Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > General Motorcycles only > Brake lines

[paynep]

Originally Posted by Shazaam!

What’s interesting is that brake line sizes are commonly either -3 (3mm I.D.) or -2 (2mm I.D.). 2mm lines will expand less circumferentially than 3mm lines. So if you run two lines, use the 2mm size to negate the spongy effect of the longer line length. Two 2mm lines will move almost the same amount of fluid as one 3mm line so flow restriction is not a concern.

Now that is something I'd never considered. And maybe why I've never managed to get the brake setup on my 851 to feel as good on track days as my identically padded/disc'd/calipered/master cylindered old 888.....

Just goes to prove that you can still get good info from the DSC site.

Cheers Larry

[NBs996]

Thanks shazaam, that's just what I was thinking.

I've been a bit curious as to why a twin setup is considered by some to be some kind of performance upgrade, when theoretically all it does is make the lever action softer. Thought I might be missing something!

I've got the twin setup on the 620 for just this reason, I've come to prefer a softer lever with a bit more travel between on and off, and lets me fine tune me braking pressure easier.

[skidlids]

As mastercylinder/lever ratios can be matched to either setup, the standard setup on bikes from the factory will also be considering costs and possibly weight as the 916 style setup with the short hose T-ing off across the mudguard must weigh less than 2 full length hoses with the extra banjo fitting and double banjo bolt.

Most of my bikes have a T piece just above the bottom yoke so there is only about 200mm of single brake line, so not alot lost on the hose expansion/softening effect over the standard system and only a little bit saved over the two seperate hose setup. But then mostmy brake setups are fitted to either Brembo or AP Radial Mastercylinders, the AP giving the best setup with its adjustable ratio

[MLC Racing]

I may be wrong but I always understood that ACU rules insist on the '1 line for each caliper from the master cylinder' arrangement. The single hose and splitter was road use only!

[skidlids]

Originally Posted by MLC Racing

I may be wrong but I always understood that ACU rules insist on the '1 line for each caliper from the master cylinder' arrangement. The single hose and splitter was road use only!

Dave the ACU rules say the Hose must split above the Bottom yoke

So you have the choice of two seperate Lines coming from the M/cyl or a single line from the M/cyl to a T piece above the top yoke and then a line down to each caliper

With either setup having a cable tie holding the two together below the line of the bottom yoke has been known to fail scrutineering