[Author Index] [Date Index] [Thread Index]
[Date Prev][Date Next][Thread Prev][Thread Next]

RE: [ST] Re: sprockets



They could have done the gearing for the gas mileage too...

It's a little tall for my liking, and thus I changed the back sprocket to a
45t.  Additionally, I have always believed that there is not enough of a
difference between 5th and 6th gear.  At cruising speeds, the difference is
really negligible.

Matt Heyer
'01 BRG Sprint ST

- -----Original Message-----
From: Lou Jiannine [mailto:LouJ9@xxxxxxxxxx] 
Sent: Monday, April 19, 2004 9:40 AM
To: ST@xxxxxxxxxxxxxx
Subject: Re: [ST] Re: sprockets


synthesizing prior posts (including the math) with my experience I would
like to add the following.

One tooth down in front or up two teeth in the back cannot make a 500 rpm
difference at cruising speed.  If your cruising rpm is 4500 then changing
the countershaft only should change your cruising rpm to 4750.

\If you change back only from 43 to 45 your cruising rpm should change from
4500 to 4710.

Changing both sprockets should change cruising rpm to 4970  (A change of 470
rpm).


Theoretical top speed is the speed that a vehicle can reach if it can pull
redline in top gear.  A Sprint ST's theoretical top speed has to be in
excess of 160 while its real top speed is no more than 150.....classic sign
of gearing that is too tall.

I feel certain that a change of 5-7% percent in gearing would not cost the
Sprint any top speed.  If the 10% change (19/18 & 43/45) adversely affected
top speed, it would not be much and the bike would accelerate much quicker.

There is no excuse for Triumph gearing (unless it allows passage of some EPA
sound or pollutants test).  If I were buying a Sprint ST today I would make
changing the countershaft sprocket to and 18t Triumph sprocket part of the
deal..


Lou



- ----- Original Message ----- 
From: "Heyer, Matthew A." <mheyer@xxxxxxxxx>
To: <ST@xxxxxxxxxxxxxx>
Sent: Sunday, April 18, 2004 8:45 PM
Subject: RE: [ST] Re: sprockets


> I have done the 43t to 45t rear sprocket change, and I would say that 
> at
80
> mph the change is an increase just under 500 rpm (maybe 400?).  So 
> yeah...
>
> Matt Heyer
> '01 BRG Sprint ST
>
>
> -----Original Message-----
> From: STeve Duncan [mailto:xhippy@xxxxxxxxxxx]
> Sent: Sunday, April 18, 2004 7:28 PM
> To: ST@xxxxxxxxxxxxxx
> Subject: RE: [ST] Re: sprockets
>
>
>
> Going from 19t to 18t countershaft sprocket results in a 500rpm 
> increase
at
> indicated 80 in 6th gear.  Past that I do not have personal 
> experience,
but
> would guess the 43t to 45t on the rear would have a similar result. 
> Combined you are looking at a 1,000 RPM increase for the same speed.
>
>
>
> Duncan
> Dallas
> Tejas
>
> "Officer, it was some 'other' Red bike, I swear"
>
>
>
>
>
> >From: rmcclaran@xxxxxxx
> >
> >Does anyone have any top end speed comparisons after going 18/45? How 
> >much higher are you revving in top gear comparitively at say, 100mph? 
> >Also, is Sprocket Specialists the consensus best source?
> >Cheers,
> >Robbie
> >
>
> _________________________________________________________________
> FREE pop-up blocking with the new MSN Toolbar - get it now! 
> http://toolbar.msn.com/go/onm00200415ave/direct/01/
>
>
>      *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
> *
>       The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
>           http://www.TriumphNet.com/st/lilley for more info
>    http://www.TriumphNet.com/st for ST, RS and Mailing List info
>
>      *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
*
>       The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
>           http://www.TriumphNet.com/st/lilley for more info
>    http://www.TriumphNet.com/st for ST, RS and Mailing List info
>


     *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
*
      The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
          http://www.TriumphNet.com/st/lilley for more info
   http://www.TriumphNet.com/st for ST, RS and Mailing List info

     *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
      The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
          http://www.TriumphNet.com/st/lilley for more info
   http://www.TriumphNet.com/st for ST, RS and Mailing List info

=-=-=-= Next Message =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=