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Thinking about new front brakes?
Posted: Tue Feb 19, 2013 10:00 pm
by duc34
300mm Brembo vs Braking

Re: Thinking about new front brakes?
Posted: Wed Feb 20, 2013 12:12 pm
by 900streetfighter
Most aftermarket discs are 320mm. I don't think your calipers/pads will fit with your existing fork legs.
Wavy discs might look a bit out of place on a 90's bike.
Probably cheaper to upgrade pads or master cylinder to improve brake performance.
Re: Thinking about new front brakes?
Posted: Wed Feb 20, 2013 12:53 pm
by Duc750
900streetfighter wrote:Most aftermarket discs are 320mm. I don't think your calipers/pads will fit with your existing fork legs.
Wavy discs might look a bit out of place on a 90's bike.
Probably cheaper to upgrade pads or master cylinder to improve brake performance.
The gold calipers are 320mm discs so you should be alright but why change ?
Better benefit would be a lighter wheel if you muct look to change unsprung weight
Re: Thinking about new front brakes?
Posted: Wed Feb 20, 2013 1:23 pm
by paso750
what is this topic about anyway ?
I think there`s no question here. duc34 just wants to show his new discs. (please post smaller pics btw or I`ll have to buy a bigger monitor

)
G.
Re: Thinking about new front brakes?
Posted: Wed Feb 20, 2013 4:03 pm
by Duc750
Ah ha but will the new monitor stop better or provide satisfying pulsing at the lever ?
Re: Thinking about new front brakes?
Posted: Wed Feb 20, 2013 4:10 pm
by paso750
you interpret quite a lot in two pictures and a (probably) rhetorical question

Re: Thinking about new front brakes?
Posted: Wed Feb 20, 2013 7:14 pm
by 900streetfighter
So can you replace 300mm discs with 320mm providing you fit gold calipers on a 90/91 907?
The fork legs are the same? 90/91 and 92 Model year? I didn't know that.
Re: Thinking about new front brakes?
Posted: Wed Feb 20, 2013 7:23 pm
by paso750
hehe, I find this topic mysterious and funny.
I don`t know if 320mm discs fit on a 907ie that originally had 300mm. In fact I was asking that myself after you brought that up.
There was no mentioning of a 320mm disc just a picture of an original 300mm disc and a new one from Braking (WK015 btw which is also 300mm).
Re: Thinking about new front brakes?
Posted: Thu Feb 21, 2013 5:24 am
by ducinthebay
Truly, in this case, the fork legs will determine if you can run a 300mm or 320mm rotor. Calipers are the same, and wheel is the same.
Unless of course you make a brake caliper adapter.
And yes, new rotors are lighter, and should have better braking. Plenty of aftermarket for both sizes. For 300mm rotors, search Yamaha YZF, which is the same bolt pattern and offset. Ive been running them for years until I found some rare Brembo cast iron rotors.
Cheers, Phil
Re: Thinking about new front brakes?
Posted: Thu Feb 21, 2013 9:17 am
by Duc750
Lets put it this way. My bike is a "94" bike i.e. one of the last registered and I believe the last one improted into the UK - It has gold calipers (standard) and 320mm discs (stamped on the carrier) - I have no idea if the fork legs are different but I don't think they are. When its back in one piece I'll go and visit my folks on it in Brentwood and you can take a look!
(Its a longer trip for you to take a look G!)
Thinking about it - just because the carriers are marked 320 doens't mean the whole disc is - hmmm tape measure time !
Re: Thinking about new front brakes?
Posted: Thu Feb 21, 2013 9:33 am
by paso750
I would also think the fork legs are different. Between disc and caliper there are only a few mm clearance. If the fork legs were the same the calipers would sit 1cm too high on a 300mm disc. I doubt any manufacturer would do that.
G.
Re: Thinking about new front brakes?
Posted: Thu Feb 21, 2013 12:01 pm
by ducbertus
the difference comes from the mounting points on the legs. The Ø 300 came after the Ø 280 mm discs from the 750 and 906. Ducati would never develop a system specified for Ø320 mm discs and mount Ø 300 mm discs. With caliper sitting to high, they will bend out much more under load as when the calipers are sitting right on top of the disc. this due the fact that the distance between the centre line of the contact area of the disc and the bolt circle of the caliper is increasing and therefore the reactionarm. Longer reactionarm wiht the same load gives a bigger moment on the calipers.
Bertus
Re: Thinking about new front brakes?
Posted: Thu Feb 21, 2013 1:48 pm
by 900streetfighter
Duc750 I have 320mm brakes. I was just wondering if 320 could be fitted to 91 bikes without changing forks as I know a couple of people with them.
Cheers, Keith.
Re: Thinking about new front brakes?
Posted: Thu Feb 21, 2013 2:31 pm
by angelix
my 907ie has 300mm discs.
Whe I had to replace them I contacted Marzocchi and at the time (2002?) they still had TWO 320mm lower fork legs and they confirmed me that the lower legs were different from the 300mm version
unfortunately the money they asked was outrageous and i decided to have a set made by Discacciati (cast iron) and never looked back.
A couple of years later I replaced the Calipers and the master cylinders with the Brembo Serie Oro (fitted on the 916) and they were a straight swap, except for a difference in the piston size, the brackets and fitting was absolutely the same as in the old original black brembo calipers.
With cast irons the only precautions are: using the correct pad compound and be careful at the first braking as they perforem better when they are warm.
Re: Thinking about new front brakes?
Posted: Thu Feb 21, 2013 3:43 pm
by 900streetfighter
Thanks Angelix that sorts that out then.