Front Disc brake rotor measurement needed

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jeffdavison

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Does anyone happen to know what the bolt circle diameter is on the standard front disc?
Also lookng for the distance from the outside surface of the disc to the outside surface where it mounts to the hub.

THANKS!

JD
 
Sounds like ya shopping for a new rotor set up but may find they are 6 bolts to fit to Norton 5 bolt hub. When I rolled my own I found a bit bigger lighter rotor and mounted it to hub by adapter plate then mounted caliper gripped on rotor wheel in forks/yokes and had the caliper mount welded on so no measuring at all for perfect final alignment.
 
Also a handy measurement I'm needint is the center hole diameter of the stock rotor.


I am designing an adapter.



Thanks


JD
 
The disk mounting bolts are on 3-in diam bolt circle at 72-degrees spacing.

I used metric (because I used a Suzuki disk) and the center hole for the boss was 51-mm (i.e. 2.008") which makes a tight, snug fit. I think the machinist I had make my parts converted back to inches and went on the low side. I think if you made the center 2.01" ID you would have a good fit, without having to drive it onto the wheel.

BTW, I had to subsequently skim my adapter a bit narrower than I designed to be because the button-head mounting bolts for the Suzuki disk just touched the fork leg, I found that out when I assembled it for the first time.

By the way, you need to be very tight on the tolerances for the bolt circle and any of the measurements that will affect the roundness or eccentricity. Otherwise, you will have a hell of a balancing problem. The gentleman that did my machining for me was well aware of that and accordingly took special care.

Hope this helps you.

Front Disc brake rotor measurement needed
 
Thanks, That'll come in handy.

I found a rotor that I want to use from an '05 Kawasaki ZX-6R. It's a full floater, 300mm diameter and is a 5 bolt mount. It has no offset. If the Kawasaki mounting bolts are used, there should not be clearence issue as they are a very low button head bolt and the rotor center has a slight counter-bore so the heads do not protrude further than the floater hardware.
Being a 5 both, it makes the fabrication of the adapter a very easy affair.

One more dimension that I need, and hopefull someone hear can get it for me, is the total thickness of the Norton disc, from outside face of the disc to the outside face where it meets the hub.

Thanks again :)


JD
 
the disc from my single and twin disc brake kits, fits directly to Norton hub.
Front Disc brake rotor measurement needed
 
I have a vast array of diffent rotor stlyes and manufactures to choose from for that model run of Kaws. as there are many aftermarket replacements out there. I can go cheap with a "take off" from $50 or so bucks way up to $350 or so going Brembo, Gafler, EBC etc....
I like to have a choice. And since the adapter I'm designing is not a complex part, it to can be fairly inexpensively, especially if I have multiple produced. Planning 6061-T6, but just maybe I'll go 7075-T6.

I'm well aware of your disc, but not that you are offering it separately. I am just not that crazy about the gold center or the hole patterrn.
I was hoping that this thread not be used as a vehicle to sell wares, but no biggie.


JD

madass140 said:
the disc from my single and twin disc brake kits, fits directly to Norton hub.
Front Disc brake rotor measurement needed
Click to expand...
 
There is an a thread on here somewhere with a Suzuki disc (and caliper) on a Norton hub. Basically the Suzuki disc was redrilled to match the Norton hub then an aluminium 'cover plate' was made to cover the old holes in the disc, the cover also had a spigot that went inside the disc and over the spigot on the hub to centre the disc something like this

Front Disc brake rotor measurement needed
 
I designed and had them manufactured for my single and twin disc brake kits, my object was to make the brake setup look as production as possible, to the extent of casting special sliders as well so no disc or caliper adaptors are not required.
This is not a sales pitch. just stating that there are other options to retro fitting parts from other bikes to Nortons.
 
All I was really looking at was measurements for my project rather than alternatives. Thanks all for the input.

JD
 
The total thickness from outside to outside is .880" on one I have measured (and the friction wiping disc portion is .255" thick).
I don't know what the manufacturing drawing states, I don't have that available. Since the caliper does not float you need to be fairly close with the location or the disc may push one piston all the way in and contact the inside of the caliper slot. I'm sure you already considered this but why don't you just measure the one you have?
Keep in mind that by making and applying a spacer / adapter you are also applying a moment to the disc retaining screws that the original application does not suffer from in the same way. Just food for thought.
All the best.
 
Jeff, its too hard to get good measure off my mounted rotor but think I've a loose one in shed so will get back with the the bolt hole ring diameter and thickness-distance of back of rotor hub mount face to the outside of friction surface if that'd help.
 
The most common source for that 310 mm rotor is pre SRAD GSXR 750 and 1100's to about 1995/6.
The black centered 310 mm rotor with the Brembo caliper is off bikes like a 2008 and up Hayabusa and the GSXR1000 from 2005 on.
It might be worth mentioning those rotors use 10 mm shouldered hex heads to and counter bored wheel hubs centralise the rotor not the centre bore in the OEM mounting.
 
Time Warp said:
The most common source for that 310 mm rotor is pre SRAD GSXR 750 and 1100's to about 1995/6.
The black centered 310 mm rotor with the Brembo caliper is off bikes like a 2008 and up Hayabusa and the GSXR1000 from 2005 on.
It might be worth mentioning those rotors use 10 mm shouldered hex heads to and counter bored wheel hubs centralise the rotor not the centre bore in the OEM mounting.
Click to expand...


That sounded a bit odd so I had a look at the one I have in the garage and you are correct about the fixing system. What is strange though is that the disc centre bolt holes are stamped yet the centre hole has been machined.
 
Corona850,

What did you have to do to use the hard pipe into the Brembo caliper? Was it a straight fit or?


JR





Corona850 said:
The disk mounting bolts are on 3-in diam bolt circle at 72-degrees spacing.

I used metric (because I used a Suzuki disk) and the center hole for the boss was 51-mm (i.e. 2.008") which makes a tight, snug fit. I think the machinist I had make my parts converted back to inches and went on the low side. I think if you made the center 2.01" ID you would have a good fit, without having to drive it onto the wheel.

BTW, I had to subsequently skim my adapter a bit narrower than I designed to be because the button-head mounting bolts for the Suzuki disk just touched the fork leg, I found that out when I assembled it for the first time.

By the way, you need to be very tight on the tolerances for the bolt circle and any of the measurements that will affect the roundness or eccentricity. Otherwise, you will have a hell of a balancing problem. The gentleman that did my machining for me was well aware of that and accordingly took special care.

Hope this helps you.

Front Disc brake rotor measurement needed
Click to expand...
 
OK....... got parts fabricated and mounted. Fender still needs paint. I found the Suzuki rotor (19.5mm offset 300mm diameter and 5mm thick) and sourced the Galfer replacement for it (DF321CW). I found a surplus 2002 Indian rear disc caliper that just happened to be the correct 40mm spacing 30/34 Brembo caliper needed on eBay fo about $85 less than retail and I like the silver better as well. The disc rotor needed 3 parts to work; a 3mm spacer, a hub adapter (64mm outside dia. to 2.08 inside dia.) and a cover. Drilled 5 new holes on the Galfer disc carrier and with 5 ARP stainless 12pt. bolts, all went together perfectly. I had to relieve the inside of the right fork slider about 1/16" deep about an inch tall for some clearance for the disc floater rivets... easy enough with out comprimising the wall thickness of the slider too much. Clubman Racing supplied the caliper adapter, and I fabricated a short 10mm banjo to -3 AN female brake hose to mate with the existing SS hose.

JD

Front Disc brake rotor measurement needed

Front Disc brake rotor measurement needed
 
jeffdavison said:
Corona850,

What did you have to do to use the hard pipe into the Brembo caliper? Was it a straight fit or?
Click to expand...

Sorry. I hadn't looked at this thread recently.

I just bent the hard pipe a bit to make it fit. It's long enough and has the correct connections.
Looks like you've got it covered with that short hose, though. Looks good. I am sure you will like the stopping power, and control.
 
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