That’s it right there - don’t really need to say any more, (so just like every other idiot with an opinion, a keyboard, and an internet connection I’m going to proceed to say quite a lot more )
I think for a lot of riders a racey gravel bike with two wheelsets can 100% do away with the need for the endurance bike category that was so huge 10-15 years ago (Roubaix, Synapse, Domane, etc.) Now, could you ride a 2015 Roubaix in a crit? Sure. Could you do well? Sure. Could you do as well as someone of similar ability who is on a Tarmac? Probably not unless they make some mistakes and you don’t.
Does that make it worth cleaning up your old CAAD10 in the back of the shed and replacing the worn rear tire for the crit? Definitely. Does that make it worth BUYING a new Tarmac? Maybe, maybe not. Depends on your finances, storage space, and whether you consider crit racing a primary discipline.
So it’s not a ‘don’t bother trying’ situation, just ‘don’t expect equivalence’. If crits are learning experience, skills practice, and a bit of fun for you then it might work out great. If you’re trying to cat up and win your local series then you’re going to end up buying a different (or additional) bike before long.
Tarmac SL7 and a racey-ish carbon gravel bike. The gravel bike is just a very slightly more relaxed position (though I could set it up to be almost identical to the Tarmac if I wanted - just couldn’t switch back and forth very quickly). Gravel bike also has a 48/31 chainset, compared to the 52/36 on the Tarmac. Wheels from the Tarmac are a straight swap to the gravel bike (rotors spaced evenly with shims, etc.) With identical wheels fitted the gravel bike feels smoother and more forgiving than the Tarmac but doesn’t actually seem significantly slower overall really. I’m happy riding it even in the fast group on a bunch ride and never feel at a disadvantage.
In a crit I choose the more aggressive position, snappier handling, and bigger chainset of the Tarmac because I can, but if I had to ride the gravel bike instead I don’t think any of those would be the thing that limits me. Crits are very much a secondary (or tertiary) discipline for me though, so I’m pobably not overly picky.
For a roadie 100 mile hilly day or a long z2 road ride I almost always choose the gravel bike with the Tarmac’s wheels. 48/31 and 11-30 is amazing for that kind of riding. For an audax I’ll even go as far as to fit the 11-34 gravel cassette on the road wheelset. And the position is a lot nicer for long hours too. (sounds a lot like I’m describing a 2015 endurance road bike, eh?)
I’m riding the Tarmac in road races, but I’ve never done one over 3 hours. If I had a road race that was 5hrs and 10,000ft ascent then I might actually consider riding the gravel bike instead of the Tarmac (even though it’s heavier). Not sure where exactly the tradeoff point would be for me.
- Gravel bike started out 1x and I could either have good gearing for road or good gearing for gravel but not both. I considered having two different length chains and swapping out chainrings depending on use, but that’s actually a fair bit of work so I knew I’d never end up doing it. 2x is a must for this kind of use IMO. (especially if you’re swapping wheels with other 2x bikes)
- Buy some disc rotor shims - I’ve said this in probably a dozen different threads now but they still don’t seem to be very common. Just like swapping chainrings between uses, if you have to re-align your brake calipers when you swap wheels you’ll just never bother to swap. Syntace make 6-bolt ones and you probably have a local shop that does centrelock ones (there’s no major brand because they are actually just a generic shim from a machine parts catalogue in a specific size)
- B-tension is usually a waste of time. Set it for the biggest cassette you’re going to regularly put in the bike and then forget it. Every once in a while I’ll dial it in for crisp shifting on my 11-30, but usually if I’m riding that setup it just doesn’t matter enough to be worth the time and effort. Indexing isn’t an issue either - usually just a couple clicks one way or the other on the barrel adjuster is all it takes.
- Tyre clearance - I mentioned above that the Venon concerns me there. May be different where you live, but even a ‘fast’ gravel race bike should be able to fit 700x42-45 IMO