Top speed?
 

OK, so I got the new Hi-Bird GY200 up to about 55 MPH yesterday. I think I still had a little power left, but not much...and boy was she screaming! What speed should I expect from her given that I tip the scales @~225lbs.

I have a 46 tooth rear sprocket, is that where I should be looking to get more top-end speed? What do you guys suggest?

Also, I've got this annoying "rattle" that I can't for the life of me figure out where it comes from. Is it just the push-rod engine, or is there more to it? It seems to fade in & out @ different RPM's.

Thanks guys,

joeyo25

I think our pushrod engines are geared internally lower and benefit from an even smaller rear sprocket like a 42.

I have done 65-70 actual speed on my lifan with a 45T and it was 8000-8500 rpm. 70 with a 42 is about 8K.

The rattle may be the valves/lifters rattling.

Allen

My pushrod engine has a lot of top end rattle. Glenski's does not.

I don't know why....but it keeps on tickin' in any case (literally).

Mine seems to max out at 65 or so as well.

Funny, seems to reach that speed quickly enough. :)

With 17/46 sprockets I get an easy 62 mph. At that speed it doesn't sound like the engine is screaming. I've hit 70 mph and even at that speed is doesn't seem like the engine is screaming. The engine just runs out of breath.

Q

My Hi-Bird 200GY only goes 55mph as well. That's top speed redardless your weight.
And my Hi-Bird also had the strange rattling noise at different RPMs. However it doesn't rattle anymore. The little black o-ring thing that holds the exhaust pipe into the front of the motor lost it's bolts and came off and now just rattles on the exhaust pipe. Check those two bolts where the exhaust connects to the motor in the front behind your front wheel. Tighten those suckers down then see what happens.

You right about it just running out of power! I spend 95% of my riding time at 60 -70mph. On the occasion, I will do 80mph with a strong tail wind.

I remember driving a guy's very old VW (in 75') and it behaved the same way. On hills, 55 wasn't always possible and on the flats, 65 tops with a tail wind. :lol:

Lately mine seems to have become slightly more noisy. I found an oil change last night seemed to reduce some of the vibes. An interesting note, that only about 600cc of oil actually came out during the change, plus the fact that the change was long overdue seems to have reduced the noise.

As far as top speed I can't really comment seeing as I have done a lot of my carb mods while my speedometer cable was broken. With the bike stock though I would do well to hit 110 kph downhill w/ tailwind.

I have had my 2007 A.L. to 65mph for a couple of miles and felt there was a little more left in her but was concerned about the rpm's.

I had my 150cc doing 65mph for just under an hour. then I filled up the tank and did it again. 12 fillups in a day and I was in Quebec :D 12 more fills and I was back in Toronto 8O . I did not spare the whip!!!!!!

My bike runs flat out every day +/- 110kmh for 2 hours a day and still going strong! Now at 9,000km