305 Dream Top Speed?

[michael-nadav]

in 1963 my father bought his new cb77 and at that time he took till 170 km/h

[Dana01]

jleeweb,

This supercharged dream was built to run at Bonneville. Can't remember how fast it went, but well under 100

Do you have the racer's name, race number, and/or year he ran? He has a Bonney sticker, so he did indeed make a pass. I can go look it up.

The cool thing with smaller displacement scoots is that many of the <750cc classes (there are over 500 cycle classes) are still "soft" (easily attainable with little expense and effort), which makes them still desirable for entry level Land Speed buffs. That's what drew me to that brand of insanity.

That being said, the "blown" (turbo or supercharged), 250-350cc classes have records ranging from 71.6 through 136.4 mph:
http://www.scta-bni.org/Bonneville/BNI_records.htm

Seems to me the M-BG (modified frame, blown, gasoline) record of 8/10, at 71.666mph] seems quite attainable by a 305 ... hmmm ... I'm having some brand new thoughts 8^0

Without the Supercharger, the normally-aspirated records jump up to 137 ... set in 1995 on a Yamaha 250 ... probably a TZ.

Interestingly enough, the MPS-BG (modified frame, partial streamlined, blown, gasoline) class record is held by my friend Jon Wennerberg aka Seldom Seen Slim. He and his wife Nancy both race and both are in the "200-club".

[yellow60]

This summer I saw 85mph. I was passing traffic at a decent pace on a 65mph speed limit highway. but I've also been in a good head wind and can barley hang with traffic on the highway.

[hotrodhendrix]

Some of these posts make me think my fueling isn't right. My speedo reads about 10over what it is actually doing. My highest speed going downhill with wind at my back was about 70(80 on speedo)

~james

[DianneB]

I had a CB77 in 1966 and it topped out at 116 MPH with chin on the handlebars. Of course I was skinny then and 110 pounds (and immortal LOL!)

[Dick Eastman]

I don't know what the trans ratios and sprocket ratios for the Dream are, but here are the calculated speeds for the Super Hawk, per 1000rpm:
crankshaft sprocket - 15T, clutch sprocket - 47T; for every 1000rpm of the crank, the tranny main shaft is turning 319 rpm [15/47]. 4th gear is 1:1, so the countershaft sprocket is also turning 319 rpm, and, with a 15/30 sprocket pair, the rear wheel is turning 159.5 rpm [15/30 = .5; .5x319=159.5].
I measured the circumference of my rear tire [Michelin Gazelle M62, 3.00 x 18], with the bike on the center stand, and a cloth tape ; 77.0"or 6.4166' per one revolution of the rear wheel. Granted, this number would be slightly more accurate if I sat on the bike, marked the tire and took a measurement for, say, ten revolutions of the wheel on the ground and divided by ten [a load on the rear tire would change the rolling circumference slightly].
6.4166 feet/rev X 159.5 revs/minute X 60 minutes/hour = 61405.5 feet/hour divided by 5280 feet/mile = 11.63 miles/ hour [per 1000 rpm]. At 9000rpm, this calculates to 104.67 mph.
For different sprocket combos: 14 and 30, for example: 14/30 = .466. Since a 15 and 30 final ratio has been already calculated above [15/30 = .5] as a stock baseline, divide .466 by .5 to equal .9333. I.E. a 14 and 30 combo is .9333 as fast as a 15 and 30 combo: .933 X 11.63mph/1000 rpm = 10.85mph/hr or 97.69mph at 9000rpm.
I have a 15 and 34 combo, so 15/34 = .441 and this divided by.5 gives me .882 as fast as stock, or .882 x 104.67 = 92.35mph
Using the above, one could also calculate speeds at various revs in gears. The above is for fourth gear at 1:1. The manual says first gear is a 3.12 ratio, and the inverse is 1/3.12 or .320 as fast as 4th, so 3.727mph per 1000rpm or a max of 33.5mph in 1st at redline.
I'm not sure I like my 15/34 combo out on the road, but it is nice around town.

[hondadreamca77]

I have made 70 couple times on mine.