Front brake calliper upgrade

[Lucky Phil]

In progress.

Phil

[Speedfrog]

  we need the popcorn emoji...

 One too many “L” btw...

[gstallons]

And what are you swapping to ?

[Lucky Phil]

17 hours ago, Speedfrog said:

  we need the popcorn emoji...

 One too many “L” btw...

Try telling the spell check on this site. Both are acceptable apparently, US V British differences. 

Phil

[Lucky Phil]

9 hours ago, gstallons said:

And what are you swapping to ?

I thought it was obvious

Phil

[O2 V11]

 Very nice, those should work very well, quick question, are you having to change your brake lines to suit? Don't forget to give us a rundown on how they perform, are you upgrading the master cylinder as well?

Rob

[docc]

31 minutes ago, Lucky Phil said:

I thought it was obvious

Phil

Says "BREMBO" instead of " Brembo ?"

[Lucky Phil]

2 minutes ago, O2 V11 said:

 Very nice, those should work very well, quick question, are you having to change your brake lines to suit? Don't forget to give us a rundown on how they perform, are you upgrading the master cylinder as well?

Rob

Yes the brake lines need to be replaces as the orientation of the Banjo is 90 deg different. These as 34/34 pistons as opposed to the original 30/34 so about a 10% difference. The original M/C should be OK. I will also see if these will work.

https://www.aliexpress.com/item/4000378552965.html

phil

 

[Lucky Phil]

6 minutes ago, docc said:

Says "BREMBO" instead of " Brembo ?"

They are different callipers docc. Brembo p4 34/34 with 4 individual pads as opposed to the original( pictured) 30/34 callipers with 2 pads.

Phil

[Speedfrog]

5 hours ago, Lucky Phil said:

Try telling the spell check on this site. Both are acceptable apparently, US V British differences. 

Phil

I’ll trust you on that, it’s all bloody English to me...

[Scud]

Curious about why you are doing this. As I understand it, two different size pistons in a 4-piston caliper allows the smaller pistons to move first, followed by the larger pistons. This gives a certain feel where you can get a bit of braking power, then a lot of braking power. With all four the same size, what performance improvement are you looking for?

[docc]

19 hours ago, Lucky Phil said:

 . . . These as 34/34 pistons as opposed to the original 30/34 . . .

 

 

36 minutes ago, Scud said:

Curious about why you are doing this. As I understand it, two different size pistons in a 4-piston caliper allows the smaller pistons to move first, followed by the larger pistons. This gives a certain feel where you can get a bit of braking power, then a lot of braking power. With all four the same size, what performance improvement are you looking for?

Here we go. Back to school, docc.

As many times as I have cleaned and rotated my pistons, I never saw the size difference. I have always tried to get them to all move the same. Apparently, this is not the actual design!

Looking carefully in at the pistons, in situ, it appears the smaller pistons are on top of the caliper (the trailing side of the pad). So, light braking moves the smaller (top) piston and engages the trailing side of the single pad first?  And full braking engages to entire pad, but the trailing side still "bites" ~10% harder?

Fascinating . . .

[Lucky Phil]

3 hours ago, Scud said:

Curious about why you are doing this. As I understand it, two different size pistons in a 4-piston caliper allows the smaller pistons to move first, followed by the larger pistons. This gives a certain feel where you can get a bit of braking power, then a lot of braking power. With all four the same size, what performance improvement are you looking for?

This is a new interpretation on me Scud. Piston movement is pretty much irrelevant as the pads are only a few thousands of an inch away from the disks. When you grab the brakes the actual movement of the pistons is very small. Once the pads contact the disk it's about applied pressure over area. My understanding of the original reason for differential piston size was to provide even pad wear and pad performance. The leading end of the pad experiences quite different thermal and therefore frictional conditions to the trailing end hence the differential piston size and pressure applied to the shared pad to compensate. This later calliper design uses 4 separate pads to, I suspect mitigate the original issue. It also has a central bridge over the pad slot to increase rigidity. These were the last generation of road calliper from Brembo before the Radial style calliper took over. I've never seen a Brembo design in 50 years that was a step backwards. Anyway like the majority of upgrades they usually don't stand the scrutiny of "what's absolutely necessary". I'm channelling the "American" in me with my Guzzi in that a lot of it's about "individuality" and "nobody else having one like it"  

However I'm also mindful of maintaining the bikes place in "its time" so upgrades such as later USD forks with radial callipers and radial master cylinders etc are not really up for consideration.

Phil

 

[Scud]

Cool - I'll await riding impressions to see if you can tell the difference. If not, you have a unique upgrade and got new brake lines in the process. I didn't even know about those calipers that use 4 pads (one per piston). Always something to learn here.

[docc]

1 hour ago, Lucky Phil said:

This is a new interpretation on me Scud. Piston movement is pretty much irrelevant as the pads are only a few thousands of an inch away from the disks. When you grab the brakes the actual movement of the pistons is very small. Once the pads contact the disk it's about applied pressure over area. My understanding of the original reason for differential piston size was to provide even pad wear and pad performance. The leading end of the pad experiences quite different thermal and therefore frictional conditions to the trailing end hence the differential piston size and pressure applied to the shared pad to compensate. This later calliper design uses 4 separate pads to, I suspect mitigate the original issue. It also has a central bridge over the pad slot to increase rigidity. These were the last generation of road calliper from Brembo before the Radial style calliper took over. I've never seen a Brembo design in 50 years that was a step backwards. Anyway like the majority of upgrades they usually don't stand the scrutiny of "what's absolutely necessary". I'm channelling the "American" in me with my Guzzi in that a lot of it's about "individuality" and "nobody else having one like it"  

However I'm also mindful of maintaining the bikes place in "its time" so upgrades such as later USD forks with radial callipers and radial master cylinders etc are not really up for consideration.

Phil

 

Alright, so . . . when cleaning and "equalizing" the piston movement during brake service (on the original V11 caliper pistons), the smaller pistons, closest to the brake line input, should be expected to move first (if I understand this technology, now).

And that, this not so much to put "more" pressure on the trailing side of the pad, but to even out the pad wear and contact over this rather long pad (of the original V11 single pad Brembo) due to the "quite different thermal and therefor frictional conditions" between the leading and trailing edges of the pad.

Yes?