MB Services – Skim a disc

These jobs come in every now and then. Not as many as they used to when we only had Genuine Innocenti disc hubs to work with.

Now the world is flooded with all sorts of remade copied hubs both inboard and out board.

I could lift the rear wheel off the ground using our MB designed outboard discs – I could do it 2 up and once had a friend raised higher than me giving the front brake a fist full. Anyone who’s ridden a Scooter hard into a fast corner and found the disc is warped will know how scary they can be. 

I raced around the IOM TT one year on my Carbon Gp and used the front brake so many times. Coming home on one of the last corners before I got to work on a very fast in out roundabout the front disc had warped and it was a case of both feet down just to keep upright! It was like a tank slapper they you can get on a big bike. The only time I ever raced on a track was at Bruno in the Czech republic in the 90’s. I borrowed a Group 6 race bike without a practice and on every corner using the front brake I would get a tank slapper that tried to throw off. All I could do was not use the front brake – I came 6th in the European championships with only a back brake!

Standard Lambretta discs can warp, they also get glazed over so the pads don’t grip. Most Genuine discs get rusty over the years and sometimes I have to re-machine them.

It’s not a hard job, it only takes a few minutes, the hard part is clocking the disc to run true, machine one side and clock again and machine the other side.

Whilst this gets done, its just as easy to remove any rust with some emery cloth. But this can be a bit pointless as the first time you ride in the rain or you wash it the rust comes back and there’s nothing you can do about it.

The trick to get internal discs to work is to make sure the disc is free on the 3 pins and remove the anti rattle clip. Then set up the static pad and then they work very well. Don’t do this and they hardly ever work!

Here’s a disc which needed de glazing and some rust removing. 



  1. Martin higgs 23rd August 2023 at 8:17 pm - Reply

    Always like reading your tech site its full of imformative info and how you get over any issues and make better than innocenti could ever have done keep the top work up mark

  2. Tim 23rd August 2023 at 10:29 pm - Reply

    In the 80’s used to love the inboard disc and the first thing I did as advised from the seventies lot was take out the the anti wrattle circlip

  3. stephen mark dunne 24th August 2023 at 5:33 am - Reply

    the beauty of a lathe

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