Jump to content
Sign in to follow this  

Sustained Cruising RPM

Recommended Posts

Everybody talks about if the DRZ400 will cruise at _ _ speed on the highway. I believe that speed is somewhat dependent upon your gearing. What I am curious about is what is a safe RPM that the DRZ400 can sustain for any period of time or miles, say 1 to 3 hours at a time. I feel comfortable, except for my a$$, riding all day at 5,600 to 5,900 RPM's. What are the thoughts about this?

Share this post


Link to post
Share on other sites

seems like an emotional argument, which is a bit of a fallacy.

If you want to discuss what makes you FEEL safe, that is an argument you can only have with yourself

If you want to talk about what actually damages DRZ engines, cruising on the freeway at realistic RPM's ain't a problem. I've yet to see anyone comment on this issue that said "yah, I used to cruise at X RPM but had repetitive failures (or any failure that could realistically pinned on it)

high RPM cruising on the freeway is relatively easy on the engine compared to aggressive dirt riding. I wouldn't worry about it even if you were turning 8 or 9K rpm's

Share this post


Link to post
Share on other sites

On my last oil sample (I have 3200 on the bike), I rode 1000+ miles on Mobil-1 10/40 motorcycle oil. It sheared down to a 10/30, which is much better than the dino oil I ran for 500 miles prior to that (sheared to 20wt in 500 mi!).

All the wear metals were fine, and there was no fuel in the oil. I literally beat the crap out of my bike, in my opinion, over that 1k miles. Probably 500-600 miles was highway riding at 70-80 mph, and the rest was hammering it on twisty two-lanes in the mountains. I showed the bike no mercy.

I haven't had any issues yet, but I re-geared to 15-40 for highway. I run 14-47 off-road.

My buddy, a service manager at a Suzuki dealer, has had to warranty two motors on SM's that were used for commuting. These guys both were doing high-speed commutes without gearing up. The bottom bearing on the con-rod was the point of failure on both bikes. He said he wouldn't warranty any more motors like these from customers. They must have been running near the rev limiter for long periods...

Share this post


Link to post
Share on other sites

RPM is not the issue. Everybody talks RPM because it is easy to measure, see and feel. But why care about RPM? UncleBob has it right. The real measure is piston speed in feet per minute which is dependent on stroke. You are not even close. Run it at the RPM that is confortable for you, the motor don't care. In June I took a trip with 3 other guys all on small bilkes, 2 Hodaka 90's. a 175 Bultaco and a 160 Honda. The Hodaks ran for 4 days, 700 miles at full throttle. Didn't phase them a bit. Your DRZ is a lot tougher than a Hodaka.

Share this post


Link to post
Share on other sites
On my last oil sample (I have 3200 on the bike), I rode 1000+ miles on Mobil-1 10/40 motorcycle oil. It sheared down to a 10/30, which is much better than the dino oil I ran for 500 miles prior to that (sheared to 20wt in 500 mi!).

All the wear metals were fine, and there was no fuel in the oil. I literally beat the crap out of my bike, in my opinion, over that 1k miles. Probably 500-600 miles was highway riding at 70-80 mph, and the rest was hammering it on twisty two-lanes in the mountains. I showed the bike no mercy.

I haven't had any issues yet, but I re-geared to 15-40 for highway. I run 14-47 off-road.

My buddy, a service manager at a Suzuki dealer, has had to warranty two motors on SM's that were used for commuting. These guys both were doing high-speed commutes without gearing up. The bottom bearing on the con-rod was the point of failure on both bikes. He said he wouldn't warranty any more motors like these from customers. They must have been running near the rev limiter for long periods...

Hi loop, 👍

I don't run my bike hard, but I run it a lot (18,000+ miles in 2 years) and a good portion is freeway riding at 65-75mph indicated...

...whichis an actual 60 to 70mph @ 5,400 to 6,400rpm with 15/39 gears...

Start going over 70, and you really pay for it in reduced gas mileage.

My oil test was similar to yours albeit over a much longer run cycle. 1,700 miles on Rotella 5/40 synthetic. Completely normal wear with no issues, good numbers for so many miles, and the oil also sheared down to 30wt with no gas in it. Likely the transmission is doing that.

Take Care,

Greg

Share this post


Link to post
Share on other sites

I'm not sure about the motor, but my berries really start to buzz after about 45 minutes of sustained high RPM's... so that about my limit.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the input. It seems that I am concerned over nothing & I can kick it up a notch or two. To clarify when I said "feel safe" I was referring to motor damage. I guess I feel "safest" off road when you don't have to worry about a car or truck turing in front of you because they don't see you.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...