Hello to all! Just bought a '90 CBR100F a few months back and love the bike. I have a question to all you seasoned CBR riders which I'm not: I get a buzzing feeling through my handlebars when I'm going fast, say anything above 70mph or so. Below 4000rpm, the bike is silky smooth but above 5000 or so, my arms get numb from this buzzing. It is not a vibration as I can let go of the handlebars at 100mph and there's absolutely no shaking. This is more of a buzzing which is killing my hands if I ride for more than 1 hour. Is this normal for an inline 4? I had an old FJ1200 and don't remember getting this at all, my twin honda 600 does not do it either. Would heavier bar ends cure this? Thanks to all of your inputs on this. Cheers!

 

I get the same thing after a long ride, somewhat like mowing the lawn with a push mower! I've always thought it was normal though.

 

Its pretty common to have a little buzz at certain rpms. It might just be that your cruising rpm is in the "buzzing" zone. A lot times, it will be around 5-6 thousand rpms. If you go over that, it usually disapears again. it will usually come back again further up the rpms, and again disappear.

Its possible somebody put a different set of sprockets on to get more power down, and in the process, put your cruising rpm in a bad spot. Check to see if you have stock gearing or not.

You could buy a set of aftermarket bar ends. Sometimes that will cure it.

Or, if your not to concerned about low end power. You could install a set of sprockets that moves your rpms lower at your cruising speed. Being that its a liter bike, you can probably drop 2 teeth on the rear sprocket and drop your rpms down some and really wont have any ill effects from it. Unless your a drag race demon and need all that the bike has. But if your using for cruising more than anything else, a sprocket change would be a great place to start looking into.

 

check to make sure your "clip ons" have the lead weights inside. this dramaticaly reduces vibrations.
i have a '87 and my hands dont go numb.

 

check your valves and sync your carbs.

 

Heavier bar ends...... thicker grips......

 

When i had my 91 CBR1000F, I could ride for hours with no buzzing. Make sure the lead weights are in, as said above, and also make sure your barends are tight. Also make sure that your motor is running smoothly.

 

Thanks for everyone's input on my handlebar buzzing issue. I will check the bar ends to make sure the weights are inside, and may also check for a smaller rear sprocket as you've recommended to take my cruising rpm's out of the 5k range since the bike is silky smooth at around 4500. I think my speed is around 80-85mph at 5200 right now, 4500rpm would be ideal at that speed because anything slower and I feel I'm not even moving. FYI; The lawn mower comment was dead on!