Author Topic: lower RPM's on my bandit (Read 5803 times)

onenicebandit · « **on:** May 15, 2007, 06:28:10 PM »

Hey all. Haven't posted in a long time. My B4 is running awesome, and just getting ready to turn over 5000 miles. I took it out on the highway today, and sometimes...I just feel bad for this bike. I know it was built to rev high, but I hate having to leave it at 7-8 grand for a half hour straight. Do you think I should drop a few teeth in the back to lower the rpm's,...or just get something bigger. I did wash it up the other day and sit it out front, 3 fellas dropped by and asked me if it was for sale, and I told them yeah, for the right amount of money. Just don't know how much it would be worth, 92 B4 with 4900 miles, still everything stock, even the tires that CAME on the bike. Let me know what a fair asking price would be for this bike. Thanks everyone.

BrianM · « **Reply #1 on:** May 15, 2007, 06:34:50 PM »

I've lowered the gearing (15/47) and in 6th now hit 6k at 65mph.... and it may just be my bike, but that's Right where the WORST vibes are. I jumped on the interstate for about 20 miles, 80mph (so 8k rpm) and the bike smoothed right out and MUCH more comfortable to ride.

So, stop feeling bad for the bike and rev it (or at least make Certain that the vibes aren't terrible at lower RPMs before doing the change).

As for what your bike is worth, whatever someone will pay (or whatever you'd take). I wouldn't take less than $3k for mine right now because of the difficulty in getting a replacement bike. At least with 3k I could walk into the local Kawi dealer and get an EX250 (I don't finance bike, and there's no used street-bike market here).

turbofb · « **Reply #2 on:** May 16, 2007, 12:10:42 AM »

Ive been thinking the same thing about the gearing.
I hoped that a new set of tires would help to slow things down,since my old tires were very worn out,but thats not the case.

In addition to the high feeway revs,1st gear seems just ridiculously low.....Im taching the piss out of it in 1st and Ive still barely made it across the intersection.Its got to the point that Im just starting out in 2nd gear.The excrutiatingly loud Yosh pipe doesnt help....

Im gonna take the 1st and 2nd gear ratios and the stock final drive ratio and do some math to figure out what sprokets I need to split the difference between the current 1st and 2nd gear.I need a new chain anyways.
That should help out quite a bit with the low speed screaming in 1st,and whatever bit it helps in 6th,on the freeway,will just have to do.

Bartjan · « **Reply #3 on:** May 16, 2007, 12:15:47 PM »

this might help

pmackie · « **Reply #4 on:** May 16, 2007, 01:16:24 PM »

Quote

92 B4 with 4900 miles

At 15 years old with 5000 miles, it will corrode away before you ever wear out the engine

Seriously, don't feel bad about putting some revs on it. Keep the oil and filter fresh and the revs won't cause any undue wear. Most of the wear occurs at start up. Once things are up to operating temp, and full oil flow, everything is basically floating on a film of oil.

I know the 400 guys say you can wear these bikes out, but at 5000 milies, your not close.

BUT...15 year old tires are in need of replacing. Also...fork oil, brake fluid, etc.

stormi · « **Reply #5 on:** May 17, 2007, 03:14:00 AM »

Quote from: "pmackie"

I know the 400 guys say you can wear these bikes out, but at 5000 milies, your not close.

-Some- of the b4 guys say that. At about 46K kms ( so just shy of 30K miles), we disassembled Dita, thinking she needed a camchain. It was carbonned up valves, and you could still see the honing on the cylinders.

The moral of the story? Don't ride like Jay (gsxr400 racer), and the bike will last forever.

onenicebandit · « **Reply #6 on:** May 17, 2007, 06:29:20 PM »

well...I don't doubt that this bike will last me a while yet if I keep it, I'd just like it to be a little less high-strung, What is stock gearing on it, I was thinking of dropping two teeth in the back, I don't know how much this will do, if anything, but it's worth a try. Thanks all.

stormi · « **Reply #7 on:** May 17, 2007, 06:44:59 PM »

I just searched the b4 forum, the official word is: 14/46 for '91/92 and 14/47 for '93

This thread will help you.. link

two teeth on the back is equivalent to one on the front. We went up one on the front, and it was fairly significant. Of course I threw most of this out the window when I changed the exhaust.

What is it that you're finding her high strung about? What sorts of situations, or is it just the high revs?

Bartjan · « **Reply #8 on:** May 17, 2007, 06:51:28 PM »

Quote from: "stormi"

two teeth on the back is equivalent to one on the front.

one teeth on the front is equivalent to almost 4 teeth at the back

stormi · « **Reply #9 on:** May 17, 2007, 07:06:38 PM »

Hmm,.. that's right,.. sorry I forgot. The other half mentioned about 3ish, but for some reason 2 was stuck in my head.

One thing though is that going lower on the front -may- not be as good a solution, as it makes the turn for the chain sharper. If I was going down, I'd likely go the route of changing at the back. Going up though, we changed the front.

onenicebandit · « **Reply #10 on:** May 17, 2007, 10:10:45 PM »

The only thing I don't like about it is how high it revs when I'm traveling 70-80 mph. I know this is how the bike is designed, but I'd like to be as easy on the bike as I can be, sometimes I'm on the highway for 60-90 miles at a time when I take it for a ride. I use this bike as my gas saver and all around fun time machine. I'll drop 2 teeth in the back and see what happens.

zelig · « **Reply #11 on:** May 17, 2007, 11:20:03 PM »

Quote from: "onenicebandit"

<Can't seem to get it to run even though it only has 2500 miles on it and it starts up>

Time to update your sig.

How'd you get it running, anyway?

turbofb · « **Reply #12 on:** May 18, 2007, 01:59:25 AM »

Did all my math last night and I came up with a good combo to split the difference between 1st and 2nd,but without going too tall.

Stock 1st gear with stock sprokets nets you a 11.25 ratio.
Stock 2nd gear with stock sprokets nets you a 7.73 ratio.

Thats a big jump and I really find 1st gear to be almost useless.Its no wonder she almost power wheelies in 1st!!

With a difference of 3.52 between 1st and 2nd,I figured resetting 1st to the middle of that range would make 1st more usable,without getting too doggy off the line.I didnt want to go too far,so I figured on the low side and came up with this....

Stock 1st gear with +1 in front and -1 in back equals a 10.30 ratio.
Stock 2nd gear with +1 in front and -1 in back equals a 7.06 ratio.

That combo will err on the lower side between the stock 1st and 2nd total ratios.I can easily take off from a stop,in 2nd gear with stock 91-92 ratios.Being part way between the current 1st and 2nd should feel just right.And if it ends up feeling too tall,I can always revert back to the stock front sproket and keep the -1 rear sproket for a factory 93 ratio.

Herr Tod · « **Reply #13 on:** May 18, 2007, 09:40:53 AM »

I have an excel sheet for this, but it's in Dutch and read-only except for the variable fields.

Because of my RGV 250 rear wheel I went from a 46 rear sprocket to a 43 rear sprocket. 6th gear with the 46 sproket is now 5th gear with the 43 sprocket. I rather like it, pulls into the rev limiter pretty quick up to 4th gear, which is 193 km/h. In theory it could reach 242 km/h in 6th gear

Bartjan · « **Reply #14 on:** May 18, 2007, 11:31:41 AM »

you can remove the read-only feature and make it english.
or send it to me, i'll do it

i guess your theory doesnt take the air-resistance into account? you mean if you had enough power to use the full extend of the 6th gear you could reach 242km/h