2 smoke lover
I thought I would ask on here as well as trying to figure it out myself. I have a pair of Brembo 05's for a Post classic race bike. I got them to replace a pair of sliding pin caliper's on it originally and just used the Master cylinder that was all ready on it, it was a bit wooden but OK. But for the life of me I cannot find it now. So what Bore size Master cylinder suits Brembo 05's for racing? If I am lucky, I will have that size in the shed or at least know what size to buy. Cheers
Compare Pornography now to 50 years ago.
Then extrapolate 50 years into the future.
. . . That shit's Nasty.
2 smoke lover
Typically, I went to myself " i didn't look in that box" and you already know what was in the bottom that box. It turns all it is a 19mm bore size which going by the chart I have looked at point to the brembo 05's feeling a bit soft and 17mm would be a bit quicker acting and harder feeling. I would welcome any thoughts on the matter. I would of thought the 17 would be softer and the 19mm harder.
Compare Pornography now to 50 years ago.
Then extrapolate 50 years into the future.
. . . That shit's Nasty.
Hardcore Biker
you are right - the smaller master cylinder gives more pressure for more travel
Embracing mediocrity
Force x surface area, so the larger bore will feel softer for the same force being applied at the caliper, the smaller bore harder and more travel to move the volume of fluid. I think.Originally Posted by diesel pig
Riding cheap crappy old bikes badly since 1987
Tagorama maps: Transalpers map first 100 tags..................Map of tags 101-200......................Latest map, tag # 201-->
No8 Wire Extraordinaire
No. Jimi is right and you are wrong sorry.
Think of it as leverage.
Take things to extreme to illustrate your point.
A 1mm bore would displace hardly any fluid and would go to the bar easy. But it would have incredible advantage.
A 60mm piston would be like wood and not move. You'd be better putting you feet on the ground gor the effect it would have.
Don't you look at my accountant.
He's the only one I've got.
No8 Wire Extraordinaire
Old yamahas had such flexible deteriorating rubber lines that once you replaced them with braided they had little movement or 'feel'. They actually needed smaller cylinders to get them back into the sweet spot of travel that riders like.
That would also create more leverage. More power applied to the disc.
I like to go low on size and see if you can bleed it to get it firm enough. If there is too much travel it is not safe to use. Go up a size.
Don't you look at my accountant.
He's the only one I've got.
No8 Wire Extraordinaire
You can also do this with mechanical leverage.
Make your brake lever 500mm long but bend it so your fingers can reach. Damn it's super powerful at first. But your run out of travel before the piston can really get some stroke.
Next buy some fancy Shorty levers from Aliexpress. . Hmm. Less leverage.
(I don't care if you think you only use 2 fingers. Look how the slide to the end on a longer lever. Dirtbikes ride on slippery surfaces).
This works well on heavy clutches. Extend the engine lever to make it lighter.
But the limit is -the better leverage means less travel. Ok up until it still drags fully in.
Don't you look at my accountant.
He's the only one I've got.
Embracing mediocrity
Yeah, that stuff kind of bamboozles my brain, as it's application of force and also displacement of fluid.
That tracks once I actually think about it though, larger clutch slave on the ducati makes the lever lighter, but longer travel. So presumably the reverse, smaller master, would have the same effect.
Riding cheap crappy old bikes badly since 1987
Tagorama maps: Transalpers map first 100 tags..................Map of tags 101-200......................Latest map, tag # 201-->
In the riders seat
The 05 is the smaller caliper fitted to the Pantah , I doubt it'd be much bigger than a 13mm master cylinder, I had a 14mm m/c on the MHR I had with the 08 calipers which gave good feel, my Darmah with the 08 calipers had a 15mm m/c which always felt a bit on the hard side, the 05 should be a 32mm caliper piston compared to the 08 at 38mm
"If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough power."
2 smoke lover
How Annoying! I just checked the calipers with verniers and they are 08's I mucked up and thought brembo's did smaller numbers bigger brakes but it is larger numbers bigger brakes (those bloody Italians being logical for once!) I will have to do the numbers again.
Compare Pornography now to 50 years ago.
Then extrapolate 50 years into the future.
. . . That shit's Nasty.
2 smoke lover
I must of done my home work the first time as the chart says 19mm would work well for 08's for racing. And it was for the reasons F5 pointed out.
Compare Pornography now to 50 years ago.
Then extrapolate 50 years into the future.
. . . That shit's Nasty.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote
Bookmarks