What grade is too steep?

1600/3/5280~.1  10% is steep.  30% is basically a wall not a hill.  Good luck.  I ride up 13-15% with a 30x25 granny gear.   You could basically walk up the hill at the same pace.

TW

Ummm....Tom's math is right...it's a 10% average grade, which is doable over 3 miles, in an 39-23, 39-27 will make it easier.  I've ridden a hill that averages 14% for 2 1/2 miles, with some spots 21 or 22%, and that's clearly the limit for most normal riders, myself included.  If you're not a billy goat, at about 21-22% you 1) start walking, 2) fall over, 3) weave.   

I'd be VERY surprised if there were spots in the road that were 30%.   If you can make it up the hill, fine....but coming down, it's not safe for cars, trucks, or road bikes.  I'm pretty aggressive on the bike, and I wouldn't touch that one.  One little pebble, one sneeze, one crack in the pavement and *poof*, you're over the top, and you're going to slide a LOOOONG way.  No, thanks.

If there are spots of 30% grade, and you really want to ride it, pull out the MTB.  It's safer.

Funny you posted this on March 25, which this year was the official date of the Fargo Street Hill Climb in LA.  Check out last year's pix at

What road is this?

There are some very steep climbs in VA. I know of a couple that go up to 16%, on gravel noless.

What sort of gearing do you have?

Rise over the run. It's calculated above, rise is 1600 feet, run is 3 miles at 5280 feet per mile=15,840 feet.

%grade = 1600 ÷ 15840 = 10.1%

I've done the Mt. Washington hill climb in NH which is just short of a vertical mile in elevation gain over a distance of 7.6 miles.  And to top it off, about 30% of the road is hard packed gravel with the rest being paved.

If you're not a major cyclist, ANY ride rated moderate or above.  (Finally figured this out after downloading some various routes from some different cycling clubs - going on them and wondering if I was going to die.)

Cyclists would rate Mt. Everest as a "somewhat challenging" climb.