Ken 12R
Novice Class
Posts: 86
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posted July 25, 2008 02:31 PM
Zx14 Landspeed gearing.
Anybody worked out whats the tallest gearing you could run on a 14??
I know I can fit a 19 tooth front sprocket on my ZX12 but there does not look like there is enough room for a 19t on the ZX14.
Likewise I can run a 38 rear but on a ZX14 this looks close to the swingarm.
The bike in question is a prototype turbo 14 with a motec ecu so it will be able to pull the tallest gearing that will fit.
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www.uklandspeedracingassociation.co.uk
  
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smokinzx14
Needs a life
Posts: 10197
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posted July 25, 2008 02:34 PM
Brock ran a 17/40 and ran 200 ....
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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wrongway
Pro
Posts: 1078
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posted July 25, 2008 02:49 PM
I ran an 18t front and a 38t rear without any issues.
Roy
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wrongway
Pro
Posts: 1078
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posted July 25, 2008 02:55 PM
I had heard that a 19t front will work if you remove the metal chain guard. I am not sure what the turbo busa guys run to go 250+ mph .
Roy
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busa200
Parking Attendant
Posts: 23
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posted July 25, 2008 04:58 PM
overdrive 5th and 6th, 20 and 41
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259.85 mph
how fast have you been?
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Halvefast
Zone Head
Posts: 806
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posted July 25, 2008 07:39 PM
quote:
overdrive 5th and 6th, 20 and 41
Whoa! 
Wow Charlie, that's some tall gearing.
What will that net you at the rear wheel tapped out in 6th gear?
____________
Texas Mile 200.256mph - Oct. 2007 (Update 202.577mph Oct 2008) NOS assisted
ECTA Ohio Mile 195.132mph
TexasMile 2012 199.9 mph all motor!
Streetriders Shootout 2008 series Pro/ET Champ!
Streetriders Shootout 2007 Series Pro/ET Runner-up!
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Halvefast
Zone Head
Posts: 806
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posted July 25, 2008 07:42 PM
I know XXX ran a 19t front sprocket,
but not sure what he used on the rear
to go 230mph last TX Mile meet in Oct 08.
____________
Texas Mile 200.256mph - Oct. 2007 (Update 202.577mph Oct 2008) NOS assisted
ECTA Ohio Mile 195.132mph
TexasMile 2012 199.9 mph all motor!
Streetriders Shootout 2008 series Pro/ET Champ!
Streetriders Shootout 2007 Series Pro/ET Runner-up!
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zxbob
Pro
Posts: 1692
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posted July 26, 2008 08:18 AM
quote:
I had heard that a 19t front will work if you remove the metal chain guard. I am not sure what the turbo busa guys run to go 250+ mph .
Roy
I've run a 18/38 combo ...... I had to remove the chain derailer just to get the 18 on the front.
Bob
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Good parts aint cheap and cheap parts aint good !
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wrongway
Pro
Posts: 1078
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posted July 26, 2008 10:32 AM
I got the 18 on without removing it , but i had to put the chain on the sprocket and than slide the sprocket on shaft. But I doubt that anything larger would go on with that guard coming out.
Roy
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BobC
Pro
Posts: 1736
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posted July 26, 2008 12:32 PM
 Edited By: BobC on 26 Jul 2008 13:37
I think wrongway's right, I ran an 18 tooth sprocket for my 205mph and it was a tight fit, removing the guard would probably allow a 19.
Currently using 17/40 for Landspeed gearing and ran a 203mph. No point in higher gearing without the power to pull it.
____________
Candy Thunder Blue 2006 ZZR1400
Stock wheelbase
Max: 205.4 mph in 1.25 miles
2012 ZZR1400 in Golden Blazed Green
Brock CT Full System. etc
Max: 203.1 in 1 mile (so far)
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kspz3
Expert Class
Posts: 334
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posted July 30, 2008 06:35 PM
I am running 18/38 - Stock pulls about 200 with speedo healer give or take - depending on tire wear and profile. Actually - as I recall - Brock was hitting rev limiter just under 200 - I was pitted next to him and if my memory serves me right he made a change prior to going just over ......
Kevin
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BobC
Pro
Posts: 1736
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posted July 31, 2008 04:42 AM
Edited By: BobC on 31 Jul 2008 05:56
Everyone here knows that what determines maximum Landspeed for a particular motorcycle and rider is first and foremost engine power, right?
Measure the power output, then work out what speed that amount of power could achieve and then work out what gearing that speed requires. If you get the sums wrong by gearing lower or higher you'll go slower.
That's an over-simplification of course. The hard bit is finding out the relationship between bhp and top speed so you can begin the arithmetic and then allowing for other variables like wind and weather.
____________
Candy Thunder Blue 2006 ZZR1400
Stock wheelbase
Max: 205.4 mph in 1.25 miles
2012 ZZR1400 in Golden Blazed Green
Brock CT Full System. etc
Max: 203.1 in 1 mile (so far)
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Cajunboyz
Zone Head
Posts: 702
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posted July 31, 2008 06:11 AM
Bob what was your gearing when you ran over 200+???? Also, whats your weight??
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"Cajun Boyz with Bad Ass Toys"
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BobC
Pro
Posts: 1736
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posted July 31, 2008 07:04 AM
I weigh about 190lbs in shorts. Gearing was 18/41 for the 205.4mph run but there was a tail wind for that event. I dropped to 17/40 for still air and ran a 203.1.
Hope that's some help.
____________
Candy Thunder Blue 2006 ZZR1400
Stock wheelbase
Max: 205.4 mph in 1.25 miles
2012 ZZR1400 in Golden Blazed Green
Brock CT Full System. etc
Max: 203.1 in 1 mile (so far)
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Cajunboyz
Zone Head
Posts: 702
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posted July 31, 2008 02:21 PM
Thanks Bob
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"Cajun Boyz with Bad Ass Toys"
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burnout
Expert Class
Posts: 216
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posted July 31, 2008 05:14 PM
Bob,
I was looking at a gearing calculator for the 14 and 17/40 showed 209.7 MPH @ 10,800 RPM. If you had 10 HP more at the wheel on your bike would you stick with 17/40 or would you consider another gear? I guess the question is would an extra 10 HP even give you 4 mph at those speeds? FYI, 18/41 was like 216.6 at 10,800 RPM according to this particular calculator.
____________
1/8 5.66@129.77
1/4 8.74@159.60
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BobC
Pro
Posts: 1736
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posted August 01, 2008 05:00 AM
Edited By: BobC on 1 Aug 2008 06:04
Whether I would change the gearing with another 10bhp depends on what RPM peak power is at. Also depends on any data from previous runs which prove or disprove the theory.
I think I would be tempted to try the 18/41 ratio again because peak power in 6th at around 10250rpm is 205mph on that gearing and there's some headroom to rev beyond that too. If you are hoping to go 216mph you are going to need rather more than another 10bhp, more like another 50.
____________
Candy Thunder Blue 2006 ZZR1400
Stock wheelbase
Max: 205.4 mph in 1.25 miles
2012 ZZR1400 in Golden Blazed Green
Brock CT Full System. etc
Max: 203.1 in 1 mile (so far)
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Cajunboyz
Zone Head
Posts: 702
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posted August 01, 2008 07:08 AM
Hey Bob, check your PM
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"Cajun Boyz with Bad Ass Toys"
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Halvefast
Zone Head
Posts: 806
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posted August 01, 2008 07:46 AM
Edited By: Halvefast on 1 Aug 2008 08:47
quote:
Bob,
I was looking at a gearing calculator for the 14 and 17/40 showed 209.7 MPH @ 10,800 RPM. If you had 10 HP more at the wheel on your bike would you stick with 17/40 or would you consider another gear? I guess the question is would an extra 10 HP even give you 4 mph at those speeds? FYI, 18/41 was like 216.6 at 10,800 RPM according to this particular calculator.
Remember gearing calculators don't take in consideration wheel slippage!
So the wheel maybe turning 209 but you might barely break 200.
Most bike suffer 3-4% slippage from what I have seen from others,
in my case my bike had 6% slippage, ran 200.256mph while tire was spinning 212
I hope to cure that issue with some set-up changes to help reduce slippage this October. 
____________
Texas Mile 200.256mph - Oct. 2007 (Update 202.577mph Oct 2008) NOS assisted
ECTA Ohio Mile 195.132mph
TexasMile 2012 199.9 mph all motor!
Streetriders Shootout 2008 series Pro/ET Champ!
Streetriders Shootout 2007 Series Pro/ET Runner-up!
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burnout
Expert Class
Posts: 216
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posted August 01, 2008 11:55 AM
quote:
Whether I would change the gearing with another 10bhp depends on what RPM peak power is at. Also depends on any data from previous runs which prove or disprove the theory.
I think I would be tempted to try the 18/41 ratio again because peak power in 6th at around 10250rpm is 205mph on that gearing and there's some headroom to rev beyond that too. If you are hoping to go 216mph you are going to need rather more than another 10bhp, more like another 50.
I see what you are saying, I've been looking at the rev limit, not the peak power RPM. That is really helpful for me. I'm so used to gearing for the top of 5th for the 1/4 mile, I had presumed that you gear for the top of 6th in the mile.
Your 50 hp estimate to get another 11 mph is also useful as I have no other benchmarks for what kind of mph gain one gets for added hp. I wouldn't have guessed that you would have gotten that much mph and was guessing under 210, but then again I have zero clue on these things. I'll let you know after October's Texas Mile what a 50 rwhp shot of N20 nets a Brocked out 14 using 18/41.
____________
1/8 5.66@129.77
1/4 8.74@159.60
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burnout
Expert Class
Posts: 216
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posted August 01, 2008 12:07 PM
quote:
Remember gearing calculators don't take in consideration wheel slippage!
So the wheel maybe turning 209 but you might barely break 200.
Most bike suffer 3-4% slippage from what I have seen from others,
in my case my bike had 6% slippage, ran 200.256mph while tire was spinning 212
I hope to cure that issue with some set-up changes to help reduce slippage this October.
Wow, that is something to consider. Did you data log your runs or was that reading off of the speedo via a yelow box or speedo healer? If you were reading RPMs you could have also been driving through the clutch. Do you run a lock-up? Did you run a soft compound tire? Any set-up advise you have for a newbie would be much appreciated. l just mailed in my registration. Looking forward to the event.
____________
1/8 5.66@129.77
1/4 8.74@159.60
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Cajunboyz
Zone Head
Posts: 702
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posted August 01, 2008 12:42 PM
YesBurnout, Thats A good question to BOB C, How is your clutch set up??
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"Cajun Boyz with Bad Ass Toys"
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Halvefast
Zone Head
Posts: 806
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posted August 02, 2008 08:00 AM
quote:
Wow, that is something to consider. Did you data log your runs or was that reading off of the speedo via a yelow box or speedo healer? If you were reading RPMs you could have also been driving through the clutch. Do you run a lock-up? Did you run a soft compound tire? Any set-up advise you have for a newbie would be much appreciated. l just mailed in my registration. Looking forward to the event.
That was actual RPM thru the traps run thru a gearing calculator with 18-40 gearing
on an actual dyno'd 45Hp shot (total Hp 225), fresh clutch shimmed 0.180 with a 190/50-17
Conti Sport Attack @ 63-64" (35psi) you could feel the back-end swaying around in 6th gear.
Definitely showed lots of tire wear by the end of each run.
Found that I picked up 5mph with a change in riding style alone.
____________
Texas Mile 200.256mph - Oct. 2007 (Update 202.577mph Oct 2008) NOS assisted
ECTA Ohio Mile 195.132mph
TexasMile 2012 199.9 mph all motor!
Streetriders Shootout 2008 series Pro/ET Champ!
Streetriders Shootout 2007 Series Pro/ET Runner-up!
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shane661
Needs a life
Posts: 11494
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posted August 02, 2008 08:03 AM
Edited By: shane661 on 2 Aug 2008 09:05
quote:
Most bike suffer 3-4% slippage from what I have seen from others,
in my case my bike had 6% slippage, ran 200.256mph while tire was spinning 212
How do you know for certain that the tire was spinning to 212? Are you certain that tire height did not have something to with it? How did you measure tire height?
A little off topic, but what were your mods to get to 200 mph?
Shane
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flyboy
Pro
Posts: 1536
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posted August 02, 2008 09:10 PM
Ken,
You going to Bonneville?
____________
'There's more living in five minutes flat-out on a bike than some men have in an entire life'.
"The World's Fastest Indian"
One fast red ZX-14,
Three World and four National Land Speed Records,
One faster red and white Cessna Turbo 210
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