Cassette question: 12-23 vs 12-25 and 12-27 (Page 2)

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2008-05-19 10:38 PM
in reply to: #1411396

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27
And DON'T forget to make sure you have enough chain going to the 27 from the 23 !!!!! If you don't and accidently go into the 27 while in the big front ring you can destroy a rear derailuer in a heart beat. I changed mine out the night before a 100 mile hill climbing ride and forgot about the chain. 15 miles into the ride, small mistake, and my day was done.


2008-05-20 9:03 AM
in reply to: #1411396

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27
The other thing to think about is what you have upfront. If you have a compact (50/34), a 12/25 in the back should be plenty. That is what I have and I live around a ton of "hills" and I am a weaker biker.

If you have a 53/39 upfront, then you might think about the 12/27 (I know that I would). You just have to watch shifting the last few gears.

Cheers.
2008-05-20 10:48 AM
in reply to: #1411396

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27

Thanks guys for all the responses.  After reading all these posts and talking with my LBS wrench last night, I think I'm going to go with an 12-27 cassette. 

Like it's been stated, I'd rather have gears and not use them, then need a gear and not have it.  I also like the idea of not burning out my legs on climbs.  This past weekend I really burned my legs out on the bike and my run suffered severely as a result. 

My LBS wrench said he may have to tweak the derailleur but since the chain only has 500 miles on it, it should be fine. 

 

 

2008-06-08 10:23 AM
in reply to: #1411396

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2008-06-18 11:22 AM
in reply to: #1411396

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27

 There is no rocket science in gear selection... there is a good article covering this on slowtwitch:

 http://www.slowtwitch.com/mainheadings/techctr/gearing.html

I run a compact crank 50/34 pushing a 10SP 12-23 on my road bike (Cerverlo Soloisit Team) and I upgraded to the 12-23 to reduce the 2 teeth jumps in the mid to low.  I'm in Florida and ride mostly flat terrain and i can turn 140RPM so top end isn't a huge issue.

I run 50/39 pushing an 11-21 on my QR Kilo (650C wheels) and average around 90-100 RPM when I timetrial (again mainly flat courses) so I spend a good amount of time in the 15,16 & 17 cogs

The 34x23 is pretty low if you ask me but then again, my "big" climbs are bridges that only reach about 100 feet of incline over maybe .1 mile and I regularly climb those on my fixed gear bike running a 48x16.

 

2008-06-18 1:01 PM
in reply to: #1411396

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27

Hincappie would tell you that no one ever complains about having an extra climbing gear on race day.

I think you will be happiest long term with the 12-27.

2008-06-18 4:43 PM
in reply to: #1411396

Master
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St. Louis
Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27
Unless you want to brag about your "corn cob" rear cassette, there really isnt much of a reason not to run a 12-27.

I would say the only exception would be during a flat time trial. Having the ability to change just 1 tooth can come in handy to maintain the exact right cadence/speed you want.

During training, and for the bike portion of a triathlon, I havent found it to be as much of an issue.
2008-06-18 4:52 PM
in reply to: #1475345

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27

ranger5oh - 2008-06-18 4:43 PM Unless you want to brag about your "corn cob" rear cassette, there really isnt much of a reason not to run a 12-27.

As flat as things are over here, I never use my 23. There isn't much of a reason to run a 12-27, either.

2008-06-18 5:28 PM
in reply to: #1411396

Elite
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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27

OP.  Thanks for asking this question.  I have learned an aweful lot!

I live in a super hilly area.  I CANNOT climb the hills on my tri bike with an 11/23.  If given a choice, I'd go for the 12/27.  Most triathlons are going to have pretty varied terrain.  You want to be able to tackle all of it with as little fatigue as possible.

2008-06-18 6:07 PM
in reply to: #1475424

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27
owl_girl - 2008-06-18 5:28 PM

Most triathlons in my area are going to have pretty varied terrain. 

Fixed that for you. Again, that whole flat south Louisiana thing. I've yet to do a tri with a climb bigger than a bridge or highway overpass, or that I couldn't ride with an 11-21.

2008-06-18 6:16 PM
in reply to: #1475493

Master
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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27
the bear - 2008-06-18 6:07 PM

owl_girl - 2008-06-18 5:28 PM

Most triathlons in my area are going to have pretty varied terrain. 

Fixed that for you. Again, that whole flat south Louisiana thing. I've yet to do a tri with a climb bigger than a bridge or highway overpass, or that I couldn't ride with an 11-21.



Sounds like a great reason to do a destination tri!


2008-06-18 6:21 PM
in reply to: #1475510

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27

ranger5oh - 2008-06-18 6:16 PM Sounds like a great reason to do a destination tri!

And have to buy a new cassette? No thanks. I do hope to resume the "destination marathon" thingy again sometime soon, though.

Cool

2008-06-18 6:24 PM
in reply to: #1413517

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Subject: RE: Cassette question: 12-23 vs 12-25 and 12-27
Dream Chaser - 2008-05-20 11:48 AM

Thanks guys for all the responses.  After reading all these posts and talking with my LBS wrench last night, I think I'm going to go with an 12-27 cassette. 

Like it's been stated, I'd rather have gears and not use them, then need a gear and not have it.  I also like the idea of not burning out my legs on climbs.  This past weekend I really burned my legs out on the bike and my run suffered severely as a result. 

My LBS wrench said he may have to tweak the derailleur but since the chain only has 500 miles on it, it should be fine. 

 

 



Where on Long Island is there a hill like that! Average 11% gradient for 1 mile! Damn, that's serious! That center 1/4 of it looks like a wall.
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