Most people think that uneven chain tension is the result of crooked sprockets, well after over tensioning my chain, I found out another more likely possible cause. It took me a while to figure it out because the tension would change but not once per wheel revolution but once per chain revolution and unevenly at that. Well if the chain is over tensionsed and the suspension gets compressed the moment it gets compressed it stretches the free sections of chain and the sections on the sprockets stay relatively unaffected. Well my chain is nearing the end of it's useful life anyway and will be needing replacement soon, I've ordered a new chain and 18 tooth front sprocket. The front isn't worn out but I thought I'd try the 18 tooth to see if I can improve gas mileage. Just wanted to let you guys in on it in case you guys experience this problem, and may be thinking of ordering a whole new chain and sprockets, you replace them thinking I solved it, must have been bent sprockets all along, when in reality it was just an unevenly stretched chain. Hope this helps.
That actually applies to me... sorta. I had uneven chain tension but I think mine was to to dumping the clutch at 5 grand at the 1/4 mile the other day. I ended up adjusting my chain every time I stopped and it would either go limp next stop or act over tight. Frustrating. But I've checked out both sprockets, no gots there. I'd diagnosed it as the chain. Swapped the chain... no more stupidness.
Uneven chain tension is almost always due to kinking links, new chain will fix.
Be careful with that 18 tooth sprocket.It will not want to pull off as easy.Another problem with lowering rpm causes charging issues.The alternator/generator doesn't start charging until 3000 to 3500 rpm.Be aware of this so you don't kill the battery.It will stress the engine pulling hills and will be har to pass without dropping to 4th gear.
Quote from: qwertydude on April 30, 2008, 11:16:26 AM
Most people think that uneven chain tension is the result of crooked sprockets, well after over tensioning my chain, I found out another more likely possible cause. It took me a while to figure it out because the tension would change but not once per wheel revolution but once per chain revolution and unevenly at that. Well if the chain is over tensionsed and the suspension gets compressed the moment it gets compressed it stretches the free sections of chain and the sections on the sprockets stay relatively unaffected. Well my chain is nearing the end of it's useful life anyway and will be needing replacement soon, I've ordered a new chain and 18 tooth front sprocket. The front isn't worn out but I thought I'd try the 18 tooth to see if I can improve gas mileage. Just wanted to let you guys in on it in case you guys experience this problem, and may be thinking of ordering a whole new chain and sprockets, you replace them thinking I solved it, must have been bent sprockets all along, when in reality it was just an unevenly stretched chain. Hope this helps.
changing gears will get you 0 difference in gas mileage. The only thing that will change is your top speed meaning you will be able to top out at a faster speed but it will take the bike longer to get there in terms of rev's and rpm. Just wanted to let you know this so you arent surprised later. The only thing that can affect gas mileage in this case is engine performance and riding habits.
Quote from: ben2go on April 30, 2008, 03:49:05 PM
Be careful with that 18 tooth sprocket.It will not want to pull off as easy.Another problem with lowering rpm causes charging issues.The alternator/generator doesn't start charging until 3000 to 3500 rpm.Be aware of this so you don't kill the battery.It will stress the engine pulling hills and will be har to pass without dropping to 4th gear.
I think I'm safe I ride like 95%+ freeway miles and my commute every day is like 70-80 miles solid freeway, so I'm not too worried about a little loss in charging capability. Plus on the freeway I can already pass cars in sixth just by giving it some gas since I only weigh 130. My 75-90 top gear acceleration is hovering about 5.5 seconds so that's still plenty faster than most cars so a slight loss in that is also no problem. What I wanted to drop the gearing for is to reduce valve recession and increase gas mileage. High sustained revs cause more valve seat wear.
Quote from: ImportBabe on April 30, 2008, 04:07:06 PM
changing gears will get you 0 difference in gas mileage. The only thing that will change is your top speed meaning you will be able to top out at a faster speed but it will take the bike longer to get there in terms of rev's and rpm. Just wanted to let you know this so you arent surprised later. The only thing that can affect gas mileage in this case is engine performance and riding habits.
Umm.. Lowering the rpms will give you better highway mileage. It's what overdrive is for in cars. Try riding the freeways in 4th gear all the time and see how bad your mileage gets. Or installing a -2 front sprocket. And as far as top speed, the GS is drag limited which means gearing up won't give you any more top speed. Sure you'll theoretically be able to redline at 170 but I guarantee you don't have the power to push it. Actually the GS is geared so that redline top speed in sixth is somewhere in the 150 mph range but we never reach that because of drag. Actually gearing up will probably cause a reduction in our top speed because less power is able to get to the ground for two reasons, higher gearing means less mechanical advatage is given by the gear ratio and the engine is placed further out of it's power range by the gearing itself. This topic has been endlessly discussed in a forum that actually cares about top speed because they're always wringing their engines out on a daily basis, try a search on rebel250.com . I'm also a member there and everyone who has geared up thinking it'll make them go faster ends up going slower.
I installed a 14tooth front sprocket, and it didn't change fuel economy a single bit. riding is ALOT smoother, and passing without gearing down is really nice. and 55 mph @ around 5200 rpm isn't THAT bad
Quote from: jeremy_nash on May 01, 2008, 10:02:23 PM
I installed a 14tooth front sprocket, and it didn't change fuel economy a single bit. riding is ALOT smoother, and passing without gearing down is really nice. and 55 mph @ around 5200 rpm isn't THAT bad
you drive 55 ? you must live in the city :)
highways are 60 mph around there parts
Quote from: pbureau69 on May 02, 2008, 02:24:45 AM
Quote from: jeremy_nash on May 01, 2008, 10:02:23 PM
I installed a 14tooth front sprocket, and it didn't change fuel economy a single bit. riding is ALOT smoother, and passing without gearing down is really nice. and 55 mph @ around 5200 rpm isn't THAT bad
you drive 55 ? you must live in the city :)
highways are 60 mph around there parts
70 mph here.
I'm usually going the speed of traffic in the left lane. Which when it's not jammed up is in the 80-85+ range. Then you get a bad jam everything slows to a crawl for absoultely no reason at all, then clears up and everyone's back into rush mode doing 80 for another half mile until you have to slam the brakes again. Good thing in cali we can split lanes all that crazy stop and go will surely mean a motorcycle is bound to get rear ended.
Quote from: qwertydude on May 02, 2008, 09:55:48 AM
I'm usually going the speed of traffic in the left lane. Which when it's not jammed up is in the 80-85+ range. Then you get a bad jam everything slows to a crawl for absoultely no reason at all, then clears up and everyone's back into rush mode doing 80 for another half mile until you have to slam the brakes again. Good thing in cali we can split lanes all that crazy stop and go will surely mean a motorcycle is bound to get rear ended.
Yea.I always stay on the outside lanes and get ready to shoot down the emergency lane if I see it coming.It's illegal here to split lanes and use emergency lanes.It's better than getting hit from behind.I never split lanes or use emergency lanes.It's dangerous.Stupid people around here will cut over just for shets and giggles to see you wreck and destroy your bike.