Perhaps a silly question about Highway or Interstate cruising speed

[qurtrn10]

The Buell is my first bike, which I bought earlier this year. All of my riding has been in town.
I'm now at the point where I feel comfortable taking it on a small day trip (an hour or two away from home).
With a stock '03 xb9, how fast should I go on the highway? If I hold 65-70 for a length of time, do I have to worry about holding 3k, 3.5k, or 4k and over heating the bike? What do most do for long drives?

[MikeyLawless]

Sometimes i do 90 on my half hour to an hour ride to school and never have any problems. Especually this cooler time of year.

[fishxb12]

Never a silly question if it has to do with blowing up your bike,lol. You are fine. They are air cooled engines. As long you have the proper oil level, should not have any issues. People take these bikes on long road trips all the time.

[user_deleted]

think of it in these terms which are automotive terms but apply to any motor:
an automobile with any configuration motor that has a red-line of 6000rpm can sit there and cruise at 3000rpm which is 1/2 its red-line for 5 years. an exaggeration but you get the point. same applies to your XB9. at 70mph it is spinning roughly 1/2 its factory redline.
you can also get technical and think of your motor speed in terms of piston distance calculated in feet per mile. take your XB cylinder bore and multiply it times your cruising rpm then divide by 6. you'll find it's a very low number which correlates to longevity.

[qurtrn10]

Thanks all. I'm just used to cruising around 2k on the bike and in my cars, so holding a higher rpm is just out of my norm. I'm going to take it out today, and not sure where I'll end up.

Thanks again!

[mrlogix]

:D

lunatic: I am continually impressed with your knowledge. The admins will not let me give you another rep point (said I have to spread it around). Anyway, it's nice to see that this forum has as many technically qualified members as we do. A lot of forums I wouldn't wish on my worst enemy.....

[fishxb12]

I got a rep point for lunatic . Very cool info!

[user_deleted]

lunatic: I am continually impressed with your knowledge

thanks very much for the kind words john. i really appreciate it my friend.

I got a rep point for lunatic

fish: what i posted is a standard formula for computing how hard your motor is working, how long it is likely to survive, and how much internal stress is being placed upon the piston/cylinder/rings/wrist-pin/con rod/con rod big end bearing assemblies. a simple # to generate is a 327 chevrolet V-8.....or the 302 cube Z/28 of 67-68-69 vintage. both motors had a 4 inch bore. 4 inches X 4000rpm divided by 6 = 2666 feet per mile in piston travelled distance. a fair amount of cruising rpm for a vintage V-8 but not all that much actual piston speed. to put it in perspective a 358 cube nascar motor at talladega held on the mat all afternoon will generate approx. 6300 feet per mile piston speed and live for 500 miles and change but that's about it. a cummins turbo diesel dodge loafing down the interstate @ 2100 rpm only generates approx. 1750 feet per mile. and we all know how long those motors live.

[jetlee]

Despite his vast knowledge (i do mean that, I even repped you for the formula), I know lunatic hates my corrections...but...shouldn't it be stroke instead of bore, since the stroke is the length the piston moves where the bore is merely the diameter?

On my 07 9R, I ride for about 45 minutes each way to/from work around 4krpm. Haven't had any serious issues yet.

Use a good oil, change on time and you should be fine.

[go cytocis]

No risk of damage at sustained freeway speeds.

I'm just used to cruising around 2k on the bike and in my cars, so holding a higher rpm is just out of my norm

If anything, you're at greater risk of engine damage while you're lugging around town at 2000 rpm. At low revs the oil's not up to full pressure or circulating fast enough to optimally cool the motor.

Don't be afraid to give it some revs! :D