Grimeca disc brake

Anyone know if SIP will sell a disc brake kit (classic) with a handle bar master cylinder instead of a fork mount one?

And anyone know the difference between Master Cylinder 56378800 and pressure transducer 30060000?

Yeah, that is a help. I was intending to buy the sip fork, which seeing as it is based on a pk fork would take a grimeca kit (as in vba restoration). Not sure if a PX set-up will work on the PK fork? Would a PX fork fit into a VBB?

Yes, you use a PK fork and shock and a PX disc assembly, complete. You have to use a PK XL type fork with the PX style (but different length) fork with a 20mm axle pin. All PK XL pins are 20mm. The only mod is very minor, you have to ream one of the mounting bolt holes.

dog leg levers look fairly similar and are cheap

The sporty stepped levers, look on sip products to see why they have been called dog leg in the past. They offer a better clutch action than the stock single curve lever as the leverage is better.
You could use the sip adjustable ones like on their racers, they look ok with odd levers due to hydraulic brakes.

I am really undecided about a vespa or grimeca disc set-up. Which one? Will a vespa px set-up really be simple to fit?

There are two routes to do as you want. The older style disc brake originally supplied as an aftermarket bolt on, which comes with a dished brake disc and fork mounted master cylinder and buy a handlebar mounted master cylinder extra and goodridge hose. Two choices of the Grimaca master cylinder, The type that mounts to a tube, like the polini gas tube(300600) or the PX disc mount type (56378[H] that has a flat plate that bolts to a flat plate on the handlebar. The other type is the PX disc type disc brake with a flat disc, doesnt come with a master cylinder and buy extra the master cylinder to suit you. The PX disc type is a better disc brake for several reasons, Unsprung weight, parts availability, cost and ability to ungrade to malossi drilled disc and better compound pads. They are also standard fitment to aVespa from 1998 so they are available second hand if you shop around, Last one I got for £100 from a main dealer! Mouting a mastercylinder needs modification using either h/bar type and if you can get a bit of alloy welding done the PX disc is easiest, and cheapest. You dont need to buy a complete 98 type h/bar and you can retain a standard throttle tube, instead of a Q/A . Any Help? You can also get a m/cyl from a bike breakers, RD/TZR 125 are the right bore/piston size but does take a bite of adaption similar to 300600.

so you don’t think a standard px disc will fit to a pk fork? even with a pk shock?

I might take you up on the throttle tube. I will wait until I get the parts then have a look at how it all goes together.

I think price will decide whether I go Grimeca or Vespa disc. I suppose if a PX disc is easy enough to fit to a PK fork then it will be a cheaper option.

Do you know if you can get a clutch lever to match the brake one, otherwise it might look odd with 2 different levers.

Or I could go for a hydraulic clutch, but people seem to have problems with these.

A motorcycle cylinder will give a better brake than the fork mounted semi hydraulic ones. If you want to trick up your scooter I can make you a new billet aluminium throttle tube to fit it to. I use bigger cylinders than the vespa disc one to improve the brake further. The Grimeca ones SIP list are 11mm piston, vespa disc cylinders are 12mm, but I use Suzuki ones at 12.5mm or 14mm (or upto 17mm if you are disabled and have poor hand / grip stength, basically a cylinder for a 200mph twin disc bike with 6pot calipers is evil on a scooter). All you need to do to a drum brake headset is cut the lever pivot off to make a notch to fit the cylinder into (dont cut too much off at first and you wont weaken the headset) you can fill any gaps with a liquid metal, or have it welded, or just leave it if you only trim the minimum off to fit the cylinder as it will cover the hole. See mays Scootering, or my LML threads on the board, or the next issue of Scooterist Scene (i think it is in the next one but won`t be sure til i see it) or arrange to meet me at the isle of wight rally in august.

Dog leg levers?

Can I have your email Adiran so I can talk to you about the throttle tube

I havnt any knowledge of the dimensions of your fork leg, but if sip are using a PK fork then I would use that. aPX fork is longer than a PK fork from the bottom steering bearing to the axle. A PX fork will make it sit up too high at the front, also the shocks are different, by nearly two inches so thats also the corresponding increase in overall length. Therefore you probably require a PK XL fork, Disc brake assembly and as there is an increase in unsprung weight an uprated shock/spring rate, Ideally the biturbo as the adjustments are both more incremental and noticeable.

SIP call them sport levers but when i got my first vespa in 1986 they were called dog leg cos of the shape (p7+8 of grips & levers in RACKS,CRASHBARS ETC)

Hi, the px disc is easy to fit to the 20mm axle forks, you take the plastic cover off, undo the hub nut, gently tap it to release the hub and away you go, then it is just the circlip that holds the drum back plate/ caliper carrier/speedo drive on. you can either drill a hole to take the brake hose in the mudguard, but what i did was drill the brake cable hole bigger and run it through the forks. my email address is: [email protected], i make brake hoses too if you want.