building a moped STUNT BIKE

Back in February of 2018, I decided I was going to try and learn how to wheelie my Puch Maxi. I had seen some videos on youtube of kids riding wheelies on their mopeds so I knew it was possible. I practiced pretty much every single night and eventually got the hang of it. (Here is a thread with videos of me learning)

When I first started, I was riding an e50 maxi with a kstar 70 kit, 16sha and mlm people's pipe. Keep in mind, you can wheelie on just about any STOCK moped, it's all about the rider technique. So the 70 kstar setup worked well.

As I got better and better though, I started to out ride my bike. It was time to modify and keep pushing the envelope of what you can do on a moped! This thread is going to highlight some of the things I learned and what I did to the bike.

20190309_133629 by max jureckson , on Flickr

Headset Bearings: Ok so let's start with probably the first issue I ran into with wheelies... Head set bearings. All the slamming down from the wheelies really beats on your bearings and the bearing cups. I think I destroyed and replaced about 10 of the lower cups before I finally decided to do something about it. My solution was to replace the lower cup and bearing with a Tomos one (much beefier). For this to work you basically just need to shave down the OD of the cup sleeve that goes into the head tube. I also had to sand the paint off the fork tube for the lower race to fit on. The lock on the frame had to be ground off so the larger cup could fit. Other than than, they fit perfectly and have been standing up to some serious abuse!

20190316_093958 by max jureckson , on Flickr

20190316_094007 by max jureckson , on Flickr

Exhaust: The next issue I was having was scraping my pipe. As I got better, I learned to "drop back". It's basically when you go back beyond the balance point and use your rear brake to keep from falling backwards. Unfortunately most exhaust pipes for mopeds extend past the back wheel, which is no bueno. I decided to modify my MLM pipe and cut the baffle short. Why use the MLM pipe? Well, it gives me awesome flat power which is perfect for trying to control the bike on the back wheel. I have tried circuit pipes, simo, estroil all kinds of pipes and this people's pipe is the best imo. It still revs high and has a noticeable power band, but the low and mid is awesome.

20190316_094027 by max jureckson , on Flickr

Engine: As I said before, you don't need power to wheelie on a moped. Everyone wants to know what my setup is because they can't believe the bike can lift the front wheel. So here it is, nothing crazy, a lot of you are probably on more powerful bikes. It's a kickstart e50, unported polini 65, o-ring head, 16SHA, 96 main jet, 15mm MLM intake, hpi internal, Trickmetric Hammer clutch, and the MLM poeple's pipe. Gearing is 15x40. Top speed about 52 so just a hair over 10k rpm. This is a super snappy setup, very reliable and decent on gas. I can basically get vertical on the bike and the SHA doesn't starve for gas. I also keep the carb turned at a slight angle on the intake so I it can handle the wheelie angle better. No light coil on the HPI, so I used some super bright rechargeable LED lights.

20190316_094020 by max jureckson , on Flickr

Wheel bearings: No pictures here, but I originally learned how to wheelie on snowflake puch rims. I converted to sealed wheel bearings with the kit sold on treats. Well, they ended up wallowing out the saddles where the bearings press in. The bearings actually fell out when I serviced the wheel and there was noticeable wobble when you rode it. Bummer since those are 1 piece rims. I ended up getting sealed bearing 5 stars and have had no issues since, they seem much stronger.

Stunt Pegs: After riding with my buddy on a stunted out WR250R, I realized having some rear pegs to stand on during wheelies would be cool. All the street bike/super moto/grom dudes with hand brakes have them, so why not a moped! Here is what I came up with. I welded chrome plates on the original book rack. Then I welded studs through those plates. This let me use bolt on pegs that I had laying around. They are strong and also removable in case I ever want to take them off.

Stunt pegs on Maxi by max jureckson , on Flickr

Stunt pegs on Maxi by max jureckson , on Flickr

Screenshot_20190312-083719_Instagram by max jureckson , on Flickr

Throttle: Another thing I added was the quarter turn throttle. This one is Tomaselli brand. It makes throttle blips when you wheelie much easier. Paired with the little SHA and you basically have an on/off switch for a throttle. It's great.

20190316_094116 by max jureckson , on Flickr

........ ok that's it for now, I'll post more about this bike soon!!!!!!!

Re: building a moped STUNT BIKE

Good read!

Ever considered conical headset bearings?

Re: building a moped STUNT BIKE

Dirty30 Dibbs /

That pic doesn't do its justice showing how angled that Sha is mounted at and still works fine. Killer bike and even better rider.

Re: building a moped STUNT BIKE

Dirty30 Dillon /

Lancaster County Police Department had been notified of the illegal modifications you've made to your motorized pedal bike.

I'll pray for you.

Re: building a moped STUNT BIKE

Alrighty, let's discuss my favorite part of this bike....

Rear brake: If you ask someone that knows how to wheelie what the most important part of doing it is, they'll probably say rear brake. It is your life line when on the back tire. Do you need it to wheelie? No. Do you need it to keep from falling on your ass when you go beyond balance point? Yep.

The 5 star rims come with 80mm drum brakes. I spent the better part of a year constantly tweaking and chasing ways of improving that brake. I tried different cables, pads, levers, brake plates, all of tricks. At the end of the day though, it never did what I wanted it to do. The feel of the brake was vague, and the stopping power was always weak. By normal riding standards it was fine, but for me it just didn't cut the mustard.

I finally decided it was time to upgrade it to a hydro disc brake. Now if I wanted to add it to the front wheel, it would be a piece of cake. Lots of people do front discs, but not so many people do a disc rear. Info on ways of doing this was limited and I really didn't want to pay for someone else to fabricate it, so I did it myself.

I started by buying the mike thomas rotor since the bolt pattern was the same as the 5 star hub. This was sort of key in making this work and saved me a lot of extra headache.

mike thomas rotor by max jureckson , on Flickr

I also picked up a left side rear hand brake setup on treats

lever and caliper treats by max jureckson , on Flickr

Once I had the parts, It was time to start figuring out how to mount this rotor to the hub. Since the hole pattern matches the hub, all I really had to do was space it out and get longer bolts. I designed some spacers and had my friend make them for me on a lathe out of aluminum.

20190303_170127 by max jureckson , on Flickr

20190302_140744 by max jureckson , on Flickr

The final dimensions were actually a little different than my drawing but you get the idea. It worked well, the spacers sit about a 1/2" down inside the countersunk part of the hub.

20190302_140802 by max jureckson , on Flickr

20190303_170149 by max jureckson , on Flickr

20190303_170155 by max jureckson , on Flickr

Before I could mount the rotor for good, I had to clean it up. I think these are laser cut? Whatever they used to cut them left a big burr on one side. I'm sure this would smooth out on it's own, but I didn't want to kill my first set of brake pads. So I went ahead and deburred it by hand with the file.

20190303_183203 by max jureckson , on Flickr

Nice in smooth now!

20190303_185415 by max jureckson , on Flickr

Ok the rotor was the easy part. Onto the caliper and the mount! Unlike front disc setups, the rear caliper has to slide back and forth so you can adjust your wheel/chain tension. I looked at some common motorcycle designs and came up with a design very similar to the stock drum brake plate.

20190303_194426 by max jureckson , on Flickr

20190303_195111 by max jureckson , on Flickr

As you can see, it will mount around the axle. I am going to weld it to the axle spacer. The threading for the bicycle freewheel was in the way though, so that had to be cut off so the caliper mount could clear everything.

20190303_171950 by max jureckson , on Flickr

20190303_173308 by max jureckson , on Flickr

This is the position that the caliper is going to be mounted.

20190303_170204 by max jureckson , on Flickr

Now it's time to figure out how to keep the mount rigid while still being adjustable.

20190307_200301 by max jureckson , on Flickr

20190307_200307 by max jureckson , on Flickr

20190307_220532 by max jureckson , on Flickr

I ended up welding an axle spacer to the first plate I made. Then I made that fork looking piece and welded it to the first plate. Now I have something similar to a drum brake plate.

Next I needed some sort of stop pin on the inside of the swing arm. This pin will fit in between the channel on the caliper mount, and keep the mount from spinning when I hit the brake. I drilled through the swingarm and welding in a bolt. I ground the head of the bolt down a bit for clearance.

20190309_130721 by max jureckson , on Flickr

Painted the brake plate. Welds are ugly since I am using my splatter welder mig but whatever, they're fused. It's still just mopeds.

20190309_132101 by max jureckson , on Flickr

And here it is all finished. Brake works AMAZING. Night and day different. I locked the rear up at like 50mph and nothing broke or cracked, so that's good. Caliper mount slides with the wheel and everything is adjustable as it should be. Caliper is also mounted so it can be easily serviced.

20190309_133643 by max jureckson , on Flickr

20190309_133638 by max jureckson , on Flickr

20190309_133712 by max jureckson , on Flickr

My only complaint is the master cylinder suckkkks, I already ordered a better one. Don't get these cheapo ones, they are for kids chinese ATVs. I already ordered one on ebay made for Vespa big body scooters, should have it this week and I'll update the thread.

Thanks for reading!!!!!!!

Re: building a moped STUNT BIKE

yeah I have considered it but I think the amount of fab work for that outweighs the benefits. It would be hard to do it on normal moped forks since the head tube is so short, so you'd prob use dirt bike forks. I have a set of cr80 hydro forks but I don't want to use them, my spring ebrs are lighter and the tomos bearings are holding up great

> alex . Wrote:

> -------------------------------------------------------

> Good read!

>

> Ever considered conical headset bearings?

Re: building a moped STUNT BIKE

This is some great innovation. I would like to use a foot actuated version of this on my moped. Well done puch_plumber!

Re: building a moped STUNT BIKE

kevin Smellaflange /

if your serious there are 3 things to consider...

(1)know when to stop, after u launched an epic floater.

(2) yes a touchie back brake is KEY

(3) a human..or ...(carbon based unit)...looking to impress the younger folk & influence people NEED to convey all the steps YOU got to your point of skill...

ps...learn to balance on a wide inner tube 1/2 filled with water, blind folded...in-order to achieve a sleeper balancing act.

...the last part should be put on you-tube, for humility.....fin

check out the kid (brazilian) maybe? crankin' on a moby, at will.

Re: building a moped STUNT BIKE

kevin Smellaflange /

AND...back in the day some dirt bikes used the rear sprocket as a disc also...so u would have in effect 2 rear brakes ..use the same lever but branch off maybe...

Re: building a moped STUNT BIKE

Can you wheelie yourself or are you just spouting off random stuff?? I'm kinda lost.

I'm guessing you are referering to João Moby?? He's a very talented rider

Re: building a moped STUNT BIKE

ehh not really any point to that. If anything, you run two seperate calipers with one hand brake lever and one foot brake lever. That way you can do no hand wheelies and also do seat stand tricks without ever losing brake coverage.

Most street bike stunt riders do this. Two levers on the left bar, one clutch and one L hand brake. Then you also have a foot brake.

> Brent Eaton Wrote:

> -------------------------------------------------------

> AND...back in the day some dirt bikes used the rear sprocket as a disc

> also...so u would have in effect 2 rear brakes ..use the same lever but

> branch off maybe... (edited)

Re: building a moped STUNT BIKE

boss! so nice and mostly using easily accessible tools and parts, that's what I really dig about this.

Re: building a moped STUNT BIKE

Thanks Will! Yeah everything was done with an angle grinder, mig welder, and other basic hand tools in my shop. Metal was all scrap pieces we had laying around. Only thing I couldn't make were those 5 aluminum spacers for the rotor. Human bean Andy H made those for me.

I try to keep serviceability in mind, so that can determine the parts I use. I know I can get tomos bearings easily, I know I can get more pads for that caliper, the pegs I can get more of and they are a standard size, 5 star rims are fully serviceable, etc

Re: building a moped STUNT BIKE

yeah but can u kickflip it

Re: building a moped STUNT BIKE

kevin Smellaflange /

yes..what max said, he get's it.

Re: building a moped STUNT BIKE

Cristian Luna /

How do you like that mlm swing arm does it make it feel more sturdy ?

Re: building a moped STUNT BIKE

kevin Smellaflange /

in answer to he get's it max...

i've owned 2 BULTACO SHERA T 350s

and 2 1975 KAWASAKI KT 250s

2 YAMAHA TY 250s

and rode trials with people that you have never even heard of...no brag just fact...( you asked ) that being said my 3 step method is a type of off road survival..people who actually ride will understand.

Re: building a moped STUNT BIKE

I like it a lot! It definitely does make it feel more sturdy and gives more tire clearance. Make sure you get the hardware for it if you get one though, doesn't come with any and you can't reuse your old nuts and bolts

> Cristian Gnome Wrote:

> -------------------------------------------------------

> How do you like that mlm swing arm does it make it feel more sturdy ?

Re: building a moped STUNT BIKE

Dirty30 Dillon /

Brent's over here responding to his own posts with whackadoo, colloquial nonsense about how riding with old-timer Trials guys somehow makes your scatterbrain ideas understandable.

2019: The Year of Competent Communication.

Re: building a moped STUNT BIKE

You sound like a person who gets invited to a lot of parties.

> Brent Eaton Wrote:

> -------------------------------------------------------

> in answer to he get's it max...

>

> i've owned 2 BULTACO SHERA T 350s

>

> and 2 1975 KAWASAKI KT 250s

>

> 2 YAMAHA TY 250s

>

> and rode trials with people that you have never even heard of...no brag

> just fact...( you asked ) that being said my 3 step method is a type of

> off road survival..people who actually ride will understand.

Re: building a moped STUNT BIKE

Actually Binx, he's partied with people we never even heard of.

Re: building a moped STUNT BIKE

haha this is great!

lots of the same stuff i've done to maxi's over the years just to beef them up for handling dubs riding

never tried an SHA on a polini... runs good huh?

i am doing those PW80 forks but i switched them over to a tomos headset, the OG headset is ball bearing but its huge, either way the pw80 forks are pretty light and they are hydraulic but only like 22" like a 1/2 inch shorter than maxi stock.

Re: building a moped STUNT BIKE

kevin Smellaflange /

you guys rule...

rule what?

( just rule) that should be enough...

video is the only way to prove anything...

yeah, i thought so.

Re: building a moped STUNT BIKE

Dirty30 Dillon /

> Brent Eaton Wrote:

> -------------------------------------------------------

> you guys rule...

>

> rule what?

>

> ( just rule) that should be enough...

>

> video is the only way to prove anything...

>

> yeah, i thought so.

https://www.instagram.com/717squirrel/

Go suck an egg, Brent.

Re: building a moped STUNT BIKE

Graham the SHA runs real good on the Polini!! I love it, super snappy and responsive

Re: building a moped STUNT BIKE

Yep it is!!!! I'll wait for the footage of you putting those trials bikes to work ;)

> Brent Eaton Wrote:

> -------------------------------------------------------

> video is the only way to prove anything...

Re: building a moped STUNT BIKE

kevin Smellaflange /

dear 30ish...

easy to say all the way over in Brooklyn

in your mums basement

i don't you've been a member long enough to spew

your niceties...no posts from u ever...stop hiding

Re: building a moped STUNT BIKE

Dirty30 Dillon /

> Brent Eaton Wrote:

> -------------------------------------------------------

> dear 30ish...

>

> easy to say all the way over in Brooklyn

>

> in your mums basement

>

> i don't you've been a member long enough to spew

>

> your niceties...no posts from u ever...stop hiding

Brooklyn is nice, my apartment and shop space are unaffiliated with my parents in CT.

I have been a member long enough to see you start using this site, and I'll probably be a member when you leave.

I am not hiding, but I have uncovered all your secrets

Re: building a moped STUNT BIKE

kevin Smellaflange /

go you.

Re: building a moped STUNT BIKE

Dirty30 Dillon /

> Brent Eaton Wrote:

> -------------------------------------------------------

> go you.

2wcpq2.jpg

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