GSX1400 Owners .org

Technically Speaking => General Technical discussion => Topic started by: akhendy on Monday, 17 April 2017, 10:28 AM

Title: 17 tooth front sprocket
Post by: akhendy on Monday, 17 April 2017, 10:28 AM
Hi all I was wandering if putting 17 tooth front sprocket on would lower my top speed or would it allow the engine to rev out more in top gear and maybe increase it a bit. or maybe stay the same.
I am looking for a bit more snap but don't want to lose top speed as I go to the drags with friends a few times a year
Cheers Andrew
From Australia
K4
Full Yoshi
power com 3
Lightened bike a fair bit
Title: Re: 17 tooth front sprocket
Post by: T 24 on Monday, 17 April 2017, 01:52 PM
You wont lose your top speed( if you dont have speed limiter on, they are different depending on marketing area). After putting 17 tooth front sprocket it will feel a little bit snapper, and your speedo will show a little bit more wrong.
Title: Re: 17 tooth front sprocket
Post by: akhendy on Monday, 17 April 2017, 03:29 PM
Great thanks. . I thought the same I'll give it a try. I was reading somewhere that a hayabusa 17 tooth front socket fits straight on.
Cheers Andrew
Title: Re: 17 tooth front sprocket
Post by: T 24 on Monday, 17 April 2017, 04:37 PM
Hayabusa front sprockets will fit. And GSX-R 1000 rear sprockets will fit when you drill bolt holes from 10.5mm to 12.5mm (if you need different number of teeth)
Title: Re: 17 tooth front sprocket
Post by: RickC on Monday, 17 April 2017, 10:58 PM
Your top speed will be lower, 15kms slower at 9000k so probably not too noticeable.

You are better off going up a couple of teeth on the back if you want to make it snappier, a 17T sprocket will flog your chain out a lot quicker than
a 18 or 19t front.

Have a look at this website - it will give you theoretical speed/gearing ratios once you load the GSX1400 into it.

http://www.gearingcommander.com/

Cheers,
Rick
Title: Re: 17 tooth front sprocket
Post by: T 24 on Monday, 17 April 2017, 11:59 PM
Hey haloo! That 15kmh/9000k is only theoretical, if there is enough power in your engine. I dont have, and I have 100hp more than standart 14 (to be honest,I havent even tried, my bike is too fast to me).
Top speed with 17 teeth sprocet can be (I dont say is) higher than with 18 teeth, because stock engine doesnt have power enough.
Title: Re: 17 tooth front sprocket
Post by: RickC on Tuesday, 18 April 2017, 09:38 AM
Your top speed can't be higher going to a smaller front sprocket. The back  sprocket or wheel is going to do less turns for a given RPM which equals a lower top end speed.

Your Top Speed on a timed run can be higher as you can accelerate through to your speed quicker.

I've tried a 17t sprocket on the front, I didn't mind it but it does put more stress on the chain as opposed to going up a couple of teeth on the back.
Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 18 April 2017, 03:32 PM
Thanks guys I have already ordered a 17tooth spocket.  .. Top at the moment is 245klms (well short of red line)  I say top speed should stay the same.
I'll test next week and get to you :)
Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 18 April 2017, 03:34 PM
1 more question  is going 1 tooth smaller on the front the same as 2 teeth on the rear??
Title: Re: 17 tooth front sprocket
Post by: Mick_J on Tuesday, 18 April 2017, 04:16 PM
Closer to 1 1/2.
Title: Re: 17 tooth front sprocket
Post by: T 24 on Tuesday, 18 April 2017, 05:54 PM
OK. Let us know what was the result; Top speed and revs. Was your speed taken from speedometer or GPS ?
Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 18 April 2017, 07:08 PM
245klms Speed taken from speedo.  It was still pulling very  slowly.. but the road I do it on Is not the best.
Not sure what  others with similar hp can do?
Mine was dynoed   118hp  and  128nm torque
Title: Re: 17 tooth front sprocket
Post by: Snapey on Tuesday, 18 April 2017, 07:37 PM
I'd love to see the time differences between 17T, 18T and 19T front sprockets with stock 41T rear. All done on one day of course.

I think you'll also find a stock 14 with 18/41 gearing will have a higher top speed in 5th gear than in 6th.
Title: Re: 17 tooth front sprocket
Post by: T 24 on Tuesday, 18 April 2017, 09:27 PM
It would be more accurate if you can take speed with GPS, because speedometer takes its signal from front sprocket, so the instrumental error of speedo will also change, when you change the sprocket. Or you need a speedohealer to calibrate your speedometer.
Title: Re: 17 tooth front sprocket
Post by: Mick_J on Wednesday, 19 April 2017, 05:12 PM
All things being equal the theoretical speed at max power (6800 rpm) is 144.669 mph and 191.473 at the red line (9000 rpm) but gravity, drag, the wind and a fat rider will all go against that.
Title: Re: 17 tooth front sprocket
Post by: gsxbarmy on Wednesday, 19 April 2017, 05:54 PM
All combinations and answers here in terms of sprockets, tyre sizes etc - download the Excel spreadsheet (as indicated in the link), enter the parameters and see the results

http://gsx1400owners.org/forum_test/index.php?topic=362.0

Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 02 May 2017, 08:06 PM
17 tooth fitted.   I love it.  Heeps more pull.  Speedo is only 10  klms out. It  was  5 klms before .no big deal.  Hit 240 easy and still pulling strong top speed may not be affected I'll try next weekend with gps.   Very happy
Title: Re: 17 tooth front sprocket
Post by: Gra Har on Tuesday, 02 May 2017, 08:18 PM
Quote from: akhendy on Tuesday, 02 May  2017, 08:06 PM
17 tooth fitted.   I love it.  Heeps more pull.  Speedo is only 10  klms out. It  was  5 klms before .no big deal.  Hit 240 easy and still pulling strong top speed may not be affected I'll try next weekend with gps.   Very happy

Did you need to shorten the chain, or did the adjusters loosen off enough?
Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 02 May 2017, 09:08 PM
Good day I shortened the chain.  Is was a bit long when fitted  new 2yrears ago
Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 13 June 2017, 07:31 AM
Finally checked top speed with 17tooth sprocket.   Gps 238klph.   Speedo said 255klph.  Road was getting a bit rough I could have got maybe 2 or 3 more on a smoother Rd.
16klph out at those speeds 10klph out at 100.
Bloody happy with the 17tooth  sprocket. Pulls like a train  love it!!!  :)
Title: Re: 17 tooth front sprocket
Post by: KiwiCol on Tuesday, 13 June 2017, 03:44 PM
When you say "road was getting a bit bumpy" you actually mean the closed circuit track you tested it on to get those figures.  :drool:   
Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 13 June 2017, 07:11 PM
Of course it was.   Lol     :rofl2:
Title: Re: 17 tooth front sprocket
Post by: akhendy on Tuesday, 13 June 2017, 07:12 PM
Of course it was lol    :rofl2:
Title: Re: 17 tooth front sprocket
Post by: grog on Tuesday, 13 June 2017, 07:27 PM
speedo sure is out a bit. love those high speed (track) tests.