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kelownagirl
07-23-2006, 07:35 AM
I have found I can generally do hills much better on my road bike than my MTBike. Not surprising. However, when I get on really steep stuff, and drop down to my lowest gear, I find it's *harder* than it was on the MTBike. I assume that it's because the largest cog (?) on my rear cassette of the road bike has fewer teeth than the largest cog on my MTB.

My road bike has 30/26 from what I can gather on the other "gearing" question that Morsecode posted, with 700 (mm??) wheels / tires (?).

My MTB has a crank with 42-32-22 and I can't find the specs on the cassette other than it is Shimano Deore 8 Spd and I *think* it has 30 teeth on the largest cog. (So it would be 22/30???). That bike has 26" wheels.

So.... of I have all of this information straight...(haha), can I compare the two bikes as far as granny gears go?

Do I have an adequate granny gear on my road bike? I think it's probably good as far as the bike and the terrain go - it must just be my fitness level.

Should I just keep plugging away at the hills until I get stronger or should I consider getting a larger cog on the rear cassette, if that's even possible...

This is probably a mumble of info/questions. Hope some of it makes sense.

Thanks,
Barb

maillotpois
07-23-2006, 09:11 AM
Do you have adequate gearing on your road bike? What a loaded question!!!

I have a 32/29 as my "easiest" gear. Some people with touring triples have even easier gears. Some, like Road Raven, I believe, only use a double. It ALL depends on you, your terrain and how you want to ride. Sure your "granny gear" on your MTB is easier - your gear ratios are much easier to spin up steep stuff. That's how most MTBs are and, I believe that MTBs were the first bikes to use triples, and then road riders and manufacturers started seeing some of the benefits of these easier gears. (If this is wrong, SK will correct me!)

But the question is what works for YOU. And none of use can really answer that. Can you get up the hills you want to get up? Does it hurt your knees? Do you find yourself having to stop during hill climbing? Do you have to walk?

You are probably fine with the gears you have, but if you answer those questions yes, then you might want to think about a cassette with a larger cog in the rear. That's the easiest and quickest way to get yourself some easier gears.

DebW
07-23-2006, 10:03 AM
Here are some technical (numerical) details, but as MP said, it really depends on what works for you. There are at least 3 differences I can think of between your road bike and your MTB which will make it unlikely that you'd want the same gearing on them. (1) They have different wheel sizes, (2) the MTB is much heavier than the road bike, and (3) you ride in a somewhat different position. Here is the numerical stuff:

Gear ratio (inches) = (chainring teeth)/(cog teeth)*(wheel diameter)

Your road bike has 700c wheels (27.56 inch diameter). With your low gear of 30/26, your gear ratio becomes 31.8 inches.

Your MTB has 26 inch wheels. Assuming a low gear of 22/30, your gear ratio is 19. That is, for every revolution of the crank in your lowest respective gears, your MTB goes 19*pi (=60) inches and your road bike goes 31.8*pi (=99.9) inches. The MTB gear is much lower, but, the bike is heavier. When you say that you do hills better on your road bike, it's because the bike is lighter. But when you really need your very lowest gear, it's easier on the MTB because is has a much lower gear.

My small chainring is 42, my largest freewheel cog 24, so I have a minimum gear ratio of 48 (and I seldom use the 24 freewheel cog). I like hills and I go up faster than most people, but that's just the way I'm used to riding. I can do steep hills, but never face a hill longer than 1/2 mile. If I lived somewhere else, I might have to modify my technique and change my gearing. So don't get caught up in comparing your gearing or your hill climbing ability with others - just too many variables. If you have trouble climbing on your bike, you can either train more for hills or get lower gears. Training is cheaper, but your body is worth more than your bike, so don't blow our your knees because you're cheap or stubborn (that was a reminder to self).

mimitabby
07-23-2006, 11:27 AM
My MTB has a crank with 42-32-22 and I can't find the specs on the cassette other than it is Shimano Deore 8 Spd and I *think* it has 30 teeth on the largest cog. (So it would be 22/30???). That bike has 26" wheels.

This is probably a mumble of info/questions. Hope some of it makes sense.

Thanks,
Barb

you can count those little cogs you know. Use a piece of tape to mark your place. if you are not counting challenged it shouldn't be too difficult.

kelownagirl
07-23-2006, 12:20 PM
LOL, tape - what a good idea! I'm really not as dumb as I sound... :D

DebW
07-23-2006, 12:22 PM
you can count those little cogs you know. Use a piece of tape to mark your place. if you are not counting challenged it shouldn't be too difficult.

It's much easier to do with the wheel off the bike. I just leave my finger in one notch and count til I hit my finger again. As long as you don't mind one black finger. :D

kelownagirl
07-23-2006, 01:24 PM
Counted the MTBike cogs and there were 32... It was easy. Duh.... I find the mathematical part of this really interesting...

My knees don't hurt, at least not as long as the steepest part of the hill isn't too long. I *can* get up the hills without getting off the bike but it's harder than it used to be. I guess I was expecting that hills would be easier on the road bike, not harder. I have no problem working my butt off by riding more and doing hill repeats to get stronger. I can ride on the flats here but I'm fairly limited on where I can go then. If I'm willing to do hills, I can go anywhere. Some of it is rolling, some is steeper.

Anyway, thanks for your detailed response. It really helps me to make sense of it all. Now that I have a better understanding of the differences between my MTBike and my road bike, I guess I was just wondering if I had an easy enough granny gear for my current fitness level and terrain. My SO thinks I just need to keep working at the hills and learn to use the gears I have. Sounds like he's right.

barb

Kathi
07-23-2006, 01:39 PM
You don't have to count the teeth, if you look closely there's a number stamped on each ring. That number tells how many teeth the ring has. It's hard to find but its there, good excuse for cleaning your cassette!

On your crankset there is a number on each ring, for example, mine has 48-110 stamped on the big ring and 34-110 on the small ring. That means my front chainrings are 48-34. I have a compact double that's why the 2 smaller rings on the front.