Modern Vespa

Today I deposited the money for the Mighty Kong. For the early adopters, the price was 99,90EUR + shipping. I made it just in time (SOLD OUT now). The Mighty Kong is a dust cover plate with extra support for the primary's axle. CNC milled from high strength aluminum (EN AW-7075). Deliveries near Christmas. Will keep you updated...

What problem does it solve? I'm curious.

It will help from dealing with this (photo taken from Gt6MK3's thread)...

Ah right. I couldn't see the point of it before.

Although would it really? There is a fair distance between the backing plate and the primary hole.


Also, CMD made a big fuss last year about some super-quiet exhaust they were making. They showed dynos of how it didn't lose any power (compared to the leading brands) but wouldn't say how much noise it actually made, or didn't. Just thought that was odd.

I had to look harder to see what is going on. The input shaft doesn't use the normal securing nut, but rather one of those long steel nuts shown in the photo with the digital verniers. It's attached to the CNC backplate to provide extra rigidity, and to prevent the movement and stresses that can cause the case to crack around the input shaft.

I'd love one of these for my pimped VBC motor, with the pre-P input shaft. I'm still concerned that the extra power of the BGM 190 will cause the same cracks as GT6 has experienced.

I wonder if it does actually work to strengthen that area though? The backplate itself is not exactly held solidly. I'm still a bit doubtful.

Ginch, you may have a point with regards to a P2, T5 and later PX125/150 motors. Piaggio already made improvements by beefing up the input shaft and using the odd shaped thick steel washer/spacer between the case and the nut.

I know from my VBC build that it's weak point is the case area where the thin input shaft comes through. The considerable extra torque of the 190 puts a lot more stress on the primary when I let the clutch out, which in turn must be causing lateral pressures on the case. I think the CMD setup would definitely improve things, although I don't think they have an adapter for the thinner input shaft of the old motors.

I take your point about the backplate. The stock one is only held on by three tiny screws after all.

The threads of the tiny screws need to be re-threaded. I think they'll use 3mm or 4mm crews. And then there's the blind allen screws all around. Whoever though has the Pinasco v1.1 cases is lucky. Pinasco has four 6mm holes that no one knows what attaches to them. I believe they're developing a disc brake. CMD, has adapted the backplate for these cases, so the it will be more robust...

I see your point now SWA. My VBC case has a dodgy area around the flywheel side bearing so I haven't had a close look at it or put any real power through it for ages. Yes I guess anything you can do to stiffen up that primary shaft area would help, although I would have thought welding was number 1.

Safis the Crimaz rear disc advises to tap the 3 holes to M4 to help retain the caliper bracket, so perhaps there's something in that rumour.

Resurrecting this. Still haven't found the time to mount the "Mighty Kong" on my P and since my cases were already reinforced, I decided that it will go on my T5 motor. One thing I didn't like from the start, was the elongated nut, which was round at one side so it couldn't be secured on the primary's axle securing tab. Apparently CMD redesigned the nut so I got in touch with them and asked them if I could send the nut to be re-machined. They agreed and informed me that I would only need to cover the postage costs. I said OK and sent them the nut. Today I received it, along with some really nice stickers. To my surprise they eventually didn't ask me for the postage costs (maybe cause I had also sent them some club stickers with the nut). So, props to the guys at CMD!!!

SaFiS, very useful to know. I did wonder about the tab washer not having anything to cling to. I installed mine with Loctite, but may still machine a flat in the appropriate place.

Still not convinced the Kong will make any difference !!

Ha ha, I'm with you there!

CMD make some nice looking stuff, but their "marketing" really bugs me... every new product is a guessing game as to it's purpose. Building up a bit of mystery is one thing but I think they overdo it."
For a while their muffler was the greatest thing ever... it was going to be quiet but not lose any power and they were going to make all different versions. The one thing they never talked about was how much actual noise it made compared to others... which was the main thrust of the sales talk. After the initial run they seem to have dropped the idea.

Not exactly. It has the axle, the brake pad holders, and the brake cam casings coming through it, and if machined for a tight fit, that will be enough to keep the thing in place. The 3 screws only serve the purpose of keeping it from rattling or taking advantage of the few millimeters play to move laterally. The primary holder would be an extra securing point.
What question remains is really how accurately these pieces are machined, and how accurately the Pinasco crankcases used as models represent the rest of the production.

https://www.youtube.com/watch?v=HUxF_t9PZB0

maybe this?