Gearing on 650 wheels for IM Canada

Triathlon Forum
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Anyone have any ideas about gearing–I’m having a hard time finding gearing that’ll allow me to spin up hills and pedal on steep descents, like you’d find at IM Canada. I have 650 wheels and am using a DuraAce 10-speed in back, 12-27. Front is standard 39 X 53. I thought this would be the perfect combo and used it at Coeur d’Alene but during the steepest hill, while shifting to my 27 in back, the chain came off. Maybe that was unrelated to anything–except I’m using friction shifting on bar-end shifters. I’m not good with this technical stuff, am preparing for Canada and wanted some input on my options. Thanks! (Rear derailler is Ultegra.)

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My 52 year old wife did IronMan Canada with her 650 bike set up 12-27 and 39 * 53 with no problems last year. She has 9 speed Dura shifting rather than the 10 speed.

Did your chain come off the 27 in toward the spokes or did your chain come off on the front? It should be easy to adjust so this doesn’t happen.

Its a fun race.

SciGuy

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I use an 11-21 with my 650’s for IMC but I have a 52-42-30 in front
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I have never liked the 27 because there is too much of jump in the larger cogs (24-27). I use 650c wheels and had 9 speed but recently up graded to the 10 still wit hte 30, 53 in front. With 9 I used an 11-25 I made from a 12-25. Works nicely for both the uphills and downhills. Really like the 11 for 650c wheel so I don’t spin out on downhills.

Now that I have the 10 I have made another 11-25 with one for gear which makes it great. I would suggest you do that. You will needto purchase a 12-25 if you don’t have one already an 11T cog AND an 11 lockring.

It looks like 25-23-21-19-17-15-14-13-12-11

You could leave in the 16 instead of the 15 but I believe there was more cross over.

Barb L

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I train in an area much hillier than the Okanagan region and use a 56-39 on the front and 11-23 on the back. It shifts fine. Alternately, I could see using a 42 small ring with a 12-25 cluster.

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Hi Sciguy:

Thank gawd for “sci” guys like you… I’ve done Canada (my favorite race) 3 times but this’ll be my first on my 650 wheels.

The chain came off the rear as I went into the 27 on the hill. The rear shifting must have been off, although I’d done the same hill 2 days before and there were no problems. ??? Is it possible it was user error because of nervousness and friction shifting?

I normally ride with an 11-23 on back, but for the race wanted a bailout gear, so put the 12-27 on. Since I have friction shifting, I shouldn’t have had to recheck the bike’s shifting in the rear, but did anyway at a bike shop before I left. Necessary?

Hey, I’m in your wife’s age group! I’m Kyle Dees from Oakdale, Calif.

Thanks for your help,

wife without a biking husband,

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Barb:

Thanks for your idea. Read about this being recently done on this website, but the author didn’t sound too excited about it. I think an 11-25 or 27 would be great though. Did you really mean you have a 30-53 in front or was that a typo?

Thanks,

Kyle

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Yea I caught that later. Sorry It is a 39-53 in front. Purist always say you can’t or prefer not to do it. But I’ve had both a 9 speed 11-25 ultegra for training & DA one for racing since 01 without any problems. I’ve had the 10 speed DA one since May and its been great. Just got a Ultegra to make the same thing for training. Also I always have to option of just using the 12-25 with the 16 in there by switching things out.

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Never, ever take gearing advice from a guy named hercules. My knees hurt just reading this post.

I use 12/25 on the back and 50/34 front for IM Lake Placid. It works great for me.