Granny gears for 20% gradients?
 

Hi guys,

I'm from the New England area and we have some pretty steep hills and mountains. Some are above 20% in spots and with stretches averaging 10% over miles, I must admit, they are kicking me in the rear. My lowest gear is 34-27, I was thinking about going granny gear style 34-32 for the extra steep long climbs by replacing my shimano 105 12-27 10spd cassette for an ultegra 11-32 11spd to combat my weakest area.

I'm a 5'10 194lbs rider (down from 215lbs and still losing weight). I've been doing hill interval exercises as well to try to over come my weakness. Is it worth it to change my cassette to help get myself up these hills and mountains?

Chains & cassettes wear out and need to be replaced, so getting the gearing you need that way is pretty cheap. Although you may need a longer cage rear derailleur too ... not sure. Continuing to lose weight will help too. keep it up.

It depends how impatient you are. If you can wait until the weight comes off you'll probably be OK with what you've got. If you're just using the hills for training and your knees aren't hurting then changing might not make you any faster.

Whatever gearing you end up with and however much weight you lose 20% hills are still going to hurt :)

If 34/27 aint gettin' it, then yeah, a larger rear cog would be logical. However, remember that going from 10spd to 11spd requires new shifter and derailleur, too, noting, as Homebrew mentioned, you'll want to pay attention to derailleur max tooth capacity.

I missed the part about going to 11 speed. That adds a bit of expense. No wider range 10 speed cassette ??

Oh I didn't know it would need a new derailleur, I an probably find a wider range 10spd, thanks for the heads up!

Shimano XT M771 11-32 10spd, I'm not sure if this would work with my current 105 derailleur-- Is it more geared towards mountain bikes?

You can probably get a 12-30 cassette to work with your existing RD.

Thanks for the tip, found a relatively cheap Shimano Ultegra 10spd 12-30 cassette. This will probably get the job done. : )!

A 9s Shimano MTB rear derailleur will work with your 10s 105 shifters. The MTB derailleur will handle cogs up to 36t. I have this setup (34/50, 11-36) on my commuter, and it works really well.

They don't go on for long...but I have grades that shoot up over 20% and I ride a compact crank (52/36) with a 11-28 rear. 36/28 is too fast for out of saddle so if I grind on my feet, I won't run that combo. I tried a 12-30 and found I didn't like the 36/30 for anything...too much spin.

I would imagine at this point there is a risk of falling over unless you have a nice long wheelbase.

Nah...not really...we have a few around here that are nasty...here's one of the more short/nasty ones:

Strava Segment | Kerfoot Hill

Average is 16% but it has some short sections where the grade spikes to 20+ or 25+. On this one...in 36/28 I am fully out of saddle chugging up slowly and it is everything I can do to keep moving. My mpg up it is a whopping 6.4 LOL...I have to say, the first time I took it, I was afraid of stalling out. Approaching it, it looks like a tarmac wall...

If you are just using it part time, there's a Tiagra 4600 with the same (12-13-14-15-17-19-21-24-27-30) cogs for much less, too. The Tiagra came standard on my 2013 Madone 3.1 with a 105 rear derailleur, it works just fine.

It's not that slow of a gear... You have much lower gearing available on most mountain bikes. I don't get much time at 16%+ around here, but it is nice to have that 34-30 sometimes. I'm not weak, but not quite strong.

well that's my point. A MTB typically has much longer wheel base than a crit bike.

There's plenty of precedent out there for people riding road/touring bikes with a less-than-1:1 gear ratio.

I've bottomed out a couple of times lately on my 34-27 on some local walls, and seriously thinking of borrowing my wife's 12-30 back wheel for my next assault on any of them.

Well, you could detour up Fahey Hollow Road...:innocent:

Strava climbs are sometimes very inaccurate.
Just because Strava says it's 24% for 4 feet, it might not actually be that steep in that short section. Strava seems to use the GPS recording from whoever added the climb. Most Strava segments seem very accurate overall, but I've seen a few climbs that are way wrong.

Here's one Strava climb, right next to downtown Cincinnati Smale Park. The real elevation gain is probably 25 or 30 feet, not 346 feet! Based on the wrong elevations, it reports that the leader on this segment climbed at a rate of 20000 meters per hour, 10 times as fast as the fastest Tour de France climbers.

I've seen segments near the Ohio River, which has it's water level at an elevation of about 475 feet, reporting their starting elevation of 200 feet.
~~~~

I climb 16-19% grades in my 34-29, standing and going as slow as 2.9 or 3.0 mph. That's about one pedal stroke a second, 30 rpm. I have to pay attention to balance at those slow speeds. Much over 20%, and I can only do it for a short distance, since I'm having to push hard and lever on the bars to keep the pedals turning over.

I think the 12-27 is being replaced by 11-28 so you'll gain an advantage on both ends.

At 194, absolutely. You're pulling a lot of weight and anything that can help you keep cadence on those climbs is a plus. Once you lose rhythm at 200lbs on a steep climb it is very difficult and the quality of the workout goes down.

It really doesn't matter what anyone says though. If you are doing these hills regularly and you clearly need more gears every time, get the 30 or 32.

Is this the 41? Rule #5 . Then #10 .

You need a 9 speed Shimano MTB derailleur and the 10 speed SRAM PG1070 11-32 cassette and a new chain.
Or try the 11-36 mega cassette from SRAM.

My touring bike has a triple 52/42/30 and 11-34 in the back. I do use the 30F/34R combination when I am tired or the bike is loaded.
It probably does not help that even unloaded, the bike weighs 28 lbs, and is usually around 40 lbs when I am riding.

It feels great to ride my Roubaix after riding the touring bike.

That's what I did for the steep hills in our area, although I don't think any of them are 20%. Yikes. Anyway, a 53/39 in front and a 12/30 in back work fine.

The 30-tooth rear cog makes that long, 4-mile ascent a nice place to listen to some good music.

I like to climb for my workouts (makes me keep my rate up no coasting) my 10 mile quickly from the house has a 2.8 mile part with an 1100 ft elevation gain the last .8 is on gravel.


I’m a novice on this stuff I just ride but…

Have you thought about a triple chain ring I push a not so manly
48-44-28 14-28 on my 26+ lb steel road bike and a 46-36-26 14-30 on my 30 lb MTN bike with drops I can climb this hill faster on the 26 > 30 set up than the 28 > 28 even with the extra 4 lb of bike and 26inch wheels.


You could get a Shimano-105 Triple Chainset 50-39-30 not sure it would work with your kit.


Staying in the saddle and spinning faster makes my knees much happier’ love my 26 > 14 great granny gear

Looking forward to hearing why triples have fallen from favor.

The manufacturers have decided we don't need triples and no doubt saved some money along the way.

I like triples.

If I had to ride a 20% grade like the OP does on a regular basis, I'd be putting a triple on my road bike.

This is what I run on my bike. 48/36/26 with a 12/27 cassette. I'm not riding for pure exercise so burning all my matches getting to the top of a climb isn't something I'm interested in. What's fun is riding with groups on hilly routes. This one guy made fun of me for showing up on a "touring" bike, but I passed everyone on the climb and when I got to the top, I was fresh and dropped the gear down and took off. Everyone else with their doubles had to stop and rest.

Mind you this isn't exactly an A group of riders, but don't make fun of someone that you can't outride.

I like the setup and I rarely use the small ring, but I love having it there when I need it. I'm the same size as the OP so I feel his pain pulling my weight up hills.