IM Wisconsin gearing
I wanted to get compact gearing on my P3. I just talked to LBS and they told me I'd have to get a whole new crank set and power meter to do it because of the bolt pattern. They suggested I put a mountain bike derailleur and a 32x11 cassette instead. Little help from the Wisconsin pros and gear heads? Is that going to help? My bike info...275 FTP... 175lbs... Help
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What crank and cassette(s) do you have now?
53/39 10spd with a 12/25 cassette... I also have a Quarq Riken PM... That's why the additional cost and the bolt pattern doesn't match. I've been riding this gearing for 3 years since I bought the bike.... Should I just go with it and burn a few matches come race day... or will the course prove way too troubling for that?
@Ed,
FWIW, I raced Wisconsin on your exact gearing and got destroyed. As in 6:47 destroyed. Which, of course, was followed by a long 4.5-hr walk. Didn't have power at the time, but I strongly suspect I was up ~300w just to grind up Midland. Today, I would go compact-27. You might be able to get away with standard up front and 11-28 on the back, but I still think you'll have trouble keeping the watts anywhere near 200 (.73IF) on the three steep climbs. And you'll give up some gears between that 11 and 28. Are you heading up there to preview the course? If so, you could try out the 28. Don't want to you spend big $ on a new Quarq if you don't have to.
Just my $.02. Rich knows this course better than anyone and will give far better advice.
MR
I raced IMLP with a 53/39 and 11/28 and plan to do the same at Wisconsin. That combo worked for me using my PM smartly. I think I turned a 5:45 time on a .70 IF. I cramped up badly during the run given I was on a new bike/fit more than anything else. I do not believe the Wisconsin bike course to be worse than IMLP.
Will be testing that config in RR1 while in Madison and make any needed adjustments from there.
No way I would put a MTB config on my tri-bike......
Ed,
I don't know the Wisconsin course but at 3.4-3.5 W/kg a compact or a 32 maybe useful and I'd definitely go with a 39X28. The problem with the 32 is more spacing on your rear cassette. Check out the link below of ratios or even better speed at cadence, or speed.
FYI the 34X28 give you almost the same speed at 90 RPM's as the 39X32. 34X28 @90RPM = 8.52MPH 39X32@ 90 RPM = 8.59. I'll defer to those with more course knowledge given you w/kg.
http://www.bikecalc.com
Gordon
You also have time to get lighter before the race, improving your w/kg