standard v. compact: crankset question for a lil peep riding 650s

rah2774

Sorry to bother you all with this - I was hesitant to post the Q as I suspect it's been hashed out already... I've read the wikis and some of the power and joule threads and know the EN standard, but I'm trying to figure out the "why" and am having some trouble (I admit I'm not a techie and a lot of this is new to me)... In a nutshell, I'm planning on a Quarq/Joule combo... I've gotten some conflicting advice from my LBS and local tri clubber friends whom I trust (two of whom are rockstar duathletes - one of them is also a tri coach and a bike mechanic who is tiny and rides 650s)... basically the LBS and duathlete friends advise against my going with a compact crankset on 650s.

I'm a lil peep at 5'4 (race weight 125, I hope).  My TT has 650 wheels and currently has a 9 speed DT with a standard double crankset.    

 

I dropped off my TT for a tune up and asked them to note the BB length so I could order the quarq... The techie said I wouldn't need the measurement bc the new units are built altogether... which led to a conversation with both techies who were manning the service desk.  I told thim my coaches recommend a SRAM900 and I'd need that measurement as well as the crank arm length.  One tech pulled up the SRAM page and recommended I get a S975 which has the BB built in he said it may be a bit more expensive, but worth it for the ease of changing it out, etc.  I looked it up and the 975 specs are standard double (50/39) with a Garmin head unit (I'm assuming I can work it with a Joule)

 

More importantly, the guys at the shop after looking at my bike, wheels, and my current set up both think I should stick with the standard double and that I should remind you of my size and the size of my wheels (650s) - they think losing so many teeth would mean I'll be spinning without any power and will have a gearing gap.  Their take was unless I ride mountains I should stick with the standard double.  I do ride hilly courses around here and am planning on IMWI next year... but I'm not buying the crankset for one specific race, i want it to be the best purchase for any race... regardless, I'm okay with my set up - I can get up the hills now.  I particularly like my big gears for the flats and descents...  My friends, who are very good triathletes/duathletes (one of whom was a semi-pro cyclist, the other is a coach and bike mechanic) agree with the LBS and think the S975 is my bet.

 

So why do you all recommend the compact over the standard double?   Particularly on 650s

 

Bottom line, I want to understand this because it is a MAJOR purchase.  I want to be totally at peace with it knowing it will make me a better rider/athlete/competitor.  So far the team and coaching has worked wonders and I hold your advice in the highest regards, but I'm not gonna spend this kinda money just because Mr. X said this is what I should get...

thanks everybody... oh, and answers in plain English will be helpful... I am a marathoner turned triathlete.  So, my learning curve is really high!

Steven Ford

Becky this will be interesting as I ride 650's too as you noticed I am vertically challenged (to big to be little peep)

 

 

tgarson

I'll let someone else comment on the specificity of the argument for a compact as it relates to 650's however I can offer brief anecdotal evidence for the compact on 700ccs. I currently have a Quarq built into a standard double, use a 310xt for the head unit with a Joule on the way but that is unrelated. After riding the IMWI course on 53x39T (double) and a 12-25 cassette I found that I was wholly unable to spin up the hills on the IMWI course anywhere near goal wattage. To keep a cadence of over 70, I'd easily be in the 300+ watt range. I tried to remedy this by getting an 11-28 cassette and went back out and rode the course again. It's pretty much the same result, slightly better this time, but my cadence has to be miserably low <50 in order to climb the WI hills anywhere near my goal wattage. <br />


I'm not a little peep, but I'm not a heavy one either. I'm 6'0, ~150 pounds, Watts/kg hopefully around 3.9 - 4.0 on raceday. In other words, climbing is usually my specaility, it's where I put the hurt on local riders during training. But, I sincerely wish I had a compact for Wisconsin. It had never been a problem and I always felt my 53-39 was sufficient prior to WI. So I suppose just to re-cap, while I understand their arguement when it comes to 650, I would be careful to consider whether or not the people giving you advice have ridden in accordance to strict IF guidelines (EN-ninja style) on a course like WI. You may not need the compact 95% of the time, but the 5% of the time when you may really need it (during IMWI) may be the most important 5% of the time you spend on the bike. Again, the caveat is that I am not knowledgeable enough to comment on whether 650s would nullify the benefits,

 

jburbatt

I don't ride 650s, but I did change to a compact about a month and a half ago after riding the IMWI course and really focusing on doing it the EN way. I found that even though I "could" hold my watts o.k.-ish on the hills, I was really really low on cadence, and on the bike and once I got off my knees were killing me from the pressure. I was hesitant to go compact for the reasons you stated above, I really like riding in my big ring, especially since I find my average cadence is generally lower than most (something I'm working on, but still wanted to consider that). But since going compact there are very very few times I wish my big ring was bigger (usually while flying down a hill ) but there are plenty of times I'm glad when I'm climbing any size hill, but especially really challenging ones. And my knees do not hurt as much anymore since I'm sure I'm not mashing them as much. I really really doubt you'll be missing those few teeth in the big ring, but you'll be happy with the change with climbing. Maybe others have found differently though?

mancona

I have never rode on 650s so take this with a grain of salt...

My gut feeling is that 90% of the people racing IM on 650s still should use a compact with a 50/34... vs on 700s it is probably 95% that should be riding a compact.  The exceptions to this are the folks going under 5 hours.  Ofcour

That said, everyone has an opinion... I've had many many people (who rode over 5:30 compared to my 5:07 in Madison) tell me I was crazy for riding a compact.

If you want a truly objective decision point...use this website: http://public.tableausoftware.com/v...cleGearing

This will let you figure out the exact speeds you can hold with various gear and cadence combinations on 700 or 650 wheels.  Plus it makes it easy to compare compact/standard and different cassette options.

William Jenks

Another thing you might want to check is the pair of gears you quoted.

Usually "standard" is 53/39 and "compact" is 50/34.

I'm 5'9", 145ish with 700c wheels. I'm a little slower-all around than Trevor - you can see my statistics below. I also did the WI rally, and was convinced by a similar experience to Trevor to buy the compacts. I did and am very happy. (I've got 50/34 and 12/25). I have done two HIM races since - one on a pretty Madison-like course, and I'm not going back.

Now to address the 650/700 thing.

Comparing 650s to 700s, you'll "lose" a bit less than 10% of gearing, i.e., every gear will be easier by the fraction of 650/700. So, if you spin out at 34 mph in a 700 wheel, you'd spin out at ~30.2 mph with the 650. So, what you are going to see is that the compact would give you even EASIER gearing with a 650 wheel than with the 700 wheels.

However, what you may be overlooking is that the CHEAP thing to manipulate is the cassette in the rear. If you invest in the compact crank in the front for teh >$1000 and keep the 12/25 cassette you have, it's possible you'd decide that you wanted to shift your gearing a bit to "harder" gears. But here's the good news - you can do that cheaply with a readily available cassette: [50/39 + 12/25 + 700 wheels = normal EN reccommendation] is almost identical to [50/39 + 11/23 + 650 wheels] in terms of gearing. Same high end, same low end, and 4 gears between 20 and 25 mph at 90 rpm

If you don't want to just do the math, please look at this site - it gives a great visual comparison:
http://public.tableausoftware.com/views/bikegears/CompareBicycleGearing

New cassettes are $60 (and up...but ultegra is consistently available for under $100). Coach Rich rode 50/34 and 12/25 for a long time (on a 700 wheel), so you know that it's got high enough gears for us normal peeps.

Chris G

 something else to consider, you may want to have the quarq longer than you have that bike and more and more manufacturers seem to be doing away with 650 wheels.  Regardless of the wheel size 50/11 is a taller gear than 53/12.  So if you are not spinning out with a 53/12 now you will be less likely to do so with a 50/11.  If you are spinning out 53/11 the story may be different.  What are you typically running on the rear?

TerryO

I agree with Jenks and Chris G. I know, I know....gonna hear it again. I don't know about 650's per se. But....

I'm definitely not the most powerful cyclist, but I like to think I hold my own. My FTP is 235 (about 3.4 w/kg) at 152 pounds. I have the Quarq with the Lightning compact (50/34) crankset and 170mm crank arms + Joule. I run a 12/25 in back. Down a pretty stiff wind, I've never spun out at 50/12 and have reached speeds about 30-32mph holding about 200-220 watts (85-90%). Downwind, downhill I have done it going 38+mph but how long do you hold that? For me, I don't need to go any faster. I'm barely comfortable going that fast, and not for very long. Where it counts is on them hills. I had no problem nailing goal watts on the hills of the Queen K/Road to Hawi at the HIM last June.

Bottom line...I can't see the downside of going with a compact. And even if you become a wicked, badass cyclist, and you need to step back up to a standard, just have your sponsors get you a new one!

Coach Rich

Good input from all. The 650c will change things but in a good way. Let's go with the standard EN guidance of running a compact + a 25-11 or 12 for pretty much every Ironman course.

The downside of that cassette, even with a compact, is that you are dropping 14 teeth (25-11=14) in 10 cogs...or 9 if you have a 9spd drive train. So that cassette, with good for climbing and good for going fast downhill, will have a "cadence gap" in there somewhere due to the fact that you are dropping 14 teeth across 9-10 gears.

This means that somewhere in the cassette you'll be mashing at 80-82rpm, for example, and with one shift go to spinning 97rpm (totally making this up). The problem is that you're likely not comfortable at either 82 or 97rpm, but this is just the nature of the beast with running a cassette like a 25-12 or 26-11.

But because the 650c wheel is smaller than the 700, it effectively "adds a tooth" to every cog in your cassette. So, generally, a 23-11 on a 650c wheel is about the same as a 25-12 on a 700c wheel. The good part of all of this is that the 23-11 is a "tighter" cassette than the 25-12 = less or no cadence gap.

Chris brings up an excellent point about the future usability of a compact vs standard crank on any future 700c bike.

All of this is academic to this fact:

I'm the Coach in this Haus and I will not sell an EN member a standard Quarq crank. You should ALL be riding compact, if you can afford to make the switch. Period.

We have a ton of posts in this forum, the old forum, and a very, very wide variety of members have chimed in on these threads, nearly all happy to have made the switch. If Bjorn Anderson or some other uberbiker decides to join EN and wants to buy a Quarq from us, I may consider making an exception to this "thou shalt not purchase standard cranks" rule. But until then...I won't let it happen, not on my watch

Oh, the other rule is to never, ever, ever, ever listen to the gearing advice of an LBS.

Chris G

 Maybe Bjorn would not regularly be walking in races if be had a compact 

kmepham

Hmm, I'm riding a Cervelo P2 with 53/39 crankset and 12-25 cassette. So my first priority should be replacing the crankset, rather than the cassette?

tgarson

Kevin, replacing the casette is a lot cheaper move in the short term, but the compact is the better long term solution. To be honest, I'm OK with my 11-28 on my 53x39 in the majority of races, I'd probably be fine in most Ironman races too other than say IMWI and IMSG. But since I'm a lighter guy and I'll probably tend to favor those type of races say over IMAZ or IMFL the compact would definitely be the better longer term solution.

When I can afford to, I'm going to sell my Quarq, which I got used for $1000 and probably could still sell for $1000, and build a new one into a compact crankset assuming that the MetriGear Vector never materializes (I'm not holding my breath). The 11-28 cassette was a band-aid, but long term I'll definitely go Compact.

William Jenks

Kevin -

Until recently, I had 53/39 and 12-25 most of the time, and had a 12-27 cassette, which I used for Madison last year. It was an ok solution, but I have been much happier with the 50/34 and 12-25 since I switched, though that was admittedly only a month ago. See Rich's remarks above about a cadence gap when you consider whether the big cassette in the back is better than a compact.

If you hunt around, you should be able to find a Shimano R700 compact crank for ~$150 (including the BB) right now. This is the just-obsolete version that has been replaced by the Ultegra and DA models. It's a very reasonably priced and very good quality option available so cheap because they stopped making it.

William

kmepham

Thanks, guys, that makes sense. I'd been concerned about the cadence jumps in going to an 11-28, so I can see where it would be worth the extra investment to switch the crankset instead, and stick with my 12-25. My bike came with an FSA SL-K Light carbon crankset so I want to get at least that level of quality in a compact.

William Jenks

I am pretty sure that's the same crank mine came with, but not 100% certain. I slapped the R700 on my P3, taking off whatever the stock was on that, and mancona told me that he had ridden with the R700 at least last year. (I think he has since changed it, but I'm not sure.) The R700 a bit heavier in all likelihood than what you have (and the current ultegra or DA option), but if you have an otherwise Shimano setup, you may find it shifts better. I have, and (for what it's worth) my LBS said it would in advance of my observation. You will also save a few grams due to a shorter chain. :-)

Very quick price search, all for a 172.5 mm version:

Shimano FC-R700 with BB $150 on ebay (new)

From Amazon.com, no BB
105: $210
Ultegra: $300
DA $525
FSA SL-K $360

kmepham

@William, thanks for the tip, the reviews for the R700 on roadbikereviews are very positive, including a lot of people swapping out FSA's for it and happy with the switch. Now I don't feel so bad.

mancona

As William said, I road a Shimano R700 all year last year. It is basically the 105 level of performance in the shimano line (making it 3rd tier). It worked great for me and shifted better than the flashing FSA Carbon crank I had before. Sure it was a little heavier though.

Now I ride a Quarq SRAM S900, which is their Force Level crank (2nd tier). Again, works great with no issues at all. I do have a Red Ceramic BB that spins really smooth though.

I think the reallity is that none of us in the house are generating enough force that the stiffness of having a top of the line crank makes any difference at all. The weight difference is also very small between the cranks. If you want one, go for it, there are a lot of things I want and buy, but don't let any bike store tell you that you NEED a Dura-Ace, SRAM Red, S975, FSA SLK Light, or Zipp Crank.

William Jenks

I do a lot of business with my LBS (my son also does triathlon, and I have two younger kids who keep getting bigger...). I had talked compact with them and they said they could no longer get the R700 at all. They advised me to go for it. (The manager is a crit racer my age who is state-champ level and uses the one below it -R600) They were very cool about installing it when I told them how much it was. Installation was under $20.

If you do switch from FSA to Shimano, you'll need a new BB, which runs $40 or so. (or can be gotten directly with the R700 as I mentioned)

Wm

kmepham

Bikewagon.com is selling a new Ultegra SL 6650 with BB for $170, free shipping. Anyone know how that compares to the R700?

William Jenks

Shimano has a pretty extensive web site, although it's not the easiest thing to navigate I don't think. Might want to look here:
http://techdocs.shimano.com/techdocs/index.jsp

The R700 docs are under "non series components" under road bikes and the 6650 is under "ultegra" and road bikes. I haven't looked carefully, but I imagine that they would view te 6650 as an upgrade (lighter)...but it's worth checking.

kmepham

Did some research, the Ultegra SL 6650 is basically just the R700 brought into the Ultegra series for the first time (previously compacts were excluded from the series, who knows why). Weight was reduced about 50g (all the SL cranks got reduced weight), new finish (Ice Grey), otherwise the same. Which seems to prove the R700 was an Ultegra-level component, just not branded as such. Sure sounds like, for the money, R700/6650 is the way to go. Thanks for saving me from blowing twice as much on an FSA SL-K Light compact.

rah2774

awesome info!  thanks all around... it turns out, since I posted this, the LBS found a crack in my frame (it's not catastrophic, but it can't be fixed)... so I am now searching for a new bike or frame... if all goes well, I'll find some end of the season sales (Todd at TTBikeFit may have a sweet deal for me since I'm a lil peep riding lil wheels...). 

The bike I'm eyeing comes with zipp 404s with a standard double and a 12/23 in back.  Once IMFL is done and the bike is paid off I'll get the compact quarq and a 12/25 cassette for the back Zipp which will leave me with 3 money sets of wheels in every range conceivable... everyday ride (mavics) has 12/27, 404s with 12/25 and disk with 12/23!

But, interestingly, Todd mentioned to me that he also sells Quarqs, that and that the S975 comes in compact.  Checking out the joule page, it appears to be $150 more (list price) than the S900, 110 bcd.  Is it worth it (I started another thread about this)?