Titanium. What’s the consensus

All these things are anecdotal, and I've only had my Merlin (US Merlin) for 19 years- 23mm tyres, Ultegra 9 speed triple. Rather irrationally, I only take it out in good weather. I've only had my other 'best bike ever', the Vitus Substance steel 9 speed double, for a year but my comparison is that on rubbishy North Lancashire roads the titanium gives an equally comfortable ride on hard 23mm as the steel on 55-60 psi 37mm, and is about 4-5% faster.

if you churn bikes then no, if you keep them then yes. My best bike has been a Ti bike for 13 years. Like triggers broom the only thing original is the frame. But its a bike for life and after 13 years of riding it, i'll neverr be replaced.. its timeless as the carbon paint schemes come and go..   Had carbon too..it cracked. Ride Quality..cant really tell tbh.. And the penalty is about 600 grams. 

I've never owned a Ti bike, but the impression I get is that they are like steel, but slightly lighter.

Much like steel bikes, the primary attraction is the "ride quality" over out-and-out performance, although you certainly can get race-focused Ti (and steel) bikes. Even so, they can't compete with carbon for strength-to-weight if racing is your thing.

Another attraction of Ti bikes is that they don't rust and don't need painting - so you can have that raw Ti look. Which some people love, but isn't everyone's cup of tea.

No frame will last forever - it's old now, but this article shows that Ti frames are subject to fatigue failure (indeed the longest-lived from was Al!): https://www.sheldonbrown.com/rinard/frame_fatigue_test.htm

Ultimately, IMHO Ti bikes are objects of desire rather than being objectively a sensible choice. The best reason to buy a Ti bike is because you want a Ti bike! If you don't "want" a Ti bike, then you can probably get something fit for purpose and cheaper by buying something else.

Personally not a fan. 

I'd argue that longevity and performance are not bed buddies when it comes to Ti. You can have great performance, but then the Ti alloy tends to be more brital and prone to failure, or you can have durability and comfort at the expense of performance.

Looking at long term durability, as already mentioned, there is an argument that you don't want one frame to live forever... techs develop and fashions change, are you ready for a one colour cycling future?

Personally speaking again, I prefer the ride quality of steel.. its just feels more energetic than Ti. With steel the balance is a three way thing, weight, performance and durability... choose two of the three. 

I've had a Planet X Ti Sportive, as my 'best' bike for 10 years now. The frame was built by Lynskey, I believe it was the same as their contemporary Sportive frame, just with less intricate dropouts. It came with Dura Ace 7900, which it still has, but I've upgraded the wheels (Shimano RS80), seatpost (Van Nicholas titanium) and handlebar (3T carbon). When I bought it i immediately noticed that the ride feel was significantly smoother than the aluminium Scott it replaced, but obviously there were other variables in play. 

It's been and remains a fantastic bike, but I'd agree that there aren't many reasons to believe a titanium frame is necessarily going to be any longer-lasting than a steel or carbon frame. The lack of paint obviously means it keeps its looks better though! 

Overall I'd say go for it, but the main benefits are likely to be the classic looks (vs a carbon bike) and the resilience of the finish (no paint, no corrosion). 

I splashed out on a titanium bike about eight years ago, it's an absolute dream to ride. Bikes like those from Kinesis are amazing value, yes you can get more bling for your money if you go carbon but if you want to buy something that will still be a joy years down the road you can't better a titanium frame. I can't say anything about stress points as my bike's in as good a condition today as the day it was delivered. If you're looking for a 'one bike' solution then titanium is an excellent choice. 

I was strongly considering a Ti frame for a new gravel bike build as I wanted a frame material that can shrug off chips and scrapes. However, I've ordered a Fairlight Secan as I just couldn't justify the extra cost of Titanium. Sure the steel Secan is a little heavier than a titanium frame but that's irrelevant when bike packing. As already stated, tyre choice makes more impact on ride comfort than frame material, especially with big off road tyres. I'm also a big fan of a quality steel frame and how they ride, I can't imagine titanium riding that much better.

The geometry of the Secan also suited me better, all the Titanium gravel frames I looked at had pretty upright geometries whilst I'm more used to slammed racing bikes.

To add to your conundrum, I think that wheels are a massively overlooked contributor to ride quality.  A poor set of wheels would make any bike uncomfortable.  It puzzles me when 'bikes' are tested on sites like this - when basically the 'bike' is a frame with someone elses components.

I have often been tempted with a titanium frame but keep asking myself if they are so good then why aren't there more of them around?  I cannot believe that it is just because of the cost, you only have to look at the frames, groupsets and wheels on bikes parked outside cafes on the wekend to realise that cost is not a barrier to a lot of riders.  Also, I like changing things, I tried Di2 and went back to SRAM mechanical, I change handlebars every couple of years and at £4-500 for a reasonable frame I can justify to myself changing that every 4 or 5 years.  If I had dropped £2k on a frame, even if I was slightly diasppointed with it I would feel that I had to keep it.  Similary, still being on rim brakes (for the next couple of years until my next frame upgrade when number 1 daughter finishes university) I cannot justify buyin carbon rimmed wheels which will be ground away every time I brake until they reach the point I have to throw them away.  But I digress, I cannot quite bring myself to believe that a titanium frame is an investment for life for most people.

Not such a big investment if you get a Spa model - on your doorstep, presumably? . No adverse issues after 3 years. It's light, and balances stiffness (it's an Audax model, that's what it wants to do) and comfort. Carbon forks. When you compare prices, you have to wonder who is scrimping, who is overcharging? 

Presumably any hole is a potential source of problems, All the materials will produce some instances of a cracking horror story - individual defects, general defects or abuse, I don't know. With the possible exception of steel (which is real, of course), bike frames can't be economically repaired, not when you factor in the making good, so you're right to be concerned. 

I have two Ti bikes - though old ones - they are hand-made US frames: a Litespeed Siena (initially Chorus now Ultegra 6800) and a Litespeed Vortex (same Record groupset).  Both are from the early 2000s. The Siena has been ridden daily throughout the year and has a few Paris-Roubaixs (which I think is just about as much as you could subject a bike to without taking a hammer to it).  The Vortex has been used less as it's an out-and-out racing bike, so weekends, sportives, holidays (as it's components are higher spec), but as a racing bike it holds up well to my modern bike, a Factor O2. 

I've never regretted buying either despite what were eye watering costs for the day.  They're both as sylish as they were new, have never let me down, and now I'm starting to believe what I was told when I bought them in my early 30s - and thought ridiculous: that these bikes would outlast me.  I suspect that one of the reasons Litespeed went bust was that their products didn't break...i.e. you only need one (or two in my case). 

I can't speak for some of the modern Ti frames, many of which are probably Chinese-made.  But if you are buying one then I'd strongly recommend investing in a high quality frame - it's only going to be as good as the person who made it.  I don't know much about Kinesis - apart from the fact that its a UK brand but the GTD costs £300 less than the Siena did in 2002!.  If I was going to buy one I'd ask for a video showing how it's made...