LUW

So they're not equivalent. Ok, apart from BB and seat posts, that's what I would like to know: how do they ride compared to each other. So, what say you?

Nothing against the Slate (except for the price, that I think is too expensive), but to me it's more a CX bike then anything else, and I have a CAADX that I really like. I want a more "proper" road bike.
And if I'm not mistaken that frame was designed specifically for the Slate.

Campag4life

its already been discussed in the thread

LUW

Yeah, I read the thread. But I would like to hear YOUR opinion on how they behave.

Campag4life

I agree with what the others said about how the bikes compare in ride and handling.
I own a Roubaix and prefer it to the Synapse because I like a solid and steady bike but moreover, I vastly prefer an English threaded BB and 27.2mm seat post to BB and more narrow seatpost on the Synapse...latter due to very few seatpost options. The Roubaix is the best selling endurance geometry of all time. The bike that started it all. Specialized probably has the deepest R&D of any bike company although Trek and Cannondale and Giant and other name brands are close. The Roubaix has gone thru 4 different design iterations...
The Synapse is an excellent bike...no mistake. Very popular and for good reason.
Only way to decide is take each for as long a ride as possible. The Roubaix has a bit more upright riding position which you may or may not prefer.

LUW

Cool, thanx. The problem is that I can't demo them, so I have to rely on what I read - not even close to the best solution, but it's what I can do unfortunately . I honestly think I can't go wrong with either of them, but I would like to have as much info as I can before I commit to buy one or the other.
The more upright position is a plus, since I'm no racer, so that's good to know. The BB issue doesn't really bother me, and I probably would upgrade other things first before thinking about swapping the seat post, but of course, something more universal in size is always preferable. But what about tires? Could I fit a 28C on a carbon Roubaix?

Campag4life

yes, 28c fit on the Roubaix no prob. In general, 28c tires fit on most endurance bikes.

LUW

Fantastic! So if I can shoe a 28C, the Roubaix is definitively a contender. Thanx for the info!

And BTW, do you have an idea how how much a Sport SL4 (carbon with 105) weighs?

Plotone

I run 28's on my 2014 Synapse (but, I have Mavic Ksyrium wheels that did not come stock).

It an be a tight fit getting the fully inflated tires past the brake pads depending on your setup.

LUW

So the Synapse does really accept 28Cs, great. Thanks!

Haven't thought about tubes yet, but my initial idea would be to use tubes with sealant (Joe's) in the tube. I'm doing that on the Contis 35C of my CAADX and haven't had a flat in 3100 km*. I also use the same setup on my last three 29ers and haven't had to fix a tire on the side of the road for over 6000 km. But if it's possible do the same with a 28C is a different story...

*: Well, not exactly true - I did get a puncture a few months back that took a while to seal and the tire deflated, so I had to spend a CO2 cartridge to fill the tire, but got home without needing to fix it.

Spartacus713

The Cannondale Synapse comes new with 28's on the Synapse Carbon Ultegra model on up. Why Cannondale does not sell all the Synapse models with 28's is a mystery to me. But they do all run with 28's, you just have to change them out yourself.

deapee

Pretty important to note that if your body's ability, flexibility, and core strength are not super great, a more upright position is going to allow you to transfer more power and remain more aero better than a more slammed position.

Anyone can get aero. Anyone can generate a load of power. It's a balance of the two, unique to an individual's body, that are going to create the best (read fastest or most aero and powerful) position for that rider.

That being said, a slammed and drop stem on a Roubaix will offer more saddle to bar drop than the default configuration of the cdale.
That also being said, you can't go wrong with either.

LUW

Maybe because 28Cs are more expensive? Still, if the Synapse is Cdale's endurance bike it would make more sense if all the models would come with a 28C tire - after all, a 28C is not necessarily slower then a 25C. But in the corporate world rain is not always meant to fall down, so...

I don't have the stem on my CAADX slammed, it's 40 mm above the top of the head tube (but properly a lot lower them my saddle ), and at least for the geometry of that bike it's pretty comfortable, to the point I could maybe even lower it at least 5 mm more without a problem. However I'm pretty certain I couldn't get away with that on both the Synapse and Roubaix, because of the more aggressive geometry. But from what all you guys are saying, with 28C tires I think both of them will be (enough) comfortable for what I have in mind. I'm not fast, and will not race, I just need a smooth ride on 2-3 hours of hard pedaling.

Does anyone have an idea what both would weigh with a 56 frame? Weight is not exactly a fundamental aspect, I'll be happy with anything below 10 kg, but could I hope something close to 9 kg for both?

Chi_Z

Roubaix can easily fit a 32c, currently running 28c, still have 1cm of room

deapee

My 54 Roubaix is 19.5 with bottle cages and garmin mount, no pedals. I saw a guy hang his 56 with pedals and saddle bag and it was 20.4 lbs.

LUW

That's pretty good! Thanks deapee!

Campag4life

Insightful post. Well stated.

Campag4life

Believe 32c's fitting on a Roubaix is dependent on rim width.
OP, if you insist on 28's....not sure why you would want them...not ideal for road riding unless your road is quite broken, you may want to consider a gravel bike like a Diverge which can fit a much larger tire but has essentially the chops of a Roubaix. A slightly more robust Roubaix if you will...exact same geometry but can fit wider tires. In effect a drop bar 29er..or a tall cross bike. These types of bikes are quite popular for both on and light off roading like ride dirt/gravel, single track etc. You can then keep a second wheelset with skinny tires for more dedicated road riding and not give up much in terms of speed to a Roubaix. I would own a Diverge or a bike like it but I don't ride dirt and single track any more. I prefer smooth road riding but I have spent a lot of time riding the rough stuff in my past.

LUW

The Diverge (carbon frame) is out of my price bracket. And what's the problem with 28C? For me they would be as fast as a 25C, but deliver more comfort.

SpikedLemon

As I mentioned in my earlier post: my Synapse does not fit a 28. But I've a 2014.

Perhaps they changed the rear end of the bike... I wouldn't mind using 28's for a little more float on the unpaved paths.

There's NO way I have that much space. Wow.

chrisjur

I have a 2016 Roubaix and figured that it would be my go-to bike only for long rides. However, after 400+ miles, it has quickly become my go-to bike for nearly everything. The ride quality is superb and the dampening + the more upright ride position is perfect for long hauls. I have really fallen in love with this bike and have historically been the type of person doesn't easily convince myself that I've always made the right purchase.

I did a 100 mile century two weeks ago and felt incredibly fresh afterwards. I did a metric century with a group on Saturday and then rode another 25 miles fast on my own. On my other bikes - mostly aero-style bikes - i would feel a bit beat up after rides this length. Not the case with the Roubaix.

It is no slouch on the road either. I was easily riding 25mpg for long hauls with a fast group on Saturday. No, it's not as aero as to what all the cool kids are buying these days, but unless you actually plan on riding Paris-Roubaix, I'm sure this bike will suit you in most conditions that you'll find.

And last week I was running 28 tires without an issue. 28 tires on Reynolds Assault wheels using Ultegra direct-mount brake.

Can't speak for the Synapse, but the Roubaix is a great bike.

Campag4life

well, 25 mpg isn't great mileage for any road bike. My Roubaix gets 50 mpg and therefore I can ride with a smaller gas tank which saves weight.

Campag4life

28c tires are heavier, less aerodynamic and contrary to baloney espoused on the 41 by a limited few, have higher rolling resistance than 25c or 23c tires. There is a reason why the top racing bikes sold by best makers do not come with 28c tires. Many in fact will not fit 28c tires. If 28c tires were faster, the fastest road bikes sold would come standard with them.

chrisjur

Haha, touché. But what I didn't tell you is that I'm running a V8 in that thing

LUW

I'm aware that as almost everything, it's a compromise. But for my riding (speed+roads+level) I would probably be faster on a 28C. I'm not questioning if a 25C tire is faster on good and smooth pavement, I fully understand the physics, but for me a carbon-framed bike with good geometry will deliver the most amount of fun if on 28Cs. Of course, if I can get away with 25Cs in terms of comfort, I'll opt for the faster tires obviously, but I really doubt it.

And PS: You guys drink way too much - do you use hydro packs? I need 700 ml every 30 km.

bonz50

if you're not a competitive racer, this is the only metric that matters.