P6 Carbon HiFlex Seatpost

This is my second Syntace Full Carbon P6 Hi-Flex Seat Post.It is fairly light, but mostly 'tough' works well with carbon railed saddles (some seat posts do not), has a long andsupportive clamp design that has a lot of adjustment.The flex (combined with a light carbon-railed saddle) works well (as long as you have several inches of seat-postabove the seat tube clamp) work well and you can feel it. I use a version on my non-suspension 'fat-tired' bike, andmy high-end Moots RSL road bike.

I have been riding on this seatpost for 4 months now and it is exactly as advertised! I ride a steel single speed hard tail so the flex the Syntace offers is welcomed on the trail. Another plus was bolting my saddle to the seatpost, very simple. Also the post has not slipped since it was installed, no matter the rocks or roots on the trail the seatpost stays put.

Some reviews make it sound like this thing will flex like a Thudbuster. On the other hand, another reviewer said it is all a scam and it doesn't flex at all. Well, the truth is in-between, its flex is subtle. If you hold it in your hand, you wouldn't know it is supposed to be a flexing post. It feels totally stiff and solid. So, if you are looking for something like a Thudbuster, then you better look for a Thudbuster. If you want a light carbon seatpost that takes some of the shock out of bumps, then this might be for you.It fit REALLY tight in my bike's tube, a Trek aluminum bike. I used some Park Tool assembly compound. I had to put my seat on the post so that I could then use the seat for leverage to twist and push to get the post inserted! Someone I think said they had problems with their bike tube scratching the seatpost because it was so tight and recommended putting a chamfered edge on the tube. But my bike already had that from the factory and I didn't have any scratching problems. But it sure was tight!I like the seat angle adjustment mechanism. Seems to work well. It is a solid post. It is light. It works. It doesn't do miracles though.

Okay, I've ridden this seat post now for about 500 miles on a fully rigid carbon bike. It weighs exactly the same as my aluminum Thompson Elite and it is heavier than a Thompson Masterpiece. The only reason I went to this seat post is because I felt that the stiffer aluminum seat posts were making my frame flex too much in the middle of the seat tube area. I am 210 pounds and I like to ride bikes hard. With the german quality Syntace HiFlex, the overall flex is much more distributed. Did it make me any faster? Probably not, but the ride is a bit smoother.

The Syntace P6 Carbon HiFlex is a good seatpost, but it does not deflect at all as far as I can tell.I swapped from a Zipp Service Course aluminum seat post to the HiFlex and did not noticed any difference at all in ride quality.Also if I stand next to my bike and put all my weight on it, there is no detectable deflection at all, even if I bounce. That is with the seatpost fully extended. It is a good, lightweight seatpost, and I know Syntace is a very reputable company, but it just doesn't live up to Syntace's claims.

As as avid cyclist, I once thought that wasting money on a carbon seat post (for a carbon bike) was one of the silliest things a cyclist could do.Only took one 40 mile ride -- on variable road terrain -- to learn that this purchase was most definitely worth the cost.No question there is far less road vibration transmitted through my new carbon seat post versus my handlebars.

It does absorb some heavy bumps on mountain trails. Light and no surprises.

I have a few of these posts and love them. They are well made and take the edge off of bumps on a hard tail bike. The post improves the ride more than a few 27.2mm Ti posts I have used from Moots and others.