UKC

I'm currently running 2 drop handlebar bikes, a rim braked Scott Foil and a Planet X London Road.  The Foil is my 'good' road bike and only really gets used in summer.  I've got 2 pairs of wheels for the London Road and use it for gravel riding and winter road rides.

In the spirit of rationalisation (or possibly just an excuse for a new bike), I'm wondering whether I can get one bike that does it all.  Maybe something like the Bianchi Impulso Comp/Pro or a Cervelo Aspero (one of the lower end models).

Key concerns would be gear range, the 2x setup on the Bianchi would address this but is 1x enough, and overall 'feeling' of speed.  I love digging my Foil out in Spring and feeling like I'm flying compared to the London Road.  Riding will be 70-80% gravel through the winter, then probably flips to 80-90% road in the summer.  Bike doesn't need to be able to carry luggage i.e. no bikepacking consideration.

Be interested to hear what solutions people have found to the question above.  Then I can start using the info to sell the idea to my wife.

At the risk of giving you the 'wrong' answer, I'd suggest you go back to the start and ask yourself "What problem am I trying to solve" before considering the merits of various solutions.

As for the idea of a single bike, I'm not convinced that works all that well. If you do gravel you're probably on tubeless tyres which are a pain to swap regularly. Yes, you can go for multiple wheel sets but decent ones are a significant proportion of the cost of the bike. And doubling (at least) the wear on a single groupset instead of two (again, a significant cost factor in any bike) doesn't make much economic sense. Full disclosure: I have two drop-bar bikes, a gravel/sensible bike and a nice all-road bike (to use modern marketing terms). They are not winter/summer, I use both all year round depending on the ride.

Of course if the 'problem' is how to convince your other half that you need a new bike then just admit it

The two key reasons for asking the question are firstly I'd like to upgrade both bikes, but can't afford 2 bikes at the spec level I would like.  Similarly, if I split my budget in two, I'll end up with two bikes that aren't much better than what I have now.

The second reason is space, I would definitely be pleased to get down to one bike and free up a bit of room in the shed.

Take your point on a second set of wheels being a significant cost, but I do think it should be significantly cheaper than a whole second bike.  Differences in costs associated with wear of parts I can live with, I'm not particularly heavy on kit and can do nearly all maintenance jobs at home, which softens the blow a bit.

OK, you want a new bike at a decent spec.

Makes sense.

Correct, but...

Not sure about your logic here: Twice the wear on one groupset is the same cost (long term) as spread over two. Of course the length of 'long-term' may be significant or not depending on how much you use your bikes.

I get the impression that you really just want a new bike and you're happy to just have one. Nothing wrong with that. Personally I like the convenience of having a mucky/sensible/gravel bike and a nice clean wizzy bike (currently on the turbo in the house).

One other though: Resilience: My nice bike is labelled 'all-road' (max. 35mm slick tyres) but I wouldn't really want to take it on some off the rocky off-road places (in the Peak District) where I take my more robust (feeling) gravel bike (45+mm knobblies). There probably are bikes that could comfortably do both jobs, but would they be 'jack-of-trades' or 'masters'?

I think you're probably right.  Dropped into the local bike shop today and they said much the same, it's just not realistic to have a gravel bike that will be as fast and light as my Foil.  I should probably also accept that although the Foil is getting old-ish, it's still more capable than I am.  Looks like it's time to keep an eye out for a nice gravel bike....

Honestly I think the solution is to stick with what you have.

n-1=2.

What would you do when the sun is shining and your only bike is in the repair shed due to time, lack of components etc. All year round is tough on bikes and it sounds like you have a good set up but we love an excuse to upgrade. Think of the salty crappy roads on your best bike.
I would just say after this winter and using a more road  oriented gravel bike then disc brakes would be my only reason to upgrade. (Please don’t flame me my summer bike is rim brakes). 

They have given me a lot more confidence on sketchy roads in mixed conditions  

I think I'm going to stick with the 2 bikes, but unlike the Foil, I definitely am starting to run up against the limitations of the London Road. I built it up from frame and forks with bits I had in the shed, biggest issue is gearing, 50-34 on the front and 11-32 at the back is good for leg strength but there are local routes that I avoid because I just can't get up them.  Shifters are also getting a bit dodgy, and upgrading all that will get expensive.  Plus, and I do recognise this is part of it, I'm happy driving a 16 year old car but I do like a shiny bike.

One bike to do it all is possible but will lead to compromise. Replacing the Foil with a frame also capable of running fatter tyres will probably cost you in terms of race geometry. 

Gearing wise, if 50-34/11-32 is too heavy to get up some hills then 2x GRX or similar is probably the solution. 46/32 in the front and 11-36 in the back should be possible with the right derailleur. I like 1x for ease of maintenance and cleaning and have it on both my bikes but I do sometimes feel out-paced on tarmac.

If I were in your position I'd probably keep the Foil and invest in a good (second hand?) cyclocross bike with clearance for 40 ish mm tyres for winter and gravel. 

Alternatively, have a look at something like the Rondo Ruut. Designed as a gravel bike but with an adaptable fork geometry that lets you switch between two head tube angles for cyclo and gravel. Could be a quiver killer. 

I have a PlanetX/OnOne Free Ranger and a Cervelo RS. I would happily cut the Cervelo - it maybe went out twice last year. My wife now just uses a PlanetX Tempest. By way of group sets, we're both on SRAM Force 1x, upgraded from the standard 11-42 11 speed to an 11-50 12 speed using a Ratio Technology conversion kit. This has meant that it can do all I want it to whilst also giving me the simplicity and reliability of 1x - I would highly recommend the conversion!

Intersting! I have 34-32 as the biggest gear on my gravel bike and am yet to run into trouble, even when fully loaded with bike packing stuff. Guess it's worth looking into some of the GRX chainrings, which are smaller (46/32 IIRC?) 

If it's an older foil frame, and rim brake, there are many, many (disc) frames out there that are very road orientated and will take a bigger tyre, often 30-32mm. I've got a TeamMachine, and it is certainly race geometry and takes a 32mm. 

No cyclocross bike will take 40 mm tyre, you need a gravel bike for that. 

Depending on your derailleur you could probably fit a 11-36 cassette (11-34 certainly, that's what I use). I know of people running 11-40 on a standard Shimano GS 11s derailleur.

Perhaps if you tried them regularly, you'd get stronger... I know, easy to say. I have some ~20% (cobbled) hills here that I have a love/hate relationship with.

Shifters or cables. Shifters shouldn't really wear out (barring crashes). What vintage? Merlin typically have groupsets (e.g., Shimano 105 11s) at decent prices.

But if you just fancy a new 'gravel' bike then go for it. 

That is really not true at all. My CX bike will certainly take a 40mm tyre even when fitted to a respectably wide rim. There's obviously a huge blurry area between the two categories, but it is a CX race bike rather than a gravel bike.  

^This^, smaller chainrings not bigger cassettes are the solution for making riding uphill easier.

Traditionally that used to be true but nowadays a lot of CX frames take well in excess of 40mm.

If you're a roadie I think you already have it right-"Nice" fast, light aero-ish bike for the summer and something indestructible and versatile for winter or touring or whatever you want to do with it. 

Failing that if you're willing to take a risk and fix any problems yourself then the used market is incredible at the moment.....