50/50

I went to the Toledo event last Sunday and got a tour of their bikes. One of them was a V1 and was described as a 50/50, or a 50 cc bike that can reach 50 miles per hour. As a Motron fan, I was intrigued at the possibility.

Anybody else have a V1 50/50 and how was that obtained? Bigger carb, better pipe, altered sprocket setup?

A bike kitted with everything BUT a bigger top end?

Re: 50/50

the cool 50/50 guys do it with all stock modified parts

Re: 50/50

Overpriced Parts /

50/50 is very cool and if you have other bikes I suggest you have/make one with modded stock parts but taking stock parts to the max may not be the greatest for a daily driver,

The most I like to take stock parts to still be very reliable with minimal maintenance as a daily driver is low-mid 40s mph (tomos and puch) for the more metal you take out of the cylinder and or piston, running one less ring, big carbs, big pipes increasing rpm etc. makes for more wear, hotter temperatures, high maintenance etc.

Neither is ported, only simple mods and have stock carbs, the puch has stock pipe but the tomos has a cheep 60$ chamber, both are big heavy mopeds (magnum and revival) with a 200 lb rider

Re: 50/50

I like 50+mph/50cc on variated bikes with stock top ends. If you port them right they'll beat most kitted bikes without porting. It's really fun to rip on very ported reeded stock jugs, they are super cheap to play with and usually pretty durable.

On single speeds (especially with piston port) it's much more difficult to do, as with the gearing you need to run to get to those speeds can hurt your takeoff and slow hill climbing.

Even ported well, stock 49cc jugs will always go slower uphill than kitted just because of the torque available from the extra displacement.

Re: 50/50

Thirty years ago, I took my first Motron, which already went 30 mph with just an 11t on the front, and replaced the rear 44t with a 36t. This brought the speed up to 40 mph on level and downhill. Everything else was stock. At the time, I wouldn't have considered any other mods. I'm not sure many were available back then, either.

Re: 50/50

Richard Eberline /

Roff man is correct, very unstable motor. It is a ticking time bomb. To get a stock Motron over 40 mph, you need to go downhill with the wind at your back. Also the speedometer is as accurate as a Michigan weatherman. Your call and add a couple mph to the total.

Re: 50/50

Stock V1's are pretty easy to hop up. The intake port is tiny, and there's a lot of room to open it up. Same with the intake manifold.

I had the 19mph version, with the intake hole smaller than a dime. Grinded it out almost twice the size, welded a new intake and used an 18mm mikuni. Modified a ktm 50 dirt bike pipe and had 10-36 gearing.

It'd hit mid forties easy. Slow off the line and uphills, though.

Never ported the case and jug, but that woulda got me into the 50s. Probably.

But it was too easy to just slap a polini on it and get instant satisfaction.

If there was ever a 50/50 spec race, I'd dive into it a bit deeper.

Re: 50/50

OOOH good opportunity for us to get a brag in!

I've been close a bunch of times. 2 heavily modified e50 I took over 45, 1 was an a55 cylinder, both ported and modified heavily. Port and build specs're on garage I think http://garage.1977mopeds.com/build/Clint%27s+old+maxi

I've had 2 hobbits also get close, on stock carb too, notched vario, except the pipes it was all just modified stock shit and they'd rip but again peak just over 45

My 2 speed sachs D would top out regularly dead on at 46. I had a regeared honda cub 4 stroke 3 speed 50 that I topped out at 46 too. Still that last 10% always escaped me.

But the only true 50/50 I had was totally cheating because I didnt do any of the go-fast engine work.

It had a basically stock morini s5, with a stock dirtbike pipe (hack/welded to fit) and a phbg19. I had that topping out over 50, fastest gps was 53. it screamed too, hell on the clutches but holy fuck it was fast and tiny.

Re: 50/50

Also I think typically speedos (at least cheap moped ones) are based just off a spring and calibrated to the max speed, usually 30 or 35. So zero's zero and you set it to read 35 at 35, and it's pretty accurate in between, but becomes farther and farther off outside the intended range. Then you've got tomos folks like "holy shit it's wrapped around past 45!" but really are maybe going 38

Re: 50/50

> Born to be WillD Wrote:

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

> OOOH good opportunity for us to get a brag in!

>

> I've been close a bunch of times. 2 heavily modified e50 I took over 45,

> 1 was an a55 cylinder, both ported and modified heavily. Port and build

> specs're on garage I think

> http://garage.1977mopeds.com/build/Clint%27s+old+maxi

>

> I've had 2 hobbits also get close, on stock carb too, notched vario,

> except the pipes it was all just modified stock shit and they'd rip but

> again peak just over 45

>

> My 2 speed sachs D would top out regularly dead on at 46. I had a

> regeared honda cub 4 stroke 3 speed 50 that I topped out at 46 too.

> Still that last 10% always escaped me.

>

> But the only true 50/50 I had was totally cheating because I didnt do

> any of the go-fast engine work.

> http://garage.1977mopeds.com/assets/images/builds/12226/de87e9d6d2ec94b758db0e71b72caba1.JPG

>

> It had a basically stock morini s5, with a stock dirtbike pipe

> (hack/welded to fit) and a phbg19. I had that topping out over 50,

> fastest gps was 53. it screamed too, hell on the clutches but holy fuck

> it was fast and tiny.

Big fan of the bmx style, i remember when you first built that. I wanna build a bmx moped now

Re: 50/50

i have got close on a peugeot with the super cheap 50cc cylinder. (pretty much a stock euro cylinder) stock tsm pipe and sha 15.15 i was getting 46 on the flats but broke 50 on some hills more than once (using phone gps)

same bike and cylinder with lots of vario tuning a phbg 19 and polini sport pipe i can hit 50 on a flat and almost 55 with a hill

Re: 50/50

Emil Kniemel /

Someone give me a formula for derbi FR 50/50. This is my first 50cc build. Hitting 45.X but can’t tell if its got anymore in it. Gila 50cc.

Re: 50/50

Brandon Weiss (Detective brandon to you) /

> Emil Kniemel Wrote:

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

> Someone give me a formula for derbi FR 50/50. This is my first 50cc

> build. Hitting 45.X but can’t tell if its got anymore in it. Gila 50cc.

what pipe are you using?

Re: 50/50

Emil Kniemel /

Big muff. 16x38 gearing. Stock 6 roller with various aftermarket ramp plates. 12gs is the lightest i got (3 weights). 15mm amal carb.

Next buy will be the rk replica metrakit but people i know in person recommended the muff but online people say muff sucks.

Tbh it seems ok but i dont have anything to compare it against.

Re: 50/50

A lot of performance can be found by just derestricting the engine. Manufacturers muzzle the engines so they can comply for homologation on the streets in various jurisdictions: 20 or 25 or 30 mph typically. Generally in the intake/carb diameters and the exit of the exhause for most production engines and gearing for the power train will keep a production restricted but reliable. remove the restrictions and you will have reliable with better performance... further enhancement will bring you up to 50/50 without kitting with a awesome 50cc jug...

Re: 50/50

> Emil Kniemel Wrote:

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

> Someone give me a formula for derbi FR 50/50. This is my first 50cc

> build. Hitting 45.X but can’t tell if its got anymore in it. Gila 50cc.

RPM is king. You have to have to port to increase blowndown and use a pipe that will deliver big peak power at the cost of range - then use the cvt to stay in the power. Small modifications to the cvt make a big difference. and making sure everything is well lubed including the cvt parts.

I had luck with and Airsal 50cc, HPI, scooter rear pulley, low compression ratio, lots of porting, VM18, LeoVince scooter pipe, sealed wheel bearings. Mine was a revo and it was easier than you would expect - it got me just over 60 a few times and made me give up on my plans to go with a big water-cooled cylinder

I tried 10x as hard on other 1 or 2 speed bikes and couldn't break the 50 mph mark

Build Thread:

https://mopedarmy.com/forums/read.php?1,3298541

Re: 50/50

the big muff is just too big

Re: 50/50

Emil Kniemel /

60/50 good lord. I wonder how many people skipped that thread cause it was titled qt50.

I guess at the end of the day 50/50 prolly wont be a reliable daily-rider type bike.

> Max (ツ) Wrote:

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

> > Emil Kniemel Wrote:

>

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

>

> > Someone give me a formula for derbi FR 50/50. This is my first 50cc

>

> > build. Hitting 45.X but can’t tell if its got anymore in it. Gila

> 50cc.

>

> RPM is king. You have to have to port to increase blowndown and use a

> pipe that will deliver big peak power at the cost of range - then use

> the cvt to stay in the power. Small modifications to the cvt make a big

> difference. and making sure everything is well lubed including the cvt

> parts.

>

> I had luck with and Airsal 50cc, HPI, scooter rear pulley, low

> compression ratio, lots of porting, VM18, LeoVince scooter pipe, sealed

> wheel bearings. Mine was a revo and it was easier than you would expect

> - it got me just over 60 a few times and made me give up on my plans to

> go with a big water-cooled cylinder

>

> I tried 10x as hard on other 1 or 2 speed bikes and couldn't break the

> 50 mph mark

>

> Build Thread:

>

> https://mopedarmy.com/forums/read.php?1,3298541

Re: 50/50

Start with yellow clutch springs.

Get yourself a piece of sheet metal about 3 mm thick put it under the cylinder with a gasket on each side.

Then do some porting widen the exhaust millimeter and a half on each side and bring the floor down so it is at the top of the piston when the Piston is at the bottom of the stroke.

Widen the transfer ports on the intake side 2 mm.

And bring the bottom of the transfer ports flush with the top of the piston at bottom of stroke.

You want your in take transfer Port timing to be approximately 120/122 degrees.

And you want your exhaust Port timing to be 170/272.

With the center of the port at the top Flat 12 mm wide then a flat radius into the corners.

You will need to trim bottom of the piston on the intake side and open up the intake piston port do you have 135 degrees of piston Port timing.

After completing the above you will need to trim off the top of the cylinder so you have a squash of .8 mm 1.1mm at the outer edge of the piston.

Set the ignition timing so that it is 1 mm retarded on the flywheel timing mark check with timing light.

Install app 15 mm sha carb.

Jetting should be in the range of a 68 to a 74.

Notch the slide do lean out the mix at idle look it up!

Sprockets should be in the range of a 12 on the front and a 40 or 42 on the rear or any other comprable confirmation.

Re: 50/50

> Dr No Fun Wrote:

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

> Get yourself a piece of sheet metal about 3 mm thick put it under the

> cylinder with a gasket on each side.

> After completing the above you will need to trim off the top of the

> cylinder so you have a squash of .8 mm 1.1mm at the outer edge of the

> piston.

this whole post is good stuff, i dunno if its minarelli specific or what... but this part is really tough for most people in home shops, the v1 has that stepped sealing area on the head that makes it really tough to cut down, especially 3 mm.

my general 5 star had an evracing pipe (basically a tecno bullet), a 15mm bing, and very very mild porting, went 40 + with stock gearing and trucked, probably could have been 45 with taller gears. You don't have to mess with lathes and spacers and all that, but the specs (165 exhaust/ 135 intake) are kinda the max for stock cylinders without loosing a bunch of low end.

I don't really port transfers on stock cylinders much, that might be the difference between 45 and 50 mph bikes, it just seems like a lot more work than its worth unless you just want to be able to say you did it. All the single speed 50/50 bikes i've ridden have been pretty doggy off the line. I like my 45 mph stockers that rip hard off the line.

Believe it or not, the guys that designed these did actually know what they were doing, they were just targeting reliability, torque, and a 30 mph max speed. It takes surprisingly little porting to wake them up.

Re: 50/50

The information is specific for the V1 you will have to put some tape on the jaws of the lathe to hold the cylinder so you can cut the top down and a relief so it will fit into the cylinder head.

But these timings are good for most 50/50 setups.

Ringland porting and lightning the Piston by drilling holes in it will keep the engine in balance at higher RPMs and the ringland porting will help prevent the piston ring from fluttering at high RPMs.

Buy intake timing I assume you're referring to the Piston Port timing not the transfer Port timing.

The thing is you really need to get the transfer Port timing and close to 120 degrees with a blow down in the range of 22/24 Max or you'll never get anywhere close to the 50-50 Club(edited)

Re: 50/50

Dirty30 Dillon /

> Dr No Fun Wrote:

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

> you have a squash

Str8 Up Wayne

Re: 50/50

Damn beat me to it....

Re: 50/50

Man I hope so.

I'm all about going 80% as fast with 20% of the work. It's a big jump from 45, 47 mph to an honest 50.

Re: 50/50

You don't need a head gasket on a stock V1 head, as long as it's clean and not warped. That'll bump up your compression.

Re: 50/50

True just take some lapping compound and use the cylinder turning the head back and forth to match the surfaces.

I have found that when using a larger Bore Kit like the Pelini that using the head gasket well actually cause problems due to the fact that the gasket protrudes into the combustion chamber carbon will build up behind the gasket at the bottom and eventually pucker the edge of the gasket into the cylinder area to the point where the Piston will start to tap it giving you the indication that something major is wrong.

I have found it bye recutting the cylinder head and removing the step that the head gaskets it's in and reshaping butthead for a better squish area in the range of 50% of the area seems to work best on the V1.

As far as compression goes that depends on if you're running at stock exhaust or a expansion chamber and just how powerful the expansion chamber is Will dictate the compression ratio.

So you want to have a higher compression ratio with a stock non expansion chamber system and less compression that's the power of the pipe increases stuffing of the chamber.

Re: 50/50

> Graham Motzing Wrote:

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

> I'm all about going 80% as fast with 20% of the work. It's a big jump

> from 45, 47 mph to an honest 50.

That is the truth. It gets tiring throwing tons of money and time in bikes. I am all about the least amount of work for the biggest increase in performance. An honest 50 is a hard number to hit even with a kit. For some reason most kitted bikes carbed and piped up stop climbing at 47 or 48mph. Speed is just a number. It is more important to love a bikes take off, dependability, and ability to preform in traffic.

Re: 50/50

I came up with this about a year ago... i was stoked to put it on a stock aluminum cylinder then i realized/remembered that the studs are casted-in. I was thinking it might be worth actually buying a tccd 50 with good transfers. I've never liked those cylinders but i think with a reed you could really make one shred.

Plan was to do tomos/a35 style porting but leave the flange intact so i don't have to use a mill, since i don't really have access to one right now.

IMG_20190410_160124 (1).jpg

Re: 50/50

oh yeah...

so part of the reason it stalled is because a) i needed to get the bike it was going on ready for a rally fast and i just bought a kit and slapped it together and

b) if you end up using something like a tccd 50 kit, then why not just use an A35 50cc cylinder which is definitely a 50/50 setup ported right. I guess the draw of this was just to do it... i still might, i'd have to drill out the cast-in studs, at a certain point it makes a lot more sense to just mill the face for the reed block right on there.

i dunno.... its a fun idea but i got enough irons in the fire its tough to justify a bunch of time spent on a build like this.

Re: 50/50

Dirty30 Dillon /

> EH FCC of the QCB Wrote:

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

> > Graham Motzing Wrote:

>

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

>

> > I'm all about going 80% as fast with 20% of the work. It's a big jump

>

> > from 45, 47 mph to an honest 50.

>

> That is the truth. It gets tiring throwing tons of money and time in

> bikes. I am all about the least amount of work for the biggest increase

> in performance. An honest 50 is a hard number to hit even with a kit.

> For some reason most kitted bikes carbed and piped up stop climbing at

> 47 or 48mph. Speed is just a number. It is more important to love a

> bikes take off, dependability, and ability to preform in traffic.

I can't express how "DITTO'D" I am on this.

If I have a need for 50+ and reliability, I have a handful of shifties that can do it. I'd rather have power to 45. Especially here in NYC, where if you have a quick 35mph bike you are 3x as fast as street traffic

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