Getting Geared for Doing The Ton

[Texasstar]

First, if you haven't read Sonreir's tutorial on how to build a functional cafe racer. Please do so! It is a must read!
5 stars!

Our little CB200 had some limitations from the beginning. One of them was gearing. But for 14 bucks we changed that and grew closer to our goal of doing the ton. I wanted to share a web site that will help you back into doing the ton with your build.

In order for us to Do The Ton we will need a minimum of 10,500 Rpms with our 17/35 gearing. Our stock redline is 9500 and as you can see with the stock gearing of 15/35 we were LIMITED to 77 mph @ 9k. Now to increase your RPMs like we have you should read Sonreir's Speed Reading.

Hope this helps!

 

[Texasstar]

10500k stock gearing

 

[Sonreir]

Not sure if that site lets you, but changing tire sizes also has an effect.

 

[Texasstar]

Not sure if that site lets you, but changing tire sizes also has an effect.

yes it does and you can do "what if scenarios" by doing custom gear ratios. However it does not work on a Safari Browser.

 

[SONICJK]

Yup I use that site as well.
Its nice that its all pre-loaded.

 

[OJ]

That's a cool site.

On a bicycle, with 1/2" pitch chain, larger sprockets are more efficient, so I am assuming, that the same applies to motorcycles with greater pitch. I'm mostly thinking about the front sprocket and making that one larger for better efficiency. We're probably talking about few points at best, but still...

 

[620dark]

Wow, that site is very cool. I just discovered that my 360 should be able to do 101.1 at 9000 RPMs in 6th thanks to the 110/90-18" I'm rocking on the rear of it. Hopefully the oiling mods I've made to it will help the top end hold together long enough to hit the ton.

It seems to work fine on desktop Mac OS Safari for me...

 

[Texasstar]

Wow, that site is very cool. I just discovered that my 360 should be able to do 101.1 at 9000 RPMs in 6th thanks to the 110/90-18" I'm rocking on the rear of it. Hopefully the oiling mods I've made to it will help the top end hold together long enough to hit the ton.

It seems to work fine on desktop Mac OS Safari for me...

the site wouldn't work on my iPad or iPhone until I switched to google chrome.

 

[620dark]

Ah ok, gotcha! It would be good to have it on a portable device so you can size up the competition when you're lining up against someone

 

[crazypj]

That's pretty cool and seems to be pretty accurate, CB200 does show about 80mph top end.
My modified CB360 should be doing just over 200Km/hr (didn't see how to change to MPH)
200K is 125mph so 120 is reasonable assumption as I've clocked Brendon at 115 when he got scared due to cross winds and could feel it moving around (it's a light bike )

 

[Texasstar]

That's pretty cool and seems to be pretty accurate, CB200 does show about 80mph top end.
My modified CB360 should be doing just over 200Km/hr (didn't see how to change to MPH)
200K is 125mph so 120 is reasonable assumption as I've clocked Brendon at 115 when he got scared due to cross winds and could feel it moving around (it's a light bike )

crazypj how are your feeling? You can change to mph at the top...labeled "units"

 

[Texasstar]

I entered what my redline was in the minimum rpm box and it reversed the graph..from 10.5k down to 9k...a glitch that is usable!

 

[mydlyfkryzis]

Just keep in mind that besides gearing that allows you to run the engine within its operating range, you do need a bit of horsepower. The reason CrazyPJ's bike is faster than stock isn't just gearing, it's has a little testosterone in the engine to provide enough HP to do it.

Otherwise, a 50CC bike geared right could do the ton too....

 

[crazypj]

Otherwise, a 50CC bike geared right could do the ton too....

NSU did over the 'ton' in 1956 with a 50cc moped engine than normally produced less than 3bhp. (197Km/hr)
They used a Wankel supercharger (Wankel was originally designed as supercharger and not an engine)

http://www.elsberg-tuning.dk/recordbikes.html

 

[emcarthu]

Great site. I just finally pinned my 350 and got it up to 91mph. I really want to see that "100" on my speedo.

 

[mydlyfkryzis]

NSU did over the 'ton' in 1956 with a 50cc moped engine than normally produced less than 3bhp. (197Km/hr)
They used a Wankel supercharger (Wankel was originally designed as supercharger and not an engine)

http://www.elsberg-tuning.dk/recordbikes.html

A little more aerodynamic than a stock bike though.....

Aerodynamics are the biggest restriction to speed. An "naked" bike is the worst case for aero.

The only way to overcome wind resistance is with aero body work and HP....Both are ideal....

 

[crazypj]

Yep, I think one of the magazines did some tests and 'naked' bike, rider with loose leathers had about a drag coefficient around 1.3~1.4
A house brick has 'better' airflow (1.0) ;D

 

[Texasstar]

NSU did over the 'ton' in 1956 with a 50cc moped engine than normally produced less than 3bhp. (197Km/hr)
They used a Wankel supercharger (Wankel was originally designed as supercharger and not an engine)

http://www.elsberg-tuning.dk/recordbikes.html

the word wankel makes me smile!

 

[mydlyfkryzis]

the word wankel makes me smile!

He said Wankel, not wanker.... 8)

 

[Texasstar]

He said Wankel, not wanker.... 8)

We are about to wankel! Meaning to go faster like a crazypj! We have our fairing ordered! If that doesn't get us there crazypj just gave us another idea. Just wankel some more!