1. Cervelo S3 stiffest piece of aero crap I have ridden. Rode it. Gave it back. Hated it. Super uncomfortable. S5 worse. Loved my R5

2. Trek Madone. Best bike I have ever ridden

Disclaimer... I've ridden Kuota, Time, Trek 5900, Cervelo P3, S3, R3, R5, Trek Madone

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@rhyspencer

I rode a 2015 S3 for two years (still have it), same as current model other than the paint job AFAIK. I just recently built up a Madone frameset to be my new main bike.

I thought the ride quality of the S3 was pretty good when I first got it (compared to other aero bikes at that time, at least) thanks to the thin seatstays. My biggest complaint was that the tire clearance wasn't great, the widest tire I could run without getting frame-rub was a 24c Conti Force. The seatpost/clamp design was also not the greatest, and it was bad about dropping the chain if I backpedaled while in certain gears (large chainring and 2-3 cog in particular). I never could get things adjusted to completely remove this despite running a Di2 groupset.

I've now had the Madone built up for several weeks and have been riding it quite a bit. Ride quality is definitely better than the S3. Hard to say how much of that is the seat post design vs being able to run wider tires at lower pressure, but either way it's a definite improvement. Handling overall seems more responsive than the Cervelo and it also feels more stable at higher speeds. I think this is due to stiffer front end.

So yeah, my recommendation would definitely be the Madone. It's a great bike and I'm really happy with my purchase (even though the frameset is overpriced compared to the 9.0 bike).

ISOspeed makes the Madone a much more livable bike.

You're crazy. I've ridden the S3 (owned the previous design) and owned the S5 for 3 years and they are fantastic bikes. When I bought the S5 I thought it would be very uncomfortable, but it has been one of the most comfortable bikes I have ridden in a long time. It had just enough road buzz that I could actually feel the road, but not enough to be uncomfortable. The S3 was very similar. My race team has been on the S3/S5 for the last 3 years and most of us have purchased the bikes after the season.

The Madone simply felt flat. Like I was running on a super low tire pressure. Very disappointed in the road feel. I thought many of the features were fantastic, but there was no real feeling to the bike. I could not ride it.

Pretty sure I'm not "crazy". WTF dude.

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@rhyspencer