I would assume it has some tyres that are more specific for gravel riding, so I'd be looking to swap them out with something made for the road (GP5000s would be a good shout).

I'm not sure if the bars will allow it or not, but you could always try and stick on some clip-on aero bars.

Might be good to swap a higher geared cassette on there as well since you'll be at road speeds instead of gravel speeds

LegendJeff has a good point with the gearing, but I'm guessing you already have an 11 tooth cog, so hard to go smaller.

Do you have a 1x or 2x? Diverge Comp is spec'd with a 40t chainring and 11-50t cassette, I believe. That gives you a range of 26MPH to 6MPH @ 90 RPM.

Honestly, for a 70.3 that's probably just fine - unless there's a long gradual downhill that you'd want to be averaging over 30MPH, just coast the downs and use it as a chance to fuel.

If it's a flat race, you could consider a tighter cassette, like 11-32, which would give you more options to find your ideal cadence & power combination.

I have a Diverge Expert 1x. If I were to turn that into a road bike, here are my suggestions:

* slick tires (but keep them tubeless)
* clip on aero bars
* gearing.... how do you feel about your range of gears now, specific to the 70.3 course you want to ride? My Diverge 1x came with a 40TT front chain ring (I'm laughing at the above post about mph range.... because this in no way accounts for % grade). My gravel riding is pretty hilly and my stock set up was such that I couldn't do hills >10% grade (I can do 15% well on my compact crank 11x28 TT bike, so this pissed me off). I put a 36TT chain ring on so I could manage the hills better, but I sacrificed my gearing at speed. I spin out at ~25 mph. The 1x gearing irritates me quite a bit and I'm considering going with a 2x so I have more options.

Otherwise, the Diverge is a really fun bike and capable of doing a LOT of different things! Have fun!

I have two Carbon Diverges. One is mechanical 2x and my newest is SRAM 1X. I really notice spinning out on the top end on my 1X, usually around 22 mph. If I had to use one of those bikes for a 70.3 I'd take my older mechanical 2X and run ContiGPs tubeless 700 x 30s. I tried aero bars on it when I first got it but never could get comfortable - too much reach and too low for my back.

Mine is a diverge expert carbon with SRAM etap axs, 1x12 with 11-50, 40t. The 42mm pathfinder pros do a really good job on all surfaces. Given how comfortable the bike is, it might be a great choice for a 70.3 with rough roads. Definitely would not be front of the pack, but might help with save the legs for the run. Good luck!

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"The more you suffer, the more it shows you really care.”

Yes, while 40x50 @ 90RPM is always going to be 6MPH, regardless of grade (ignoring downhill, of course) the Watts required to maintain that 90rpm is a different story! 6MPH, however, is a pretty good low end. Much slower and you might as well hop off and push the bike :-)

If you really want to explore the math, here's a good calculator: https://www.bicyclegearcalculator.uk/derailleurgears.htm