Question RPM/Gear selection

[OldBoots]

This may be a naive question but I'm asking anyway. Yesterday I was riding back highways in North central Oklahoma. The wind was very strong and the roads were "hilly" for the Oklahoma definition of hill. If you are bucking a headwind is it OK to just leave the bike in 5th gear for 65 mph? In 6th gear I kept finding my speed dropping and 6th seemed (at least to me) to be struggling to pull back up to speed.

Thanks!

 

[itsmenc700]

While I'm sure others will say dont, I say its ok to leave it in 5th.

 

[670cc]

If the wind and/or hills load the engine too much for the engine to easily sustain your speed in 6th gear, you should definitely drop to 5th, or even 4th, if necessary. I run the highest gear possible that allows the engine to smoothly pull the load, without unnecessarily high RPM.

 

[the Ferret]

Technically, you can run it in ANY gear, so long as you dont exceed the upper and lower limits of the engine. The lower limit being bucking and chugging often referred to as lugging, and the upper limit being in the red zone. Any gear that will pull cleanly between those two boundaries is ok.

 

[dduelin]

I’m going with ‘operate the engine at the correct rpm for what you are asking it to do.” In the situation described I’m probably in 5th gear. If I was anticipating a need for quick acceleration I might be in 4th.

 

[wheel_of_steel]

Yes, it's totally fine, the engine has a wide range of acceptable load/RPM combinations. You will burn a little more fuel in lower gears, that's all.

The automatic bikes have it in 6th gear by about 40 mph, so 2000 RPM upwards must be an acceptable cruising speed for these engines.

It's a long-ish stroke engine with a heavy-ish valve train, that means more side loading on the cylinder bores and more start-stop intertia for the valve seats and camshaft to deal with. So if you spent years cruising around at 4000-5000 rpm, the bores would oval out and the valves would recess faster than on the bike that spent most of its life at 2000-3000 rpm.

I think that's a long long time away so it's not worth sweating the difference to be honest.

 

[OldBoots]

This is my first road bike and in comparison to how I drove cars with a manual transmission, this motorcycle has a ton of overlap in usable RPM/Gearing. And I did not anticipate the power of the wind to just be able to knock MPH down like that. I also did dirt and gravel roads for the first time on this bike this weekend. That was an interesting experience too.

 

[melnc]

If the wind and/or hills load the engine too much for the engine to easily sustain your speed in 6th gear, you should definitely drop to 5th, or even 4th, if necessary. I run the highest gear possible that allows the engine to smoothly pull the load, without unnecessarily high RPM.

what is considered high rpms at highway speeds? new to 700x ownership

 

[davidc83]

what is considered high rpms at highway speeds? new to 700x ownership

When you hit the rev limiter. 75mph in 6th gear, the bike is at 4000 rpms, 2000+ rpms below the rev limiter. I don't think you can hit the rev limiter in 6th, don't know about 5th gear- never tried. I maxed the speed in 6th gear once (100+ mph) and was below 6000 rpms.

 

[670cc]

what is considered high rpms at highway speeds? new to 700x ownership

I wrote “unnecessarily high RPM”. If a lower RPM can sustain the speed you’re going, then a higher RPM is probably not necessary. There is no specific RPM number, because speed, wind, hills, drag from windshield or side cases, etc. are variables.