Quote from: martinf on November 12, 2026, 07:56:06 AM

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... And I once saw a carbon-fibre racing bike literally shatter when the rider touched a moving car.
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A friend of mine crashed a few times on his carbon bike.  Was nervous about it, had it inspected.  (The engineer doing the inspection used to work for Trek, knew what he was doing.)  He found a lot of cracks in the downtube, some of which converged in one spot, suggesting that an impact caused the damage. 

My friend did not want the frame back, the engineer cut off the dropouts with a hack saw before putting the frame in the dumpster to make sure that nobody retrieved the frame and built it up.

I have never owned anything with carbon fiber for bicycling, plan to stay that way. 

But, I really like my carbon fiber kayak paddle.

I can see where you’re coming from. Stainless steel and aluminium are both familiar and cost a lot less than titanium. Titanium can save a decent bit of weight, but I’d want to see some good long-term comparisons before spending that much. I’d be thinking about strength and load capacity too, a bit like the concern you mentioned with carbon, even though they’re very different materials.

My view - not really relevant for the large-wheel bikes I use for touring or utility rides.

But I do have a fair number of titanium parts on my "light" Brompton. The main idea here is to reduce the weight of the folded bike and make it easier to carry.

Titanium parts :
- Fork
- Rear triangle
- Handlebar
- Lower section of my telescopic seat post
- Mudguard stays
- Square taper bottom bracket axle
- Saddle rails (on a reasonably light synthetic saddle, not the minimalist type used by racers)

The fork is a bit more comfortable than the standard steel fork, as is the handlebar. The synthetic saddle is much less comfortable than the Brooks B17 or Flyer saddles that I use on most of my other bikes, but it is acceptable for the relatively short distances I ride when I use this Brompton.

These titanium parts save a bit more than 1 kg over the standard parts. I wouldn't bother about saving 1 kg on most of my bikes, it doesn't make a significant difference to me when riding.

But I really notice 1 kg less when carrying the folded Brompton.

Thanks for sharing your Brompton setup — that’s a really useful example. It sounds like the weight saving matters most when you’re carrying the folded bike, rather than while riding it. Would you choose titanium parts again for another bike, or was it more of an interesting one-off upgrade? Given the cost, I’m curious whether you feel they’re worth it for you.

The weight saving for titanium over steel for components like bicycle frames was never as significant as a comparison of their relative densities would seem to suggest, because of its lower Young’s Modulus, larger tubes with thicker walls are needed. These days even that small weight advantage has been to some extent negated by the widespread use of carbon fibre, which in most cases is both lighter and cheaper.

My preferred material for frames, forks and luggage carriers is steel. But for a Brompton folder, getting a lightweight steel frame and forks custom-made would cost more than the same parts in titanium, which are available as factory-produced parts. I don't like aluminium alloy forks and frames, because they don't have the "springiness" of steel and titanium, and aluminium has a different failure mode than steel and titanium.

Aluminium alloy is good for some things, especially rims used with traditional rim brakes, where it works much better than steel. In my experience the sidewalls on aluminium rims generally wear out before there are any metal fatigue issues.

I don't have any carbon fibre parts. This material isn't suitable for my idea of a touring or utility bike, where the weight doesn't matter much for me. I don't want carbon fibre on a folder because I don't trust it to resist the lateral shocks that occur sometimes when carrying the Brompton on public transport. I am sure it is OK for a lightweight road bike that is looked after carefully and replaced fairly often, but I saw lots of broken carbon fibre parts at my local bikeshop before it closed a few years ago. And I once saw a carbon-fibre racing bike literally shatter when the rider touched a moving car.

It’s attraction for me lies in its anti-corrosion properties; titanium frames retain their good looks and require no costly repainting, a property also shared by martensitic stainless steels.

The anti-corrosion properties of titanium don't really matter to me for frames, forks and luggage carriers. I regularly touch up the paint on my steel-framed bicycles and steel luggage carriers, and repaint them completely (using a paintbrush) if I reckon this is needed (not very often). So my bikes don't look so good as when they were new, which I take as a plus as it reduces their appeal to thieves. I still have my 1977 steel-frame lightweight tourer, on which the Reynolds 531 steel frame and forks are the only original parts left.

My view - not really relevant for the large-wheel bikes I use for touring or utility rides.

But I do have a fair number of titanium parts on my "light" Brompton. The main idea here is to reduce the weight of the folded bike and make it easier to carry.

Titanium parts :
- Fork
- Rear triangle
- Handlebar
- Lower section of my telescopic seat post
- Mudguard stays
- Square taper bottom bracket axle
- Saddle rails (on a reasonably light synthetic saddle, not the minimalist type used by racers)

The fork is a bit more comfortable than the standard steel fork, as is the handlebar. The synthetic saddle is much less comfortable than the Brooks B17 or Flyer saddles that I use on most of my other bikes, but it is acceptable for the relatively short distances I ride when I use this Brompton.

These titanium parts save a bit more than 1 kg over the standard parts. I wouldn't bother about saving 1 kg on most of my bikes, it doesn't make a significant difference to me when riding.

But I really notice 1 kg less when carrying the folded Brompton.

Components?  I see no great advantage for components that could otherwise be made of aluminum or stainless steel.

That said, I have always wanted a titanium bike.  Did I need it?  No.  But it was some bling that I always wanted.  I got lucky, got a great deal on a titanium touring frame made by Lynskey.  Built it up in 2017.  I really like the bike.  But knocking a kg or two off of the weight of a touring bike that otherwise could be made from steel is not really cost effective for the higher cost.  I would not have paid full price for the frame I got.

Other people that I have met that had titanium frames really liked them, but the only thing I can think of where titanium continues to be used is for frames. 

And only a few frame makers actually build up titanium forks to go with their frames.  I do not know why titanium forks or handlebars are extraordinarily rare.

I think Tubus makes a rack from titanium that costs a LOT, but in my opinion it does not have any great advantage over steel.

What do you have in mind?