I am 210 lbs, and live where there are a lot of mountains and climb a lot, there i use a triple(52-42-30) crank set, and 11-25 cassette, would it be similar if i put a Compact crank set(52 or 54- 34) and a 12-27 cassette? i don’ like how the triple chainring looks. but a use it a lot.
Can some of the experts help me?
Thanks in advance
As long as ‘Compact Crank’ doesn’t become your new nickname, I say go for it!
“As long as ‘Compact Crank’ doesn’t become your new nickname, I say go for it!”
well said.
On current equipment, is a triple a bad thing? If so, why?
The 30-25 is a lower gear than 34-27. 31.7 gear inches opposed to 33.3 gear inches. It’s not a huge difference, but if you spend a significant amount of time in your bottom gear now, you’ll want to go with a wider cog on the back.
You would go out and buy a new crank just for fashion?
Pssst… I’ve got a carbon bike just for you!
Personally, I don’t understand the compact crank bruhaha. If you want/need spinning gears, just use a triple. Get over the stigma that seems to come with it. (No stigma to a rear der that hangs like a donkey in Tijuana?) A triple gives you an even wider range than the compact and you can still have that 52/11 combo (or more) for that massive downhill tailwind section.
It is not classic, and i don’t like how it looks
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IMO, compacts are the way to go. A 50/34 with 11-23 gives a closer ratio gear box than a 53/39 with 12-25. If you live in a really hilly area I’d go with a 12-25 cassette with the compacts.
I had one bike with triples and definately prefer the compacts. Somehow two rings are just tidier than three.
I’m sold on the compacts and ain’t ever goin’ back.
I do not ride a lot in the 25, i have used it but rarley, what do you recomend?
Read this article:
http://www.slowtwitch.com/mainheadings/techctr/gearing.html
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it is not hilly, it is high mountains, really steep.
If you don’t spend significant time in your bottom gear then the compact with the 12-27 should be fine. Only you will ultimately be able to answer that one. When riding in the bigger hills I like to have a bailout gear, if you go this route you may want to research a wider cogset. If you’re runnig 9 speed, I think some Ultegra cogs go all the way to 30.
First off your 52 or 54 in front with a 34 in the back is past the magic 16 tooth jump in order to shift correctly. Assuming a couple of things like 172.5 crank 700x 23 tires and 90rpm your current triple gets you a range of 31.3mph in the 52 x12 and 8.7mph in the 30 x 25. If you go to a 50 x 34 with a 12 x 25 at 90 rpm you get 30.1 mph on the top end and 9.8 mph on the bottom. If you dont use the 30 x 25 very often maybe you can swing the 34 x 25 but you are going to loose a little on the top end unless you go with an 11x23 cassette which will put you at 32.9 on the top end but 90 rpm on the low end is going to be 10.7 mph. Check out Shldon Browns calculator, it allows you to plug in all kinds of crap and see what happens.
I just went from a 52/42/30 with a 12-25 over to a 52/36 with the same 12-25. I used the 30-25 on the really steep stuff or when I had bonked, but the 36-25 seems to be plenty. I also changed from 172.5’s to 175’s in the process.
where’d you get a 52/36?
"where’d you get a 52/36? "
I believe that 52/50/48 big rings and 34/36 small rings are available in the 110mm compact crank bolt pattern. I’m fairly sure that Stronglight makes these rings and assume others probably do.
where’d you get a 52/36?
They came with my Rotorcranks.
I doubt a 52 or 54 / 34 would work. I have a 50/34 and that’s about all my front derailure will handle. Its okay as long as I am not in 34/11. 34/12 is okay though.
What about with a triple derailurer in the front and back?
Ok, I know I am going to get severely flamed by you STer’s for this but here is my suggestion: run 50/34 with a 12-27 and don’t bother changing to a long cage rear derailleur. I have been racing with this set up for 3 years on my 'cross bike with no problems at all. Of course, I never cross gear to my big/big but that is just common sense, right?
One small caveat, if you are running a 10 speed Shimano set up, you will need new shifters, because unlike the 9 speed Ultegra and 105 stuff, the 10 speed Ultegra (and next year 105) shifters are not double/triple compatible. Maybe Shimano will change that with next year’s 10 speed 105, because when 9 speed Ultegra and 105 first came out it was the same story but they eventually made them double/triple compatible on later models.
You will get less overlapping gears this way than running a triple front chain ring, it weighs less, the shifting and chain line issues are reduced on a double crank vs. a triple and finally, you can get a 52/38 or even 52/42 set up for when you ride in the flat lands. This is the chain ring set up I switch to on the 'cross bike when I use it as my outdoor winter road training bike.
Really, the difference between 34/27 as your lowest gear and 30/25 is something like 1.6 gear/inches which is so minimal as to be insignificant. And if you need more top end speed than 50/12, for gawd’s sake, learn to spin more than 90rpm (your knees will thank you in the long run, or ride as the case may be) Hope that helps, now let the flames begin!!!