Different Cassette?

[Aggie_Ama]

Okay, I am going to try to ask my question without sounding too stupid. I currently have the stock set up on my Cannondale, 30/39/50 with 12-25 rear. I read about some of you running mountain or touring set ups on your bikes. I really like climbing rides but I am not strong and they often suck the life out of me after only a few miles. I do not anticipate ever having enough hours in the day to train to get better, so I need to make life a *little* easier.

What is needed to make an easier set up for the steep hill country? Do I have to change everything (shifters, deraileur, cassette) or can I just change the cassette? Also will I be giving up the ability to go fast on the descents, I already run out of gears?

And just in case I didn't get the information right, this is my bike:
http://www.cannondale.com/bikes/07/c...el-7RWC3T.html

[SadieKate]

I assume this is a 9 spd bike? Because that what my answer assumes. . .

You need to know what kind of rear derailleur you have (short, med or long cage). Since you have a triple, you probably have a rear derailleur that can handle up to a 27 Shimano cassette or maybe a 28 SRAM 9 (about one more gear than you have now). If you swap the rear der to a Shimano XT, you can put on a Shimano or SRAM cassette with a large cog of 32 or 34 (about 3 to 4 gears lower than currently).

You will need a new chain to accomodate the larger cassette no matter what. So determine your rear derailleur's capacity and then choose a cassette to match, or budget in a new rear derailleur also.

Editing -- I'm taking almost everything back that I said above because the bike is a 10 spd. You can put on a 28 SRAM 10-spd cassette. I didn't look at the rear derailleur specs, but you need to be sure the cage will handle the larger cassette.

[SadieKate]

Since you're running a 50 as your large chain ring, you could also swap your granny for a 26 or 28. You'd want to do the same research (talk to your LBS) about whether than rear derailler can take up all the chain length.

[Aggie_Ama]

Thanks SK, always a wealth of knowledge. My bike is about due for a new chain, so I will talk to the LBS about a different cassette first.

I think just one more gear would help, although if I ever want to get up Jester (.75 miles and 17%) I need more than one extra gear.

I am totally clueless, but swapping the granny would to a 26 or 28 would also make things easier? By that I mean I could in theory spin longer up the hills? Right now I am down to mashing on the pedals to barely pull myself up the big hills and I am completely dead at the top.

[SadieKate]

Anytime you can go both smaller on the front and larger on the back you are going to gain more low gears. Not knowing the capacity of your derailleurs but knowing that you're unwilling to change your chain yourself tells me that you should put this in the hands of your shop mechanic. You are stuck with the capacity of your front der, but you could possibly go as low as a 26 ring. The rear der could be swapped out for a mtb rear derailleur and then you can go as much as a 34.

Do you use the granny gear much? What type of terrain do you normally ride? A lot of flat with a scattering of hills? For that, I'd prefer the smaller granny and only the 28 cassette. Then you won't lose the close spacing of the cassette for the flatter portions of your rides. On flat terrain, the big jumps between gears on a large cassette drives me bonkers because I always want the gear inbetween.

[Triskeliongirl]

The simplist thing to do is swap the 12/25 for a 12/27 but I don't think that will get you low enough.

As SK recommended, I also recommend replacing the RD with an XT or XTR, and putting on an 11/34 casette. (These are mountain parts, but they'll work just fine). I ride the hill country and I use a 50/34 in front with an 11/34 in back. This too is assuming you are running 9spd, but I know that terry is spec'ing their new Isis sport with a 10 spd 11 or 12/34 casetted by SRAM so it must also be possible for 10 spd.

If you do this I don't think you need to mess with your front chain rings at all.

[Aggie_Ama]

Not knowing the capacity of your derailleurs but knowing that you're unwilling to change your chain yourself tells me that you should put this in the hands of your shop mechanic.

Yes, I am just not very mechanically inclined. Cleaning my chain is about as technical as I can get, sadly. I will definitely be letting someone else do this now that I know it may be possible. I will have to consider my options.

Do you use the granny gear much? What type of terrain do you normally ride? A lot of flat with a scattering of hills?

When I get to longer climbs I use the granny gear a lot. The area around my house is a lot of rollers, but west Austin is steep and I enjoy riding there too.The problem is aspire to do mountains when I can get out to them and more in the Texas Hill Country but right now rides over 30 miles are killing me because the climbs are taking too much out of me. Last weekend we went out to the mountains and I was spent after the first climb and felt miserable the back 50 miles.

Trisk- It is a 10 speed. I was hoping not to spend the money on a new deraileur yet, but that may be my best bet.

[SadieKate]

but I know that terry is spec'ing their new Isis sport with a 10 spd 11 or 12/34 casetted by SRAM so it must also be possible for 10 spd.

Huh, it's an IRD cassette, but it still needs a long cage mtb derailleur.

Talk to your LBS and compare the budgets for each. A 30 chainring x 34 cog gives you 23.82 gear inches just a tad lower than a 26 chainring x 28 cog which gives you 25.07.

The chain ring swap is probably cheaper. The risk is you may still want to swap the rear cassette to a 34 someday. A 26 x 34 combo would give you 20.65 which I adore for really, really steep grades but pay the sacrifice of having big jumps in the cassette spacing.

[Aggie_Ama]

Thanks, I will talk to the LBS about options and pricing. Hopefully they will be as helpful and not try to stick me with the "norm". I find the shops sometimes do not want to think outside of the box, it is a shame.

I just want to climb easier, I am not trying to win any honors just complete 60-100 hilly miles and enjoy it. I like climbing rides, I am just not that good of a climber!

[violette]

There is a thread in the open topic (Double chainring - yikes). I had this problem and it was solved with all the advice. Take a look at it. (I changed my cassettte to a Mtn bike and love it!)

[OakLeaf]

Does a smaller puppy gear (with no change in the middle and big rings) increase the risk of dropping the chain? Or make shifting rougher?

[SadieKate]

You never want the difference in ring size to get too large - I think it's pretty universal that you never should go larger than 14. 50-34 compact cranks have the greatest differential at 16 and they've had their challenges with quick shifting and dropped chains though this is improving over the years. You can always add a Deda Dogtooth on the seat tube near the bottom bracket. A lot of the pros run these because they don't ever want to chance a dropped chain, no never.

The larger the gap, the longer to shift up and the greater chance of dropping when shifting down. This doesn't matter whether it is a double or triple crank.

[violette]

I changed my cassette and Ultegra derailler to a Mtn bike cassette. The difference is amazing, but I lost my higher end derailler. The gear shifting is not as smooth as with the Ultegra, they changed my chain and it works like a charm. I would seriously consider changing if you do steep climbs. The LBS told me that some of his customers go to France to try the Tour the France route and they change their deraillers and cassettes, because the mountains are so steep, they could never do it with their regular gears and they have the high end bikes.

[aicabsolut]

I wouldn't put a 32 or 34t cog on the back with a little 30T chainring. A 1:1 ratio of gears (e.g., 30 and 30) means that you get one wheel revolution per revolution of your pedals. This definitely takes little force to accomplish, but you start having to spin like mad to keep enough momentum to keep yourself upright, particularly when gravity is working against you as well. I would most definitely NOT go greater than 1:1 (the 32 or 34 rear cog), because that will mean more than one revolution of the pedals to get a complete revolution of the rear wheel. You just won't be able to go fast enough. I'd advocate sticking with your normal 10sp derailleur and putting something like a 12-27 (shimao or sram) or 12-28 (sram) on the back. That will get you close to a 1:1 and still be pretty easy while allowing you to keep your momentum up such that you don't tip over. If you're running campy, then the current rear derailleur can accommodate a larger cassette (I forget if it's 29 or 32..i think 32), but I still wouldn't go past 1:1.

Basically, you're going to get to the point where you have to see if you can make things easy enough that you can manage to go a little farther without putting yourself in a situation where you will be pedaling your heart out and going at a pace that you could probably beat by walking.

[SadieKate]

Does a smaller puppy gear (with no change in the middle and big rings) increase the risk of dropping the chain? Or make shifting rougher?

Oakleaf, can you clarify whether you were asking about the difference in chain rings sizes (number of teeth difference between each chain ring) or the difference in size between the small chainring and the largest cog. My answer had to do with the shifting performance pros/cons of the gap between chain ring sizes. It had nothing to do with cassettes.

aicabsolut, Northern CA has plenty of hills where a smaller chainring than the largest cog is appropriate. Tourers use small rings. Mtnbikers use a 22x34 all the time and manage to stay upright. It all depends on the demands of a specific person's terrain and her body.

From Peter White: "My most popular chainrings are 48 - 38 - 26 and 24 tooth replacements for Shimano's Ultegra and 105 triple cranks."