Carbon fibre v Titanium

[Sturat0]

Please could someone give me some advice on which is better: a carbon fibre frame or titanium. I have been looking at the former however I notice that a titanium is not much dearer (and looks nicer!) - however what are they like to ride? I am looking ideally for a frame that will take guards and 25 or even 28mm tyres. Thanks.

[splott]

makes no difference what a frame is made of.
it is the build that makes them different.
try them and buy the one you like.

[rogerzilla]

CF is best for performance, Ti is best for toughness (it'll dent, not crack). If you want a bike for life, CF may not be it. Don't overlook lightweight steel.

[djnotts]

What splott said, +1.

BUT carbon frames built for >x25s and with 'grd space and mountings are quite few and far between - and probably MORE pricey than Ti, so for your spec that's probably better bet!

[gilesjuk]

It does make a huge difference what the frame is made of.

Steel is a nice ride, decent steel forks with some flex in them soak up the trail bumps nicely.

Aluminium is cheap, fairly lightweight but harsh.

Carbon Fibre can be light, but on thin parts it can fracture and fail.

Titanium has some of the qualities of steel but lighter and doesn't rust. But frames can crack around the welds. It depends on quality and how you ride.

Personally it's a choice of steel or titanium. Steel is the best value for money, takes some looking after, stone chips, rust etc.

I have around 6 bikes, none of them are made of aluminium. One is titanium, one is carbon and the rest are steel.

[PW]

The latest steel (R953) has twice the tensile strength of Ti, is harder than military armour plate and stainless so it won't rust.
End result, the slightly oversize tubes have a wall thickness of 0.3mm, the frame is featherweight and it handles like a dream. It can also be built/altered locally by an artisan builder. Ti needs to be welded in an inert gas atmosphere, the only British worker I'm aware of offering to work on it is Vernon Barker.

[PH]

Ti needs to be welded in an inert gas atmosphere, the only British worker I'm aware of offering to work on it is Vernon Barker.

Enigma are also doing some manufacturing in Ti... and when you say the only British worker it ought to be pointed out that there's plenty of non cycle Ti welders around who could do a repair.

[Si]

Steel is a nice ride, decent steel forks with some flex in them soak up the trail bumps nicely.

Aluminium is cheap, fairly lightweight but harsh.

It's not quite that simple I'm afraid. In lab tests done a while ago (C+) there was no discernible difference caused by the material - all differences appeared to be down to the way that a frameset was built. Some Alu framesets were found to be less harsh than some steel and vice-versa. However, it all pales when tyres are added into the equation - these make a lot more difference to comfort than frame material. Traditionally the real differences between steel and Alu have been how long it will last and how easy it s to fix when it goes. The former is becoming less of an issue as makers have got better at Alu (and, it's very easy to build a rubbish steel frame).

[EdinburghFixed]

I was going to say, there's a great article by Sheldon on why it's a myth to associate frame material with certain ride properties.

However, while the material a frame is made of does not define its ride qualities, it's probably accurate to say that frame material is correlated with certain design decisions (i.e. a race bike rides stiffly/harshly, a race bike is made of aluminium for weight saving). So, if you're looking for a flexy ride, you probably do want to look for steel.

[Chodak]

I have two titanium bikes, a tourer with a pretty robust frame built by Sabbath (Silk Route) in Russia, made to measure to a fit done by Paul Hewitt. My other bike is a Justin Burls audax bike with a frame made in the far east. They are VERY different in character, despite the shared material.

The Burls ride is very comfy, light, lively and 'racy' (20lb with mudguards, 28mm tyres and a triple chainset), the Sabbath is very comfy, stable and predictable but weighs in at 26lb with mudguards and luggage carriers. The Sabbath can do full on heavyweight touring, the Burls can manage credit card touring.

I have ridden aluminium bikes up to £1,100 and would never go down this route again having ridden titanium, just personal preference I'm sure, but to my mind it's in a different league. I have never ridden great quality steel, but know quite a few who swear by it. I've been warned off the extremely stiff 953 by the very best builders (Mercian for one) as being fit only for ultra stiff racing bikes. Some steel bikes ridden by friends are over 30 years old and look great, with lovely paint jobs. My bikes are plain metal, with welded joints rather than craftsman's fancy lugwork, they look nice, but not artistically stunning. I suspect the titanium is stronger and should inherently last longer, other things being equal, but since when have other things ever been equal in this world!

I stick with the decision to buy Ti due to the strength, the lack of worries about corrosion or paint chips on bikes that are at least as comfy as steel, far tougher than ali and way, way more robust than carbon.

Carbon may be worth a look if speed is of paramount importance and you plan changing the bike on a fairly regular basis as it will be more vulnerable and to my mind will go out of fashion faster than steel or titanium bikes, which are probably never going to be fashion items in the first place!

[TwoWheelsGood]

I've been warned off the extremely stiff 953 by the very best builders (Mercian for one) as being fit only for ultra stiff racing bikes.

Not heard that one before, but there again 953 was only available in a relatively limited selection of tube sizes until recently which could have made it more difficult for a 953 frame to be built with a relative emphasis on comfort. (A 953 fork is now available as well.) One framebuilder I spoke to (Brian Rourke) claimed that the only real difference between the different Reynolds steels was the weight, and this included 953 when it was still a relatively new material for bicycle frames.

It's a combination of good quality materials and good design that creates a good quality bicycle frame; conversely with something like poor quality "gas pipe" steel it's next to impossible to build a frame that is lightweight yet feels comfortable and responsive at the same time. You could also theoretically create an overweight and unresponsive frame using carbon fibre or titanium.

[hubgearfreak]

a search through this forum and cyclechat will show up a fair few carbon bikes whose owners are wondering whether they should ride them, because the frames been chipped, scratched, etc.

rogerzilla has it about right above, but if you're able to be certain that you'll never bash, scratch, knock or otherwise damage the frame, then cf may be a valid choice.

as for steel rusting to the point of structural weakness, i've only ever seen it once, on a trade bike that'd had many decades of neglect.

[al_yrpal]

As an engineer who spent a lifetime designing metal and plastic structures, reading some of the folklore here makes me smile.

Any similarly sized piece of steel deflects equally within its elastic limit under the same under load. When its elastic limit is reached it will permanently deform. Properly designed bicycle frames should never do that. Ultimate tensile strength has absolutely nothing to do with anything related to shock absorbing properties and thus comfort. Aluminium is almost exactly 1/3 the weight of steel and its elastic properties mean it will deform three times as much as a similarly sized piece of steel. Enlarging sections overcomes that. The percieved differences experienced by some here have lots more to do with the designers choice of frame geometry and tube sizing between frames than material.

The biggest determinent of comfort remains tyres which deflect enormously under load in comparison to any distortion of the frame. Tyres absorb shock and vibration on a scale far greater than any frame. Tyre pressure is a huge factor. Sidewall stiffness has a small effect, its biggest being on rolling resistance.

The other factors - cost, susceptibility to damage, and difficulty of welding are far more significant in the choice of frame material. Carbon fibre is an excellent choice to reduce weight, but it has many well known disadvantages too. Skinny lightweight frames are useless for a heavy person carrying lots of weight, they are often not laterally stiff and can turn into metronomes.

I presently have two Aluminium bikes and I have had steel ones, and ones with carbon forks. They all rode differently. The type of tyres, stiffness and weight of wheels, correct design of a frame to carry the intended load, presence of suspension, saddle type and material, weight distribution of components, tube sizing, steering geometry, fork rake, all effect how a bike feels. Don't put it all down to frame material its a very minor factor.

When choosing a bike ride it for a few miles and see how it feels.

Al

[531colin]

Unless you go for something individually made, mudguards and 25 to 28mm. tyres takes the OP to Audax type bikes. That will also mean that certain ride characteristics are designed in, irrespective of frame material.
But something puzzles me - where are all the titanium forks? The stuff is springy, and resistant to fatigue, corrosion and damage, surely ideal for forks? But most titanium bikes have carbon forks, susceptible to damage. The Sabbath tourer has steel forks, as I remember.

[Gearoidmuar]

I stick with the decision to buy Ti due to the strength, the lack of worries about corrosion or paint chips on bikes that are at least as comfy as steel, far tougher than ali and way, way more robust than carbon.

I've posted this before, but I and a friend were hit by a car which did a U-turn across us at speed as we were passing it, it being in a parked position.
My hand was wrecked by going through the windscreen and he somersaulted over the car and lay unconscious on the road for a couple of minutes.
I was riding an aluminium MTB with suspension forks. My bike looked fine, but I scrapped it. His bike had carbon forks which looked perfect. This titanium bike was like this...



M'lud, I rest my case for the defence of aluminium and carbon fibre...