Campag4life

You can run 25mm tires on the stock rims that come on the Diverge and the bike will be fast enough for pavement riding. The Roubaix will be lighter and a bit more aero and faster on pavement but honestly, not that much. There is a bit of overlap between the Roubaix and Diverge in fact. The Diverge is really a cross bike but the same stack and reach as a Roubaix i.e. has more endurance geometry than their stock cross bike aka the Crux.
If you size up a Crux the stack and reach is pretty close to a Roubaix/Diverge...maybe just one stem length size (10mm) separates them.

zymphad

Don't know much about Diverge.

Roubaix is RACING bike. It was designed with Boonen, winner of Paris-Roubaix to be a bike that can ridden over rough tarmac. Not to cruise around going over gravel and through woods. But to WIN RACES.

So while for most, a diverge with 25mm tire will be just as fine on tarmac as a Roubaix, the difference you asked? Roubaix is a RACING bike that can be ridden comfortably over rough roads.

revchuck 

Funny you should say that...my first A race next year is 106 miles, of which ~25 miles is gravel, and most of the race is through the woods. A Roubaix would do fine, a Diverge might be better still. It'll be interesting to see if one shows up.

MRT2

Maybe I am missing something, but the Diverge looks like a newer version of the Secteur Sport Disc OP already owns. So, what am I missing? As far as I can see, the Secteur is every bit as much of a "real" road bike as is the Diverge.

halfspeed

The Roubaix isn't a race bike, it's a geriatric fred bike. Boonen's Roubaix is not the same thing.

Plus, racing on gravel is a thing.

zymphad

Then Specialized are liars! They total deceiving me! I want Boonen's bike, not a geriatric fred bike

Jay Olson

Everybody's definition of what makes a "gravel bike" is different, but to my mind, you need the capability of running big tires (i.e. 38mm or more). By this criteria, the Diverge misses out. However, for a mixed purpose, go-anywhere bike, the Diverge certainly is a contender.

halfspeed

" As before, Boonen is riding a frame with semi-custom geometry, dubbed "60 pro," which has the same reach as a 61cm frame but drops the front end considerably, creating the long, low position Boonen prefers."

Read more at Pro Bike: Tom Boonen's Specialized Roubaix SL4 - VeloNews.com

halfspeed

As a side note, Trek is now selling a pro geometry Domane.

zymphad

What about Tirpstra's Roubaix that won Paris-Roubaix 2014?

newbie101

It looks like Diverge is an all disc brake line, while the secteur line has standard calipers.

Campag4life

One notable aspect of Terpstra's S-works SL4 Roubaix was he ran a 0 setback 2 bolt seatpost to allow him to get real aero and support his big saddle to bar drop. He also ran 30mm wide tires.
His winning bike below:

Paris Roubaix 2014 - winner's bike, Specialized Roubaix SL4, NIkki Terpstra - YouTube

halfspeed

I'd be shocked to learn of any pro riding a stock geometry Roubaix, Domane or the like.

Campag4life

The Secteur is available in a disk version which has more tire clearance...a different frameset than the caliper version of the Secteur...disk version has a shorter head tube and taller fork for more tire clearance...disk version is 135 versus 130mm rear drop out width.

halfspeed

"The S-Works Roubaix bike that Niki rides is essentially the same as the Roubaix SL4 that you can buy in the shops ... However, like most of the other bikes prepared for the professionals, there appear to be a few subtle changes that you can’t get on a regular frame. Those changes include a shorter head tube and longer top tube, creating a more aggressive geometry favoured by the pros."

WorldTour bike: Niki Terpstra?s Specialized Roubaix SL4 | road.cc

Campag4life

And because the average rider shopping for a road bike is nothing like a world class rider, what you write is irrelevant. They provide custom geometries because they can. The average guy can size down and run a longer stem. I have two CAT 2 friends who race Roubaixs and they can likely drop 99% of those on this forum...and they ride stock geometry.
Also there is a point lost here when it comes to the custom Roubaix geometry which has been around for a long time dating back to the early Boonen bike where they combined molds between Tarmac and Roubaix. The Roubaix raced in the classics is very close to the geometry of an off the shelf Tarmac. The reason for the synthesis of both is the greater tire clearance on the Roubaix and the more laid out geometry of the Roubaix which attenuates road shock. The only difference between a stock Roubaix and a custom mold is the height of the bike which the average guy doesn't want. In fact, it is the height of the Roubaix that appeals the average rider and makes the bike the most popular endurance bike ever sold.

stephtu

That was for 2013/2014. It looks like for 2015 they've dropped discs from Secteur line and made those rim brakes only. Basically disc Secteur & Tricross lines dropped, now become Diverge lower end models (I think using same frame as last year's disc Secteur), plus they added the higher end Al & carbon models (with new frame designs).

Campag4life

Great input. The cross over between the Secteur, Roubaix and Diverge was palpable and with the debut of the Diverge, makes sense they eliminated the disk version of the Secteur. There is always the disk version of the Roubaix which I believe has more tire clearance for a slightly blurred line with the Diverge...the Roubaix still targeted as more racy for pavement riding.

halfspeed

Oh, I certainly agree that the Roubaix is a fine bike for old guys who don't bend so good any more. And while you can race it, it's not really designed for it, which is why the pro version has to have the geometry modified. Same thing with the Domane. They don't change it "because they can" but because that's what's required to make it appropriate for that use.

Campag4life

But the subject here isn't what bike is appropriate for the best racers in the world. Not even close. Nobody here qualifies. So the fact the bike makers create custom geometries for top racers isn't relevant to us in the least. Rather, what geometry of bike is relevant. It is the very geometry of the Roubaix that makes it so popular because the geometry is more compatible with average riders with average flexibility.

MRT2

OP said in his first post he has a Secteur Sport Disc.

MRT2

So last year's Secteur Disc Sport is this year's Diverge. Doesn't sound like any upgrade at all unless OP wants to go full carbon.

zymphad

Just get the Roubaix. You can fit 28mm tires on it.

halfspeed

There's nothing wrong with riding a grampa bike, but there are plenty of us for whom a more aggressive geometry is more suitable. My flexibility is above average.

zymphad

And your climbing ability over dirt road, above average.