How fast on an uncorrected speedo?

[Mythos]

This is fun. I'm gonna add you to that following thingy a mijig feature.
Squish=height increase...concur.
55 tire=speedo fix...cool.
If my math serves me correct brother Mythos, going from a 50 to a 55 tire solution would/could also be achieved by a +1 tooth increase on the countershaft sprocket if desired. Then a stock tire could be run if desired. Some bonus's to the larger sprocket too. Less chain wear for example. The chain doesn't turn as tight a circle,etc. Downside... Acceleration with a +1 or a taller tire will be less than the stock set-up.I could decipher that number if desired. I would have to think about it,build or find the equation.We have the four values,just need the formula. I'm just about positive the ensuing brain splitting headache would be well worth it. View attachment 1622277
Rubb.

How about sticking with stock tire size and stock countershaft gearing but go +3T on the rear? That would be about equal to +1 on the front, no? Man, +3 T on the rear sure seems like it would increase the speedo more than going fro 190/50 to a 200/55 tire. My head is starting to hurt already though.

Then there is the fact that tires do not comply exactly with the sizes marked on them, which can render a spec based discussion moot! Molds are expensive and I had read that they are reused. So if the tire compound is changed but the same mold used, the result can vary.

Rubb must have an equation for all of those.

 

[rubbersidedown]

But you have brought in squishfulness to the conversation so it seems that the final product of size changes is unpredictable.

"squishfulness" Wheeew..... I was worried there for a second you didn't receive that thesaurus/dictionary combo I sent you for Christmas.

Rubb.

 

[rubbersidedown]

Rubb must have an equation for all of those.

Where did I leave that Extra Strength Tylenol...

OK,where's that "un-follow button"

Rubb.

 

[Mythos]

How about sticking with stock tire size and stock countershaft gearing but go +3T on the rear? That would be about equal to +1 on the front, no?

I screwed up again!

I meant to say -3 on the rear should be about equal to +1 on the front. Just guessing, it seems like either one of those would be overcorrecting the speedo by quite a bit. That's just my guess.

Gearing commander is very useful. Gearing Commander - Motorcycle Speed and Drive Train Calculator v7 I've heard it's not always perfectly accurate but it will give you a close estimate.

 

[rubbersidedown]

I screwed up again!
I am not here to judge.

I meant to say -3 on the rear should be about equal to +1 on the front. Just guessing, it seems like either one of those would be overcorrecting the speedo by quite a bit. That's just my guess.
Going +3 would have made your Busa slower,but faster getting to top speed. Your indicated would be slower than actual.

Gearing commander is very useful. Gearing Commander - Motorcycle Speed and Drive Train Calculator v7 I've heard it's not always perfectly accurate but it will give you a close estimate.

I didn't click on your little calculator thingy ^ but I ran the idea past my friend Brad and he sat down with the Gearing Commander guy.

Anyway... I should have asked if you were Gen I or II.
17f/40r is a ratio of 2.35 (stock)
18f/40r " " " " 2.22
17f/43r " " " " 2.52
One increases the ratio,the other reduces.

18f/43r is a ratio of 2.38 (stock)
17f/43r is 2.53
18f/46r is 2.55
Both changes increase the ratio.

The only real problem is that you don't have an accurate number to start with because the Busa speedo is not 100% accurate. (the problem we are trying to correct)
Its all messed up.To find the perfect correction you would need to calculate what the speedo reads as compared to actual speed.
To do that...oh good grief...
#1. Set up a test. Speed reading from point A to point B measured by GPS (not 100% accurate,but close)
#2.Get the speed reading shown on your speedometer (near impossible on analog equipment) A little needle on a circle with numbers...

3. Add or subtract #1. from #2. or 2 from 1... to get the value you need to fix.
4, Apply the gearing change to make up the discrepancy.It may be none of the values(gearing ratio's) listed in the tables above.
In the end,I don't like it. I like my world black and white and this has "gray area" written all over. To many variables.
The Gen III better have an accurate GPS or forward facing radar of some sort or we may as well go back to a cable driven speedo run off a little spinny thing attached to the front wheel hub.

Anyways...all make sense to you Bro.

It doesn't to me.

Rubb.

 

[Mythos]

@rubbersidedown space and time are less relevant when approaching the speed of light anyway. I'm happy to know a close approximation of my speed!! Happy 4th of July bro!

 

[rubbersidedown]

@rubbersidedown space and time are less relevant when approaching the speed of light anyway. I'm happy to know a close approximation of my speed!! Happy 4th of July bro!

PLEASE Bro,do not mention any of that space,time continuim type krap.It will attract the attentions of member @Tetsuo1000 ....oops...
Happy 4th to you as well My Brother From Another.
We had our (Canadian thing) July 1st.
Rubb.

 

[Mythos]

@rubbersidedown a-AHh so yur Canadian den dere, Rubb? I was born a YOOper which is aboot as close as it gets to bein' a Canadian Sout o da border, eh? Well hoppy 1st to you den.

 

[rubbersidedown]

@rubbersidedown a-AHh so yur Canadian den dere, Rubb? I was born a YOOper which is aboot as close as it gets to bein' a Canadian Sout o da border, eh? Well hoppy 1st to you den.

View attachment 1622423

Ya bruddah...I is from Canerdah. But dunt tells nun buddy,dis site is dun chocka block full a bigertry,intolleratin' and yer dascimanatorian thing.
I wont be playin da foo. Ya heer now.

A canadian christmas song

Rubb.

 

[Mythos]

Take off you hoser!!!!

 

[WuzzaCBXRider]

She obviously likes him, or would really like to.

l

 

[K8busajoe]

Error is not linear. More mph is more % error. I’ve seen this on a dyno with no tire slip. Dyno mph and rpm correlated directly, speedo got worse as mph increased.

Facts mine went from dead on on lower speeds then 10mph off 15-17off and around 20mph after 160ish