Mountain Biking - "Out rev-ing"

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nathank8792
05-30-07, 12:52 PM
I know that this sounds stupid, but the only way I can describe this feeling is out rev-ing. When one is going downhill, eventually you get to a point where the wheel is spinning faster than you can pedal, so your legs don't really do anything. I guess this also happens when I'm in a small gear, like 1-3 and if I pedal fast, I eventually can't pedal anymore, because I'm not even pushing the bike. What causes this, and is this the reason why road bikes have large cogs, so that you can pedal faster without "out rev-ing"
cyccommute
05-30-07, 01:00 PM
I know that this sounds stupid, but the only way I can describe this feeling is out rev-ing. When one is going downhill, eventually you get to a point where the wheel is spinning faster than you can pedal, so your legs don't really do anything. I guess this also happens when I'm in a small gear, like 1-3 and if I pedal fast, I eventually can't pedal anymore, because I'm not even pushing the bike. What causes this, and is this the reason why road bikes have large cogs, so that you can pedal faster without "out rev-ing"
It happens because Trek has put stupidly low high gears on your bike. A 42/11 gear is pretty low. A much better one would be a 44/11. If you can change your chainrings, it's pretty easy to fix. However bikes like your 4300 sometimes don't come with changeable rings.
The other thing to do is to learn how to spin your legs faster. Or just enjoy the ride and coast;)
What causes this, and is this the reason why road bikes have large cogs, so that you can pedal faster without "out rev-ing"
Serious?
If you go faster than your legs can pedal...umm...that's what causes it.
Yes...road bikes have taller gear ratios because they maintain a higher speed. (usually...unless I'm riding one)
Back in the old days...DH'ers used 54tooth chainrings because downhill racing was faaaaaaaaaaast. These days, it's more technical and less fast.
The term is "spinning out" - -as in spinning out of the available gear range. And, yes, that is the reason for higher gear ranges on road bikes.
There have been two downhill courses where I've actually spun out of a 44T top gear: Schweitzer in Idaho off the top; and Sun Peaks about mid-course where it plummets off an open ski run. Few other off-road situations have approached those speeds for me.
diff_lock2
05-30-07, 01:41 PM
Try riding fixed... you will NEVER have that "problem" again.
The term is "spinning out" - -as in spinning out of the available gear range. And, yes, that is the reason for higher gear ranges on road bikes.
There have been two downhill courses where I've actually spun out of a 44T top gear: Schweitzer in Idaho off the top; and Sun Peaks about mid-course where it plummets off an open ski run. Few other off-road situations have approached those speeds for me.
You will have that problem more often now that you have the new rig...go speed racer!:D
nathank8792
05-30-07, 05:44 PM
Ok, I know i'm stupid. But I'm pretty sure I get this now. But my the Cannondale that my friend has never seems to "out spin", even in while in very low gears. His crankset is even smaller than mine, I think its 22/32/44. but even in the 22 it doesn't out spin
santiago
05-30-07, 06:23 PM
Ok, I know i'm stupid. But I'm pretty sure I get this now. But my the Cannondale that my friend has never seems to "out spin", even in while in very low gears. His crankset is even smaller than mine, I think its 22/32/44. but even in the 22 it doesn't out spin
You use the largest chainring at fast speeds.
BugsInMyTeeth
05-30-07, 06:36 PM
Ok, I know i'm stupid. But I'm pretty sure I get this now. But my the Cannondale that my friend has never seems to "out spin", even in while in very low gears. His crankset is even smaller than mine, I think its 22/32/44. but even in the 22 it doesn't out spin
No offence, but that doesn't make any sense.
You can 'out-spin' any bike, unless your riding is eternally up hill. Which would really, really suck.
This is sort of an odd thread.:rolleyes:
aero540t
05-30-07, 07:33 PM
I've always been curious, what kind of speeds are you guys getting when you're "spinning out" on your last gear downhill?? I only have a MTB right now but ride to work every now and then and there's one spot down hill where I'm at this point...
With a big ring... 45'ish mph. (my old Super-V 22/32/44 with 11-32 8spd down a local grassy hill)
My AM rig has a bash ring so it's more like 30-35'ish. (that's an estimate b/c I don't have a 'puter on it)
I went 55mph on a downhill mountain gravel road with a 48t big ring (trekking bike)on a my dad's Huffy. There was no way I could help by pedaling.
aero540t
05-30-07, 08:13 PM
With a big ring... 45'ish mph. (my old Super-V 22/32/44 with 11-32 8spd down a local grassy hill)
My AM rig has a bash ring so it's more like 30-35'ish. (that's an estimate b/c I don't have a 'puter on it)
I went 55mph on a downhill mountain gravel road with a 48t big ring (trekking bike)on a my dad's Huffy. There was no way I could help by pedaling.
....:eek:
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