Top Speeds at Road Atlanta (600cc SuperSport)

domarena33

domarena33

Track Day Superstar
I ran Road Atlanta this past weekend with my new to me CBR600RR; the bike is decked out, race ready and an absolute missile. With some contacts and paperwork that came with the bike, a close NEMRR Expert friend of mine tracked it back to 4 possible previous owners. 2 of which were Eric Wood and Teagg Hobbs. Accounting for a 3% discrepancy in speedometer accuracy, I was hitting 168mph EASY and all over the rev. limiter for an extended period of time. I do already understand the fact that since I'm in T9 and leaned over, I'm actually increasing my engine RPM's due to a change in circumference of the tire by riding on the side and not the middle but, I'm hitting rev. limiter at 168 before I start turn in to T9.
Regardless, the bike will definitely go faster. I thought it was odd that while reading a motoamerica "duly noted" article from the 2023 SS Races at Road Atlanta that Tyler Scott was topping out at 166mph on his GSX-R. What are you guys hitting with your rice rockets? Do I have a prior AMA / M.A bike or are you guys seeing similar speeds? With that being said, I'm going up one tooth on the front sprocket to see if I can alleviate the constant action on the rev. limiter through T9 in the future.
 
domarena33

domarena33

Track Day Superstar
Gauge said 172. A 2007 article from cycle world has the 07' CBR600RR speedometer off at a 3% discrepancy, so 4-5 mph off. This is the best info I have as my lap timer just froze.
 
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rpm894

Member
Gearing changes from OEM alter the speedometer reading, a lot. If you have shorter gearing than stock, it will read faster than you are really going. And 3% error at top speed is generous. Unless your engine is built to last maybe a few weekends, your 07 600rr was probably closer to 150. I’m pretty sure the CBR is known for being down on power. Is it built for race fuel and have a very large aftermarket radiator?

My 17+ R6 with OEM gearing (tall) was hitting 155 GPS speed last year, but I was only doing 1:38 laps.
 
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rpm894

Member
rpm894 said:
Gearing changes from OEM alter the speedometer reading, a lot. If you have shorter gearing than stock, it will read faster than you are really going. And 3% error at top speed is generous. Unless your engine is built to last maybe a few weekends, your 07 600rr was probably closer to 150. I’m pretty sure the CBR is known for being down on power. Is it built for race fuel and have a very large aftermarket radiator?

My 17+ R6 with OEM gearing (tall) was hitting 155 GPS speed last year, but I was only doing 1:38 laps.
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Edit. 1:40s.
 
domarena33

domarena33

Track Day Superstar
@rpm894 thank you. Its a built bike and it very well could not have stock gears. Gearing totally evaded my mind for some odd reason. Im not sure if it's built for race fuel and not sure about the radiator. I've never owned a 600cc I-4 supersport. Not sure how big or small they should be. All I know is it needs a new one soon bc the fins are all jacked up.
 
domarena33

domarena33

Track Day Superstar
TimTheAsian said:
lol 600rr and missile shouldn't be in the same sentence. Something in me doubts you're seeing a real gps 168mph.
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damn, hating on the CBR :rofl: it's pretty quick! I do trust your guys' better judgement that im not hitting 168. I've got one of those stealth GPS-4 lap timers and it just froze the entire weekend, Thing is a POS. @MK3Brent i will count some sprocket teeth and assume the rest of the tranny is stock, use the calculator you sent and try and figure out whats going on here.
 
bmart

bmart

Control Rider
The smile-o-meter means more to me personally than the speed-o-meter, and I smile a lot on my ancient 600.

Eric Wood is awesome.

My 2003 R6 with 15/50 gearing reads 153.7 MPH on GPS at Road A around the same area. The feeling being passed like I'm stopped by big bikes is really something.

Ignore the speedo...at all times.
 
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rpm894

Member
domarena33 said:
damn, hating on the CBR :rofl: it's pretty quick! I do trust your guys' better judgement that im not hitting 168. I've got one of those stealth GPS-4 lap timers and it just froze the entire weekend, Thing is a POS. @MK3Brent i will count some sprocket teeth and assume the rest of the tranny is stock, use the calculator you sent and try and figure out whats going on here.
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I doubt Brent is telling you to count the teeth considering that he doesn't know how to count that high. There should be a marking printed / stamped on the sprockets.
 
MK3Brent

MK3Brent

Treebeard
rpm894 said:
I doubt Brent is telling you to count the teeth considering that he doesn't know how to count that high. There should be a marking printed / stamped on the sprockets.
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53625853811_23095b18eb.jpg
 
NothingClever

NothingClever

ATP/3C
@domarena33 - concur with others - I’d hold off on any conclusions until you have GPS readings again.

Motorcycle speedometer = padded bra; great for confidence but not an accurate representation of the real thing.

I’m decently spring-loaded (albeit with stock gearing and ECU) on corner exit out of T7 but I’m only getting up to 145mph (actual) before running out of straightaway on my 959 Panigale. I don’t roll off until starting down the hill. My Ducati speedo will indicate 161mph. The manual states that it’s 5% proud but that’s more like 11% proud.

Where I do want to be a missile is in the braking zone and corners, slipping past the aircraft carriers when they slow to channel and port speeds.

In comparing my data, I’m finding my faster lap times don’t reflect a higher top speed; they’re the same or sometimes even a little bit slower. However, they do reflect slower speeds in the corners. I think efficiency in and between the corners is more valuable than straightaway speeds.
 
domarena33

domarena33

Track Day Superstar
NothingClever said:
@domarena33 - concur with others - I’d hold off on any conclusions until you have GPS readings again.

Motorcycle speedometer = padded bra; great for confidence but not an accurate representation of the real thing.

I’m decently spring-loaded (albeit with stock gearing and ECU) on corner exit out of T7 but I’m only getting up to 145mph (actual) before running out of straightaway on my 959 Panigale. I don’t roll off until starting down the hill. My Ducati speedo will indicate 161mph. The manual states that it’s 5% proud but that’s more like 11% proud.

Where I do want to be a missile is in the braking zone and corners, slipping past the aircraft carriers when they slow to channel and port speeds.

In comparing my data, I’m finding my faster lap times don’t reflect a higher top speed; they’re the same or sometimes even a little bit slower. However, they do reflect slower speeds in the corners. I think efficiency in and between the corners is more valuable than straightaway speeds.
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145 is surprising. I know that the 959 isn't the fastest bike in the world but its definitely not a slug. And to your point, I will become an Arleigh-burke class destroyer in a world of kitty hawk class carriers on the track. :rofl: Finding the balance in gearing is key, you are right about the efficiency in between corners but I am spending too much time on that rev. limiter. That much time in redline cannot be good for the engine. :like:
Since it was a NH / MA bike and the two possible owners were from NH, it could be that the gearing has been changed for a track like NHMS (which has a tiny straight) and im seeing that rear its ugly head on a fast track like R.A.
 
NothingClever

NothingClever

ATP/3C
rpm894 said:
I doubt Brent is telling you to count the teeth considering that he doesn't know how to count that high.
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Folks, let the history books prove you were witness to it here …

RUS invasion of UKR? Nope.

PRC invasion of TWN? Nope.

World War III started with an insult towards a DEU engineer about his math abilities.

In a US motorcycle forum for crying out loud.
 
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