PlanetMinis Forums banner

serious questions about mph

4.7K views 54 replies 23 participants last post by  doopsx3  
#1 ·
i am lookin to seriously g0 about over 80 mph.... if i can make my zb runn this fast and be reliable i will keep it.... can any one send me some real ideas..... i see all of u guys r swappin engins...why not build the zb motor up....??????
 
#43 ·
Sorry for all you guys north and east shoveling snow and all, it was about 70 and sunny in so cal today, perfect to go rip around the canyons.



Enough theory from you guys. I have clocked 82 on GPS, although I cheated a bit. Flat road 75-76 WOT in full tuck I hit a nice long downhill section and got that high. My Vapor tach showed 11280 rpm as max and I'm sure it was going into valve float and stopped pulling. I'm running a lifan 120 based 141 which I bought used from a PM member, with a TB300 cam (I think), oko carb, honda ignition, and pitster exhaust. gearing is 17/35 with a 130/70 kenda rear tire.



I have logged around 1800 miles on this china motor on one oil change, it has been reliable so far, and shows no signs of letting loose anytime soon, hopefully.



So to answer the question 80 on the ZB is possible, but 65 is more of a comfortable cruising speed. To get away from cops in NYC, LA or anywhere for that matter you need skills and a good handling bike that you can snake through cars, sidewalks, parks and stairs where cops can't follow... in theory of course ;) Speed will get you killed faster.
 
#45 ·
80mph in a zb50 should actually be pretty easy. Its controlling it, stopping it, handling it that becomes difficult!



Lighten it up a bit with some aluminum wheels and some good tires. Put on some clipons or clubmans, and pop in a YX177 V2 motor. Gear up 17/28 or so on 10" and pray you don't come off.



I've cracked 80mph on only one of my mini's...my CL70...I still have the motor I did it on too. I've been thinking about putting it in another ZB50 Frame I have and seeing what will happen, but I don't really know if I should. So...I have a motor that will do it if you're interested...not a YX though.



Other things to consider...rear footpegs.
 
#46 ·
WOW.... we dont ride hard.... hahahaha. Hes a joke. Anyone who brags about how "hard" they ride usually doesn't.....



My honest experience..... and i rode both.



1TrickZB is hitting 79.9 MPH with a boared out 125 china motor (i think its 138 now).



Chriswilder is hitting about 70 MPH with a china 140cc



I think with a out spending oodles of money, a GPX160 geared right will do 80 all day in a ZB.



ChrisZB have you ever done over 80MPH on a ZB? I had (very recently) a YSR that did 115MPH.... very well built.... but ULTRA sketchy. If you looking to run from the cops..... get another bike...



~Shawn
 
#47 ·
fatcaaat said:
80mph in a zb50 should actually be pretty easy. Its controlling it, stopping it, handling it that becomes difficult!



Lighten it up a bit with some aluminum wheels and some good tires. Put on some clipons or clubmans, and pop in a YX177 V2 motor. Gear up 17/28 or so on 10" and pray you don't come off.



I've cracked 80mph on only one of my mini's...my CL70...I still have the motor I did it on too. I've been thinking about putting it in another ZB50 Frame I have and seeing what will happen, but I don't really know if I should. So...I have a motor that will do it if you're interested...not a YX though.



Other things to consider...rear footpegs.




well for me my gpx on my st-90 w/mild mods on a rolling 1/4 mile has seen 74mph w/no room to stop though it might have been a good night maybe a lucky day but even with good brakes it was hard to stop.. i ran against a real fast mini one NY cold night on gps and it was the hardest thing to stop at the end of the run its a cross street.

i run well balanced set of stock wheels w/ great tires and am 238lbs and the china crappy motor has held together and still running since 2005, every time i take her out am on the gas wot the more i give her the more that motor likes it.

maybe i have a wednesday motor who knows but it has been well worth the minor mods the cam bigger cam porting etc love doing burn outs!!

but dont we all!!!

maybe the next cheap build will hit 80+ time will tell
 
#48 ·
zb chris said:
i see you guys have alott to do..sittin here tellin me i am crazy to do 80 mph on a zb 50.....butt none of u guys ride the streets serious like we do hear in newyork city ...we get chased by cops all day long we dont sit n ride in parkin lotss like half of these guys do ....we ride hard not hardly ride ...thast why i w ant a lil extra speed.... i just bought a 2006 drz 400sm supermotard to have funn with so my zb is for sale now first 1500$$$ takes it away clean title first 1500$ takes it.....


no one is saying you're crazy for doin 80 on a zb50 they are saying you can't do it with that motor, ass. calm yourself and realize 1) if you are running from the cops all the time you are prolly a douchbag anyway so everyone should make fun of you and 2) YOU NEED A BIGGER MOTOR!!!!!!!
 
#49 ·
Well the more money you are willing to spend the easier it will be. Another thing that has to be taken in to regard is that if you lose comfort on your bike you will probaly go faster but it won't make it safer...

For instance losing the headlight, winkers, meters and all the other stuff you don't really need which puts up weight, but then again you could probaly figure that out yourself.

I can't emphasize enough on the importance to have a safe rolling frame, and remember that a good rolling frame will not only make it safer but it wil alsow add a few mph, correct chain tension, tire pressure, wheelbearings running smooth, brake friction,...

Chain tension being the most important, personally i feel that it can be the cause of like 90% of things that reduce speed.



Now about the engine!

I can really recommend a TJR 174 Superhead engine using 18-28 sprockets or even a heavier ratio. The torque is crazy but since you're looking for top speed you could go as heavy as possible I guess.



Speeds up to 90mph and more have been reached here at Belgian meetings as far as I know.



I.m.o speeds like that are fun from time to time but if you really want to have a blast you should be looking for an engine with massive torque ( like the one I mentioned ) and just the perfect road with lots of corners, but that's just my 2 cents.



grtz

Tim
 
#50 ·
my honda nice motor should crack 80mph easy

in its current tune 180cc daytona dohc honda nice

66stroke 59 bore

28 mikuni flatslider



in my bbr perimeter crf motard

i will project for 90mph also



i have rode a u.k monkey z.b owned by gary d.r.p (dragon racing parts)

his was 160cc nice motor

tjr tuningparts (crank ,piston ,head with ti valves)

26 mikuni carb



reaching 77/78 mph



my motor should produce more than 24hp

with the correct chassis components eat 80mph



here is a slightly lighter tuned version of my motor built also by my friend in germany





YouTube - Honda Monkey Nicemotor mit 24,3 PS auf PrĂĽfstand Dyno Jet