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seagrave6
11-08-2010, 03:31 PM
What is everyone spinning these days? I am in the process of removing the 42/52 that came with my older bike,and was wondering what to replace it with?I have read great reviews about 50/34 - 11/21 setup.The hills are really starting to kill me,and its getting harder to keep my pace,when everyone else is spinning past me,so any thoughs.
P.S. I am 43 in good shape.

Dirt
11-08-2010, 06:47 PM
Norm for most fit and non-racer folks around here is 50/34 compact with an 11-25 in back. If you ever go to Skyline Drive, you'll probably want a 26 or 27.

That's what I rode last year. This year I went to 52/36 with the 11-25 and it felt good. Next year I'm likely to go back to 53/39 with an 11-26. That gearing is on my featherweight Cervelo. On my steel road bike I stick with 50/34 and 11-25.

With modern 10 speed drivetrains, the 11-25 is a really nice cluster.

I don't think there's much reason to go with more than a 50t big ring unless you find yourself spinning out a 50-11 combo. I do at least one flat century ride each year and have found that I really like a 52 or 53t when I'm riding in a pack. When I ride in the Alps or Rockies, I throw the 50/34 compact crank back on.

Fixie around town I ride 46-16 pretty much everywhere. If I head to the Eastern Shore I'll bump that up to a 50-15.

I'm a 46 year male that does 300+ mile weeks during the spring, summer and fall and 200+ mile weeks in the winter. I'm 6'4" and ride with 175mm cranks.

I know that's more info than you asked for... Hope that helps.

Pete

invisiblehand
11-09-2010, 04:24 PM
From my perspective, a better formulated question would involve what you have in the rear now, what you intend on using the bike for, and your riding style.

Personally, I have learned to spin at a relatively high cadence. I've had a ~90 RPM cadence for a few years but recently noticed it regularly hitting 100-110 since riding on the recumbent. So unless I'm going downhill and feel like keeping my legs warm, even a 50/11 is pretty silly.

Now the problem with the typical compact crank -- 50/34 -- is that there is more shifting with the big chainring in my experience. But the overall gear range is much more useful. Perhaps a 48 or 46 tooth big chainring would be better theoretically, but if you use non standard chainring combinations your front derailer performance typically suffers with index shifting. Pick your poison.

I'm speculating that you're talking about road/race/performance bikes here with little to no loads. Pre-recumbent, I would sit and spin up hills as opposed to mash and I tend to carry a decent stash of supplies for my 60-100 mile rides. So my compact crank is mated with a 12-32 10-speed cluster in the rear. Personally, I think any narrow cluster with 10 or more cogs is a phenominal waste of metal -- the additional granularity would only come into play while pacelining at a very competitive level. But the selection of hi-grade brifters with less than 10 speeds is pretty close to zero now; so I'd get a cluster with a 27 or 28 big cog since they are more reasonably priced than what I have. If you're a strong ride and like to mash a bit, chances are that you will rarely use the big cog, but when you need it you will be grateful. With the setup listed, I would spin up the 41ST hill regularly.

You could be a much stronger rider too. You didn't mention how often you find yourself in the big chainring now and how often you're bonking on long climbs. So it is hard to give specific advice to your situation.

P.S. I read that SRAM has an 11-32 (12-32?) cluster for their entry road groupo (Apex?). That might be reasonably priced and I would consider that.

Dirt
11-09-2010, 05:01 PM
Good perspective, Invisiblehand. You're right that a lot of gearing is a matter of riding style and personal preference. It also makes a big difference what bike you're riding. I ride smaller rings and bigger cogs on my 22lb steel bike than I do on my 14lb carbon bike.

1) I have the Apex cluster with a 32t biggest cog (forget if it is 11 or 12 for the smallest) on my cargo bike. Works great.

2) Biggest cog is definitely a personal preference. I rarely use the 25t in this region and really love the much closer gear ratios of the 11-25 or 12-25 (I have a few of those too).

seagrave6
11-09-2010, 10:00 PM
Thanks for the ideas,maybe I will try 50/36-11-25,I am riding an older cannondale around 18Lbs,I am truely a weekend soldier maybe 60 miles week in the winter.I want too try my hand at racing this summer.

invisiblehand
11-10-2010, 01:23 PM
Good perspective, Invisiblehand. You're right that a lot of gearing is a matter of riding style and personal preference. It also makes a big difference what bike you're riding. I ride smaller rings and bigger cogs on my 22lb steel bike than I do on my 14lb carbon bike.

1) I have the Apex cluster with a 32t biggest cog (forget if it is 11 or 12 for the smallest) on my cargo bike. Works great.

2) Biggest cog is definitely a personal preference. I rarely use the 25t in this region and really love the much closer gear ratios of the 11-25 or 12-25 (I have a few of those too).

Thanks. I think one can generally work out a decent guess by playing with a gear inch calculator (http://www.sheldonbrown.com/gears/). My guess is that we're recommending a pretty big drop in gear inches for the OP assuming a standard rear cluster. 36/42 --> means about a 15% drop. 34, of course, will be a bit more. Although now I'm wondering what is the Cannondale's age. If it is really old, the OP might want to check the OLD and whether it is 130mm instead of 126.

If my memory is right, I've seen the Big Dummy with pink bar tape a few times ride past my house. I was really disappointed to miss out on the Big Dummy frameset sales last year, but it would have been a risky purchase for me since it still isn't clear what my future is with uprights.

seagrave6
11-10-2010, 07:27 PM
I forgot to mention that it has a 13/25 in the rear,now I am starting to think I may be able to get by with 39/52-13/28.Any thoughts?

invisiblehand
11-11-2010, 12:41 PM
I forgot to mention that it has a 13/25 in the rear,now I am starting to think I may be able to get by with 39/52-13/28.Any thoughts?

Changing a chainring and a cassette -- you do have a nine speed cassette in the rear ... right? -- will almost certainly be cheaper than a crankset and a cassette. High quality 39-tooth chainrnigs are readily available. A 13-28 cassette would be a custom job. If you go custom with the standard road double, you might consider something like a 13-30 which your road derailer will almost certainly handle.

http://www.sheldonbrown.com/k9.shtml
http://sheldonbrown.com/deakins/lowgears.html

Now that Captain Bike is gone, I've had lots of good experiences with Tom Deakins if you decide to pick up a custom cassette.

BTW, regarding swaping your 42 for a 39, you should be forewarned that the shape of many front derailers are designed for a specific combination of chainrings. So you might get finicky STI shifting up front once you swap the 42 for a 39. Lucky for you, front derailers are relatively inexpensive. But you should consider this additional expense before modifying the bike.

seagrave6
11-11-2010, 10:12 PM
Thanks,I will keep you all posted on how it turns out!!

seagrave6
11-19-2010, 09:59 PM
ok now I have test rode the bike with the 39 up front it helps,but now I am going to try 36/50-13/25,by the way I am starting to get some chain rubbing the big ring.
The fun continunes,thanks for all the input.
Ride for fun,live to ride!

invisiblehand
11-20-2010, 12:57 PM
ok now I have test rode the bike with the 39 up front it helps,but now I am going to try 36/50-13/25,by the way I am starting to get some chain rubbing the big ring.
The fun continunes,thanks for all the input.
Ride for fun,live to ride!

That should make a pretty big difference.

Just to be clear, you are writing that when you are in the 39 tooth chainring, the chain rubs the 52 tooth chainring? I assume that this only happens when you are in the small cog in the rear.

You might try flipping the 39t chainring over. Has the chain fallen off when going from the big to small chainring?

What type of bottom bracket do you have? Square tape or octalink/ISIS?

seagrave6
11-20-2010, 10:42 PM
Yeah it only rubs when riding on the lower chainring,never miss shifts,its a square taper that I plan on upgrading with the new crankset.

Just161
11-22-2010, 08:06 AM
Newbie question - what do all these numbers and ratios mean? I think I need a cheat sheet!

invisiblehand
11-22-2010, 12:29 PM
Yeah it only rubs when riding on the lower chainring,never miss shifts,its a square taper that I plan on upgrading with the new crankset.

If your plans change, you should put a spacer and shift the crank out a mm or two to eliminate the rubbing.

skreaminquadz
11-22-2010, 01:03 PM
Newbie question - what do all these numbers and ratios mean? I think I need a cheat sheet!

The higher numbers 50/34 generally refer to the number of teeth in your front rings (the ones attached to the crank you're pedaling on). So a 50/34 means your big ring has 50 teeth, and your smaller ring has 34 teeth. So having three numbers, means you have three rings.

The lower numbers 11-25, refers to the number of teeth in your rear cluster. So 11-25 means that you have several cogs (rear rings) that span from 11 teeth to 25 teeth.

Intuitively, in the front the larger the number the harder it is to pedal.

Not-so-intuitively, in the rear the larger the number the easier it is to pedal.

I’m no expert here so if anyone has a better explanation or correction to my response, please feel free to chime in. Hope this helps.

seagrave6
11-23-2010, 07:43 PM
thanks for all the helpful info!!! I purchased a 50/36 13/25. I have to work,until Monday before I can test ride it on the hills here in Takoma Park.