone here, although most are probably looking for Brembo stuff.

MikeV

I would first call Michael at Vintage Brake: 209-533-4346. He's always very helpful and does list AP stuff. Old school good too. His preference was for me to mail a check for those Ferodo pads, and he shipped them before the check could possibly arrive.
Bill
http://www.vintagebrake.com/index.html

I went to his website and added it to my favorites [again] Bill. The narrative example he gave with an RD350 racer is exactly what I have here; small SS rotors, big 2-piston calipers, and a big M/C. Using his narrative and chart, even the 5/8th inch AP classic is too big, I think, never mind the .70 inch version. Maybe this explains why the 14mm I first installed in 2011 was ok, and why the 11mm rear still seems fine. It seems that the NOS 12mm Brembo M/C I have would be pretty good.

So, I am facing the dilemma of my feeble attempts to create historical accuracy on this bike, or making it work. Sorta like less filling vs. more taste............

PS: According to his chart, the big 15, 16, and even 17mm (vintage Goldlines) front masters with 1980s-era Brembo calipers should not work well either! Or is that were the CI vs. SS rotor material used is part of the formula? He did not cover that in the narrative before the chart. What am I still missing????

Thanks for you help Bill.

MikeV

Hello Mike,

Why not have your AP mc sleeved to 12mm?
Most good brake places can do this, or do it yourself if you have a lathe.
My Norton had 5/8 mc and was terrible. Sleeving it to 12mm worked wonders.

Regards
Graeme

Hello Graeme. I have heard of this before. But, where do I then get a 12mm kit (the guts) for an AP Lockheed master? Surely I can't just pop in a Brembo version? MikeV

I think what you are missing is, you have (4) caliper pistons. The ratio I again calculate for a m/c with a piston dia. of 15.875mm and (4) caliper pistons each with a 41.3mm dia. is 27.073, which is exactly the sweet spot on Vintage Brakes feel chart (which I know works). The stock Norton Commando Lockheed master was working on a single two piston caliper (which was clamping on a chrome plated iron rotor no less), so that sleeving fix worked good. If you are thinking of sleeving your existing Lockheed .70" master cylinder, I strongly recommend sleeving it to 16mm if you're working on (2) AP CP2696-38EO calipers.
Bill

Now I understand Bill. Total pistons, and that make sense. Thanks, MikeV

Hey Mike, I fell in love with this bike the first time I saw it in the flesh at Barber. It just looks right. More importantly was the look on Pat's face when he saw it that weekend. That was the start of his desire to come visit us every year. Lou