Sip anodised vespa brake caliper

hi can you tell the distance between the mounting holes on your anodised vespa brake calipers is it 56mm or 52mm . the reason i ask is ive got a pm  tuning lambretta tubless alloy wheel that id like to change the caliper on

cheers martin.


it is with a 52mm center to center




Hi, I have used two of these calipers on a Lambretta twin outboard disc set up and I'm really struggling to bleed them up. I have carried out this procedure on many different types of brake set up, so did actually think I knew what I was doing.

However am struggling bleeding these up (I don't think it's anything to do with the calipers), I know the system is full of fluid (am running two seperate hoses from new AJP res.), I pump the lever  repeatedly, pull it in, slacken caliper valves (independantly with one way bleed pipes on) and only fluid comes out, repeat on both sides and still no lever.

As I'm using drop bars I have alsojacked up th stand leg on that side to try and level the res., still there is no feel to the lever and pads not even starting to bite.

Any ideas or advice very welcome.