Modern Vespa

so, I've come to the conclusion that no matter what I do, I'm not going to be satisfied with the tiny front drum on my scoot. after messing with shoes, different drums, adjusting the lever, checking the cam, adjusting the cable, etc, it's still pathetically, and dangerously, weak.

and with winter coming and me needing something to keep me occupied as i quit my smokey treat habit, I figure I should do a wheel conversion.

looks like I'm going to want a PX fork so I have an easy path to a disc if i ever want to go that route, but I'm seeing 2 different axle sizes and am wondering about the column lock. which axle size do i want? the 16 or the 20?, and what will be involved in getting the column lock working? a new lock? is it plug and play?

complete n00b at this stuff, so tips would be appreciated.

Its a big bucket of hate that you are looking at here.

I take it that you are looking at converting your cushman 125, three speed, 8" tire scooter to a 10" rim with a fork. Its not easy, the result will look really odd, and the gearing and speeds, stance and handleing will be totally changed.

That said, I have seen it done, front and rear swap to 10" hubs and rims.
The 20mm is more common that the 16, you probably want to pick that for its easier to find a disc for it.

There is info out there, if you want my further opinions, you can PM me. Personally, I would change engines if I did this conversion.

I do intend to do an engine swap in the future, but that's another can of worms and I'm still torn between doing an LML150 injected or tracking down a p200.

I know the ride height will be different, as well as the look, but I currently don't feel safe with how ineffective the brake is, so I'm willing to compromise in favor of safety and confidence.

No, don't do it to a '63 Cushman. Get a different scoot, preferably a P-series, and upgrade to the SIP/Grimeca semi-hydraulic setup. Keep the Cushman for looking good at rallies, but don't mess it up w/ new forks and engines.

I have a p200 motor for sale, if you want to go that route.
The GL is not the best frame for the job, but...

I did a fork conversion from a sprint v to a PK with disc. Now my scoot is everything that I wanted it to be.

PM me and I can send you a link to the for sale pics on my motor. And, I can tell you all about the fork conversion issues.

well if u want a stronger brake with a bigger drum why dont u just do it in ur rear wheel and leave the front fork just the way it was i done that in my vbb2 and my brake is much much better also look like a old time drag race bike

why not go the whole hog and restem some auto forks and shove them in

The PK fork is the one to use but I would advise getting a p200 to put a disk on instead of converting the 8" wheel.

with an 8" wheel bike I would first get the rear brakes working great, odd as it may sound that's where most of your stopping power is on that bike. For the front brakes anything that makes them work better will make the front dive more. That said, the length, routing, and condition of the cable will be the biggest factor. Second would be the lubrication of the cam as it passes through the hub.

I've always wanted to do a disk conversion that keeps the stock 8" wheel, that would be cool.

I would love to find a running p within my budget for a second scoot, but it's pretty unrealistic(I currently have about $600 in my scooter budget, which I'd rather spend on the VNB), besides, I honestly like alot of the nuances to the styling of the old bikes.

Not sure $600 will get you the upgrade you are looking for. The PK fork will be at least $200 plus some cutting and welding to get the lock, steering stops, and headset mount all lined up. then some body work to fit the front fender, or maybe save the original one and get a new one to modify. You'll also need a new rear hub, backing plate and shoes. And a new center stand.

I can do it for 600, provided any fabrication done is DIY. one advantage of being in KY is there are alot of redneck farmers who like to fabricate their own atvs. so it would require modification to get the lock going then?

The P fork is longer, you will cut it.
The threads do not go down far enough, so you will cut them into the tube further down its neck.
The steering stops are not the same, so you will remove what is there and make new ones that line up and keep the steering from angling over too far.
To line up the cylinder lock, you have to insert the fork, mark where the notch should be cut away and then grind off enough so that the lock slides in correctly.

The PK fork is friendlier, but modification is still needed.

I bought a PK fork from SIP years ago, it came with the above machining already done. Although it was spendy, and supposedly perfect, my cylinder lock does not match up, and it is useless.

Refitting the fender over the shock and hub of a larger size gets interesting with mixed results. Some folks go with the hugger style fender, some like me just bend and fabricate answers until the stock one fits rigidly.

Bitubo shocks work as they are inboard the furthest, and tightly fit under the fender. I have pics of all of this.

I do have a good piece of news -
If you want to go fully hydraulic with a disc, then I have good machine drawings that put a plate under the headset, into the mirror mount holes, it then holds a normal grimeca master cylinder upright, and puts the lever right where you want it. The best part is that you don't have to grind off the stock lever's perch to get it to fit, in case you ever want to go back to stock. SIP makes one as well, it is also spendy, and it doesn't work as well. Get a farmer to weld one up, done.

p

would this be what you're referring to?
http://www.sip-scootershop.com/EN/Products/13347200/Steering+column+VNBVBBT4.aspx

https://modernvespa.com/forum/post745363

Yes, that is the SIP setup that I got, only mine wasn't that expensive at the time.
The steering stops are a bolted on T bridge piece, that works fine. Its my column lock that is fubar.
I was lucky enough to get hand delivery from a friend that travelled to Germany and back to see family. He was close enough to SIP to swing by and shop. In turn, I gave him my sprint fork to replace his Bajaj fork, which was starting to look rather sketchy in the welds.

And, the fork that is for sale looks like a rally/sprint style, with the spring and damper assembly in that fashion. This was the fork that I upgraded away from to the SIP PK version. If you go that route, be sure to add the stiffer coil spring, it makes a huge diff.

Here are a few images in the midst of the assembly-

http://gallery.me.com/portergieske#100364&bgcolor=ltgrey&view=grid