Considerations of carbon frames

[2pies]

The Carbon v Alu discussion has been raised many times and I've tried to read as many as possible. What is often mentioned is that entry level carbon bikes have inferior components to Alu bikes. This may be true, but if one was to compare similar bikes, just different materials, what comparisons can be made?

Two bikes I'm looking at seem very similar; same 105 groupset, Easton wheels and bar, Schwalbe tyres etc.

Cube Peloton Race £999
Cube Agree GTC £1259

Lets, for a second, assume I could afford either. Supposedly, the carbon bike will give me a slightly smoother ride. I would plan to use it almost exclusively for club rides, typically 40-50 miles each weekend, and a few medium length sportives, perhaps 50-70 miles. All things being equal, e.g. geometry/tyre pressure, would I notice much of a difference?

My concern is damaging a carbon frame by transporting it around, keeping it in a shed with other bikes and young children who could, potentially, knock it over or, more likely, knock another bike into it.

I'll try to get a test ride of each, but it may be difficult as I'm after a 60 or 62cm frame which few shops will have in stock.

FWIW, I bought a Spec. Tricross last year for commuting and have been on a number of club runs on it. For the most part I'm OK but struggle to keep up on the fast sections of the rides where the weight of the frame, cheap wheels and wide tyres seem rather sluggish (oddly I'm fine on the hills, I seem to be quite good at climbing). As I've embraced road riding more than I expected, I'd like to buy another, sportier, bike for this purpose and keep the Tricross just as a commuter, which is what it was bought (and designed) for.

Apologies for dragging up an age old topic, I'd just like your thoughts when, purely, comparing frame materials.

 

[YahudaMoon]

Aluminium 6061 Double Butted is probably the cheapest Alu frame you can get. Plus the welding on that Cube frame is poor. I have no idea how it compares to the carbon frame ?

Unlike a Italian the aluminium Dedacciai tubing frames that Brian Rourke could build

Or even A1 Aluminium or A6N to name a few other good materials.

 

[vickster]

My carbon roadbike 'toy' is very comfortable on tatty roads compared to my commuterised Specialized Sirrus with carbon forks, I wanted something different when I went to drop bars, hence th carbon

Cannondale, from what I have read, are meant to make excellent alu frames, the CAAD models are raved about

http://www.bikeradar.com/gear/category/bikes/road/product/review-cannondale-caad10-105-12-45526

 

[tiswas-steve]

I've got a Cube Agree Race GTC and while I love it to bits, I'm very protective of getting any marks, scratches etc on it. I can't really comment on the strength issues of carbon V alu but would you really be happy chucking your full CF pride and joy amongst the kids bikes and bits and bobs in your garage ? So taking into value the price differences and what not ill go for the Peloton, it's still a lovely looking bike and best of all it's a CUBE !! ;-)

 

[smokeysmoo]

WARNING - BIASED CANNONDALE INFO FOLLOWS

As YM says, the CAAD bikes are raved about, and for extremely good reason as tehy are utterly fantastic machines, and I'd challenge you to find a negative word written about them.

You could get the CAAD10 105 with a tiny stretch of your budget. Don't forget too that all CAAD10 models have exacty the same frame, (just different colourways). So the CAAD 105 frame is identical in every technical respect to the £2.6k Dura Ace model. Anyhoo, check them out here; http://www.cannondale.com/gbr/2012/bikes/road/elite-road/caad10

For pricing have look here; http://www.wheelbase.co.uk/products/cannondale-caad10-105-2012.htm

My opinion on CF is well documented and I'm not going to start again, but FWIW, the CAAD frame is lighter than most all CF frames, (except maybe a few very high end ones), so don't fall into the trap of thinking of cf as an upgrade as it isn't, it's just a different material - maybe no better, maybe no worse, and forget about weight as these bikes absolutely fly

 

[2pies]

Aluminium 6061 Double Butted is probably the cheapest Alu frame you can get. Plus the welding on that Cube frame is poor. I have no idea how it compares to the carbon frame ?

Unlike a Italian the aluminium Dedacciai tubing frames that Brian Rourke could build

Or even A1 Aluminium or A6N to name a few other good materials.

Thanks. Could you elaborate on that point about 6061 frame? I've seen some frames advertised as triple butted, does that mean the welding is better? Any other numbers to look out for?

The CAAD8 uses 6061 while the CAAD10 uses 6069

I've got a Cube Agree Race GTC and while I love it to bits, I'm very protective of getting any marks, scratches etc on it. I can't really comment on the strength issues of carbon V alu but would you really be happy chucking your full CF pride and joy amongst the kids bikes and bits and bobs in your garage ? So taking into value the price differences and what not ill go for the Peloton, it's still a lovely looking bike and best of all it's a CUBE !! ;-)

I may be paranoid and would do my best to avoid any scratches, its just more of a concern.

WARNING - BIASED CANNONDALE INFO FOLLOWS

As YM says, the CAAD bikes are raved about, and for extremely good reason as tehy are utterly fantastic machines, and I'd challenge you to find a negative word written about them.

Yes, I'm familiar with 'Dales. The CAAD 10 may be out of my limit, but the CAAD8 105 is another bike I've considered.

 

[PpPete]

When I got back in to cycling and started venturing out in lycra my wife said "I suppose you'll want a carbon fibre bike next"....
I proved her wrong though.....bought titanium instead!

 

[gbb]

The Carbon v Alu discussion has been raised many times and I've tried to read as many as possible. What is often mentioned is that entry level carbon bikes have inferior components to Alu bikes. This may be true, but if one was to compare similar bikes, just different materials, what comparisons can be made?

Two bikes I'm looking at seem very similar; same 105 groupset, Easton wheels and bar, Schwalbe tyres etc.

Cube Peloton Race £999
Cube Agree GTC £1259

Lets, for a second, assume I could afford either. Supposedly, the carbon bike will give me a slightly smoother ride. I would plan to use it almost exclusively for club rides, typically 40-50 miles each weekend, and a few medium length sportives, perhaps 50-70 miles. All things being equal, e.g. geometry/tyre pressure, would I notice much of a difference?

My concern is damaging a carbon frame by transporting it around, keeping it in a shed with other bikes and young children who could, potentially, knock it over or, more likely, knock another bike into it.

I'll try to get a test ride of each, but it may be difficult as I'm after a 60 or 62cm frame which few shops will have in stock.

FWIW, I bought a Spec. Tricross last year for commuting and have been on a number of club runs on it. For the most part I'm OK but struggle to keep up on the fast sections of the rides where the weight of the frame, cheap wheels and wide tyres seem rather sluggish (oddly I'm fine on the hills, I seem to be quite good at climbing). As I've embraced road riding more than I expected, I'd like to buy another, sportier, bike for this purpose and keep the Tricross just as a commuter, which is what it was bought (and designed) for.

Apologies for dragging up an age old topic, I'd just like your thoughts when, purely, comparing frame materials.

We can only bring or (probably) limited experiences to the table, and they may be biased of course, but here's my simple analogy..
Cheapish budget cro-mo Raleigh roadbike...rattled and banged along. Good bike but harsh ride.
Moved onto a Bianchi Via Nirone...alloy frame, full carbon fork....much much more comfortable, less road buzz, it absorbed most of the lumps and bumps.
Just got a Ribble Sportive Racing...full carbon frame, full carbon forks, handlebars and seatpost...the one thing i notice instantly is how smooth it is...fabulous. It just seems to glide over the road.

I am a sceptic, i don't automatically assume things are better just because ive brought them (some people do this)...but the ride IS better, noticeably.

Caring for a carbon bike....well my alloy bianchi certainly didnt stand mild abuse very well. The frame was chipped in many places, stones, occasional things dropped on it in the shed, careless leaning it up against walls etc, the paintwork certainly didnt like it.....so how much worse can it be for a carbon frame ?
I intend getting some helicopter tape stuff for mine, just to protect the exposed areas. But ultimately, if you (or i) take care...it won't get damaged.

 

[henshaw11]

Thanks. Could you elaborate on that point about 6061 frame? I've seen some frames advertised as triple butted, does that mean the welding is better? Any other numbers to look out for?

The CAAD8 uses 6061 while the CAAD10 uses 6069

From http://www.gtgtandems.com/tech/materials.html
"What is a "triple butted" tube? While triple butted sounds like a 50% improvement, it's usually an easier-to-produce variation of a double butted tube where the two thick ends don't match (i.e. 10/7/8). Because the optimal .3mm differential only exists at one end of the tube, a triple butted tube is typically less expensive (removing the taper-producing mandrel is relatively simple when one end of the tube is only partially butted). While many tubing companies hyped triple-butted tubing in the early '80s, enlightened consumers have made these tubes rare."

On the other hand, it might just save a little weight. Doesn't mean the welds are any better or worse.

Cannondale have been using T6061 since they started making frames - needs heat-treating after welding, whereas T7000 (T7075?) doesn't generally AFAIA. T6061 vs T6069 ? - dunno, some difference in the alloy. A1 is just Specialized's name for whatever alloy they use (E5's another one).. I don't think it's worth getting too hung up an exact alloy types, it's how they use it which is the important bit.

 

[cadleigh]

I've only ridden an aluminium framed road bike for very brief trips (swapping with a mate on a ride, and so on), so am in no position to comment on them from a position of any great experience. I do have a mid-90's steel and a 2010 carbon road bike, though.

There are a few differences I've noticed - I can see the steel bike flexing beneath me at the back when I pedal hard; the carbon doesn't budge. So you'd think the steel would be more comfortable. And on general slow rides, it probably is, as all that flex seems to absorb a lot of bumps.

But there's a long, fast, twisting (and occasionally terrifying - depending on what you find around each bend) descent near me with a really crap surface - by the time I got to the bottom on the steel bike, my shouders and wrists were always killing me, to the point where I had to sit up to wiggle and flex my shoulders and wrists and relax before carrying on. On the carbon bike, I was amazed to be able to simply carry on cycling.

Similarly, the effect when climbing is markedly different - I like climbing anyway (even though I'm not built for it) and on the carbon bike I sail up climbs I used to find a chore on the steel one. All that flex has its disadvantages in lost energy, I suppose.

On the other hand, a saddle that was perfectly comfortable on the steel bike hurt like hell on the carbon. To the point where - with slightly sick feeling - I wondered whether I'd made a bad choice of bike. I'd already abandoned the saddle that I bought to go with the bike - lauded by many in any number of reviews as very comfortable - as it was the worst I've ever ridden and felt like I was sitting on the spine of a book, to the point that I sold the saddle.

Similarly, the cut-out saddle that was fine on the steel bike was a nightmare on the carbon - and even after I took it off and tried another one that finally worked, I suffered a couple of months' worth of hangover from the cut-out saddle before my poor sit bones recovered from the pounding they'd taken. It took me three saddles to find one I liked on the carbon frame.

I had a bad crash last September and have just started going out again. It's a bit like starting from scratch, so my arse is still being toughened up all over again - and I still find if I'm heading out to where I know there are really bad roads around here that simply reducing the tyre pressure by half a bar helps more than anything else.

I think the only thing to say is what people always say - try to have a go on each and see how each bike suits you. There are so many variables - contact points, your size and weight, the bike's frame size, tyre type and tyre pressures, road surfaces you'll be riding on - that one person's comfortable, smooth ride is another person's ride from hell.

However, one point with regards toughness of carbon - that crash (round a fast bend on relatively smooth tarmac, I suddnly encountered what appeard to be a couple of buckets of gravel, just chucked into the road) sent me and the bike flying sideways through the air and my first thought as I was lying in the road afterwards, blood pouring out of my arm, wrist buggered and temporarily too stunned to rise, was... "My BABY!" The impact left chunks taken out of a pedal, a brake and brake lever and the bar tape shredded - but the frame must have bounced, as it doesn't have a scratch and is absolutely fine.

(Apologies for the tediously long post).

 

[RecordAceFromNew]

On the other hand, a saddle that was perfectly comfortable on the steel bike hurt like hell on the carbon.

Assuming the tyre and pressure were the same, do you think this was due to carbon vs steel or due to differences in contact point positions and hence your posture / pressure points? The reason I ask, is because I suspect difference in vertical flex due to frame/fork material or construction is likely quite small compared to tyre/wheel flex and saddle compliance etc. - the diamond frame is an exceptionally rigid structure in the vertical plane; while forks flex, test data seem to have shown that variation between different ones is small.

However, one point with regards toughness of carbon - that crash (round a fast bend on relatively smooth tarmac, I suddnly encountered what appeard to be a couple of buckets of gravel, just chucked into the road) sent me and the bike flying sideways through the air and my first thought as I was lying in the road afterwards, blood pouring out of my arm, wrist buggered and temporarily too stunned to rise, was... "My BABY!" The impact left chunks taken out of a pedal, a brake and brake lever and the bar tape shredded - but the frame must have bounced, as it doesn't have a scratch and is absolutely fine.

Do you think this has got to do with the toughness of carbon or that the frame did not hit anything? IME it is usually the bits that stick out (bars, levers, pedals, saddle, wheels etc.) taking the brunt if a bike simply slides along or even cartwheeling on tarmac. The lacquer/epoxy encasing CF has to be extremely susceptible to scratching if it had been in contact. CF is not generally considered tough, but it can take tremendous tensile load (but next to no compression or bending, which is my next point).

Because CF is not isotropic, I think few will dispute that a CF frame is quite a bit trickier than a metal one to look after (see e.g. recent thread on its transportation). Since one can never know how previous owners handled it I don't think I will ever buy a used carbon frame. Do they have relatively lower resale value as a result?