Hello fellow race fans. I recently bought a pair of discs from a dealer on Ebay that were purported to be suitable for an 851. The discs are 320mm Brembo’s on CNC machined carriers with fully floating rotors, held with bobbins and circlips.
These discs are not standard fitment as they have 20mm offset. I’m now scratching my head as to what they came from and wondered is the SP model also used Brembos with a 20mm offset?
They certainly wont fit my 748 SPS
Do you still have the discs and do you want to sell them?
Mate there probably rare disc’s . 748 , 916 disc’ are different tottally . I have a set of racing iron disc’s and pads that will fit your 748 if you want them .
I guess there pretty rare
Thanks for the response. Yes, I’m sure they are very rare but unless you have a buyer who wants them, they are just paperweights! Geoff Baines thought they may be from an early 851 SP race bike? The carriers are CNC and would have been expensive to make.
I’m hoping to find/swop/buy a set of original 748 cast iron rotors to get my bike back to original but have yet to find a suitable pair. If you have a set, stick a picture of them on the forum and we might have a deal.
The discs are for sale with a view to buying an original set of cast brembo’s for my SP.
I’m hoping someone has a good set they want to sell?
Where abouts in the country are you?
I think I may know what they are from. On the discs, if you could you measure the distance between the flat plate where the disc mounts onto the wheel and measure down to the disc and also the thickness of the disc. This will give the offset. If you can give me that I can probably tell you what they are off.
Good Morning. As I stated in the advert, the disc’s are offset by 20mm but I’ll double check and confirm what I thought a bit later.
Its odd the set I have are 25mm to the centre of the disc 22.5 and 27.5 either side. If you could remeasure.
I hope you are well. Did you get chance to measure the discs? Thanks Paul.
Morning Paul, no I haven’t yet. Thanks for reminding me. Rather more pressing issues at the moment!
Sorry yes I totally understand.
They’re possibly “Wide track” discs for a 851/888 Corse/Race bikes.
The racers had the discs offset farther out into the cooling air than the road ones.
Hello again. I managed to find the disk’s. They are 5mm thick and have 20mm offset.
I did take some pictures but they are on my phone.
Stay safe, Stay in the workshop
I’ve had a look on Google and I can confirm they are 888 Corse racing disks, thanks for the help!
That’s doubled their value!
Hi sorry for the delay in coming back to you. I have been doing some digging around. It was the 20mm offset that was throwing me. I believe the disc are from a customer race 1994 851/888/926. I brought one from Holland about 3 years ago. It had been dry stored for about 20 years. I have begun renovating. it If you look at these bikes very little is off the road SP. Mine is a 91 Roche Corse and the bike with some period upgrades is about right. One thing that is not are the wheels. Instead of 3 spoke they are the later five spoke Marvic ones. On putting the bike back together it appears that with these wheels the 1991 discs with the offset at 22.5mm offset move the disc off centre in the calipers. I was going to get the wheel machined down. I now believe that those discs go with the 5 spoke Marvic wheels. In a book by Mick Walker, one of the 94 model year changes was ‘narrow-face front brake disc and lighter 5 spoke Marvic magnesium wheels’. I would still like to purchase the discs and use them with these wheels whilst I try to find the correct wheels for this bike. Please contact me if you wish to sell. In the meantime does anyone have a pair of Marvic 3.75/17 6/17 three spoke magnesium wheels that measure 85mm across the front wheel disc mounts? I hope that helps. Paul
Thanks for the background Paul. It’s a black art to determine what components were fitted to what bikes during a season of racing as they were all essentially development machines.
I’ve advertised the discs on my Ebay account, Fortissimoto78, so you can have a look and make me an offer. I’ll be honest with you, I paid £200 but I think I stole them of the seller as he had no idea what they were from. Bizarrely, if you type in the part number that is on the tag (300182005), they bring up the discs from the manufacturer.
If your bike has Ohlins 9050 forks, these can be swapped left to right, this then moves the brake calipers out farther to suit the “Widetrack” Corse discs. Or you could find some Ohlins 9051’s which set the calipers In the correct position.
Just over a year ago I bought new from Marvic a pair of “Streamline” 3 hollow spoke “Period correct” wheels in the sizes that you’re after, for my ‘92 851/955cc “Bitsa”.
Marvic made them to my spec’, the turn around was about 2 months with the cash paid up front and they weren’t cheap…Circa £2.4K.*
*They were the final step that saw my 851 scale 350lbs fully wet, inc’ a set of road legal lights and a starter motor.
More power than a Factory 926cc at less revs and similar weight to the customer 888 Corse.