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Main Area => General GS500 Discussion => Topic started by: jen_ on May 21, 2006, 09:57:18 PM

Title: pwned at 8,000 feet
Post by: jen_ on May 21, 2006, 09:57:18 PM
Where I live and ride is at about 400 feet above sea level.  Today, I rode up to Big Bear and over the highest road in Southern California, over Onyx Pass.  Just before the summit, there is at long straight at about 8,000 ft altitude.  Chasing abter a bunch of 4-cylinder bikes, I opened up the GS.  Throttle fully open, turning 6,500 RPMs, I topped out at 85 mph.  Ug.  Being at the bottom of the powerband, I didn't think upshifting would help, downshifting would move the RPMS up to 8 or 9k is my guess, around the top of the powerband.  I had to brake and downshift for a curve before I had too long to think about it.  Is this all altitude's effect on my carbs?  As I got back down the mountain, I could hit 100+mph again with no problem.

...being dusted by bikes that are 2-up is a drag...

(http://idisk.mac.com/jenstrona/Public/Pictures/sbn_bigbear_may06/0DSCN5335.JPG)
Title: Re: pwned at 8,000 feet
Post by: aplitz on May 21, 2006, 10:23:16 PM
We had a discussion about this a couple years ago.  I live about 20 minutes from the shores of Lake Tahoe, and many of our passes are in the 8,000 foot + range.  I was discussing how on group rides I was constatnly getting my ass handed to me.  The bike just ran out of poop up in the mountains. 

Many of the GSpundits here were spouting all their trite 'its the rider not the bike' BS.  Just not realizing what elevation does to such an underpowered bike.  Their twisties are just over sea level, and go up and down, but never see enough change to neuter a small bike like the GS.  Corner speed ain't gonna be your saving grace if you can't even build momentum.
Title: Re: pwned at 8,000 feet
Post by: john on May 21, 2006, 10:55:12 PM
Even at 5000 feet I otice the difference on the 1000.  Altitude kills power.  Watch the superbike race in Pikes Peak on Speed and they'll explain wht the bikes make so much less power up in the thin air.
Title: Re: pwned at 8,000 feet
Post by: LeChatNoir on May 21, 2006, 10:57:37 PM
That ride up highway 38 is a nice one. I rode from Redlands up to my folks's house in Big Bear about a month after I bought my '05 500F. It had plenty of power for an absolute beginner, but then again, I wasn't trying to keep up with anyone.
Title: Re: pwned at 8,000 feet
Post by: Queso on May 21, 2006, 11:06:31 PM
Racing anything while riding 487cc's?  :cookoo:

I know I'm still a complete noob, but I have no desire to race anyone. Never did in cars either. If it was fast enough for me, it was fast enough. For the time being, the GS is plenty fast enough  :icon_mrgreen: Isn't street racing a "squid" thing anyway? I guess driving such a small, slow car for a so long has rid me of any competitive instinct involving motors. The GS is SOOOOooo much faster than my car was. I'm happy  :icon_mrgreen:
Title: Re: pwned at 8,000 feet
Post by: ajgs500 on May 21, 2006, 11:07:39 PM
I dont think she was racing as much as she was just trying to keep up.  :dunno_white: :dunno_white:
Title: Re: pwned at 8,000 feet
Post by: pantablo on May 21, 2006, 11:51:50 PM
I've ridden ACH back when it went all the way through to  Wrightwood and I think that tops 7300ft (?). I never noticed a drop in power on the gs but I was usually just riding a consistent 65-70 mph over the whole thing...
Title: Re: pwned at 8,000 feet
Post by: NWDave on May 22, 2006, 12:14:36 AM
Try living at 4400 feet, everytime I get into medford it starts to run like crap cause I've got it tuned for this alt.
Title: Re: pwned at 8,000 feet
Post by: Egaeus on May 22, 2006, 06:53:49 AM
What I can't figure out is how you were doing 85 at 6500 RPM.  Do you have a 17T sprocket on it or something?  According to my speedo and tach, you should be doing closer to 77.  Of course, that could just be natural variation between speedos and tachs.
Title: Re: pwned at 8,000 feet
Post by: rangerbrown on May 22, 2006, 01:37:49 PM
i am at 90 at 7000 i think. i took the gs off the road for now. tearing it down  for some mods, but even at 5k feet i could tell there was a big dif in power, and 5 and 6 th gear all but becam useless
Title: Re: pwned at 8,000 feet
Post by: jen_ on May 23, 2006, 11:10:29 AM
Quote from: Egaeus on May 22, 2006, 06:53:49 AM
What I can't figure out is how you were doing 85 at 6500 RPM.  Do you have a 17T sprocket on it or something?  According to my speedo and tach, you should be doing closer to 77.  Of course, that could just be natural variation between speedos and tachs.

Hm, interesting.  I was under the impression that my bike is stock, but I did buy it used, with a new rear tire, so I guess it could have a funky sprocket.  I'll check when I get home.

And to Queso--  No, I wasn't racing.  Just doing some "spirited cruising". :thumb:
Title: Re: pwned at 8,000 feet
Post by: TragicImage on May 23, 2006, 11:23:13 AM
see, thats why you should just cruise WrightWood instead of Bear.


Bear is pooty.
Title: Re: pwned at 8,000 feet
Post by: Queso on May 23, 2006, 02:49:45 PM
Quote from: jen_ on May 23, 2006, 11:10:29 AM
And to Queso--  No, I wasn't racing.  Just doing some "spirited cruising". :thumb:

That's the best way to do it  :thumb:  :icon_mrgreen:
Title: Re: pwned at 8,000 feet
Post by: Emmajoe on May 23, 2006, 03:52:54 PM
a good rule of thumb is; you loose 5hp per thousand feet. I know it's not quite right but it work for cars, so I'm sure bike are pretty simaler
Title: Re: pwned at 8,000 feet
Post by: GeeP on May 23, 2006, 07:13:33 PM
The chart on page 2 may be of interest to you:

http://www.kellyaerospace.com/articles/Turbocharging.pdf
Title: Re: pwned at 8,000 feet
Post by: CirclesCenter on May 23, 2006, 11:17:35 PM
I live at 4,800 and have hit 120, still pulling. (Tucked in like crazy.) Trying to follow my buddies 87 ZL1000. Just a hint for ya, I lost.... horribly....
Title: Re: pwned at 8,000 feet
Post by: BaoQingTian on May 24, 2006, 02:51:35 PM
Quote from: aplitz on May 21, 2006, 10:23:16 PM
We had a discussion about this a couple years ago.  I live about 20 minutes from the shores of Lake Tahoe, and many of our passes are in the 8,000 foot + range.  I was discussing how on group rides I was constatnly getting my ass handed to me.  The bike just ran out of poop up in the mountains. 

Many of the GSpundits here were spouting all their trite 'its the rider not the bike' BS.  Just not realizing what elevation does to such an underpowered bike.  Their twisties are just over sea level, and go up and down, but never see enough change to neuter a small bike like the GS.  Corner speed ain't gonna be your saving grace if you can't even build momentum.

Hey I live in Carson too.  I went on a ride last friday for lunch up in Tahoe with a bunch of guys from work.  My little bike was working hard, but it kept up.  It's definately the bike that's underpowered.  Plus, it doesn't help that I'm 6'3, 200 lbs.  I end up going up Kingsbury in 4th the whole way, with RPMs about 7-8K
Title: Re: pwned at 8,000 feet
Post by: CirclesCenter on May 24, 2006, 02:54:19 PM
Carson? I live in Reno, we should ride after I get my bike sorted!!!!

O0 O0 8) 8)

I'll admit I'm a bit of a hell raiser, but I'll keep it in check while with you guys.