I would love to get input from your personal experience with Giant bikes. I am brand new in the biking world and welcome your thoughts.
I have a friend who just got one recently, he is a large and very powerful guy and finds the stiffness to be excellent. The Giant has custom integrated brakes, he says they brake well but introduce a little bit of hassle as they are not as easy to adjust for different widths as normal brakes.
Comparable bikes would include the Cervelo S5/S3/S2 and Specialized Venge. Both of those use standard brake calipers. All three of these bikes are excellent in my opinion.
that hurts, man.
-SD
My bad, I would also include the latest Felt aero road bike in that category =)
that hurts, man.
-SD
I haven’t ridden the propel but have been on the tcr sl before and can attest to giants build quality and stiffness. They make terrific bikes. That said I recently purchased a scott foil and I think it’s the best bike I’ve ever thrown a leg over. I’ve owned and raced an S2, rode a buddies S5 a few times, and I know I’ll catch flak for this, but I don’t think the cervelos come close(slowtwitch gasp). The foil feels every bit as stiff as the tcr sl but with much better aero properties. If the propel is close to the tcr in stiffness I’d take it over a Cervelo any day.
I’ve owned and raced an S2, rode a buddies S5 a few times, and I know I’ll catch flak for this, but I don’t think the cervelos come close(slowtwitch gasp).
I won’t give you flak I would just ask that you carefully expound on what isn’t close about it exactly.
=)
Fair enough:) I think the foil rides nicer and simply out performs the S5. I also think the overall build quality( fit and finish) is superior on the scott. It’s also better looking(oh snap)! I had seen an article somewhere, maybe bicycling magazine, they tested several aero bikes and while the S5 was slightly faster in the wind tunnel, the foil tested better in responsiveness and stiffness.
I have owned the following Aero Road Bikes:
2010 Cervelo S3
2012 Cervelo S5
2013 S-Works Venge
2014 Giant Propel.
I have also had use of a Scott Foil for an extended period of time.
The Propel is easily the best of the bunch in my opinion having cycled and raced on the previously mentioned bikes, and the lab/wind tunnel data agrees with this assumption. It’s really fast and stiff but I did not feel uncomfortable on it at all in fact I was comfortable right away . At times I could feel the S5 flexing in the bottom and the front as well and it is a pig when going up-hill. But the S5 is certainly fast on the flats/rollers though.
The Venge was awesome. I had the S-Works Venge and had it built up with Dura Ace 7900 plus HED Stinger 6 tubular wheels.
I have the Propel Advanced SL1 which is full Dura Ace 9000 mechanical. I swapped out the stock Zipp 404FC clinchers for tubulars, I switched the stock Fizik Arione R3 saddle (which is for sale btw), and I just swapped out the stock Giant Carbon Handlebars for my ENVE bars which are stiffer. The stock Giant bars are beautiful though and it was a difficult decision to do the switch but I absolutely love the look and feel of my ENVE bars. The photos below show the bike before I switched the handlebars.
http://www.flickr.com/photos/108068805@N04/10741876844/
http://www.flickr.com/photos/108068805@N04/10741858886/
http://www.flickr.com/photos/108068805@N04/10741777095/
http://www.flickr.com/photos/108068805@N04/10741778005/
http://www.flickr.com/photos/108068805@N04/10741877824/
http://www.flickr.com/photos/108068805@N04/10742084203/
http://www.flickr.com/photos/108068805@N04/10741782075/
How would you compare it to the foil? All things being the same( components, wheels, etc)
For what it is worth my S5 went uphill exactly as its mass and my application of power suggests it should, as did every other bike I’ve put a power meter on.
Not sure what you are implying about the S5 going up hill… it just doesn’t climb well at all regardless of power output. It flexes like a noodle! The propel also is not a climbing bike but it does climb noticeably faster than the S5 most probably because it is much stiffer in the bottom. My S-Works Tarmac SL4 on the other hand flies up hill.
Btw your propel is one of the nastiest bikes I’ve ever seen. Great build dude
I’m implying that the idea that the S5 or any other decent bike is going slower uphill due to frame flex is completely false and challenge anyone to demonstrate that it is true by use of a power data.
Either by showing that it goes uphill slower at a given power with all other variables held constant or by showing that power is lost due to frame flex using a crank and hub based power meter together. (for what it is worth, people have done this on various bikes and cannot measure any power loss due to frame flex)
If you were investigate this I think you would find this uphill speed difference you notice between bikes is either due to your imagination or other uncontrolled variables (position, wheels, tires)
I think in fact you would find the propel is faster up most hills than your tarmac =)
Not sure what you are implying about the S5 going up hill… it just doesn’t climb well at all regardless of power output. It flexes like a noodle! The propel also is not a climbing bike but it does climb noticeably faster than the S5 most probably because it is much stiffer in the bottom. My S-Works Tarmac SL4 on the other hand flies up hill.
I ride/train/race with Power Meters as well and I have a pretty good idea of how fast or slow myself (and my bike) can ascend. I’ve owned these bikes and I am speaking from my own personal experience. In the climb you can noticeably feel the S5 flexing while going up hill. Same with the Venge. With that I’m not going to argue with you anymore.
Cheers
Then you have the tools at hand to check whether the flex you feel is actually sapping watts away. Knowledge is power and a few careful experiments would tell you whether your propel is slower up a hill than your tarmac. No need to argue with me about it.
I ride/train/race with Power Meters as well and I have a pretty good idea of how fast or slow myself (and my bike) can ascend. I’ve owned these bikes and I am speaking from my own personal experience. In the climb you can noticeably feel the S5 flexing while going up hill. Same with the Venge. With that I’m not going to argue with you anymore.
Cheers
I do believe the strain gauges inside my power meter are measuring the amount of power being applied to my cranks/spider not how much the frame is flexing. 
Have a good one dude.
Perfect, then you know the power going into the bike is constant, thus if you hold that constant between tests the time up a given hill should tell you whether one bike is slower than the other, and if it is to a degree beyond what you would expect from their difference in weight.
A powertap would actually invalidate testing the question =)
It’s a Quarq… notice I mentioned the Crank/Spider.
What Jack is getting at is though you feel a difference between the bikes which could be flex, it doesn’t have a detrimental effect on the speed. If you are putting out the same power at the crank.
I don’t think that is a good test however. It is much more complicated than that. What we really want to know is if the flex is sapping the rider’s ability to produce power… power that is moving the bike forward.
I’ve spent some time thinking about this, and for seated riding I believe that flex that occurs during the early part of the power phase of the stroke will be almost entirely returned before you get to 180 degrees… so little or no loss except for some hysteresis. When standing though, a large vertical force continues past 180 which flexes everything laterally… and that isn’t recovered… as far as I can tell.
And then you have the added friction of torsional flex misaligning the wheels.
But another important factor is how the flex effects the muscles. There was one manufacturer who marketed a hub with a spring inside, claiming that the considerable flex increased the rider’s ability to make power. Some pros have favored flexible frames for sprinting, though that isn’t common. Track frames and wheels are usually very stiff.
Probably the only way to solve this puzzle is to do a blind test, where cyclists climb seated and standing and also sprint at max effort over a range of distances, and determine if there is a measurable trend in the amount of effective power they can produce.
Not sure what you are implying about the S5 going up hill… it just doesn’t climb well at all regardless of power output. It flexes like a noodle! The propel also is not a climbing bike but it does climb noticeably faster than the S5 most probably because it is much stiffer in the bottom. My S-Works Tarmac SL4 on the other hand flies up hill.
You’re on drugs if you think either an S5 or a Venge is a “noodle”. I’m thinking you’re perceiving something else…
Hey no need to be rude - This was my personal experience and I was comparing it to other much stiffer bikes which I have both owned and raced. I would not comment on bikes which I have no experience riding and racing. I wouldn’t call the Venge a noodle that’s for sure, I loved the bike and I have won with it but I could certainly get the S5 flexing pretty good and I am 160 lbs. I certainly know climbing has much more to do with frame flex - mass, power to weight ratio (of rider + bike), wheels, tires, inertia. So many factors.
If you read a lot of the reviews about the S5 online they are really really good, it’s FAST but one of the knocks against it indeed is the stiffness, compared to a number of the other aero frames out there. So tell Velonews, or Cycling.cc that they don’t know what they are talking about.