Explain Cassette Gearing

[Cataboo]

I keep reading all these numbers about triple cassettes and compact doubles, and I don't really understand what they mean. Could someone explain this to me? My bike has a 12-25 cassette, and a 48x38x28 chain ring (triple). Is that adequate for serious hill climbing? Someone suggested that I needed a bigger rear cassette. I'd like to know if that is necessary. Thanks.

The combination of the 28 chain ring with the 25 cassette in the back should really be able to get you up hills... However, that depends on you, your biking style & your legs. If you need more gears to get up hills, you can put a bigger cassette ont the back of your bike - a 12-28 or a 12-37 if you want to get a mountain bike rear cassette & derailleur on your bike.

The smaller the # of teeth on the front chain rings, makes it easier to go up hills. The larger the # of the teeth on the rear cassette makes it easier to go up hills. You have smaller chain rings up front already than most road bikes.

[Jiffer]

The smaller the # of teeth on the front chain rings, makes it easier to go up hills. The larger the # of the teeth on the rear cassette makes it easier to go up hills.

Pretty sure this was spose to say that the smaller number of teeth on the front chain makes it easier to go DOWN hills.

I have an 11-28 double. I LOVE being able to pedal faster on the downhills. When I got my bike, all the components came off dh's previous bike. It had an 11-25 cassette. I rode that bike for over a year before dh realized I had such a difficult climbing gear. And, of course I didn't know any better! He sent me and all our riding buddies an email saying that I was an insane climber for doing the climbs I had done with that big gear. I was a snail going up hills, had to work so hard, and was mentally depressed to be passed by the entire world on hills. Since he changed it to an 11-28, I am STILL one of the slower climbers, all the more reason to give me the better gearing! But what a difference it makes. That and making myself climb hills to get stronger. I just experienced great joy last weekend on the club ride when I passed three people on a difficult climb. I don't think I've ever passed anyone on that particular climb EVER. Definite ego boost.

[indysteel]

Pretty sure this was spose to say that the smaller number of teeth on the front chain makes it easier to go DOWN hills.

I have an 11-28 double. I LOVE being able to pedal faster on the downhills. When I got my bike, all the components came off dh's previous bike. It had an 11-25 cassette. I rode that bike for over a year before dh realized I had such a difficult climbing gear. And, of course I didn't know any better! He sent me and all our riding buddies an email saying that I was an insane climber for doing the climbs I had done with that big gear. I was a snail going up hills, had to work so hard, and was mentally depressed to be passed by the entire world on hills. Since he changed it to an 11-28, I am STILL one of the slower climbers, all the more reason to give me the better gearing! But what a difference it makes. That and making myself climb hills to get stronger. I just experienced great joy last weekend on the club ride when I passed three people on a difficult climb. I don't think I've ever passed anyone on that particular climb EVER. Definite ego boost.

Hmmmmm; I'm pretty sure the post you quoted is correct. A smaller front chain ring and/or a larger rear cog make climbing easier, especially when used together. The smaller the gear, the less resistance you need to pedal, and the easier it is to climb. Although I'd further add that to spin fast during a climb takes pretty good aerobic capacity. It's easier for some, but harder for others.

IMO, no particular gear makes going downhill easier. Gravity does a pretty good job that on its own. Rather, using bigger gears on a downhill allows you to pedal without "spinning out." As such, you can go downhill faster.

I would assume that even with a 25 cog as your biggest cog, you should have been able to pedal pretty easily while going downhill. I personally, don't pedal on steep descents. I'm already going as fast as I want to go. If I do pedal, it's merely to keep my legs moving after a steep climb. For that, I just keep it in a fairly easy gear and spin.

I do, however, pedal through rolling hills so that I use momentum to my advantage. That typically means shifting from the smaller gear I used to climb the hill to a bigger hill for the downhill and then back to a smaller gear for the next roller when gravity starts to slow me down. Depending on how steep the rollers are, that may require multiple shifts--front and back. For that reason, I think rollers can be rather exhausting mentally. The second day of the Horsey Hundred in Kentucky is like that and by the end of it, my brain is beat.

[Jiffer]

Hmmmmm; I'm pretty sure the post you quoted is correct.

I don't think my brain will ever make sense of all this!!! I'm apparently a cassette and chainring moron!! Thanks for the correction.

But yes, I was referring to going downhill "faster", which having a bigger downhill gear makes it "easier" to do ... because I do pedal as much as I can on descents. I have friends who can't keep up with me sometimes and, therefore, the group on the Saturday club ride when we do a big descent together after regrouping at the top of a climb. One of my friends sometimes loses the group and, therefore, can't finish the rest of the ride with them once it's flat again. A bigger gear would make it "easier" for her to keep up. She did actually change her cassette and does have a harder gear than her Ruby came with, but she still has to work hard at keeping up and if she's not strategically at the front of the pack when we descend, she may lose us.

Funny this post came up. Shortly after reading it, my dh told me he's thinking about switching something else on my bike to give me easier gears. (Not even going to pretend I remember which "thing" on which part of the bike he said he was going to change!) But yay for me if it helps my pathetic climbing!!!

[Cataboo]

Erm. A bigger chain ring in the front will make it "easier" to go downhill without having to spin too fast. Or a smaller cassette ring in the back.

A smaller chain ring in the front will make it easier to go up hill or a bigger cassette ring in the back.


the downhill thing I think depends much more on weight, wind resistence, etc... As a solid heavy little person, I tend to go down hills very fast whether or not I'm pedaling. tires & hubs'll affect it as well.

[Zen]

As the reigning Queen of Liberal Brake Application I can't imagine pedaling downhill

[Cataboo]

As the reigning Queen of Liberal Brake Application I can't imagine pedaling downhill

Erm.

It maybe good for you to keep those shoddy brakes on the aurora for now.

If we ever go mountain biking together, I'll use my brakes all the way down with you then.

The bf likes to "adjust" my brakes so they don't work very well before mountain biking to try to make me get over that.

It usually gets fixed after the first downhill.

[Jiffer]

the downhill thing I think depends much more on weight, wind resistence, etc... As a solid heavy little person, I tend to go down hills very fast whether or not I'm pedaling. tires & hubs'll affect it as well.

Weight does greatly affect downhill riding, but no matter how much you weigh, if you are just spinning and not engaging a gear, you can no longer pedal to improve downhill speed. If your bike has another harder gear, you can keep pedaling. Sometimes I pass people who weigh more than me because they can't pedal anymore and I can ... and I choose to use it. Which is another point. I pass people who could physically go faster, but choose not to. I make up for my slow climbing by excelling on the downhill. I'm a stat freak. Love trying to improve my average pace on each ride.

[ttaylor508]

I ride mostly with guys who out weigh me by quite a bit and on descents I can pedal my heart out in my biggest ring (52 on front, 11 on back) and they can still beat me down the hill without pedaling, so I believe weight does factor in quite a bit. On our last ride we were going down a pretty steep section and DH and our other buddy were doing 53+ MPH and I was at 47MPH.