Whenever I click on this link my computer tells me it's a security risk and warns me not to go there
http://jimsitton.net/ratiocalc/
Is this the link?
Top Speed, 80cc Chinese motor? what is the record?
- Thread starter scottcason69
- Start date
http://jimsitton.net/ratiocalc/
Is this the link?
Yup... that's the link, it tells me the same thing but it's harmless. If I remember right I think it has something to do with being a home made program so there's no security certificate and it'll trigger windows' firewall
Well I tried to go there and it doesnt show to be a valid link, I tried it in my opera browser and IE browser, both will not go there.
This is what I get when I try the link
Index of /ratiocalc
Parent Directory
gearratio.exe
Apache Server at jimsitton.net Port 80
Last edited:
Yeah a lite bike and rider do help, but 49.2 mph and flat ground take a good strong engine to turn those needed rpm's, 49+ mph is hauling buttocks on a bicyle...LOL!
I get some crazy looks on mine when I'm zipping down through an area where the speed limit is 40-45 mph and I'm running with traffic, people at the plant where I work have seen me and they come to work talking about it and shaking their head about seeing me running with traffic on my bicyle, Ive got into a lane next to our sheriff running down the main highway through town at 45 mph and he just looks and grins at me...LOL!
Nice to live in an area where even the people that dont have a motorized bike think its as cool as I do and the laws get a kick out of them instead of acting like idiots and trying to make me slow down or try to give me a hard time in some other way.
most of the thime I'm cruising at 30-35 mph though.
That's what I got too, u need to download the exe and open the program on your computer would be my guess
It's that gearratio.exe link on that page... forgot to mention that part, depending on your windows settings it might not even let you download or run it, but I got it working on my end and can run the calculations if you let me know the speed, wheel size, and sprocket size then post the results back in here...
Yes that was an all out speed run, I usually just cruise and it does that nicely at 30-35
Ok... good deal... now you can play with it, I had to guess the rpm because it asks for rpm amd tells speed but by guessing close and all you can pinpoint the rpm pretty quickly
Same here... I weigh in at about 225lb and the bike another 50 or so, so it does take a little extra power to push me...
Also, that's what I like about Texas law and these little bikes... most the time the cops just smile and wave or even give a thumbs up when they pull up next to me going the same speed as the traffic... and mine is pretty loud with a 1" diameter stinger and no muffler... sounds like a pissed off chainsaw on stearoids going down the street... lol
According to the calculator I was turning 8,950 RPM @ 52 mph on the bike with 24" wheels and a 30T sprocket
On this engine I did good port cleaning, used two base gaskets, deck not milled so compression wasn't as good as it should have been, piston had ramps at transfers and exhaust, piston had 12 3/16" holes drilled in skirt to lighten it a little, engine had Puch Hi Hi 70cc head and home grown free flowing exhaust, no expansion chamber and RT Carb.
With the jug shaved down to get compression up I'm sure I would have gained a few extra MPH and it would have got there quicker.
Thanks for digging this up Dave
even if you run a street bike hard all day long, it's still less torture than a 20 minute race.
think of pulling in the clutch while your engine's still revving at 9000+ in every corner, slipping the clutch to keep the power up, and doing this non stop for ten laps.
in a race, the engine never gets a chance to relax.
on a long trip at wot, the engine is still getting a lot of air to cool it down, and will usually continue to run properly. and it's at a constant rate.
now imagine riding that same trip and grabbing the clutch every 20 seconds and letting the engine rev to the max without being under load, then dumping that clutch so your engine has to grab at full rpms over and over.
the only thing worse would be sitting in your driveway with the clutch pulled in, revving till your engine explodes.
unless you've actually beat your bike to death on the track, it's tough to realize how much more stress racing has on an engine.
and it happens to every hardcore racer out there. even the best built engines will fail. mine, arrow's, venice, ccc, we've all destroyed them.
but on the street, as an example, i had a bike crack the case when the chain broke and whipped around the day before the big "born free" mc show that was held in belmont shores, ca that year.
i had a fully built, brand new motor i was saving for my next race bike so i put that in and rode 35 miles each way down pch to the show and back, all at full throttle on opti 2. no probs whatsoever.
pch (pacific coast highway) runs along the ocean, has a huge bike lane, and most areas near me, the stoplights are a mile apart. so the bike ran for miles without even slowing down.
this was my 24" colson cruiser with a28t on it and would hit 55. i even rode in traffic with "real" motorcycles, getting thumbs ups all the way.
that engine lasted on that bike till i flipped over the bars and took it apart. it's in my garage now and ready for another bike. if i ever build one. i think i rode it at least two years, every day, as it was my main transpo.
plus, it was the last of the grubee starfires. the best engines ever made.
wait... what were we talking about?...
think of pulling in the clutch while your engine's still revving at 9000+ in every corner, slipping the clutch to keep the power up, and doing this non stop for ten laps.
in a race, the engine never gets a chance to relax.
on a long trip at wot, the engine is still getting a lot of air to cool it down, and will usually continue to run properly. and it's at a constant rate.
now imagine riding that same trip and grabbing the clutch every 20 seconds and letting the engine rev to the max without being under load, then dumping that clutch so your engine has to grab at full rpms over and over.
the only thing worse would be sitting in your driveway with the clutch pulled in, revving till your engine explodes.
unless you've actually beat your bike to death on the track, it's tough to realize how much more stress racing has on an engine.
and it happens to every hardcore racer out there. even the best built engines will fail. mine, arrow's, venice, ccc, we've all destroyed them.
but on the street, as an example, i had a bike crack the case when the chain broke and whipped around the day before the big "born free" mc show that was held in belmont shores, ca that year.
i had a fully built, brand new motor i was saving for my next race bike so i put that in and rode 35 miles each way down pch to the show and back, all at full throttle on opti 2. no probs whatsoever.
pch (pacific coast highway) runs along the ocean, has a huge bike lane, and most areas near me, the stoplights are a mile apart. so the bike ran for miles without even slowing down.
this was my 24" colson cruiser with a28t on it and would hit 55. i even rode in traffic with "real" motorcycles, getting thumbs ups all the way.
that engine lasted on that bike till i flipped over the bars and took it apart. it's in my garage now and ready for another bike. if i ever build one. i think i rode it at least two years, every day, as it was my main transpo.
plus, it was the last of the grubee starfires. the best engines ever made.
wait... what were we talking about?...
Nice bike...
I don't see much in the way of brakes
I would think on a bike capable 49.2 mph I would wont a t least a good V Brake on the front to go along with the coaster on the rear..LOL!
Don't get me wrong here not being critical at all, just thinking of how you would get that streak of lightening shut down if you had to.
I'm not finished with braking power, either v brakes are going on or a sunlite springer with a disk up front. And like I said that was an all out speed run, it usually just cruises around 30ish
That clears it up a bit, i can't imagine slipping the clutch that much....LOL and never really thought about ya'll riding like that, but I know very well how much damage you can do to an engine when its revved out of its mind without a load on it.
I guess I'd be an exception if I were on the track, because I wouldn't slipping the clutch like that on my engine, never heard of such a practice honestly, but I've never raced motorized bicycles on a track either...LOL!
You're right though, racing and running down the street is two different things and I have always had good performance from Opti2 oil, 25 mile runs like I've done in the hot dry Texas weather has proven to me many times that Opti2 is and excellent product.
I guess I'd be an exception if I were on the track, because I wouldn't slipping the clutch like that on my engine, never heard of such a practice honestly, but I've never raced motorized bicycles on a track either...LOL!
You're right though, racing and running down the street is two different things and I have always had good performance from Opti2 oil, 25 mile runs like I've done in the hot dry Texas weather has proven to me many times that Opti2 is and excellent product.
even if you run a street bike hard all day long, it's still less torture than a 20 minute race.
think of pulling in the clutch while your engine's still revving at 9000+ in every corner, slipping the clutch to keep the power up, and doing this non stop for ten laps.
in a race, the engine never gets a chance to relax.
on a long trip at wot, the engine is still getting a lot of air to cool it down, and will usually continue to run properly. and it's at a constant rate.
now imagine riding that same trip and grabbing the clutch every 20 seconds and letting the engine rev to the max without being under load, then dumping that clutch so your engine has to grab at full rpms over and over.
the only thing worse would be sitting in your driveway with the clutch pulled in, revving till your engine explodes.
unless you've actually beat your bike to death on the track, it's tough to realize how much more stress racing has on an engine.
and it happens to every hardcore racer out there. even the best built engines will fail. mine, arrow's, venice, ccc, we've all destroyed them.
but on the street, as an example, i had a bike crack the case when the chain broke and whipped around the day before the big "born free" mc show that was held in belmont shores, ca that year.
i had a fully built, brand new motor i was saving for my next race bike so i put that in and rode 35 miles each way down pch to the show and back, all at full throttle on opti 2. no probs whatsoever.
pch (pacific coast highway) runs along the ocean, has a huge bike lane, and most areas near me, the stoplights are a mile apart. so the bike ran for miles without even slowing down.
this was my 24" colson cruiser with a28t on it and would hit 55. i even rode in traffic with "real" motorcycles, getting thumbs ups all the way.
that engine lasted on that bike till i flipped over the bars and took it apart. it's in my garage now and ready for another bike. if i ever build one. i think i rode it at least two years, every day, as it was my main transpo.
plus, it was the last of the grubee starfires. the best engines ever made.
wait... what were we talking about?...
I definitely agree on the difference between a full throttle run and the pure torture of the race tracks where rpm needs to stay up by any means possible so heat goes up the same but with less opportunity to cool the engine...
Wow Map if yours is running 8950 to hit 52mph your engine probably spins as fast as mine if they were both geared the same... Compression is important on a 2 stroke for low rpm torque and power, but as the rpm's climb up it becomes less important so the power's probably about the same as mine at those rpm's too...
I know my static compression ratio is 12.7:1 but the actual is quite lower since the actual is measured from the top of the exhaust port instead of the bottom of the stroke like a 4 stroke engine, this ratio varies tho on the 2 strokers because as rpm increases and if an expansion chamber is used the ratio can go up a few numbers so it's more like a virtual compression ratio that falls somewhere between static and actual.
Wow Map if yours is running 8950 to hit 52mph your engine probably spins as fast as mine if they were both geared the same... Compression is important on a 2 stroke for low rpm torque and power, but as the rpm's climb up it becomes less important so the power's probably about the same as mine at those rpm's too...
I know my static compression ratio is 12.7:1 but the actual is quite lower since the actual is measured from the top of the exhaust port instead of the bottom of the stroke like a 4 stroke engine, this ratio varies tho on the 2 strokers because as rpm increases and if an expansion chamber is used the ratio can go up a few numbers so it's more like a virtual compression ratio that falls somewhere between static and actual.
