why carbon ?

dod 1

what are the pros and cons of carbon bikes also can anyone tell me if the raleigh airlite carbon is any good as i can pick one up for £840 if not can you recommended another carbon bike .

nolf

Pros carbon-
Light,
Stiff,
Strong,
Doesn't rust,
Can absorb a bit more road buzz than aluminium
Looks cooler

Cons of carbon-
If any part of the frame cracks the frame has to be chucked,
Expensive to replace,
Bit more delicate-
Aluminium can be welded and fixed, also aluminium is cheaper to replace

I think C+ did a review of it and they gave it a good score if I recall- like an 8 or 9 out of 10

Niland

Well aluminium isn't that fixable, if it gets bent it's a write off - steel and titanium can be repaired.

What interests me is the merits of lugged carbon versus monocoque carbon.

Smokin Joe

I've never had a carbon frame (Yet!!) but I would go for a monocoque on the basis that a joint - particularly a bonded one - is a potential cause of failure, in the short term if the adhesive hasn't set properly and in the long term if it breaks down.

aracer

Niland wrote:

Well aluminium isn't that fixable, if it gets bent it's a write off - steel and titanium can be repaired.

I agree about al being unrepairable, but whilst ti might be theoretically repairable, does anybody really get a ti frame repaired if pranged?

Arguably an impact which would crack a carbon frame would also structurally damage a thinwalled al or ti frame.

amt27

I agree about al being unrepairable, but whilst ti might be theoretically repairable, does anybody really get a ti frame repaired if pranged?

Arguably an impact which would crack a carbon frame would also structurally damage a thinwalled al or ti frame.

ti needs to be welded in an inert environment, as welding it absorbs a lot of oxygen which can make the weld brittle, so repairing will cost a small fortune,

carbon can fail on impact easily from forces it has not been designed to withstand, this can be useful in absorbing energy in an impact, did you see that carbon wheel hit a dog in the Tour, it crumbled and the rider did not fall far from the bike and carried on, a steel or aluminium wheel would have caused the rider to have more energy and fallen further, similar to a crumple zone on a car,
however i doubt any bike or component designers consider this much when designing,

carbon is not constrained by mass production of metal tubing and extrusions from metal producers as a mold is used, this means the frame dimensions and shapes of tubes can be manipulated for weigh saving and greater strength,

possible for the polymers in carbon fibre to break down in extreme temperatures, this also applies to the adhesives if a tube and lug construction

aluminium can salt corrode, especially under paint where a scratch allows water to get between the paint and metal, can be left bare or anodised to increase thickness of oxide protective layer,

kevin_stephens

I think you have to get quite an expensive carbon frame to get all the benefits

My aluminium Ridley Compact frame is light (1.3 kg), stiff, looks great and at around £500 was a lot cheaper than heavier bottom end carbon frames

aracer

Kevin Stephens wrote:

My aluminium Ridley Compact frame is light (1.3 kg), stiff, looks great and at around £500 was a lot cheaper than heavier bottom end carbon frames

A lot heavier than my cheaper carbon frame. Even the generic Nero Corsa is significantly lighter, and can be bought for little more than that, depending on source.

kevin_stephens

well Ribble sell the nero for approx £715 including fork and headset (as the Ridley was priced) and I got mine from a LBS as part of a bike build up. 150 gm lighter does not make a lot of difference to overal bike weight (18.0 lb for mine), the money saved can go to better wheels and components which can save weight in other areas

The only point I was making is that carbon is not automatically better value for money and its worth having a look at the whole picture. Of course if I wanted to have spent more and gone for a sub 16.0 lb bike, then a light carbon frame would have done very nicely

campagsarge

Interesting topic this. I guess you get what you pay for maybe with carbon? I think (and maybe someone can confirm or disprove this) one of the most expensive things about a carbon mono frame is the actual mold.

cougie

I wouldnt advise an absolutre beginner to get a carbon bike. One fall and it could be game over. Steel is sturdier - and with a CF fork - its quite a good ride.

nick hanson

cougie wrote:

I wouldnt advise an absolutre beginner to get a carbon bike. One fall and it could be game over. Steel is sturdier - and with a CF fork - its quite a good ride.

I agree about the CF fork.I had a Dolan badged (bulk imported job lot) alloy frame which i bought from him when he was building frames over on a pig farm (I kid you not!) in Lancashire.It came with Alloy power forks.When i changed over to CF forks,the ride was transformed.The frame is now doing sterling service as a winter bike,& the upgraded frame to make my best bike (a Raleigh titanium) on first ride isn't much different in ride quality (just don't feel as beat up at the end of a Century ride).
Value for money,get a light Alloy frame,say,a Ribble end of season special,that fits.That way,you won't feel guilty if you upgrade the frame in a year or two!

kevin_stephens

I wouldn't recommend crashing an alumnium bike or carbon bike. Great thing with crashing an aluminium bike is that it's much easier to tell if it's damaged or not and safe to carry on riding

aracer

campagsarge wrote:

Interesting topic this. I guess you get what you pay for maybe with carbon? I think (and maybe someone can confirm or disprove this) one of the most expensive things about a carbon mono frame is the actual mold.

As has been discussed a lot on here recently, the most expensive thing about a carbon frame is generally the logo on the side. Hence you don't get what you pay for.

I did say depending on source - only £550 for a Nero f&f here

Barney 2

And how risky is taking a a carbon bike on a plane?

wildmoustache

Barney 2 wrote:

And how risky is taking a a carbon bike on a plane?

buy a bike box and there is pretty much zero risk it seems. I have never heard of anyone's carbon bike, when packed in a bike box, coming to any harm.

if you have spend the wedge on a carbon bike, and you're flying abroad to ride it, then you are clearly fairly serious about cycling, and a decent bike box would make a sensible investment.

the whole carbon is fragile thing is overblown . There hundreds of thousands or cabon frames and forks out there working perfectly.

schlepcycling

Smokin Joe wrote:

I've never had a carbon frame (Yet!!) but I would go for a monocoque on the basis that a joint - particularly a bonded one - is a potential cause of failure, in the short term if the adhesive hasn't set properly and in the long term if it breaks down.

Are you suggesting that Colnagos are all a bit dodgy because they are lugged and not monocoque. :P

schlepcycling

Kevin Stephens wrote:

I wouldn't recommend crashing an alumnium bike or carbon bike. Great thing with crashing an aluminium bike is that it's much easier to tell if it's damaged or not and safe to carry on riding

I wouldn't recomment crashing ANY bike!.

pliptrot

All materials have there reliability issues, and it was said for a long time that the only thing wrong with steel frames could be fixed with a coat of paint. Modern carbon frames have eclipsed that philosophy, but it's worth remembering that if a steel frame fails you will generally get some warning - cracks spread slowly- Ti has similar failures (Ti DOES fatigue!) and aluminium ages, often failing suddenly (the old thin-tubed Vitus frames had quite a reputation for (aluminium) fork failures). The thing with carbon is that it often fails catastrophically, i.e. it will go completely and suddenly without warning. Never seen this, and I'm on my second carbon frame without (so far) problems. one would normally expect manufacturers to be conservative and cautious in their designs, so as to put safety first, but with the weight war going on I wonder. Certainly everyone and his uncle are offering carbon frames now, so why is the price not falling?

pliptrot

IMPORTANT CLARIFICATION

When I wrote...."often fails catastrophically".... I was referring to the mode of failure is often just this, in the very rare and infrequent (and NOT often!) cases of failure. Remember, composite, carbon (call it what you will) is used extensively in applications where reliability is arguably much more important than in cycle frames - aerospace, defense and so on. The latest Boeing is made using unprecedented amounts of these materials, and it's unlikely that they would do this if there was any increased risk compared with aluminium alloys thus far used.

cougie

But aeroplanes are subject to strict manintenance schedules andt tests. Not left in the garage for ladders and what have you to fall on, and be generally left uncleaned for months on end...

I ride carbon, but I do at least clean all my bikes, so I can see if its been scraped or anything.
Same with alloy and steel - is it safe if the bike is under a coating of mud ?

pliptrot

Quite. I made that point once before and someone claiming to be in the aerospace industry gave a howl of protest. I suspect his reaction was more to my polemic than due to his insider's knowledge. I'd also like to bet that QA and acceptance testing done by the aircraft industry and airlines are somewhat different to those of the cycle industry. Imagine buying a carbon frame and insisting on a complete ultrasound before accepting it!

Barney 2

Carbon is now the norm as far as fork material goes and I woul guess a fork will flex more than the frame, so I don't understand some peoples reluctance to a full carbon bike.

giant_man

The best thing about a lugged carbon frame compared to a monocoque one is that if any of the tubes are damaged, you can replace them whereas with a monocoque if you crash it the whole frame has to be discarded.

Why do you thing Colnago, and Parlee come to that, make lugged frames?

There is nothing wrong with a good carbon frame. On the right road surface, a carbon frame makes for a very smooth and fast road bike.

aracer

As I said earlier regarding ti frames - does anybody really repair a lugged carbon frame by replacing a tube? You'd have to not only remove the damaged tube, but also debond the joints with some of the undamaged ones in order to fit a new tube in. I can't believe that would actually be financially viable - anyway doesn't anybody have insurance which would simply pay for a new frame?

Fairly sure the main reason for the existence of lugged carbon frames is simply that they are cheaper and easier to make. Colnago seem to be a company living on their past reputation, as from what I can see there is nothing special about their cheaper carbon frames which justifies them charging over £1000 for a lugged frame when you can get a lighter monocoque for £500.

(for reference I've probably got more experience with carbon frames than most - have a 9 year old lugged carbon road bike, a 10 year old carbon monocoque TT bike and have been riding carbon MTBs for over 4 years - my first carbon MTB I rode with a damaged tube for almost a year without any particular concern).

pliptrot

I'm with you, aracer. It's a little ironic that Trek get slated for offering lugged carbon frames, and yet Colnago, Look and others claim it -and are believed- to be the best way to do it. I suspect otherwise. The early carbon frames had carbon tubes and aluminium lugs, and were called (rather disparagingly) "black aluminium". I suspect little has changed in the way frames are put together since then, to the chagrin of the industry. certainly lugged construction fails to capitalize on the real benefits of composites.

dod 1

thanks for all the info but what i really want to know is what is the best value for a cyclist like me who does not race but goes out with his club twice a week and wants a bike that is light can climb and gives a bit of comfort.

redddraggon

dod 1 wrote:

thanks for all the info but what i really want to know is what is the best value for a cyclist like me who does not race but goes out with his club twice a week and wants a bike that is light can climb and gives a bit of comfort.

Focus Cayo

or

Plant X

They seem to be the most popular

bigmug

Quite new to carbon frames I was impressed by how well it transferred pedal force to forward motion. But am worried about clamping things at the correct torque - stems, bars, set-pins etc cos it seems this is where self inflicted damage can occur.

My question which has not really been answered by shops is 'is road grit thrown up by the front wheel (no guards obviouisly) chipping away at the protective laquer and then shot blasting awy the carbon?? - should we be covering the down tube??

pliptrot

I'd worry little about road grit damaging a frame and even less about anything experienced through normal usage. All frame materials can fail, and all frames can fail. It's true that carbon failures get more attention, and it's true that carbon can be damaged in a way which may not show and may cause sudden, catastrophic failure, but such events are very rare. When we bought steel frames they were defined by the tubing used, and now with carbon in vogue this information is not volunteered, so we have little information with which to make a choice.

Pick something which looks good to you, is from a decent LBS (for support), and enjoy. Worry nothing about the doomsayers, such as I, who diss carbon automatically. I ride a 7 year old carbon frame which I have battered, crashed, crushed in workstands, flown all over the world, frozen, covered in mud, grit, Belgian toothpaste (cowsh*t) and ridden over cobbles and regular roads more than 30,000 miles. I reckon it's just about run in, and ready for it's 3rd groupset and 4th pair of rims. I'm not sure about carbon cranks, though.

Niland

well it's interesting reading people's thoughts on lugged vs monocoque.
A good number of the most highly rated carbon frames are lugged frames: Say Parlee, Time and Colnago.
One thing people haven't mentioned is the finish and quality "should" be higher with lugged - the fact that the tubes can be fully inspected and checked. If you wanted to check a monocoque - you'd have to cut it open. I'd think there should also be a greated posibility for tuning the vibration/stiffness quality with a lugged frame.