GStwin.com GS500 Message Forum

Main Area => General GS500 Discussion => Topic started by: Church6360 on December 22, 2005, 05:06:39 PM

Title: sprockets
Post by: Church6360 on December 22, 2005, 05:06:39 PM
where (online) is a good place to look for sprockets (aftermarket)?

soon my gs will no longer need to make freeway trips, so i can drastically shorten the gearing without being terribly inconvenienced.

any reccomendation on how short to go? how much it too much?

thanks for opinions and suggestions,
Title: sprockets
Post by: makenzie71 on December 22, 2005, 05:27:09 PM
http://www.sprocketspecialists.com/
Title: sprockets
Post by: Church6360 on December 22, 2005, 05:44:22 PM
they make rear sprockets as big as 74 tooth? damn. that i think would fall on the side of too much.
Title: sprockets
Post by: RedShift on December 22, 2005, 06:04:10 PM
I bought my 17-Tooth front sprocket at BikeBandit (http://www.bikebandit.com/partsbandit/Aftermarket-Parts.asp). They offer several flavours, but I bought an AFAM.
Title: sprockets
Post by: makenzie71 on December 22, 2005, 06:07:22 PM
stunters use them
Title: sprockets
Post by: Church6360 on December 22, 2005, 07:24:22 PM
hmmm... trying to find out how much impact on mph at a given rpm a change of teeth makes.
Title: sprockets
Post by: makenzie71 on December 22, 2005, 07:33:52 PM
simple math, man...don't try and make it hard:

Say your speedo is 100% accurate with a 15/40 setup.

but you want a little more zip?  Try a 15/42 setup.

40/42 = .95%

Now, when you're speedo says you're moving 70mph, you'll actually only be goign 95% of that.

70 X .95 = 66.6mph
Title: gearing
Post by: bulletproofcycle on December 22, 2005, 07:51:25 PM
Mackenzie71

You are partially right.

His speedo won't be affected only his rpms. So when he used to go 70mph at say 6000 rpm it will be 5% more. The speedo reading is from the front wheel.


Even if you go to a 15 tooth with the stock gearing rear sprocket 39 you only go about 250 rpms more, which is good anyways as the gs can't redline in 6th anyways.

Hope that helps
Title: Re: gearing
Post by: makenzie71 on December 22, 2005, 07:55:38 PM
Quote from: bulletproofcycleMackenzie71

You are partially right.

His speedo won't be affected only his rpms. So when he used to go 70mph at say 6000 rpm it will be 5% more. The speedo reading is from the front wheel.


Even if you go to a 15 tooth with the stock gearing rear sprocket 39 you only go about 250 rpms more, which is good anyways as the gs can't redline in 6th anyways.

Hope that helps

yeah completely disregard what I just said...I'm very sorry about that.  I've been dealing with my TL1000S for so long that I don't typically stop to think that not every bike gets it's speedo reading from the transmission.
Title: sprockets
Post by: Church6360 on December 22, 2005, 08:00:50 PM
i had some spare time today and was trying to figure it out kinda accurately.

39/16= 2.4375
42/15= 2.8

2.4375/2.8= .87
100-87= 13

if i'm thinking right a change from stock to 42 rear and 15 front would make my bike have a speed 13% slower in any gear at a given rpm.

math/ thinking guru's am i right?
Title: sprockets
Post by: makenzie71 on December 22, 2005, 08:02:00 PM
no speed stays the same...your speedo reads off the front wheel.
Title: sprockets
Post by: Roadstergal on December 22, 2005, 08:03:20 PM
Quote from: makenzie71no speed stays the same...your speedo reads off the front wheel.
He's not talking about the speedo reading - he means the speed at a given RPM - or the RPM at a given speed, same diff.
Title: sprockets
Post by: Church6360 on December 22, 2005, 08:04:45 PM
i know my speedometer reads off the front wheel, but if i put the engine at 5000 rpm in 6th i will be going X mph with stock gearing.

with the changes i would be going 13% slower in sixth at 5000rpm
Title: ...I suck at multi-tasking...
Post by: makenzie71 on December 22, 2005, 08:07:02 PM
yeah...that's should be correct, if you did the same thing I showed you but using RPM instead of mph.

~just double checked it, 13% is correct.
Title: sprockets
Post by: dgyver on December 22, 2005, 08:07:10 PM
http://evilpumpkinracing.com/eprlinks.htm has a gearing calculation chart. That is the one I use.
Title: sprockets
Post by: Roadstergal on December 22, 2005, 08:11:47 PM
That's a good tool...

OK, now that the useful information has been posted, every time I saw this subject line, I thought (http://img60.exs.cx/img60/9499/dieter30av.jpg)...
Title: sprockets
Post by: makenzie71 on December 22, 2005, 08:14:15 PM
Quote from: RoadstergalThat's a good tool...

OK, now that the useful information has been posted, every time I saw this subject line, I thought...

I'm not sure who that is, but mr. spacely keeps coming to my mind...
Title: sprockets
Post by: Badger on December 22, 2005, 08:17:50 PM
Quote from: RoadstergalOK, now that the useful information has been posted, every time I saw this subject line, I thought...
Would you like to touch my monkey?
Title: sprockets
Post by: Roadstergal on December 22, 2005, 08:17:57 PM
Dieter and the Sprockets from SNL.
Title: sprockets
Post by: dgyver on December 22, 2005, 08:24:38 PM
Quote from: RoadstergalThat's a good tool...

but of course  ;)
Title: sprockets
Post by: makenzie71 on December 22, 2005, 08:24:40 PM
awww...I don't ever get to watch SNL anymore...

(not that anyone who watched it with miller, spade, farley, hartman and the rest of the cursed thinks it's still good...)
Title: sprockets
Post by: Roadstergal on December 22, 2005, 08:25:47 PM
I stopped watching about in '91, and only know the Sprockets because I have a German boss and a friend sent me captures.   :lol:
Title: sprockets
Post by: Church6360 on December 23, 2005, 01:37:10 AM
thank ypu dgyver. that iss exactly what i was looking for. looking at that i might go as short as 15 / 47, but i'm not quite sure yet, i do want sorter gearing, but i don't want to be shifting constantly, maybe just the 15 / 42. i dunno.

once again thanks for that link.
Title: sprockets
Post by: RedShift on December 23, 2005, 09:36:10 AM
Quote from: Church6360hmmm... trying to find out how much impact on mph at a given rpm a change of teeth makes.
I may be a bit late to give this, but just in case there's still interest in the effects of sprocket changes, have a peek through my Adding a Tooth -- Going Up to a 17T Front Sprocket thread.  

I did a practical comparison of Speed & RPM between the stock 16T and my updated 17T.  Nonetheless, I like the link to the Go Faster Tools that
dgyver pointed out.   :thumb:
Title: sprockets
Post by: Church6360 on December 23, 2005, 10:46:10 AM
good thread, yeah, if an a change of 5.86% made a difference of about 400 rpm in a given gear at a constant speed then a change of 13% would be about 900ish rpm difference.

and going 15/47 would cause a change of 22.2% from stock.
which would cause a change of 1500 ish rpms in a given gear at a constant speed. (if my math is correct)

hmmmmm... i need to go ride my bike and then ask myself if i'd really be comfortable with that kind of gearing.
Title: sprockets
Post by: scratch on December 23, 2005, 10:47:24 AM
From Kerry's site: http://www.bbburma.net/Documents/GS500_Chains&Sprockets.txt
Title: sprockets
Post by: RedShift on December 23, 2005, 11:23:53 AM
Quote from: Church6360good thread, yeah, if an a change of 5.86% made a difference of about 400 rpm in a given gear at a constant speed then a change of 13% would be about 900ish rpm difference.

and going 15/47 would cause a change of 22.2% from stock.
which would cause a change of 1500 ish rpms in a given gear at a constant speed. (if my math is correct)

hmmmmm... i need to go ride my bike and then ask myself if i'd really be comfortable with that kind of gearing.
There's got to be someone on this board that's done this.  

Kinda radical in my view -- you should be able to skip half the gears when shifting and not have the bike complain.  :dunno:
Title: sprockets
Post by: Church6360 on December 23, 2005, 11:37:32 AM
yeah, i might as well give it a shot, i think when i get around to it i may order a few different sprockets, like a 15 and a 17 for the front, and a 47 for the rear. the front ones are cheaper, and that way i can play around with the ratio's a bit.

if 15/47 is too short i can switch to 17/47 which would be a more manageable 12% shorter than stock.
Title: sprockets
Post by: JustinNoob on December 25, 2005, 03:17:43 PM
Sprockets???    Undt now ve dance......