Wednesday, August 27, 2014

Tour magazine test of "under 800 gram" frames

Tour Magazine did a web feature from an article in the Dec 2013 printed magazine "Lieichte Rahmen unter 800 Gramm." This featured 8 bikes, all exceptionally priced, which presumably get under the challenging 800 gram mark for a bike frame.

Now 800 grams is hardly new. For example, Ruegamer showed a custom frame under 700 grams at the National Handbuilt Bike Show 6 years ago, and that frame is still ridden a ton by weight weenie legend Don Becker of Berkeley. Spin, a company in Germany, was also around the same mass at that time.

But production bikes tend to be overbuilt due to the need for mass production margins and since sometimes the fattest riders buy the lightest bikes, irrationally. It's not a good thing if a 100 kg rider snaps his 51 cm frame after hitting a pothole on his 3 mile bike commute. Additionally, 1500 watt sprinters may perceive an extra few mm of flex in a super-light frame, causing irrational fear that precious watts are being squandered. So the game has more often then not been to claim lower weight by changing the protocol (for example, without paint, without derailleur hangers, even in the case of Pinarello without bottom bracket shells.... I'm still waiting for a company to leave out the epoxy and just weigh the carbon fibers). Cannondale, for example with the Evo, used an "equivalent" mass attained by adjusting for various design features on the frame, on the basis they could have made it that light had they designed the frame differently.

Despite this, big US media almost always report the claimed mass of the frame. After all the claims are from advertisers, and it doesn't do well for advertising revenue to indicate any lack of trust in their claims. It's been said "the customers of magazines are the advertisers, the product is the reader; they deliver the product to the customer."

The German magazine Tour, however, ruthlessly weighs every frame they review, and that includes the frames of complete bikes, which obviously requires disassembling it. They weigh not just the frame, but also the fork and bearings, reporting each separately and rating the bike on the combined total. This is important, because usually everything else on a bike is replaceable, and in any case there's almost always various component options for each frame, so a "fair" comparison comparing like-to-like with different companies becomes impossible.

I say "ruthless" because while it's common to report the lower mass associated with smaller-sized frames (the most infamous case of this might have been the Guru Photon first shown at Interbike, a tiny custom), they target a "medium" frame, medium by German standards, which is typically what is called a 56 cm to 58 cm. The other difference is they are willing to use a white version of a bike, and since white paint needs to be applied generously to fully occlude the black background, white frames tend to be heavier, especially relative to a clear coat option. So the numbers are often on the high side. The result is if you come out light in the Tour magazine tests, that says a lot.

So back to the "800 g" article. They measured the following:

  1. Cannondale SuperSix Evo Black, a personal favorite of mine. I test rode a Cannondale Evo back soon after they first appeared in a local SportsBasement and it was very nice.
  2. Cervélo RCA: the famous $10k frame described in Cervélo's white paper. This is a wonderful combination of light, aero, and optimized stiffness but with an anomalously tall head tube which calls for a relatively long, -17 degree stem to get a racing bar position.
  3. Corratec Mauro Sannino Prima: I've heard of Corratec, but don't really know anything about them.
  4. Focus Izalco Max 0.0: Focus has always been a practioner of the "fatty down tube" style of frame design, which I don't like. But they do claim low masses.
  5. Neil Pryde Bura SL: Neil Pryde made big claims about this frame, but in the end, it wasn't particularly light compared to competition. I suspected this wouldn't do as well as some of the others like Cannondale, obviously Cervélo, Simplon, or maybe even Trek (with its expensive vapor coat paint).
  6. Pasculli Altissimo: I don't think I've ever heard of Pasculli.
  7. Simplon Pavo 3 Ultra: Simplon is one of the frames that perennially competes for the top spot in Tour's ratings. The frames are very light, but like the focus, designed with the fatty downtube philosophy which results in poor aerodynamics.
  8. Trek Madone 7.9 H1: Trek historically didn't brag much about weight, at least until the latest Emonda "fatty downtube" design, but the top-tier Madone with vapor coat does very well. Trek always comes through with a really light, super-priced top-end frame, then they beef out frames lower in the range which are sold at a consideraly lower price.

Here's the results, ranking the bikes by total mass:

modeltotalframeforkbearingsstackreachSRratio
Cervelo RCa1082704323555763871.48837
Simplon Pavo 3 Ultra1113717324725593941.41878
Cannondale Evo Black1123760303605593961.41162
Focus Izalco Max1164802293695654021.40547
Pasculli Altissimo1203789336785593941.41878
Trek Madone H11204786379395454041.34901
Corratec Mauro Sannino Prima1209783336905474041.35396
Neil Pryde Bora SL1241802374655623901.44103

Tour goes beyond mass, also measuring stiffness (good and bad) to come up with an overall score. I'll leave the stiffness scoring to them: check out the German article.

One thing which pops out here is that despite the title of the article, two of the frames are over 800 grams: the Focus and the Neil Pryde. The Focus makes up for it to a large extent with its exceptionally light fork: the only fork under 300 grams, something which used to be fairly common back in the mid naughts but which is rare now due to increased safety standards. Note the Cervelo fork is 323 grams, well above 300, despite its expensive micro-think nickel coating for strength. The Neil Pryde, on the other hand, complements its 802 grams with the 2nd heaviest fork in the group, only the Trek Madone heavier and just barely. The Trek Madone, however, has the lightest headset bearings by a decent margin.

On average, these bikes have the following masses:

avg bearingsσ bearingsavg forkσ forkavg frameσ frame
6614.3701333.528.4912767.87535.4663

Interesting here is that the difference (as reported by the standard deviation σ) in bearing mass is around 40% the difference in frame mass, and the difference in forks is around 80% the difference in frames. So just looking at frame mass, fairly common, doesn't tell nearly the whole story. And there's only a weak correlation among these frames between frame and fork mass. So you really need to consider both, unless you're planning on replacing a heavy fork.

The total mass has an average of 1167 and a σ of 52.4 grams. This σ is larger than you'd expect if the three mass componts were uncorrelated: the uncorrelated result would be 43.4. So there's a positive correlation among components.

On the specific results: the Cervélo wins on total mass (it's also the most aerodynamic, I'm fairly confident). The Simplon and the Cannondale are close behind, trailing by 31 and 41 grams. The Simplon frame is impressively light at 717 grams, only 13 grams more than the Cervelo and 43 grams lighter than the Cannondale. The Cannondale scores strongly with the light bearings and the light fork.

By the way, even though the Cervelo RCa "won" on total weight, the frame weight is higher than Cervelo claimed for even the heaviest of the size 56's. Did Tour include something with the frame that Cervelo does not? The Cervelo number includes "hardware":

Here's rankings by sub-class: frame, fork, and bearings.

modeltotalframeforkbearingsstackreachSRratio
Cervelo RCa1082704323555763871.48837
Simplon Pavo 3 Ultra1113717324725593941.41878
Cannondale Evo Black1123760303605593961.41162
Corratec Mauro Sannino Prima1209783336905474041.35396
Trek Madone H11204786379395454041.34901
Pasculli Altissimo1203789336785593941.41878
Focus Izalco Max1164802293695654021.40547
Neil Pryde Bora SL1241802374655623901.44103

modeltotalframeforkbearingsstackreachSRratio
Focus Izalco Max1164802293695654021.40547
Cannondale Evo Black1123760303605593961.41162
Cervelo RCa1082704323555763871.48837
Simplon Pavo 3 Ultra1113717324725593941.41878
Pasculli Altissimo1203789336785593941.41878
Corratec Mauro Sannino Prima1209783336905474041.35396
Neil Pryde Bora SL1241802374655623901.44103
Trek Madone H11204786379395454041.34901

modeltotalframeforkbearingsstackreachSRratio
Trek Madone H11204786379395454041.34901
Cervelo RCa1082704323555763871.48837
Cannondale Evo Black1123760303605593961.41162
Neil Pryde Bora SL1241802374655623901.44103
Focus Izalco Max1164802293695654021.40547
Simplon Pavo 3 Ultra1113717324725593941.41878
Pasculli Altissimo1203789336785593941.41878
Corratec Mauro Sannino Prima1209783336905474041.35396

Geometry in this review is primarily parameterized by stack-to-reach ratio. A bigger number is a more upright bike, a lower number is a more aggressive, lower or longer geometry. Here's that ranking:

modeltotalframeforkbearingsstackreachSRratio
Trek Madone H11204786379395454041.34901
Corratec Mauro Sannino Prima1209783336905474041.35396
Focus Izalco Max1164802293695654021.40547
Cannondale Evo Black1123760303605593961.41162
Pasculli Altissimo1203789336785593941.41878
Simplon Pavo 3 Ultra1113717324725593941.41878
Neil Pryde Bora SL1241802374655623901.44103
Cervelo RCa1082704323555763871.48837

The Trek and the Corratec are the most aggressive, each at 1.35. Then there's a pack at 1.42: Focus, Cannondale, and Pasculli, and Simplon. This seems like a good numberto me. Then there's the Neil Pryde at 1.44, and in a class by itself, the Cervelo is 1.49.

Geometry is plotted here, where each bike's point is at the center of its label:

image

Adding spacers (assuming a 73 deg HTA) moves you up the near vetical blue dotted lines. Adding a longer stem (0 degrees) moves you along the near horizontal lines to the right. A +6 deg would move you at an upward slope relative to these lines, a -6 deg would move at a less steep slope. The spacing between lines is 1 cm.

The result is that it would take around 3.5 cm of spacers, and a stem 1 cm longer, to match the position of the Madone or Corratec on the Cervelo.

Which of these do I take? I'll eat the SRratio and go with the Cervelo. It wins on mass, it wins on aerodynamics.

Sunday, August 24, 2014

fitting a Cervelo demo R5?

On a recent ride, I found a shop local to the day job, Cupertino Cycles, had a Cervelo Demo R5. Cool! Since reading the RCa White Paper, I've always wanted to try one. Indeed, I've never ridden any of the Cervelo R-series.

Recall, perhaps, the Peloton magazine review of the RCa, the prototype which led to the present R5:

There is a fury to the way the bike reacts to power -- it leaps from under you, but the feeling continues beyond the initial acceleration. Each pedal stroke delivers a new surge forward.

Who wouldn't want to ride this?

Deal is the Cervelo geometry is, as I've described, a bit tall. So it isn't obvious what frame to try. But is low-stack over-rates?

So what I did is I started with the geometry for the Fuji SL/1, which is my race bike (since I've done little racing recently, the poor thing is getting neglected).

I started with the geometry of the size small, which I ride. I use a +6 degree 11 cm stem at present (I used to use a lower position but found that the lower bars didn't actually result in a flatter back, especially since I don't use shallow bars, but instead just caused my shoulders to roll forward, which causes back strain, so I flipped the stem). In conjunction with the 71 degree head tube, this results in an upward 25 degree slope for 11 cm on the stem, which results in the adjusted reach-stack coordinates shown in the plot below. I have 1.0 cm of spacers on top of a low-stack headset cap as well, not shown in the plot:

image

The original Fuji stack-reach is shown with the "x" on the open black circle toward the lower left, then the result of the stem is shown with a "*" toward the right.

Note this is not a relaxed position: I still have 9 cm of drop, which is plenty. Really the frame is by most standards "too small" for me. I was lured to the smaller frame by the lower mass and by the possibility for lower bar position. But I overestimated how much drop I really wanted. I'd have been better off with the next size frame as it would have bought me a steeper head tube, even if it had been slightly heavier.

From this point, I want to "undo" the effect of various stems to find the frame stack-reach coordinates which would give me the same position with various stem options. I picked stems from 9 cm to 13 cm long, with angles of either +6 deg, -6 deg, or -17 deg. Note the spacing of stem angles is 12 deg and 11 deg, so they are relatively equally spaced. The target for these stem angles were the Cervelo 48 cm, 51 cm, and 54 cm R5. They have head tube angles of 70.5 degrees (this is how they manage to get such short reach on the small frame -- super-slack head tube, then compensate trail with a long-rake fork), 72.2 degrees, and 73.1 degrees. In general, I consider a 73 degree head tube to be superior to a 71 degree head tube, since it results in less wheel flop: the wheel is less prone to flopping over when the bike is tilted, resulting in better cross-wind control. But I've never done controlled experiments to verify this.

Note if the trajectory from the Fuji-with-stem position passes over a frame size, spacers can be added to the frame to bring it up to that trajectory. Additionally if the trajectory falls under a frame size I could remove up to 1 cm of spacers to bring the fit down. There's blue dotted lines on the plot showing what points are accessible by adding spacers, with roughly orthogonal dotted blue lines marking 1 cm intervals. These lines are drawn for a 73 deg head tube, so would apply best to the 54 cm Cervelo, but would also be a good approximation for the head tubes of the other frames, which differ by at most 2.5 degrees.

Fit coordinates I don't consider to be an exact science, and all I need to do is get close. With this in mind, the 48 cm frame could fit with a 13 cm stem at +6 degrees. That's obviously excessive. The 51 cm stem would fit with an 11.5 cm stem at -6 degrees. That's acceptable, not too far from the Fuji except with the stem flipped. And the 54 cm Cervelo would fit with a -17 degree 10 cm stem. That might actually be the best option since it would give the steepest head tube angle and also a shorter stem which would stiffen the front end.

In any case, the shop doesn't have a 51 cm demo, so I'd need to pick the 48 or 54. Given the choices, a 54 would be the obvious pick. However, I doubt they'll have a -17 degree stem available for a test ride. I can check, however.

Also on the plot I show Cannondale and Trek Madone H1, although the stem adjustments aren't drawn for the head tube angles on these frames. I could fit each of these as well, with shorter stems.

Consider, for example, the Evo geometries:

The 52 cm size with a zero degree stem looks like it would work, or a -6 degree stem with some spacers. The 54 cm size could also work fine: I could remove 5 mm of my 10 mm spacer stack, perhaps removing all of them with a headset cap 5 mm taller, and get the same bar position, using a -6 deg stem. There's a small error in these projections due to the head tube angle difference.

This plot shows an alternate route to the same result. Here instead of starting with the target position, I start with each of the three Cervelos. I then extend the various stems away from these positions.

image

The 13 cm +6 deg stem from the 48 cm Cervelo scores a virtual direct hit on the position I presently have with the Fuji. The 11.5 cm -6 deg stem from the 51 and the 10 cm stem -17 deg stem from the 54 come in within 1 cm of that position, low. This is easily rectified with an extra 1 cm of spacer: no problem.

So again, the big stack Cervelos work. However if I could choose a Cervelo with the Trek H1 geometry I'd probably take that instead. It would shave several cm from these stem lengths. The 54 cm frame (3rd in the series) would provide plenty of options, using either a -6 deg stem with spacers, or a 0-deg stem with fewer spacers.

Saturday, August 23, 2014

Cervelo geometry: R5Ca versus R5 and RCa

The old R5Ca, Cervelo's first version of a super-high-end stock bike ($10k for the frameset alone, and people, to my amazement, actually paid it...), used a relatively novel geometry whereby the downtube was offset forward of the bottom bracket. With the nominal 72 degree seat tube angle, this in effect gave a seat tube angle which was steeper for shorter bikes, more laid back for taller bikes. In this case by "shorter" and "taller" I mean bottom bracket to saddle.

With most manufacturers the same thing is accomplished by changing the actual seat tube angle from steeper in the smallest size (for example, 74.5 degrees) to more laid back (for example, 72.5 degrees) in the largest. But of course the effective STA doesn't then change with the amount of seat post showing.

Here's a plot I did:

image

But this was an experiment they didn't pursue. Maybe it caused too much confusion to dealers. I don't know...

In the present version of the R5, and the RCa prototype bike which preceded it, the seat tube appears to conventionally intersect the bottom bracket at its axis:

image

They've gone back to 73 degrees for all frame sizes.

Friday, August 22, 2014

stack vs reach: Calfee Dragonfly, Guru Photon, Lightweight, AX Lightness, Cervelo RCa, Trek Emonda

So far I've been sticking mostly with main-stream bike brands with the exception of Swift. This time I'm focusing on premium frames, including the stock geometries from custom framebuilders.

For reference, I include the Trek Emonda, which is obviously both light and expensive in the SLR with vapor coat model. Then I include the Cervelo RCa, the same geometry as the Cervelo R5, which is the most expensive frame here, at over $10k with the crankset, but it's also (except for geometry) perhaps the best all-around bike ever designed (the white paper is fantastic). Then I include two exotics: the AX-Lightness Vial Evo, extremely rare so far, and the Lightweight frame, which needs to be included by virtue of its name but which actually isn't that light when compared to the Cervelo and Trek. Then there's the Guru Photon, which made a bit splash when it was announced at Interbike around 5 years ago, but for which the low weight shown there was a very small frame built to the spec of a very light rider. Then I include a bike which is not at all particularly light, the Calfee Dragonfly Pro Geometry. The Dragonfly is usually custom built but Craig Calfee offers a standard geometry option.

Here's the stack versus reach:

image

The Cervelo R5/RCa is the tallest in the smallest frames, with only the Trek Emonda H2 in the larger frames. Note, however, Trek offers the H1 as well, so Cervelo wins on the tallest shortest.

Then there's AX Lightness in the small geometries, coming closest to the Cervelo 51 in the smallest of four sizes, but then following a relatively gradual slope to the largest. The philosophy here is one that going vertical at the head tube is fine: you can invert the longer stems typically used with larger frames, or use spacers. I like this philosophy as I was never a fan of the "SlamThatStem" aesthetic. I like having some breathing room under my bar position for adjustability.

Lightweight is fairly similar to the AX Lightness, following a more zig-zag trajectory through its range. It provides a more reasonable 6 sizes.

The Calfee pro geometry is middle of the road between the Trek H1 and H2, zigging and zagging, with reach actually decreasing between the 2nd and 3rd smallest. But it provides an impressive 10 sizes, the same as Colnago which I showed previously. And since Craig is a custom builder, this range shouldn't be taken as limiting. The zig-zag actually provides more options int he small sizes.

Guru Photon is another bike with a custom option. The stock range is the 2nd most aggressive on this group, with only the Trek H1 clearly lower/longer.

And finally, while Trek Emonda retreated a bit from the very aggressive Trek Madone H1 geometry, it's still the most aggressive in this group.

My preference? The Cervelo RCa white paper is a nerd's dream: I love the description of their design process. And the RCa provides the shortest reach of any of the models I've looked at here (even women's frames, which I don't consider here, tend to hit a lower bound on reach and simply reduce stack in the extra small sizes). The tall stacks, especially in the low reach range, aren't to my taste.

But could it work? My Fuji SL1 has a 51.5 cm stack, 37.9 cm reach, and a 71 deg head tube angle. It has an 11 cm, +6 deg stem, which is thus sloped upward at 25 degrees: 10.0 cm lateral, 4.6 cm up. So this is a net position of 56.1 cm vertical, 47.9 cm lateral.

The 54 cm Cervelo R5 has a reach of 37.8 cm, stack of 55.5 cm. So with 10 cm stem at -17 degrees, which preserves stack and extends reach, that puts me at essentially the same coordinates. So perhaps there is sanity in the Cervelo madness after all. At least for me a reasonable stem: -17 deg and 10 cm, seems to put me right on the 54 cm Cervelo RCa.

Given that the engineering on that bike is just amazing, balancing aerodynamics with light weight, that's the bike I'd take. Of course, that's the bike a lot of people would take, given it's $10k a pop for frame, fork, and crankset.

The Emonda is attractive except for downtubes which look like parachutes. I've not seen wind tunnel data but until I do and I'm proven wrong, not for me.

Thursday, August 21, 2014

Trek Emonda: geometry comparison and other comments

I'd left the Trek Emonda out of my previous comparisons for two reasons. One is it's technically a 2015 bike. Note, however, I'd included the Specialized Tarmac 2015, but that was an iteration on an existing bike. But more importantly I left it out because I don't like it.

You'd think I would, as it's marketed as a weight weenie special. But, unlike another weight weenie special, the Cervelo R-Ca, the Emonda is designed with down tubes which show an utter contempt for wind resistance. And for what weight savings? 30 grams. Yes -- 30 freakin' frams: the claimed weight for the Madone Vapor Coat H1 is 720, the claimed weight for the vapor coat Emonda H1 is 690 grams. There's a lot of ways to save 30 grams. 30 grams will save around 0.35 seconds up Old La Honda.... which I'm pretty sure will be squandered to wind resistance by the Emonda's bulbous down tubes. If the CdA of a rider on a Madone is 0.35, and if the Emonda is 100 grams equivalent of force more wind resistance at 30 mph (according to the Cervelo RCa white paper, the RCa is 102 grams more and the Madone 76 grame more than the Cannondale Evo, and the Emonda is almost surely more than the Cannondale Evo judging by the bulbously eccentric down tubes), then that's a CdA difference of 0.009. If you're going up Old La Honda in 16.5 minutes, that's 12.2 mph. That speed reduces the force difference to 16.5 gram-equivalents. That's 869 joules of work up Old La Honda. If you're riding at 300 watts, that's 2.9 seconds.

So weight savings is great, but paying 100 grams-equivalents of added drag at 30 mph for 30 grams of mass reduction saves you 0.4 seconds but costs you 2.9 seconds for a net time which is 2.5 seconds slower, assuming 300 watt power.

Note I assumed the wind resistance difference is 100 gram-equivalents at 30 mph. This is my best guess. But even if I'm off by a factor of two, and it's only 50, then it's still a full 1 second slower despite the mass advantagr.

So, you say, 30 grams? But what about the 4.6 kg weight? Madones are least 1 kg more.

This is really a matter of marketing by Trek. The reason the bike is so light starts with the mutant-light wheels which stock on the $14k Emonda. They are over 100 grams lighter than my Mount Washington wheels, which are already crazy light. There's a bunch of other similarly weenie-special parts on that top end Emonda. If you were to put those parts on the Madone, you'd have a bike which was very close in mass to the Emonda, with the possible exception of the semi-ISP on the Madone. The frame itself plays relatively little role in this impressively low mass. And indeed, Trek have priced the top-end Emonda so high, I'm fairly sure you could set up a Madone with that part list for less.

And if you look beyond the SLR, the top-priced Emonda frameset, the bikes aren't even remotely light. It's 1050 grams for the SL version, and 1200 grams for the S version, according to Trek. For comparison, 1050 grams is the same weight as this late 1990's Trek 5500, repainted. That's progress. My 2008 Fuji SL/1 is 860 grams for a size small.

Anyway, back to geometry. The top end Emonda comes only in the H1 geometry, according to the web site, but you can still get the SLR frame built to a more conservative part spec with the H2. The H2 Emonda is basically the same as the H2 Madone, but on the H1 Emonda Trek went a bit taller. Since a number of pro riders have adapted the Emonda over the Madone, this doesn't seem to be too much of an issue.

image

Note the H1 is slacker now, but it's still more aggressive than the Specialized Tarmac and Venge. If you slam the stem on your Tarmac, your fit on the Emonda H1 would have around 1 cm of spacers with the same stem, and your fit on the Madone H1 would have around 2 cm of spacers for mid-range sizes. In the smallest geometry only the Tarmac is close to the Madone and longer than the Emonda. Curiously the largest Emonda goes super-long, an apparent attempt to capture more of the statistical tail of tall riders, which makes sense.

Other aspects of geometry are similar to the Madone, which is a good thing. Bottom bracket drop is size-dependent, which makes sense since smaller bikes have shorter cranks and so can have a lower bottom bracket without cornering clearance penalty. Trail is relatively low, around 5.6 mm except for the smallest size which is only up to 6.1 cm in the Emonda (5.8 cm in the Madone). The moderate trail is due to the heat tube angle dropping to only 72.1\v{0.3}\-\-o\N on the Emonda (72.8\v{0.3}\-\-o\N on the Madone). Cervelo uses long-rake forks (> 5 cm) on the smallest R5's, but Trek uses a 4.5 cm fork on the smallest Madone and Emonda. Overall I think every aspect of the Trek geometry makes sense. Indeed the Emonda H1 would fit me better than the Madone H1.

So it's not really lighter, and it's obviously a lot less aerodynamic: why would any of the pro riders choose the Emonda over the Madone? One possibility is they didn't choose: the choice was made for them based on marketing. Another possibility is they fail to appreciate the importance of aerodynamics, which has strong historical precedent. Pro cyclists aren't necessarily more sophisticated than weekend warriors. But a third possibility is they've considered the aerodynamic cost, and balanced it against a benefit in ride quality. Indeed, Peloton Magazine in its latest issue reviewed the bike and said it was the "liveliest" Trek yet. Does this translate into better race results, despite the parachute-like aerodynamics? I can't say. Racing is an extremely complex dynamic. But I'd guess not.

Wednesday, August 20, 2014

Canyon versus Storck: Stapel-erreichen Smackdown

I previously showed the Canyon Aeroroad. But Canyon's perhaps more popular bike is the Ultimate, a perennial competitor for Tour Magazine's lab-dominated bike of the year ratings. A prime competitor is Storck, a more niche German company known for its engineering-based approach to bike design. Included in that approach is a relatively unique approach to geometry.

Here's a comparison of Trek, Specialized, Canyon, and Storck road bikes, where I've left off the endurance bikes this time:

image

Canyon is clearly sticking to the stack-reach design philosophy with both of its models. And for once a bike company does the obvious which is to make the aero bike lower. And the longest Ultimate is incredibly long. It must be those tall Norwegian customers.

But the Storck 0.6 is a bit bizarre. The smallest size differs only in stem length, essentially (actually with the head tube angle being slacker than 73 deg, slammed stem will result in the smallest being slightly higher). Then after that "constant bar height" move, it goes constant reach (straight up). The Aernario is basically the same with the addition of a larger size with longer reach & stack.

Tuesday, August 19, 2014

Stack-Reach smackdown: Trek vs Specialized

Last time I compared Trek to Cervelo for stack-reach. The Madone H1 and the even more aggressive Domane Race were much longer/lower than the Cervelo H1, and even lower than the more race-geometry Cervelo R-series from 2008. The Madone H2 and Cervelo R5 were comparable. The Trek Domane 6 was substantially more relaxed than the Madone H2. It's really designed more as a century bike than a race bike, although it may provide a good fit for some racers.

Here I compare the Specialized line to the Trek line. I already looked at the 2015 Tarmac. In the following plot, I add in the Roubaix endurance bike as well as the Venge aero road bike:

image

The Venge is basically identical to the Tarmac. The Roubaix is fairly close to the Trek Madone H2, not nearly as relaxed as the Roubaix: around 2.5 cm spacer difference. The Madone H1 is more aggressive than the Tarmac, however: with two lines of Madone they can afford to be more aggressive on the longer/lower version. This suggests for racing the Roubaix may well be the better choice than the Domane, unless you want to spring for the super-low, super expensive Domane Race.