achieving new levels
of a rear end comfort…
There are so many new gravel bikes on the market that promises a great level of comfort. Among them is a new GT Grade Carbon which offers a great level of comfort thanks to it’s floating seatstays. I tested it and compared to my benchmark bike to see how comfortable it really is!
What is it?
First GT Grade was among the pioneers of gravel bikes and for sure one of the best examples of what a gravel riding is all about. Its unique flexing rear end combined with comfortable geometry made a very appealing package. From my perspective the only thing that was holding this bike from winning more awards was a limited tire clearance. Fortunately GT addressed that issue with its new GT Grade version – this time you can put a 42mm tire (tested and confirmed). Add to this a new and improved iteration of flexing rear end and you, at least on paper, get the winning formula.
What is so special about it?
GT trademark is a flexing seatstays construction and in a new GT Grade we have a newest iteration of this approach – a fibre-glass seatstays covered with carbon skin are floating freely without any contact with the seat tube. Add to that a specially thinned at the bottom seat tube (allowing for even more flex) and you should get a very comfortable rear end of the bike. But GT innovative ideas did not stop there and they also made something interesting with front of the bike. Its new fork uses a special flip chip system that allows you to change the fork rake and thus its handling so when you are on a bikepacking adventure you can make your bike more agile by increasing the standard 55mm rake to 70mm.
One last thing that should be mention is the choice of the FSA Omega Crankset on the bike I tested. It has a 46/30 gearing ratio which combined with a standard 11-34 Shimano 105 cassette offer a great range of gears both in terms of climbing and riding fast on the road. During my testing I never needed something more on both ends of the spectrum. The rest of the bike is a rather standard package with a Shimano 105 groupset, WTB ST i23 rims and a WTB Riddler 37c tires.
Does this flexing seatstays work or is this just a marketing gimmick?
Yes, this was the thing that got me interested in this bike in the first place so I was very eager to see if this is a hit or miss. To my surprise it took me just a few hundreds of meters to realize that a floating seatstays is definitely not a gimmick and they really works to make the rear of the bike very comfortable. This system is so effective in dampening the vibration that you simply don’t need any extra flexing seatposts or a very comfortable saddle. I will say even more – from my experience it looks like a rather standard carbon seatpost and Fizik saddle that comes with the bike ideally complements the frame compliance. When I putted my flexing Ergon seatpost with my Brooks C17 saddle the vibration readings showed that on a bumpy forest road the GT’s stock seatpost and saddle was more comfortable. My theory is that you simply need a more firm seatpost and saddle to make rear end of a GT Grade work and show all its strengths on a bumpy road. When I compared both setups on a fast gravel route the combination of a Ergon CF3 Pro carbon and a Brooks C17 saddle reduced the already low level of vibration of another 3,3%. But from my perspective the level of comfort both on a bumpy forest road and on a fast gravel route provided by the stock GT Grade Carbon setup is more than enough and I would leave it as it is and just focus on enjoying the ride.
Do I need a flip chip fork?
Something like a flip chip is not a new idea in gravel bikes world. A polish Rondo company introduced a similar construction a few years ago. The main difference between Rondo and GT is that when Rondo was about increasing stack and shortening the reach of the bike by changing the thru axle position, GT is all about changing the steering characteristic of the bike (to be fair – when you use Rondo system you also change the head angle – by a moderate 0,5 degree but still – so the handling will also change).
But going back to the initial question…
Changing the flip chip position has a perceptible effect on the bike’s handling. You can make it more stable or more agile (with a long reach of the bike you can even call it twitchy) but to be honest we as a human beings have a remarkable ability to adjust to the changes very quickly. What I mean by that is after 5 to 10 minutes of riding all the changes disappears and you simply enjoy riding a very comfortable bike. So… do we need a flip chip solutions?
But it gave me an unique opportunity to test the bike in two different fork settings to see if this will have any perceptible effect on its vibration damping proprieties. And it looks like there is a small yet measurable difference between a fork with thru axle being closer to the rider and the second position where it is pushed away from you. When you think of it – there is a logical explanation of this difference. When a thru axle is in line with the fork axis the impacts goes straight to the handlebar and your body. But when a thru axle is put slightly behind the fork axis the impact first makes the fork bend more and thus absorbs some of the impact energy before it hits you. The fork on my Jamis Renegade benchmark bike is called a ECO Compliance fork mainly because it has a thru axle pushed back (but also it is a very long fork which promotes additional flex).
So not really, but if you are looking for every possible way of reducing vibrations then a flip chip can be beneficial.
How does GT Grade ride?
This is a fast bike. The stiff bottom bracket area along with a thick downtube creates a bike that do not waste your energy and every pedal stroke is transfered into a rapid forward movement. This is especially apparent when accelerating from standing still and of course when you are climbing. The difference between carbon GT Grade and my steel Jamis Renegade is huge in those situations. But when you are traveling at a steady speed like 30 km/h the difference is not that big to be honest. The biggest distinction between those two bikes comes from the “long reach” geometry of the GT Grade which makes you a little bit too much stretched for my liking (I am 178 cm tall and my inseam is 83,5 cm). I tested a 55 size version with 100mm stem so changing the stem for a 90mm helped a lot but still I would need to work harder on GT Grade to achieve a desired riding position. This long reach approach combined with a wide All-New GT DropTune Super Light handlebar with 16 degree flare is a recipe for a very confident bike but when you add to this formula a rather steep head angle (72,3 degree) and two flip chip options you get a very fun bike to ride. Stable when you needed and agile when you want it to be. And the combination of the stiff bottom bracket and the flexing seatstays simply encourages you to ride ahead without too much thinking about choosing the right path. No matter the surface you just go fast and simply enjoy the ride.
So how comfortable it really is?
Front end of the bike is rather stiff. Adding a shockstop stem helped a lot. And adding a 42 mm Soma Cazadero improved the front end comfort even more. As for the rear end, as you already know, GT Grade Carbon is simply a hugely comfortable bike and I honestly think that you will have a very hard time finding something more comfortable (maybe Cannondale Topstone, maybe Pivot Vault equipped with a flexing sestpost, maybe BMC URS or Moots Routt YBB but this is it). Unfortunately I did not have a possibility to test a GT Grade with a Lauf Grit fork (but I saw a builds like that) but my feeling is that when equipped with this kind of fork a GT Grade bike could be easily one of the most comfortable gravel bike money can buy. Even on its 37mm WTB Riddler tires which were surprisingly good (for its width) in terms of reducing vibrations.
Below you will find the difference between stock GT Grade Carbon vs my benchmark bike (steel Jamis Renegade Exploit equipped with Soma Cazadero 700x42c tires – 30 psi air pressure, a shockstop stem and a flexing Ergon CF3 Pro carbon seatpost with Brooks C17 saddle). But, as you may already know, I am after the most comfortable bike possible so I put the same tires (at the same 30 psi air pressure), a Brooks C17 saddle and a suspension stem and Ergon seatpost to the Grade to see how much more comfort I can squeeze from this bike (this is described as a max version). As you can see a new w GT Grade Carbon in a max version was very close to my benchmark bike in terms of a comfort and on a fast gravel route the rear end of the bike was even better that my benchmark bike (both in stock and max setup). This is a true testament of how comfortable this bike really is and how even more comfortable it can become when you make some upgrades to it.
Would I buy it?
There is no simple answer because I am from an a old steel frame school. I like steel for its flexing properties and springy ride. Moreover I am not after the most power efficient frame possible. So for my type of riding a steel bike like my Jamis Renegade Exploit equipped with a Lauf Grit SL fork, shockstop suspension stem and an Ergon CF3 flexing seatpost is a great choice. But if you look for something similarly comfortable but in the same time much more light and simply faster then you will be very happy riding a new carbon GT Grade. Just put something like a shockstop stem on it and you are ready for any road ahead…