Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > Breaks :(

[Rattler]

As Payned said above, I ran single disk with P4 for almost a couple of seasons on my 620. I found that pad wear was dreadful until I found the right combination of pad / disk.

The brakes were plenty good enough and really improved the turn in of the bike and reduced unsprung weight massively.

[skidlids]

One of the main ideas behind wavey discs was that they clean up the surface of the pad everytime you apply the brakes, hence higher pad wear but no glazed or contaminated pad surface.

Dallas also runs single disc with a 4-pad caliper, gripping on a SPS cast fully floating disc and connected to a 16 X 18 brembo radial mastercylinder, seems to work fine for him and pad wear is pretty good. Brembo pads I think

From what I could see at Combe it looks like Matt Lawsons disc isn't centred in the caliper and looks like it has been brushing aginst the protruding casting of the caliper designed for the pad to sit on.

I did mention to him about checking the thickness of the speedo spacer.
I had a similar froblem at the first ever DD race meeting back in 2005 and crashed out of the first race with brake failure and pulled out of the other two races when the lever went soft and almost came back to the bars. On each occasion the brake worked fine after it had cooled down. In my case it was the captive threaded boss in the early forks not recessing far enough, so I counterbored the fork a bit deeper and cured the problem ready for the next meeting which was Castle Combe, where they worked fine even if I did only manage a 1m 29.2s best lap.

Another cause of this can be a bent wheel spindle, the later hollow ones are quite prone to bending in a crash and then cause the Disc to run slightly out of line with the caliper.
New ones cost £52 I know this as I have recently bought two

[Rattler]

Kev, your point about the disk rubbing against the caliper might be right.

When fitting the front wheel, I found that it's important to spin the wheel and apply the brakes before the spindle is fully tightened.

IIRC, I'd fit the spindle through the forks and wheel, tighten the pinch bolts on the side where the spindle (wide part) goes through first, (non nut side)then fit caliper, spin the wheel and hit the brakes, this would centralise the disk in the caliper (all being equal). Then drop the bike off the front stand (to ensure there was no force from the stand causing issues) and then tighten the main nut and then tighten the pinch bolts on the nut side.

If that makes any sense?
Tim

[paynep]

Don't you mean:

Originally Posted by Rattler

IIRC, I'd get Chas to fit the spindle through the forks and wheel, get Chas to tighten the pinch bolts on the side where the spindle (wide part) goes through first, (non nut side)then get Chas to fit caliper, spin the wheel and hit the brakes, this would centralise the disk in the caliper (all being equal). Then drop the bike off the front stand (to ensure there was no force from the stand causing issues) and then get Chas tighten the main nut and then tighten the pinch bolts on the nut side.

[skidlids]

Originally Posted by Rattler

Kev, your point about the disk rubbing against the caliper might be right.

When fitting the front wheel, I found that it's important to spin the wheel and apply the brakes before the spindle is fully tightened.

IIRC, I'd fit the spindle through the forks and wheel, tighten the pinch bolts on the side where the spindle (wide part) goes through first, (non nut side)then fit caliper, spin the wheel and hit the brakes, this would centralise the disk in the caliper (all being equal). Then drop the bike off the front stand (to ensure there was no force from the stand causing issues) and then tighten the main nut and then tighten the pinch bolts on the nut side.

If that makes any sense?
Tim

Bit different to how I do it Tim
Once I have pushed the spindle through as far as I can and tapped it home with the nylon end of my prop stand I then do the 28mm nut as tight as I can until it tries to turn, then nip up the pinch bolts on the right fork soo they grip the shouldered end of the spindle. Then I fully tighen the 28mm nut, tighten the pinch bolts on the left (Speedo side) fork. I then undo the pinch bolts previously nipped up on the right hand side. Fit the caliper, pump the brake lever until the pads can stop the wheel spining.

I then take out the front paddock stand. Then with the front wheel on the deck pull on the front brake and pump the forks up and down so everything aligns itself as the right fork can move along the wider part of the spindle, allowing to finally tighten the right fork pich bolts.
Works a treat providing the Spacer replacing the speedo is the correct width and the spindle is in fact straight

[Rattler]

Originally Posted by skidlids

Bit different to how I do it Tim
Once I have pushed the spindle through as far as I can and tapped it home with the nylon end of my prop stand I then do the 28mm nut as tight as I can until it tries to turn, then nip up the pinch bolts on the right fork soo they grip the shouldered end of the spindle. Then I fully tighen the 28mm nut, tighten the pinch bolts on the left (Speedo side) fork. I then undo the pinch bolts previously nipped up on the right hand side. Fit the caliper, pump the brake lever until the pads can stop the wheel spining.

I then take out the front paddock stand. Then with the front wheel on the deck pull on the front brake and pump the forks up and down so everything aligns itself as the right fork can move along the wider part of the spindle, allowing to finally tighten the right fork pich bolts.
Works a treat providing the Spacer replacing the speedo is the correct width and the spindle is in fact straight

Hmmm, now I remember ensuring there was a ferw mm of the axle poking out from the side of the fork leg (not flush) to get the single disk centered up!! It was only after the pads were very low that I had any issues with proximity to the caliper though.

[Rattler]

Originally Posted by paynep

Don't you mean:


Quote:
Originally Posted by Rattler

IIRC, I'd get Chas to fit the spindle through the forks and wheel, get Chas to tighten the pinch bolts on the side where the spindle (wide part) goes through first, (non nut side)then get Chas to fit caliper, spin the wheel and hit the brakes, this would centralise the disk in the caliper (all being equal). Then drop the bike off the front stand (to ensure there was no force from the stand causing issues) and then get Chas tighten the main nut and then tighten the pinch bolts on the nut side.

Nah, he was too busy making the tea!!!