Damon Rinard's 2016 Cannondale CAAD8 105

[raisinberry777]

Is the new CAAD8 Optimo going to have a threaded bottom bracket on any models or will it all be BB30?

[DamonRinard]

The new CAAD Optimo will come in two frame versions:

- Threaded BB with rim brakes, and
- BB30 with disc brakes.

Otherwise they're the same frame: same tubes, shapes, geometry, etc.

[CultofCaad]

In the mean time I'm riding it almost every day, it's a great riding bike, handles well, feels fast and smooth. Makes me feel like attacking the lunch ride!!

What do you think of your CAAD8?

Cheers,
Damon

Damon, as you said, the bike is great!
So much comfort, very good handling, it feels like you don't need a carbon frame.
And it's beautiful, mine is "race red", so cool . I'm really satisfied !

Welcome to the new Caad Optimo for 2017. I'm sure it's a great bike too.

Thanks to all the people in Cannondale for the passion that they (and you!) put in these great bikes!

[raisinberry777]

The new CAAD Optimo will come in two frame versions:

- Threaded BB with rim brakes, and
- BB30 with disc brakes.

Otherwise they're the same frame: same tubes, shapes, geometry, etc.

Nice! It's getting harder to find nice aluminium frames with threaded bottom brackets. Pity they won't come with a nicer fork, but hey, that's what I probably deserve for not keeping up with the times.

[DamonRinard]

Speccing a nicer fork isn't easy. The CAAD8 / CAAD Optimo value price is a delicate balance. I'm trying to find out how a, for example, full-carbon fork's price could be justified: lighter weight of course, but then would the bike have to come with less expensive parts...? Maybe there's some more Cannondale aluminum engineering magic we can apply to improve the existing fork...

[istigatrice]

Nice build and impressive weight!

Not meaning to derail the thread, but it's something that has been bothering me for quite some time - why do all the smaller sized Cannondales have a ridiculously high stack (compared to reach)? Are you able to run me through the logic of the high(er) stack height/short(er) reach for your smaller sizes?

[DamonRinard]

Not sure I'm seeing the stack & reach trend you're talking about. Do you have some longer/lower models you're comparing?

[istigatrice]

The stack and reach of the smaller sized Cannondales do not increase linearly, unlike many other brands which increase it linearly. For example, SwiftCarbon have similar stack/reach on their larger models but progress their sizing much more linearly.

I'd like to understand why this is done? Or is it just a compromise to achieve desired BB drop/Fork length?

[DamonRinard]

Thanks for that example, I see what you mean.

As usual, it's more than one thing.
- Strength decreases with very short head tubes, so the stack decreases less and less with each smaller size. (This can be overcome with layup but it's not easy.)
- The first generation EVO, like most bikes of that era, was designed by changing top tube & head tube lengths, so also didn't have linear steps in S&R. Nevertheless, the fit was VERY well liked, so the second generation EVO followed that general trend (while smoothing out the zig-zags).

Luckily for the rider, the steps in stack or reach from your size to the next size has no effect on your fit. So for the rider, it doesn't matter whether the change in S&R is linear. It's mainly interesting to designers and fitters, not necessarily to riders.

Which size EVO would come closest to your fit coordinates? Which stem & spacers would you choose to get there?

[istigatrice]

interesting viewpoint, especially on the headtube since the smaller sized cannondales have some of the shortest head tubes in their size.

I'd also disagree on the fitting "VERY well" - stack and reach definitely have an effect on the rider. What if a rider needed 503mm or 480mm of stack, you don't offer that stack option, and if they're already using a 17 degree stem then your bikes just won't fit. Doesn't matter what you do with stems/spacers/reach if the stack is too high... I guess I'm going on a rant now, such a target demography is probably too small to care about anyway.

[DamonRinard]

Exactly. Stack and reach are critical for rider fit: you need one size. If it fits, it fits. If it doesn't, it doesn't. Then, once you have your size, it doesn't matter whether the next size steps linearly.

The Cannondale EVO may not fit every rider, but overall our dealers (and GURU fitting data) confirmed that many, many riders fit well on them.

On the other hand, you're right to pinpoint that Swift's two smallest sizes have lower stack, and although that is a smaller demographic, it is becoming a more important market for us, not only for shorter men in North America, but also because many women in North America, and people of both sexes all over the world, are often in that size range. It's a missed opportunity for us in this model, and an area where I think you will see improvements in our future models.

Cheers,
Damon

P.S. Edited to add: UCI rules don't apply to very many riders, but FWIW the handlebars are not allowed to go below the top of the tire. Roger Hammond mentioned that to me when I was Race Engineer with Cervelo TestTeam, and although he wasn't very worried about the rule, he was worried about skinning his knuckles on other riders' rear wheels in the peloton! -DGR

[Sacke]

P.S. Edited to add: UCI rules don't apply to very many riders, but FWIW the drops are not allowed to go below the top of the tire. Roger Hammond mentioned that to me when I was Race Engineer with Cervelo TestTeam, and although he wasn't very worried about the rule, he was worried about skinning his knuckles on other riders' rear wheels in the peloton! -DGR

Damiano Cunego must be flirting pretty closely with that rule.

[DamonRinard]

Indeed!

Here's the "CLARIFICATION GUIDE OF THE UCI TECHNICAL REGULATION"
http://www.uci.ch/mm/Document/News/Rule ... nglish.PDF

The rule is Article 1.3.022, starting on page 27:

“In competitions other than those covered by article 1.3.023, only the traditional type
of handlebars (see diagram «structure 1») may be used. The handlebars must be
positioned in an area defined as follows: above, by the horizontal plane of the point
of support of the saddle (B); below, by the horizontal line passing through the highest
point of the two wheels (these being of equal diameter) (C); at the rear by the axis of
the steerer tube (D) and at the front by a vertical line passing through the front wheel
spindle with a 5 cm tolerance (see diagram «Structure (1A)»). The distance referred to
in point (A) is not applicable to the bicycle of a rider who takes part in a sprint event
on track (flying 200 m, flying lap, sprint, team sprint, keirin, 500 metres and 1 kilometre),
but must not exceed 10 cm in relation to the vertical line passing through the front
wheel spindle.”

[RyanH]

Hi Damon,

Not exactly related to your build, but seeing a chance to enquire about stack and reach since it's being discussed, I have a few questions. If I recall correctly, Cervelo brought stack and reach measurements to the mainstream. I assume that was around the time you were there, correct? Cervelos have nice linear progression through the S/R curve, which many manufacturers have trouble offering. The question is, does that come at a cost of handling or otherwise in the largest and smallest sizes? When I was looking for an aero road frame, reach figures are relatively long, especially for the smaller frames. Cervelo S5 had the shortest reach (the one I should have picked up) while the Scott Foil was longer, but relatively reasonable compared to the Madone, for example. My second question is, if a rider is on the cusp between a 48 and a 50, what things should they keep in mind when choosing between the two frames? With the Evo, as an example, what design choices went into designing the 48 vs the 50? I have this perception, and I may be wrong, that the smallest frames will ride differently than the middle of bell curve frames, so all else being equal, choose the next size up assuming you can make it work since it's closer to the intended handling characteristics (when discussing sizes smaller than 56, opposite for larger sizes).

[DamonRinard]

Hi Ryan, good questions.

In the late 1990s, with a few exceptions frames were usually measured either center to center or center to top (of seat tube). Giant brought in "compact geometry" with sloping top tubes but the real innovation in frame dimensioning came from triathlon. With "funny bikes" and dropped top tubes the length of the seat tube no longer indicated as much about where your handlebars might end up.

So Dan Empfield started promoting stack & reach.

While I was at Trek, Lance retired (the first time) and in 2008 Trek was finally able to bring out a road bike with sloping top tube. Suddenly they had to decide how to measure it. With horizontal top tubes, Treks had always been measured center to top. So road product manager Tyler Pilger and I considered lots of potential measurement schemes, including a set of polar coordinates Gary Klein was pushing: the direct distance from BB to hand, and the angle that line made from horizontal. (Bikes are 3D, but if you ignore width then they're 2D, which means any two dimensions can fully describe where points fall in space. In polar coordinates it's a length and an angle, rather than two lengths as in Cartesian coordinates.) Long story short, Trek started reporting stack & reach. We smoothed out the zig zags in the old OCLV geometry and created H1 and H2. Later someone added H3. (And now it seems Trek's designers have forgotten stack & reach, as some of their trend lines have zig zags again.)

When I started working at Cervelo in 2008, they already had a nearly smooth S&R line. This was somewhat by luck, since HT lengths were the driver (100, 120, 140, etc.) and seat angle was a constant 73 degrees in all sizes. (Variable seat angle is what usually leads to zigs and zags if you're not at least watching S&R while designing.) There was only a kink around size 54 and 56, which no one remembers designing in. So when Gerard wanted to increase handlebar height I arbitrarily made the new geometry linear.

(By the way, in the GURU database with thousands of good fits, road riders from tall to small are happiest with a seat tube angle around 73.2 plus or minus a fraction of a degree, so Cervelo was right to fix seat angle there for all sizes. As far as I know, this is virtually unexamined and unknown outside a small number of insiders, and since seat angle has little effect on power output, and most of the world wants it to vary, many bikes still vary seat angle with size, even Cannondales.)

Trek didn't make a big deal out of stack and reach, it just showed up on the geo table. But Cervelo did, mostly in response to, for example, Pinarello dealers, who felt Cervelo's 6 sizes weren't enough compared to Pinarello's 13. But some had stack and reach points less than 5(!) millimeters apart, and lots of zig zags. So it made sense to market a rational stack and reach line to dealers. Still we knew there was no direct benefit to riders. Once you have your size, who cares what the next size is like? When buying a bike, look at stack and reach points, not lines.

To your question of handling, a good handling bike can be designed nearly without regard to how straight the stack and reach line is. Although they're both part of geometry, it sometimes helps to think of "fit" as separate from "handling." The dimensions that fix your feet, seat & hands, have only a secondary effect on defining steering response and weight distribution. Of course there are limitations, and smaller sizes often get screwed if the designer isn't paying attention. The usual crime is too much trail, which leads to understeer.

Which size?
If you can fit two sizes according to stack and reach, then look next at saddle position. Sometimes the STA gets really steep on smaller sizes. Team Estrogen Forum women have spotted that, and share sources for seat posts with more setback to fix it. Also consider water bottle space & standover.

As for "intended handling," ride what feels good. Don't compare handling to the medium size; compare it to other bikes in your size. It should handle alright to *you.* But don't get hung up on handling: after a few corners, most people can adapt to most bikes. These days it's pretty hard to buy a bike with "bad" handling. Back in the 1970s however...!

One of the cool things we've done at Cannondale is make a fork with adjustable offset. Within seconds you can be riding anywhere from 38 to 78 millimeters offset. We pass the fork around, so different people (on different size bikes) all get a chance. The usual response is "Yeah, it feels different, but I can ride 'em all!" That's not to say handling doesn't matter, just that it's not a big point to get hung up on when choosing a model or size.

One example: In preparation for Paris-Roubaix, we supplied Roger Hammond with three forks. Various combinations changed head angle, offset & trail. After riding them all for a few months on his familiar training routes in Belgium, during the January training camp in Portugal Roger summed up his impressions of how they each handled differently. But it didn't make sense based on the dimensions. After discussing with him for a few minutes (and a quick sketch on the box Thor's new bike had come in), he realized he'd gotten it backwards! That's how close most handling is. (He's a degreed engineer so was able to follow my description of the physical effects of gravity on flop and of rolling resistance on trail, etc.)

So choose what you like, but don't sweat the small stuff.

Cheers,
Damon