I’m looking at getting myself a new cassette, looking at putting my current one (12-23) on a cheap wheel and using it on the trainer, undecided as to what I should get. My bike is full 105, am looking at either 12-25 or 12-27, which do you think?
My hill climbing is not all that strong and I will be doing quite a bit of that over the coming months. I’m training for IM next year, basically flat course but a few lead up halves may be hilly. What I have found with my riding so far is that I very rarely find myself riding in the big chain ring (53-39), except when descending (have only been riding for 6 months)
If I go the 12-27 option, I would need to go Ultegra, will that be compatible with my current 105 setup? Will I need to replace anything else or make any mods (ie. chain, derailer adjustments?) or is it just a case of replace the cassette and away you go?
105, Ultegra and Dura Ace are all interchangeable (9spd). Thus you can use them in any combination (i.e. 105 HUBS with Ultegra Cassette and DA derailleur). So there are no compatibility issues.
12-27 is a bit of overkill for a 53-39! If you used a 53-42 then yes but I think the 9spd version of the 12-25 gives you the best all-round gearing for a 53-39. (Unless you plan to go to do a few Tour de France stages in the Alps - Etape) If you do not ride a lot in your 53, don’t despair! I do most of my winter training on my 39 front gear to get my legs spinning, so if you have been riding for 6 months you are doing the right thing by getting used to spinning 1st. I use a 12-25 on both training and even a disc and find it the best combo for me. Some prefer a 11-21 or 11-23 for racing but hey you probably need the 25 more than the 11
Hill climbing will come good with time… just keep at it! There is some skill to climbing and I it diff. from person to person.
I would suggest changing the chain too, depends on it mileage if your chain is still fairly new it should be fine. I’m a bit of a chain freak… I prefer chaining chains every 1200-1500 miles.
Really? Some fairly accomplished triathletes might disagree:
"I race with 39X53 and 12-27. i believe monty and i had the two fastest bike splits in our AG in wildflower, and we were probably the most “undergeared” of just about anyone in the first half of our AG. i rode in my 27t quite a lot. i rarely miss having an 11t, but i’d sorely miss my 27t in a lot of races. " – slowman (Dan Empfield)
Personally I say go with 12-27 over 12-25. Wanting a 27 on your ride and not having it available is worse, imo, than the not having as closely-spaced a gearing. But if you can spin at the cadence you want to spin at on the grades you want to ride on and never need to go lower than 39-25, more power to you.
The 12-25 and 12-27 are virtually identical except for the last (2) gear. If you have to go to a bailout gear, why not go to the 27? Esp. since you are not great on the hills.
I agree with Dan and many others that the way to ride, when you are riding long, is to spin up the hills. If you intend to go long, then I strongly suggest you learn to spin up the hills.
Resist the urge to over-gear so that you will look tough and fit in. If your goal is to finish in the best time possible then you will need to gear far under what is common.
I actually have three different cassettes - 11-23, 13-26, and 13-29. I have been training on the 23, and will use that on races that are flat or with small hills. I took my 29 with me to Wildflower LC and it worked well up Beach Hill and is also just right for climbing the mountain in my back yard (very steep at the summit). I will put my 26 on my training wheels later in the season as I prep for the Big Kahuna 1/2 and do more climbs.
As a general rule, you should use the tightest cluster you can for the ride so you can better match your cadence with your desired speed and effort. The 12-27 would be great for the hilly races, but if you are training on pretty flat roads, I would leave the 23 on.
Instead of getting another wheel, have you thought of getting a chain whip and a cassette tool so you can swap the cassettes whenever you want?
This really shouldn’t be a big decision. You ought to have 2 or 3 cassettes that you swap out as needed. It’s VERY simple to change cassettes. I have 4 and I’ll pretty much put on whichever suits the race I’m doing. Don’t be ashamed to put a 27 on there, better to have 27 and not need it, than have 25 and wish you had 27.
Like someone else mentioned the only difference in those cogs is the last two gears,and when you need those last two gears, your legs will probably be happier with the option of a 27. 90% of the time, you’ll likely be in the smaller cogs and it won’t matter. I’d get the 27, then plan on buying at least one more complete cassette soon, to give you closer ratios for flatter courses.
If you only have one cassette I would go with the 27. I am not a great climber either. I put one on before wildflower oly and it allowed me to spin up the hills, I must of passed 20 riders on the first hill, I finished in the 17th percentile in my AG on the bike because I was able to easily spin up the hills.
I did a mountain ride a few weeks ago with 5000 feet of climbing, some of the stronger climbers in our group left me in the dust for the first few miles of climbing, I passed most of them back near the top as I spun past them, they all had 23’s and 25’s and were telling me before the ride the 27 wasn’t necessary.
The chain whip, is basically a chain, attached to a handle. You just lay it over the cog, and it keeps the cog from freewheeling when you use the cassette tool/wrench to loosen the nut. You can actually take an old chain, and wrap around the cog and probably do the same thing. Anything to keep the cog from freewheeling when you unscrew the cassette. Actually the other day I couldnt’ find my chain whip(my wife probably still had it:)
and I stopped the cassette from turning with a screwdriver throught the cogs and spoke, and changed it out. Not something I’d do freqently or with my good wheels, but it got me by.
Just grab a rag, fold it over a couple of times, and drape it over the cogset. Then palm the cluster and use whatever wrench with the freewheel tool. The rag provides more than enough protection for your hand, and you don’t risk damaging stuff with a screwdriver.
