Gearing Question for steep climbing
 

I'm riding in a race w/ 12% average grade later this summer and I'm trying to dial in my gearing setup.

I'm currently running the following:

Dura-Ace components on a 9-speed
12-27 Cassette
53/39 Chainrings

It's my understanding through lots of discussion with folks that I'll need closer to a 1:1 ratio in my lowest gear. Obviously, the 39/27 ratio isn't going to cut it. I'm very aware that I could go to a compact crankset but I've only found that this gets me to a 50/34 chainring or a 34/27 ratio.

Since this is a once-a-year race, I don't want to drop lots of cash on a fancy setup that gets me to this ratio.

I've heard some creative thoughts around putting a mountain bike cassette on...not sure how to identify MB cassettes that fit a road hub. I've heard ideas about finding a creative way to put a small chainring on my current crankset. But with that bolt pattern it seems I would have to find a different crankset.

How do I get myself to a 34/32 (closest to ideal) or 34/29 (not-as-ideal) ratio without throwing on a triple?

I believe standard road derailers accomodate 27 tooth cog at most. You would need a long cage derailer to go higher.

With a 12% AVERAGE grade you are looking at a killer climb and most likely need a triple or put a mountain bike cassette and derailer on so you could at least get 39/34. Any shimano 9 speed mountain bike cassette will fit a 9 speed shimano compatible road hub/shifter. The spacing is identical, so it's just a matter of swapping cassettes. You could try it w/ a standard derailer to see how it shifts but I'm almost positive it's not recomended.

I did torture 10,000 with a 39/34 and was managable. It was 13000 feet climbing over 100 miles.

Gearing choices, in decreasing size order:

1. Compact crankset
2. MTB cassette (12-34) + MTB derailleur
3. Compact crankset + MTB cassette + MTB derailleur

12% average is pretty tough. If the course is fairly short, you may be able to get away with a 34/27 or a 39/34 ratio. But if it's long, I suggest the 34/34.

At 60 rpm up a 12% grade, here's the climbing rate:

34/27: 3738 ft/hr
39/34: 3421
34/34: 2978

Determine the climbing rate you think you can sustain, and select your gearing accordingly.

Would this race by any chance be the Mt. Washington Hill Climb?

I've gotten an Ultegra long-cage rear derailleur to shift into a 32-tooth MTB cassette. It isn't recommended, and it's not exactly quiet. You have to screw in the B-limit screw all the way to get the pulleys to clear, but it does work. I did it for the Mt. Washington Hill Climb; with a triple up front, I had a 30x32 low that I saved for the obscenely steep sections (i.e., 18%+).

One possibility is to scour E-Bay for an old MTB triple crankset / bottom-bracket combo. Strip the outer two chainrings off -- you sure won't be needing them on a 12% average grade. Keep your current front derailleur -- it can help keep the chain on. That would get you into the vicinity of a 24x27 low. You'll get smoother rear shifting, and you'll have some bailout gears should the weather be attrocious (assuming that this is Mt. Washington, it probably will be).

http://www.jensonusa.com/store/produ...erailleur.aspx

You have lots of choices when it comes to gearing. You can go to 34t, or get better ratios with 32 or 30t. You pays your money and takes yer chances....
http://sheldonbrown.com/harris/k7.html#9

I have a 39x26. I think its the biggest rear combo you can have on campy and still use a short cage derailer. Sometimes I wish I could go bigger...or is that smaller? Whatever.

+1 on the mtb crankset. You can get down to a 22 ring with those. Sheldon Brown also claims that you can mount a special 22 or 24 ring on a normal road triple, but I've never seen it done.

Here's a good website on major hill climbing (incl. Mt Washington) and gearing. Go to the climb central part. Short answer - I don't think 39x27 is gonna do it for you.

http://northeastcycling.com/

Just build up your legs. I have seen a racer go up a 35% grade with a 53/27. That was Fargo Street in LA and it was OK to do switchbacks.

But at Fargo, the time doesn't really matter, right? It probably was more a point of pride to be able to climb it in the big ring than it was a point of efficiency.

In a race, on the other hand, time/speed presumably does matter. I assume the racer could have been faster in a more appropriate gear.

Huh? How would you "mix and match" rear sprockets and chainrings? You can't mount a rear sprocket as a chainring unless you somehow rivet it into place. A compact crank (i.e., 110 BCD) is physically limited to a 33-tooth ring; you just can't mount anything smaller (well, there's probably somebody out there who makes some custom doo-hickey that gets around this limitation, but I doubt it's cheap).

That's why I was suggesting getting a cheap MTB crankset off E-Bay. The OP already needs a new crankset anyway as he currently has a standard double. If you're going to get a new crankset for extremely low gears, then you might as well get a triple. If this race is what I think it is, you're not going to be shifting the front -- ever.

you don't write how fit you are, what you weigh, how tall you are, how long the climb is, etc.

based on your equipment, I wouldn't have much of a problem racing with a 39/27 on a 12% grade for 3-4 kms. I wouldn't be winning, that's for sure :) , but I think i'd be able to manage.

If it's longer, say 10+ kms, then that would of course be something different.

We here in Japan are routinely on 9-10km climbs averaging 10-12% grades with no less than 39x27. I've only got 12x25 10sp and just not having the 27 to shift in to will routinely let me outpace my ride buddy that has the 27 in the back. Does it hurt more? Probably, but we both spin 80ish, and I get to the top first almost always.

I think the question asked best is dialing in fitness to do the climb. If you're concerned about time, then getting a lower gear won't make you go faster. It'll just let you go slower for longer time. *shrug*

go buy a new climbing bike :) with some lightweight wheels then you'll fly up the hill anyways.

Yes, this is Mt. Washington. I appreciate your experienced opinion.

My crank (arm length) is 175mm. I assume that is what you're asking.

I'm in Colorado (Ft. Collins area), so training at high altitude, climbing with each ride, 3 times/week, >100 miles/week. This AM --> 30 miles, 3200 ft. of vertical, over 2 hrs., 8% average grade.

I weigh in at ~175lbs. and I'm 6'3".

The race climb is 7.6 miles (ie. Mt. Washington). :)

Good points. My thought is to make sure I have something to spin/recover in at times. As well to deal with the ~20% incline sections and 'wonderful' NE weather. :)

7.6 of 12% avg racing... let me see, let me see, let me see... i'd either get a compact w/12-27 myslef, or a motorcycle :)

Let me get this straight. You spin 80-ish cadence up a 12% grade in a 39/25 gear for up to 10km? Excuse me for being incredulous, but I say no way.

80 cadence in a 39/25 is 9.8 mph. Either you're Lance Armstrong hanging out in Japan, or your numbers are off. 9.8 mph up a 12% grade would require around 470 watts.

Nonsense. Spinning a lower gear will keep him from running out of legs before the finish. Climb for an hour at a 30 cadence, then repeat at the same speed at a 70 cadence. Which one was easier on the legs?

I second KevinF's suggestion. I spectated at Mt Washington last year and it was really interesting to see all of the different setups that were used - there are many of them. I knew a few people that rode it but they were not techies - they let their LBS or trainer setup the gearing. Getting close to 1:1 seems to be the goal. (I recall one of them had a 6/13 and ordered a custom crank which was quite expensive). Many had removed the larger chainrings - looked odd to see all these bikes with one tiny chainring! But there were standard triples as well (not to mention three unicycles!).

Good luck!

Okay, I'll ask: Why not throw on a triple?

Because it's a hillclimb. Therefore 1) weight matters, and 2) you don't need any high gears. Thus a compact would be a better option than a triple.

I would think a 1:1 would be way too slow a gear for a race. I used to spin easy gears up big climbs but then I found that pushing harder gears works better for me. If I try to go fast in say a 34x30 then I spin like hell and my heart rate goes up too fast. Now I push a 39 x 23 most everywhere except for big climbs where I will use the 27 and I just keep turning over the cranks at low cadence but with a managable heart rate. Also I don't mind standing once and a while in fact I like it to stretch out...

I think it's a matter of personal taste. I've got an uphill time trial coming up and I was tempted to set my fixed gear bike up with like a 40 x 28 or something like that.

Agreed!

I apologize for not spacing out my statements. I didn't mean to imply I'm any more capable than any one else. :rolleyes:

As for the second point, who cares what is easier on the legs? If you're doing 12% grade for 7.6 miles, you're not concerned about "easier on the legs." You're concerned about getting to the top, completely used up. This isnt the middle of a race, or a portion of the race, it is the race, right?

IMO, this compact crank thing is just overrated. Just one more way to downgrade. I still say keep the 12x27 and 53x39. Sounds like you're doing plenty of hill climbing. I would definitely not change things out just for the sake of that ride. Stick to what you know. It'll give you greater confidence when you use it.