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12-25 or 13-26?(14 posts)

12-25 or 13-26?colker
Apr 14, 2003 12:59 PM
which one gives the best combinations with a 39/53 crank? i'm not very strong and don't like a slow cadence.
Apr 14, 2003 3:58 PM
Since your not very strong, go with the 13-26 and ride it lots.
Probably 13-26Kerry
Apr 14, 2003 5:17 PM
Presumably, you want the small cog for the situation where you are going as fast as you want without coasting - let's be honest, for most people that means downhill. Spinning out (110 rpm) a 53/12 is 34+ mph/55 kph. Can you make the bike go that fast, or would you be coasting at that point? This is the only reason to have a 12. A 13 would give you a bit below 32 mph/51 kph in the same situation. In my experience, once you are going that fast down a hill, you will go just as fast by getting down in a tight tuck.

On the other end, the difference between a 25 and 26 is minimal in climbing (0.2 mph at 6 mph/50 rpm). But since you describe yourself as a not very strong spinner, the answer seems obvious 13-26.
Apr 14, 2003 6:30 PM
I'll go out on a limb and say go with the 12-25. The reason being is that if you use that 25 gear it will eventually make you stronger. Not much difference between a 25/26 anyway. I presume you have Campy, if you want lower gears, consider a 13-29...
re: 12-25 or 13-26?wielerpret
Apr 15, 2003 2:46 AM
For your frontblades, the 13 - 26 pignon will be best (10 speed?). An excellent allround combination: 39x26 for most (not the very steepest) climbs (e.g. Ardennes, Alps, Appenines). 53x13 on descents and with tailwind, allows pedalling at plm 60 km/h. The 53 is even rather large, suitable for av. speeds of plm 40 km/h. If you ride at an average of about 28 km/h. on flat country, you could consider a 42 or even 44 front blade for better chain alignment and more use of the smaller blade, limiting your capacities for climbing though.
If you have not too much strength or time to train build it up, 170mm cranks will also suit your purpose better than longer ones.
Good luck. Luke. Amsterdam.
Apr 15, 2003 4:33 AM
Sticking to your original question, I would pick the 12-25 because there's not much difference between a 25 and 26 gear, but the 12 would really help on long downhills. However, if you truly need a climbing gear, go for the 13-29. The 13-26 has the same gears as the 13-29, except it has an 18 and no 29. If you need a climbing gear, the 29 will tackle just about anything. I used a 13-29 for a year and then switched to a 13-26, figuring I was strong enough to handle it. However, I didn't find much benefit from the 18 and really missed the 29 in the rare occasions when I needed it. The only problem with the 13-29 (or 13-26) is the lack of a really fast gear (12) for prolonged descents.
13-29 is great with a double..Spunout
Apr 15, 2003 4:58 AM
Tarwheel, have you tried to put a 12 onto the 13-29 by removing the 16?

I have a 13-29; and this season went with 12-25. I haven't hit the hills at race pace (still snow covered) yet, but the 25 should be fine. But for a bailout on race-day I may go back to 13-29 or try the 12-29. It should work, I'm not totally convinced about campy's timing restrictions.
13-29 is great with a double..tarwheel
Apr 15, 2003 7:45 AM
Haven't tried anything other than the standard Campy and Shimano groupings. I wish Campy made a 12-27, though. I don't really mind the wider gear spacing in a 13-29 because I started riding back in the days of 5 and 6-speed cassettes. Back then you didn't have a close gear cluster unless you could handle something like a 12-19.
But need a long cage rear derraileur, or maybe ...PdxMark
Apr 15, 2003 10:34 AM
... just not a short cage rear derailleur. Anyway, Centaur/Daytona will have the proper cage, but off-the-shelf Chorus likely won't (though it is available).
Med. cage Chorus works, just buy the cage; small will work nmSpunout
Apr 15, 2003 10:36 AM
how about a 12-26?Suds
Apr 15, 2003 5:15 AM
I think that SRAM makes a 12-26 road cassette for Shimano spline hubs.
13-26 is what I like..dotkaye
Apr 16, 2003 10:48 AM
race triathlons with this combination, mostly because of Old Stage hill in the Boulder triathlon. I'd like closer ratios, but need that 26 at times. Personally I spin out at about 60km/h in 53/13, but at that point I'm usually seriously considering braking anyway. If I was bike racing instead of tri racing, I'd probably want the 12, but it's redundant for most non-racers IMO. The lower gears, 26 or even 29, can be awfully handy though.
re: 12-25 or 13-26?Wheat
Apr 16, 2003 3:45 PM
Just bought a 12x27 Dura Ace with the advice and assistance from this forum. I'm ready for the hills of Iowa!!! LOL
re: 12-25 or 13-26?BenR
Apr 17, 2003 1:52 PM
I don't know about 9 speed, but my old shimano 8 speed 12-25 had some wierd gaps in it so I went back to 13-26. There were 2 places in the 8 speed where, if I was going hard, I could almost spin out in one gear and not quite be able to pull the next smaller cog. If you don't race, I would go with the 13-26. An 11 or 12 does come in handy on slight downhills when you're in a hurry though.

I currently have 10 speed 12-25 and 11-23 cassettes and there are no "gaps" in either of them. Having the 25 on my training wheels is very nice and significantly easier than a 23. I don't remember the 25 vs 26 being significantly different on my 8 speed and I would rather have a 12 than 26. I might make a different choice if I were a super-spinner, but I typically pedal at a 90 cadence and grind at 80 if I really want to get somewhere. I'm guessing that there is at least one fewer gap in a current 9 speed 12-25 cassette. hope this jabbering helps.