I’ll start of by saying my bike is optimised for my comfort
That said, I do some fast group rides and I’m genuinely curious how much speed I’m giving up in exchange for said comfort
I have a Giant Revolt Advanced 2 for road riding. This is Giant’s carbon gravel bike with a rigid fork. I chose this because the combination of stack and reach make it very comfortable for me: Revolt Advanced 2 (2024) | Gravel bike | Giant Bicycles UK
This version of the Revolt runs 2x12 Shimano whichi s 46-30T on the front and 11-36T on the rear.
Short answer is you’re giving up a lot, but you already know that.
Your position on the bike could be 50-100w at fast speeds.
This links to tour magazine test results and the slowest bike in that list is a Giant TCR Advanced 1 at 240w vs aero road bikes 210w or less. Your gravel bike is maybe similar to the TCR but it should be slower. So possibly you’re losing 50w due to the frame. But that would be if you’re on the front, way less in the draft.
There are wind tunnel tests out there for aero vs climbing wheels. Might be 10-20w for the wheels.
Maybe 5+w per tire vs GP 5000s, bicycle rolling resistance puts your 32/34 width tires in the gravel/cx section instead of road. They need to change their width cutoff for road tires to 34 imo.
I didn’t answer in speed because converting watts to speed depends on way too many factors that are unknown. For sure its a lot, for riding without draft could be 2 mph+. I recently switched from a cyclocross bike for gravel usage with shallow old rims to a checkmate and my average speed on solo rides is 1 mph greater. Its a night and day difference feels even more significant than 1 mph avg seems like, if I had known how slow my old bike was I woulda done whatever it took to get a new bike, go to a loan shark or something. Your change would be more extreme than mine was.
I had both, and there’s a world apart between them. Even with the Revolt slammed and using stem and handlebar for road bikes, the Revolt has a much higher front. You have to really force yourself to be in an aero position. While the TCR with 2 small spacers I was naturally aero without sacrificing much comfort.
Answering OP’s question, I think it’s hard to quantify it precisely. Maybe 20%? It’d be cool to borrow a road bike and do the same group ride.
One thing must be said, even though tests and theory show that a GRavel bike isn’t really that much slower than a Road bike, the feeling of speed on a Road bike is much higher. This is illustrated and commented here
I really don’t buy into the large number of watts savings suggested by previous posters. The important things are wheels and tyres and you’ve got those covered.
Maybe you’re losing a few watts to GP5000 but then maybe you’re not if you’re running higher psi than someone else on them.
The position on my Giant Revolt isn’t massively different to that of my Supersix, CAAD, Crux… And yeah, you might save some watts lower and narrower on a pure road bike but what about the watts you might lose from closing up your hip angle or constricting your chest from narrower bars?
Hard to put a speed difference on it, but there is something there between a road bike and a gravel bike.
I’ll rotate riding my Trek Emonda SLR9 AXS 48/35 10-33 28mm tires 51mm wheels, and my Pivot Vault Team Force XPLR 1x 42 10-44 42mm tires 40mm wheels on local group road rides. I can keep up, lead, and attack the group on both bikes. For me it’s how much work it is to get to and maintain the speed. The Emonda is much easier to get up to speed and keep it there. It’s lighter, more aero, etc, etc, and thus less effort is required. All those race characteristics of the Emonda really add up.
Maybe a simple test for your set up with out breaking the bank would be 28mm GP 5000’s and stay in the drops for the group ride. Just a though
Negative rise stems exist, no reason you can’t get the front end as low on the gravel bike. It’s the rider not the bike that makes the difference, OP could work on strength and mobility to enable them to ride in a more aero position.
Well don’t stress it then, you’ve got wheels and tyres covered. A bike you like riding will have a positive placebo effect that probably far outweighs any watt saving an aero bike manufacturer will try to claim!
Except I didn’t refer to manufacturer claims. The tour magazine results are real test results of how many watts to ride at a speed (with a torso dummy of course, same test for all bikes).
I think often it seems like the difference between bikes isn’t much in group rides because there is a lot of drafting. So if you’re behind people a lot then yeah doesn’t matter so much. If you’re in the wind it will matter.
I agree with you that body position matters way more than the equipment and your comments about tire pressure. You have to compare apples to apples though, if both tire options are ran at an optimal pressure for their width the GP5000s are probably faster. For riding fast a deeper wheel would be faster than a 36 deep so just depends how optimized you want to be.
Our discussion is rather pointless as doesn’t seem we’re persuading @trebor to buy a new bike anyway
I’m still sceptical of even magazine tests as they’re trying to push new products or excite their audience about new tech too. But that said, re-reading some of those numbers you’re quoting, holy sh*t, I can’t afford to be giving those up in a road race when it kicks off and there’s no longer the protection of the bunch!!
Honestly if you need the stack of a revolt for normal riding I would propose that you have bigger fish to fry than worrying about crr and cda loss from the frameset itself.
I don’t think gravel frame is that much slower if you were in same position. Practice riding in aerotuck position with vertical forearms and back. Keep head as low as you can while being able to see the road
Jesse Coyle recently compared his Tavelo to 2019 rim brake TCR and difference was less than 1kph at 350 watts.
I’ve ridden Revolt with 30mm GP5000 and 56mm deep wheels and it’s pretty nice endurance bike. Maybe bit boring for some if the flip chip is in long position.
I bought 2023 TCR after that and it mostly feels more efficient and has better gearing for road. I wasn’t necessarily instantly faster with it but after practicing it’s getting better.
One aspect you could tweak for free is tire pressure. What pressures do you currently run?
Tight-fitting clothing makes a huge difference, for example, as does being able to hold an aero position. Hence, it is better to adjust your fit to a potentially slower, but more comfortable position that you can hold for longer. So if I were you, I’d invest in tight-fitting clothing and a yoga course.
The rest of your bike already looks quite good.
Your tires are reasonably fast. They are not the fastest, but there are other considerations (e. g. comfort and puncture protection).
Your wheels are ok. They are quite shallow by modern standards, the average wheel is about 45–50 mm deep. But it is not terrible.
You didn’t say anything about bike fit or ride comfort. Are you happy with that?
I love colour on a bike (the silver on the Revolt is lovely in real life but by far the most muted colour I have ever owned).
For some reason all the new bikes have very muted colour ways (or stealth black ) so I’ll wait until burnt oranges, bright yellows and greens are back in fashion.
) so I’ll wait until burnt oranges, bright yellows and greens are back in fashion.