I don;t have any tours planned for the near future that are likely to warrant a new bike purchase. I really don't expect to do anything before the fall at the soonest and that is likely to be less than two weeks long on one of my 30+ year old bikes (by choice).

My next month long or multi month trip, assuming I manage another one at my age, I had thought I might treat myself to a nice carbon fiber gravel bike with high end components. Then I looked at the spec for the various models... I have always been fond of Cannondale bikes so I tended to look there. Splurging for something $4k or more didn't seem out of the question, but looking at the specs for the alloy models that might be less than half that I have to wonder if they wouldn't be as good as or maybe even a better fit for the task at hand. Some of the Topstone alloy choices look like a pretty good fit for my needs and a budget price. It looks very versatile, but many of my needs seem to be in a sweet spot for it.

Ya only go around twice.
If you got the bucks, why not spend a few?
My brother is a money hoarder and my sister-in-law has always said to him,
"When you die, I'm gonna stuff your coffin with $100 bills and bury you with it all!"
She's right.

Yeah, being raised by frugal parents who lived thru the depression is a blessing and a curse. On one hand I have managed to retire comfortably, on the other I tend to be too cheap to fully enjoy that.

Also I look at the choices I do question how much more I'll enjoy an almost $5k CF gravel bike than one that is about half that from the same line in alloy.

How about spending less on the aluminum bike, and use the rest for the trip?

The Topstone aluminum now has a GPX group I believe and simply one of the best bikes (mines a 105 group) I've owned in 30 years. I tend to use my road wheels/tires and ride asphalt, its a great regular road bike. I'm less impressed with the carbon Topstone which has a funky rear suspension and which has its rear wheels in an odd dish to make the wheel fit the rear with the suspension. Thats a bit funky for me, though folks owning them on the Topstone FB page love them. If I were looking at a carbon gravel, I would look at a more traditional design.

I thought I had read that the latest ones had done away with the weird dish.
Great to hear from a happy owner.

I'll ask on the FB page.

New Cannondale Topstone AL model - less proprietary!

Yes, saw this as well. Thats a good thing if you add a 2nd wheelset. Note though that they have this tread title incorrect as the Aluminum models never had an off set/re-dished rear wheel. That was only the carbon models with the rear suspension.

Or splurge and do both? It isn't a matter of what I can afford to spend so much as what I am willing to spend. I'd never let the money spent on the bike limit the trip. More likely a big trip would justify the splurge on the bike.
​​​​​​​

I'll have to be careful about the wheel spec. Needing to use proprietary wheels would be a bad thing to find out about after the purchase.

I am not convinced that a CF frame is best for touring

then buy the alloy version.
the gearing and components are the same.
you'll be able to switch/replace wheelsets easily.
it's a difference of what.............a pound?...big deal.
at our age shaving off a little weight on the frame is pointless.
BUT......paying double will keep you awake at night.

you'll be regretting paying the extra $2k for no tangible benefit.
you'll be concerned that weird rear wheel might not be replaceable/repairable in the field.
you'll be worried some baddie might steal your expensive ride.
and most importantly.........................
you'll be concerned that at any moment your hi-tek crabon bike might assplode!

I think I am fairly likely to go that way if I do buy a gravel bike. I do feel like I miss out on the feeling of indulging myself with a really nice bike though.

I am a weight weenie when it comes to my gear, sweating the ounces or even fractional ounces. The thing is that for some reason I never got that obsessive about worrying about the ounces on the bike itself other than maybe in the tires (and tubes if any) and to a lesser extent wheels. I think that is because much of the gear weight reduction is done by leaving stuff home and the rest was done mostly without buying too much super expensive gear. I managed to get the weight way down with no cuben fiber and not much super high tech stuff.

FWIW, the worry that a cf frame would "assplode" isn't something that would keep me awake at night.

wheels and tires is where it's at. rotating mass is what saps the greatest energy to move.

so don't indulge by buying an unecessary crabon frame, put your bucks to use with a new lightweight high-quality bike-a-packin' bag system, or maybe that upgraded gps unit you've been droolin' over.

If you buy the latest and greatest now, what's to say that you won't have that itch again (for the new latest and greatest) when your next really long tour comes up? Not saying you shouldn't do it though.

Yes, there is always that. OTOH, once I buy a bike I typically am happy with it for a decade or three

Yep, wheels and tires are a very big part or the equation. They have a huge impact on both performance and ride feel. My last bike purchase was a modest priced bike followed by some nicer wheels as an upgrade. For a gravel bike where versatility is one of it;s key advantages having more than one set of wheels is a big plus.

You're technically correct. However while rotational mass has a larger effect on accelerations than static weight, the overall difference is so small as to be almost unnoticeable. Also that rotational energy is given back in some proportion further narrowing the actual difference.

you need to compare the difference of rotational mass against the whole system weight. Getting 500g off a 2500g tire and wheel combo may seem like a lot. However added or removed 500g in tire and rim compared against say, 90kg of total system mass is practically a difference of almost nothing. And it needs to be emphasized that the difference of rotational vs static mass is present only during acceleration.

Tires on the other hand can have a huge effect due to rolling resistance. But even then it's more important to use the correct pressure rather than using an expensive lightweight tire. Too low a pressure is almost always faster than too high so when in doubt, go low. Thankfully there are some good resources for finding the correct pressure (I use the silca calculator)

Well, like you, I'm frugal (cheapass!)! But fortunately I married much better than I deserve and she makes me spend on stuff I want. I'm so happy with my Custom Pinion Ti tourer that I use it for daily commute and fitness as well. I only use my CF road bike on my weekly group rides with friends. There are now Ti tourers like Litespeed, or if you feel like being a rebel, the Chinese brands like custom builders Waltly, which come under 5k. Add carbon bits and the ride is very nice for a non-suspension bike.
A Ti frame may not be as aero, but fit is especially important if you are going touring off road and require 50+mm tire clearance. A CF tourer is fine for US travel, but any international remote travel is a bit more risky when you factor in damage, which is trip ending. Ti is tougher on falls etc. But yeah... spend it while you can! haha

Main question is, what is the usable life span of the bike and midway to that end what will the bike cost/worth in those future dollars.

The window of buying anything of real value at an economical cost is closing fast if not already closed...

I only took a quick glance but does the alloy version have braze ons for a rear rack and the carbon doesn't ? If so, I would appreciate the versatility of the alloy frame. And btw, today's top aluminum frames from the top companies ride wonderfully compared to aluminum frames from 30 years or even 15 years ago. Just my take.

The carbon Topstone cannot use a rear rack due to how the suspension works, I believe. The aluminum has eyelets for a rear rack, though you would need to take off the handle on the rear thru axle (or replace it) as the handle interferes with mounting a rack. The carbon fork has some form of eyelets on the inside of the fork handle. I dont recall if there are eyelets on the fork dropouts. Not sure how you mount a low rider rack on the fork. The aluminum bike would work well with a rear rack and panniers plus a bikepacking front bag on the h-bar. If using a frame bag, note theres a third bottle cage mount on the bottom of the downtube.

I just splurged big time on a custom steel gravel bike. The frame was a bargain at $1600, the splurge was the wheels and rest of the components. One advantage of steel is you can find a builder to build what you want - to get that in Ti or carbon costs much more. For a touring bike I'd always choose metal over carbon.