wsuhoops1000

Lets do this comparison, how much faster/more comfortable/nicer in general

Aluminum bike with 105 components vs Cervelo S5 with Di2, Zipp 404 Firecrest

Just wondering is it really that big a difference? Speed or comfort?

Thanks

FPSDavid

0.0000000000000001mph

gregf83 

The zipps and S5 would probably take about 20-30W less power for the same speed. Not much difference in comfort. The S5 wasn't designed as a comfort bike.

cyclezen

105 is not entry level. not fancy but certainly up to the task of some heavy duty miles without much more than routine maintenance.

theses days real entry level bikes that are a solid build are really quite nice machines - heads above the stuff sold at that level in the past. I'm not talkin Kmart-Costco or similar.

bikes are the sum of parts and little things - all small relative differences adding to more significant improvements.

the difference you ask about might be the same as the diff. between my old steel race machine and my current tarmac - it's the difference whether I get shelled earlier in the group hammerfest or much later...
at my age I really shouldn't care - but I do...

iflabs

Marginal gains. I don't think you'll be able to appreciate the difference unless you push your bike to the limits on a daily basis. My LBS doesn't carry any bike fitted above 105 components but will special order if you request.

coasting 

comfort helps ride more and ride better.

justkeepedaling

40 watts is marginal to you? OK...

jdip

105 is proven to be slightly more comfortable than Di2.

Bacciagalupe

In theory:

40km TT @ 30mph takes 48 minutes.

Cervelo S5 frame vs a "round tube" (non-aero) frame: 20 watts saved, or 82s. Aero wheels, let's say another 20 watts. That will save you 2 minutes and 45 seconds, out of 48 minutes (6.75% faster).

But that's only at that pace, and in optimal conditions. If you're riding at 15mph, drag is substantially lower, and you'll get almost no benefit. 25mph you'll get somewhere between 1/2 or 2/3 of the benefit. Real-world conditions (like crosswinds) will also change the actual results.

For climbing, let's say the entry-level bike is 22 pounds, and the über-bike is 16. You might get a 2-3% increase in speed with the lighter bike -- but again, if you're climbing slower than say 15mph, you won't have the aero benefits.

In terms of comfort, I'd expect it's a wash. Aero road bikes aren't made with comfort in mind.

An S5 with higher-end components will feel better (smoother, crisper etc) and will be more robust. Electronic shifting will require less maintenance.

An entry-level bike with Sora, a good saddle and good tires is $1000. With 105, let's say $1600. An S5 with Zipp 404 FC tubulars and Red (or Ultegra Di2) might cost $6500.

cerealkilla

At these extremes it can make a difference. I have noticed so anyhowz. And am happy to put the investment into a higher grade bike. I use the philosophy of; buy once (or twice), but buy the best you can.

Wesley36

Hmmm, interesting made-up numbers. There is a lot of math floating around the interwebs that show quite clearly that the often made claim that slower riders will get no benefit from aero enhancement is false - the slower rider gets a GREATER time saving than the faster rider. The faster rider will be more likely to win races with aero enhancements though...

Moreover, the cross-winds objection reflects a lack of understanding about what happens in a wind tunnel. All the wind tunnel data I have seen in the past 5 years specifically looks at the effects of varying the yaw - the angle at which the wind strikes the object being measured. Indeed, it is my understanding that the shift from v-shaped deep rims to the current toroidal designs has been driven by a focus on non-zero yaw drag. That is, directly into the wind v-shapes are not so bad, but once the wind is coming from the side, the toroidal shape performs much better.

FWIW, here are numbers that were gathered by Cervelo in regard to the S5 (so not impartial), but they actually reflect real research, not invented numbers. For aero data, pages 6-10 are most relevant. Note that all aero comparisons occur across a range of yaw angles.
https://www.cervelo.com/media/docs/Ce...oom=auto,0,233

Wesley36

PS Re: my first claim. 10 seconds on google turned this up:

https://alex-cycle.blogspot.ca/2013/0...er-riders.html

achoo

But then you post this:

The faster rider takes 3.3% off his time, the slower one 3.1%.

When you're finishing 5 minutes off the pace, the fact that your uber-aero wheels and frame saved you more absolute time than they saved the winner is totally irrelevant.

It's like spending thousands of dollars and putting performance parts on a Yugo. BFD. If you really want to get faster spend your money on a coach who knows what he's doing instead.

Wesley36

Which is sort of what I said - if winning counts, the slower rider is still the slower rider. Be that as it may, it is empirically false that there is no speed benefit to a slower rider using aero improvements. The slower rider with aero upgrades is in fact faster than the slower rider without aero upgrades. There is a clear and demonstrable, if small, benefit. Other interventions might have a greater benefit for an equivalent cost (ie coaching), but that is totally beside the point.

The question on the table is, will aero upgrades make a cyclist faster - not will aero upgrades make a mediocre cyclist a winning cyclist in races (obviously, no). And the answer is, yes, aero upgrades will make a cyclist faster, but probably not by as much as they might hope. And, since the 41 is a place for judgement, you could spend your resources better than buying aero upgrades.

Wesley36

To return to the OP on a different note, the S5 is definitely not designed as a comfort bike, but I would still rate it as a more comfortable ride than all of the aluminium road bikes I have had the chance to ride (such as the DeVinci Caribou, Spesh Allez, and Felt F75 - bikes with quite a range of geometries). I have liked the ride on all of these bikes, but the S5 feels like it is on another level. I would suggest that you look into test riding some bikes - it will tell you a lot more than speculation on the 41.

Bacciagalupe

They aren't "made-up." They're based on actual wind tunnel tests by a 3rd party.

https://velonews.competitor.com/2012/...visited_256023
https://velonews.competitor.com/2012/...urchase_264284


And yet, the Cervelo S5 whitepaper you linked demonstrates that, in fact, aerodynamic benefits increase dramatically at higher speeds.

At 25kph, the S5 saves you about 5 watts. At 40kph, they claim it saves 25 watts (only 5w off the Velonews numbers). I'm going to go out on a limb and say that 25 watts > 5 watts. (Page 11.)


No, it really doesn't.

Wind tunnels test different yaws, to make a reasonable approximation of real-world conditions. No one would ever say that what you encounter in a wind tunnel is exactly what you'd see in the real world. Nor did I say that wind tunnel numbers are useless -- which is why I cited them, with the proverbial grain of salt.


I'll stick with Velonews, kthx. Their numbers aren't necessarily perfect, but at least they aren't an interested party.


We should also keep in mind that in real-world conditions, we don't always see these theoretical advantages bear fruit. My favorite example for this is Mark Cavendish, who spent years sprinting on non-aero bikes (e.g. Scott Addict, Specialized Tarmac, Pinarello LSD Meltathon or whatever it was...) beating riders on aero bikes. This year he's riding a sprint-specific aero bike (the Venge), and getting pipped at the line by, uh... riders on non-aero bikes.

It's difficult to draw a specific conclusion from this. It could be due to problems with the lead-out; Cav may have had a bad line one day and not enough recovery from climbing on the next; this year's crop of competitors could just be faster; and so forth. But it may also be the case that saving 40 watts when you're cranking out 1600 just doesn't wind up having the kind of impact we'd expect, or that a harsher bike fatigues the muscles and somehow slows the sprinter down at a critical moment. We may never know.

Notgrownup

The motor makes the most difference... HP and Torque...Same as internal cumpostion...No replacement for displacement...Stonger is faset...Of course taking in account the gearing being the same.I have a CAAD8 2300 (entry level) i doubt i would have any more speed on a Supersix or them carbon Ultegra ...Until my motor is in great condition i ain't even thinking of upgrading other than the wheels...They actually be heavier than my stockers....But then i use my bike for exercise, i couldn't care less how fast it goes...as long as i get back home in 1 piece...

Bacciagalupe

C'mon, man. If you're doing a TT at 150w average, saving 30 seconds is the least of your worries. You have so much more to gain from training that it really doesn't make sense to spend thousands of dollars on a "faster" bike.

There's also the question of relevance. To a recreational rider, a 10s gain over ~20 minutes is not just irrelevant, it's noise -- and far beyond anyone's ability to detect reliably. If I'm doing a competitive TT with a precise timer chip, a 26s savings means a few placings. What is relevant to the latter is irrelevant to the former.

I also like how you blast Internet numbers... and then cite them.

iflabs

Would like to see your source that says a high end bike is 40W more efficient.

gc3

ummm...which one do you have...and did you really think anyone would answer the question directly before turning the thread into something else?

Smokehouse

There is zero point in me getting into much of this argument so ill stick with what I know.

A. The 105 is a great group that a large % of riders will fine absolutely perfect for their needs. My current 105 shifts crisp and reliably, I have zero complaints. (I don't apply "comfort" to group set.)

B. more often then not...upper level frames are stiffer to suit the needs and power more advanced riders demand. This translates to less comfort.

C. Fit and typical contact points are what help with comfort. The right kit, the rights bars/tape, the right saddle and like I said...a correct fit will make any bike more comfortable regardless of the price of the bike.

OldTryGuy

Maybe for 2012 but what about a more recent test...https://www.giant-bicycles.com/_uploa...st_Results.pdf

BTW-My Propel is awesome!

AbsoluteZ3RO

These threads always bring out a lot of nonsense. The better bike is better. Probably much better. How much faster? It depends on a lot.of.things, but assuming the ridier can put the same amount of power into each for.the same amount of time, the rider will be faster on the better bike. How much? A lot more than the .0000000000000001mph claimed in the second post. A lot less than 10mph.

hhnngg1

40 watts is wayyy too high for realistic gains from aero S5 + wheels. For a joe-average rider who might put out 175 watts in a 60min time trial (or triathlon leg), that would mean a nearly 25% power savings.

Also, the notion that someone mentioned about 4 minutes saved over 48 minutes (10% of race time) is also hugely overstated. Even with ALL the aero toys, you'll be lucky if you even get 2 minutes per hour of racing, and for most folks it'll be closer to 1-1.5mins with all the aero toys. Unless, of course, you're comparing to a fully upright nonracing position, but that's less of an equipment issue than fit issue.

I made significant progress this past season by training a lot (for me at least) on the bike, and raised my FTP by about 20 watts. It was a very noticeable difference - way more than my aero wheelset and aerohelmet combined yield for sure.

Bacciagalupe

Please read the claim again.

It's not 40 watts across the board. It's 40 watts at 24+ mph, or closer to 400w. And that's under optimal conditions.


Actually, the claim is "2 minutes 45 seconds," which is around 6%. But who's counting?

Bike Radar ran some tests, both wind tunnel and field, comparing a tarmac to a full TT setup. Going from a Tarmac with clip-on aero bars, to a Transition with aero bars, saved about 18 watts @ 40kph in the wind tunnel. Going from a road bike with a TT helmet, to the tri bike with a TT helmet, saved 31 watts in field testing. Cervelo's internal tests suggested around 25 watts in the same conditions.

I.e. we've got multiple independent tests which produce on similar numbers.

There could also be lots of reasons why you personally aren't replicating these results, but I'd rather not speculate on that point.