GStwin.com GS500 Message Forum

Main Area => General GS500 Discussion => Topic started by: mach1 on June 14, 2007, 04:50:02 PM

Title: chain question
Post by: mach1 on June 14, 2007, 04:50:02 PM
will the stock chain work if I go with a 49t rear and a 15t front? And what would be my top speed be?
Title: Re: chain question
Post by: heatherg11 on June 14, 2007, 05:42:59 PM
sorry, i'm not sure the answer to your question but your bike looks good with that headlight.
Title: Re: chain question
Post by: mach1 on June 14, 2007, 06:51:41 PM
thanks, It would have been nice to get the buell blast windscreen to finish it off but oh well. thanks again for the light.
Title: Re: chain question
Post by: TragicImage on June 14, 2007, 07:15:21 PM
49t and 15t?


about 50 mph.


and no, the stock chain won't work.
Title: Re: chain question
Post by: mach1 on June 14, 2007, 07:26:45 PM
what about a 41t rear
Title: Re: chain question
Post by: heatherg11 on June 15, 2007, 06:16:10 AM
sorry, it was already taken....but it would have matched almost perfectly....it looks good, keep looking for one if you really want one. you can find them on ebay semi cheap if you catch it right.
Title: Re: chain question
Post by: SeriousGeorge on June 15, 2007, 08:22:51 AM
A 15t front and a 41t rear may work. It'll be pretty tight if it fits. When I changed to a 15t front it put my chain adjusters just past the middle. Not sure if that would give you enough room for 2 more teeth on the back. I'd get a 112 if possible just in case and cut it if needed.
Title: Re: chain question
Post by: gsJack on June 15, 2007, 09:03:07 AM
http://tsubaki.com.au/tsscs/chain_length.htm

Using above calculator, the ideal centre distance is 25.679 inches for 16/39T OEM sprockets and 110 link 520 chain.

For 15/41T and 110 links the ideal centre distance is 25.494 inches. Since the slot in the swingarm shows or almost shows with OEM sprockets and new 110 chain, there should be no problem with the 15/41 110 combo.

You can use this calculator and with some measurements of the swingarm center distance and adjustment slot lengths you can get a good idea of what might work.

Title: Re: chain question
Post by: natedawg120 on June 15, 2007, 10:17:14 AM
Quote from: gsJack on June 15, 2007, 09:03:07 AM
http://tsubaki.com.au/tsscs/chain_length.htm

Using above calculator, the ideal centre distance is 25.679 inches for 16/39T OEM sprockets and 110 link 520 chain.

For 15/41T and 110 links the ideal centre distance is 25.494 inches. Since the slot in the swingarm shows or almost shows with OEM sprockets and new 110 chain, there should be no problem with the 15/41 110 combo.

You can use this calculator and with some measurements of the swingarm center distance and adjustment slot lengths you can get a good idea of what might work.



+1 :thumb:
Title: Re: chain question
Post by: Chuck on June 15, 2007, 12:04:56 PM
Quote from: TragicImage on June 14, 2007, 07:15:21 PM
49t and 15t?

about 50 mph.

I seem to recall cruising on my stock setup at 5500 at 60mph in top gear.  That's 92 RPM/mph.  A 15/49 would be about 25% higher.  (16/39=0.41, 15/49=0.31)  So you're around 123 RPM/mph.  So at redline (10,500) you're theoretically capable of going 85mph.  That makes sense because I'm usually at 7500 on the highway going 75-85, although my tach just bounces around at that speed.

If you have a more accurate RPM/mph number than my hazy memory, you'd get a better answer.

I don't remember the shift point in first gear, but with 0.31 gearing it's probably walking speed.  :laugh:
Title: Re: chain question
Post by: ben2go on June 15, 2007, 12:12:47 PM
This has me scratching my head.I have stock gearing and at 60mph,I'm turning 4500rpm.I have matched Kenda 671s.110/130-70-R17.What gives?My spockets look good,my cahin is in good condition,why are my rpm's so low?
Title: Re: chain question
Post by: RVertigo on June 15, 2007, 12:13:33 PM
When I replaced my chain it was 110, but the one I pulled off was 109...   :dunno_white:  Maybe the mechanic thought the 15t made enough of a difference to drop a link....


You know...  If all else fails, you can set your adjusters where you think they should be, lace the chain through, and approximate how many links to cut off.


And...  With my 15T, 7K RPMs == ~65 MPH

[edit] Maybe it's the inaccuracy of the Tach and Speedo...  One is high another is low  :dunno_white:
Title: Re: chain question
Post by: Chuck on June 15, 2007, 12:20:34 PM
Quote from: RVertigo on June 15, 2007, 12:13:33 PM
When I replaced my chain it was 110, but the one I pulled off was 109...   :dunno_white: 

Your chain really should have an even number of links.  Otherwise, you can't close it.  Maybe you weren't counting the master link when you took it off?


Quote from: RVertigo on June 15, 2007, 12:13:33 PM
And...  With my 15T, 7K RPMs == ~65 MPH

[edit] Maybe it's the inaccuracy of the Tach and Speedo...  One is high another is low  :dunno_white:

Yeah, there could be wildly differing speedo tacho measurements.
Title: Re: chain question
Post by: gsJack on June 15, 2007, 01:13:11 PM
GS500 turns about 4730 rpm in top gear at 60 mph with standard gearing, from first GS500 test in May 89 Cycle Magazine:

http://img.photobucket.com/albums/v443/jcp8832/GS500tests.jpg

Theoretical top speed in 6th gear @ redline is approx 140 mph.  Scroll to bottom of test sheet.  So 60/140x11000=4714 rpm calculated.  With speedo error, tach error, and tire wear your results may vary.   :laugh: