What I've done: converted my P200E to have fully hydraulic front disc brakes.
Why: I've been using the old beast as a daily rider for a while now, and frequently ride two-up in various conditions from hi-speed cruising to hectic stop and go traffic. Especially when I have a passenger, the stock front drum brakes can be pretty insufficient (note: proper maintenance of the drums can keep them from being useless... if they hardly work at all for you then it's probably not the drum brake's fault, but rather the condition and adjustment of the brakes).
Here's a mostly complete list of the items used for this conversion: 20mm LML fork, 5-spoked PX hub, PX-series speedo cable, Grimeca 20mm disk brake kit, PX lower headset (to provide a mounting point for the handlebar master cylinder), Grimeca/PX handlebar master cylinder, PX hydraulic brake line, PX front mudguard (the original P200 mudguard can be easily modified to fit the bill - a slot would need to be cut into the right side of the rear of the fender to allow the hydraulic hose through).
There are so many things which need to be done to make this work. It's hard to figure out where to start my coverage of the progress.
Let's start simple: I wanted to keep my P200 looking mostly like a P200, despite the upgrade. To that end, I'm retaining the original electrics and speedo, so I want to use a P2 headset cover instead of the PX cover. The problem is that the hydraulic line from the handlebar master cylinder needs to go from outside the headset to inside the headset so it can run down through the frame to the front hub. The PX headset cover is designed for this to happen, but the P2 headset doesn't know what hit it.
To get around this, and opening must be cut in the P2 headset cover to allow the brake line into the headset.
Here is the P200 headset cover on PX lower headset with master cylinder mounted:
Here is the dremel work prior to painting the parts. Now the brake line can be attached to the master cylinder and run down into the headset!
Here are the upper and lower headsets painted and ready for assembly:
Here's the PX front mudguard all painted and ready to go on. At this point I was ready to finish assembly of the fork setup and swap it onto the scoot.
Let me just say - this was a LOT of work. And it's the little things which are so annoying: hydraulic hose doesn't fit with P2 horncrest, so that needs modifying, hydraulic hose doesn't fit through neck of frame between fork tube, so that needs to be ground open wider. PX lower headset is wider than frame so it just looks a little funky. hydraulic hose doesn't fit within P2 headset very well at all - it needs to be CRAMMED in there to fit with speedo and turn signal indicator light. The LML fork tube must be ever so slightly shorter than the P2 fork tube, because the fork bearing retainer nuts are thicker than those of the P2, and prevent the headset bolt hole from lining up with the indentation on the fork. It would work fine with the P2 bearing retainer nuts thickness-wise, but the threads on the fork are a different damn pitch!
Basically - no, the P and PX bodies are not "the same," and LML inexplicably changed very small things with the fork like the fork nut thickness and thread pitch just enough that the parts aren't "compatible".
Ultimately, I got it together. And it stops on a dime. Lovely improvement in the braking and will definitely be a much safer ride. But the effort required was quite large. I always hear that the semi-hydralic setup offers inferior performance - but I suspect they ARE a good deal in terms of the labor-results tradeoff. It probably comes down to the level of performance you demand from your brakes...
Here are some images of the grinding which is necessary to run a standard PX hydraulic hose on a MK1 P. The metal fixings on both ends of the hose are too thick to pass through the opening in the frame around the fork tube. In addition, there is a metal shield around the hose which sits at the level of this opening, to prevent the hose from getting sawed through over time with the turning of the handlebars. Because this metal shield doesn't squish, it will not move back and forth through this opening with sufficient range when the handlebars are turned.
Therefore, I needed to grind the opening wider. I felt bad, but this isn't a load-bearing zone, and makes not aesthetic difference to the scoot.
In the first pic I've drawn in red permanent marker how much I needed to grind to run the hose through. However, if you can tell from the second picture, further grinding was necessary along the extent of the opening to allow the metal-shielded hose sufficient room to move (otherwise, you literally can't turn the handlebar more than maybe 5 degrees to the right without the hose getting jammed and trapping your steering in that position).
Here is the finished product - notice further grinding was done to allow the hydraulic hose room to move without jamming the steering up:
Routing the hydraulic hose was also a chore. It passes down through the gap in the frame around the fork tube and out to the finder, then down through a hole in the back of the fender to the calipers.
The hose needs to be held in place near the pivot point of the fender to fit under the horcrest amicably (but see below). On a PX, there is a hole in the frame near the fork tube at the height of the turn signals, and a ziptie with a plug attached clips into this hole and holds the hose in place.
I didn't have a good enough drill bit to run through the thick steel to replicate this hole (which is obviously absent on a MK1 P), so I settled with a ziptie on the fork tube to hold the hose in place at roughly that height. I toyed with schnazier methods, but decided it was a minor point and would be easy to upgrade/change the ziptie approach if it turns out to be insufficient (so far so good).
As hinted above, even when this is done, the MK1 P horncast doesn't have the room for a hydraulic hose passing through - the horn leaves little room behind it, and the openings at the bottom of the horncast to fit around the fork are too small for the hydraulic hose to pass through and rotate around the fork pivot point. So, I got the dremel back out and dremeled away most of this lower lip on the horncast on the right side, giving the hose room to twist and move as the handlebars turn.
It never did fit great, but it's in there. Rubber buffers on the hose at that point still snag a bit on the horncast at times, but nothing dangerous to the handling of the scoot. I'll probably dremel it a wee bit more down the road. On the upside, this modification, like the grinding of the frame near the headset, is not visible externally, so the appearance is still intact.
At last!
Here's the finished product:
The speedo cable is mis-routed in this pic - I have since moved it between the fork and the tire, rather than around the outside.
The only remaining chore was to extend the wires for the front brake switch out of the hydraulic hose hole in the upper headset to the switch on the master cylinder. This was a relatively mild chore in the scheme of the whole project - straightforward soldering is all that is required.
Overall, after months of riding on the conversion, I am very pleased. I feel much safer in tight braking situations. My efforts to keep a fairly stock appearance have me satisfied as well - the original P200 look is simpler and more pleasing to my eyes. Overall, it's turning into a very nice looking scooter from where it started, and it now stops on a dime.
Anyone who wants to pursue this modification themselves should feel free to contact me - it should be obvious at this point that it was quite a chore. Also note, I have a sport shock mounted on the front fork. I recommend a performance shock of this level or higher (perhaps a Bitubo), because with the increased braking power comes increased front-end dive. It is both a comfort and handling consideration to have a stiffer shock with these brakes.
