To go Compact or Not... (Page 3)

This has my vote.  Though it's probably still in a fairly narrow range (i.e., mashing at 50 rpm for 112 miles probably isn't good for just about anybody, nor is spinning at 130 rpm).

I think the best advice is to try to get comfortable using a wide range of cadences and then find the tighter range that works best for you when riding steady for long periods.  Then choose gearing that allows you to stay within that range as much as possible over the terrain/conditions you have to deal with.

100% right and I agree with you on all of that.  Adjusting your pace and effort via gearing allows you to maximize performance.  No argument there.  But it still goes back to, if someone is running out of gears on a hill and needs smaller gearing, then they are going to go slower, plain and simple.

The implication that seems to be prevalent is that by changing to compact gearing an athlete is able to go faster on a course with the same amount of effort.  That is completely wrong.  All it does is to allow you to fine tune your gear ranges, which as you said can be done with a compact front, various cassettes in the rear (as Shane mentioned), or by changing your effort level and cadence with the ones you have.

If someone rides a 2:45 HIM split with a 53/39 and an 11-23 they are not going to suddenly be able to ride a 2:30 by switching out to a 50/34 and an 11-21 on the same course.  A 2:30 split requires an average wattage of ......... whatever.  A 2:45 split requires less.  It really is that simple.

No, it's not completely wrong.  It takes more 'effort' to spike your power to climb that hill and then ease back and recover than it does to ride at a more steady power.  So it takes the same average power to ride a 2:45.  But the 'steady' rider will have used less effort in getting there than the 'spiker'.  Alternatively, the 'steady' rider could use the same effort as the 'spiker' and finish the course in under 2:45 (the average power would now be higher, of course).

Yes, but that's assuming that you actually need to spike it to climb with it.  Once again, we are going back to overall gearing selection and effort levels during the ride, which is NOT a compact specific thing.

My ride at LP ....... 39/23 spinning at an average of around 80 - 85 going up the hills was a very easy effort for me.  For others to put out that same level of effort (Z1 to Z2) may have required a different gear range to stay there, which is fine and good racing strategy.  I certainly never spiked throughout the entire ride and stayed even.  And I never needed an easier gear than what I had.  In fact I rode conservative as hell by riding that gear, basically conversational pace.

It is about effort and pacing.  If you are geared out and REQUIRE extra effort and spike your power then it will come back to haunt you.  If someone decides to go slower on the uphill portions, or spins more cadence, it does not mean that they will "make it up" on the flats or downhills because they saved something going up.  Unless they exert more on the flat/downhill they are going to be slower overall.

Yes, that's my assumption on why some people can say they are faster with compacts yet ride easier.  (an assertion you questioned)

Of course it's about gearing.  That's all compacts are--different gearing possibilities.

Yall are making me wonder if I should not have just ordered a compact to replace my triple that is bent.

I live in FL where it is flat but do ride some hills.  On a few of them, I have been on the inner gear in the triple and the biggest gear on the rear and doing all I can to get up the hill at about 6-7mph.

I thought that with my current fitness, using a standard double may present some issues on some hills and I really did not want to stay with the triple as it has not been a good experience due to loosing the chain.  It also seems that doubles or compact doubles are more popular... but that may just be my perception. 

I think this got lost in the shuffle and bears repeating. Seems pretty simple (and accurate) to me.

Because the one set of cranks were 170's the other 175's  

Here's the thing about "compact cranks"....It is the bolt circle diameter that makes a compact a compact, not the chainrings attached to it. You can run any gearing you want on the compact (110 BCD)...most of them come from the factory with 50-34, but you can put a 53/39 or whatever on the spider.

The smallest inner ring you can put on a standard (130) bcd spider is a 38.

That's what I like about the "compact" set-up.

Additionally, with 10-speed cassettes available (from SRAM) in 11-26 and 11-28, and with an 11-25 available from Shimano (albeit at 105 level) What the compact spider offers is a much wider variety of potential set-ups, particularly on the low end of the spectrum.

The ability to get near-triple low gearing without the issues associated with triples, plus no necessary loss of "big meat" makes the 130 bcd look like the odd-man out rather than the 110.

Zipp Vumas use a proprietary spacing.  I think you can get some for them.

But then again, if your dropping $1,200 on cranks then you SHOULD get whatever you want on them!

Oh wait ........ mine are on order (53/39 thanks) ............

Thanks!!!!  I will take a look around and see... Cranksets are about the only thing that I haven't messed with on a bike!  New challenge!!! 

We can all dream!!!!   Those things look awesome!!!!  unfortunately, I won't be seeing those on my bike any time soon. 

Here's a couple of sources for >50 tooth 110BCD rings:

http://sheldonbrown.com/harris/chainrings/110.html

and

http://www.jensonusa.com/store/product/CG408A06-Sugino+Standard+Chainring.aspx

They are not all that hard to come by. I can't speak to the flex question, but I have to think that if you're tourqueing hard enough on the crank that you're flexing the rings, maybe you need to be using a lower gear... 

OK - I agree - moving gear ratios around is all you are doing with the compact set up - and this makes it easier to spin with higher cadence up a hill with less effort - but with the bike moving more slowly.

But there may be other advantages to doing it this way than are  at first obvious- I recently read some research about the effects of cadence on muscle type recruitment.

We all have a mix of slow and fast type muscle fibres - the exact mix is mainly genetic - but can be modified a little by training.

It appears that spinning a high cadence with lower effort can recruit slow twitch muscle fibres (ie long endurance but lower peak power muscle - the type most marathoners have most of).

Mashing up the hills in a higher gear recruits increasingly more fast twitch fibres. These fibres are good for big power - but tire more quickly / build up lactate more rapidly (the ones sprinters have most of!).

SO - by spinning up the hills (on a compact?) you may be giving yourself an advantage over the course of the whole race -  you recruit a larger percentage of your power your from longer- lasting slow twitch muscle and are not tiring out the fast twitch muscle / bulding lactate.

The end result might be  a slightly slower bike leg - but probably a faster run - possibly faster overall race. (or - it may mean a slightly faster average bike leg - cos you didn't wear yourself out in the hills!)

Well - that's my theory and (cos I am little and weak - and an ex marathon runner! ) I am sticking to it.

Triassic

 Here's something that backs this up that I took off of SlowTwitch.

Yup and for most those processes take years. I just prefer to enjoy as much of that time as possible... w/ my compacts  

Fast twitch  fibers are the explosive power ones and are brought into play for hard sprints, short fast hill climbs, etc.  Fast twitch A fibers are more of a "middle ground" and over time training in endurance sports many of those will morph into the same sort of function as slowtwitch fibers and make you a better and more efficient endurance athlete.

But spinning versus mashing doesn't really use more fast twitch B fibers.  They both use A and slowtwitch.  The only place where B come into play is as I mentioned above, when you sprint and hammer hills.  Think "explosive" with the B.  There is little to no reason an AG triathlete in a non-drafting race should ever need to really use those on the bike.

Next ......

bryancd - 2008-08-14 10:27 PM I'll wait to see any of you punks go under 5 hours on the bike and a sub 3:30 (not including the weak FL or AZ course) and then I will believe..

Believe what?!?!

IT'S JUST GEARING!!!!!!!

I can't understand how we can go pages and pages on compact cranks.  You don't see pages of debate about swapping an 11-23 cassette for a 12-27.  It's the same kind of decision.  Sheesh...