FAO: EKE and the carbon doubters...

roger_merriman

if I have the money when I replace the MTB which is my "best bike" if funds allow and the bike as a whole is my type of bike then would I be fine with Carbon?

Sure why not, my MTBing tends to be slow and technical, rather than smoother and faster so any off's tend to be low impact.

But realistically the frame material i've never been that worried about.

fossyant

Some luddites here.

My steel bikes won't take a concrete slab bashing like that frame did - would look like a golf ball surface.

The thing is steel tends to stretch/bend before it fails, but carbon will take a much bigger fail pressure, but then snap.

Alu frames have some bad points too. I can squeeze the main down tube on my fixed - it flexes in and out (slightly).

Alu is also subject to the oxidisation much easier than steel rusts, while isn't structural like heavy rust in steel, but it don't half make a mess of paint jobs.

Been using carbon forks and seat pin on a heavily used commuter fixed wheel, and they have been great - no issues.

Stevo_666

Greg66 wrote:

Surely it all depends.

Carbon can be made with very few lay ups or very many. The number and the way in which the fibres cross over will affect overall strength and torsional rigidity. Alu, steel and Ti can be made thin or thick. To that extent I would guess that carbon offers more latitude to build in strength in the particular areas/directions where stress is greatest without having to resort to a "make it thicker" solution.

Yep, the permutations allowed by the different types of CF, number of layers, weave etc is enormous and allows a lot of flexibility in beefing up areas that need to be beefed up.

itboffin

I have a CF question, is laying up CF the same as fiberglass ?

Yukirin

when I can ride a 25 mile tt in the same time as a 1970's athlete I'll consider carbon. In the mean time I'll just pant my lungs out up hill.
Also, I only had £180 budget for my bike...

sketchley

My issue isn't with carbon as a material, my issue is carbon bikes are generally designed for riders of around 75kgs or less. I'm sure someone could build a decent carbon bike that won't flex for a 110kg rider, but they don't as there isn't a market for them. And yes I know specialised for example guarantee their carbon frames upto 250lbs but there is a difference between unlikely to break and being a nice ride....

Very happy with my steel bike, next best bike is likely to be Titanium.....

greg66_tri_v2.0

Sketchley wrote:

My issue isn't with carbon as a material, my issue is carbon bikes are generally designed for riders of around 75kgs or less. I'm sure someone could build a decent carbon bike that won't flex for a 110kg rider, but they don't as there isn't a market for them. And yes I know specialised for example guarantee their carbon frames upto 250lbs but there is a difference between unlikely to break and being a nice ride....

Very happy with my steel bike, next best bike is likely to be Titanium.....

The 94 kg pro rider.

So he's not 110 kg, but he probably puts out a few more watts than a few of us combined. And he doesn't tear the BB area and chain stays to pieces (AFAIK).

Cervelos don't have a rider weight limit. Pretty sure that is true of a few others too.

sketchley

Does Magnus have anything special done to his bikes though?

Twostage

I suppose most people have seen this :- http://www.youtube.com/watch?v=-lsDXEEU ... ata_player

It's obvious that he holds back a bit at the start and that once it starts to go its gone. Also the alu frame dents straight away but is probably still rideable. Pro riders crash and get straight back on. I think it's enough to convince that you shouldn't worry about a prang in the bike shed.

mattsaw

Sketchley wrote:

My issue isn't with carbon as a material, my issue is carbon bikes are generally designed for riders of around 75kgs or less. I'm sure someone could build a decent carbon bike that won't flex for a 110kg rider, but they don't as there isn't a market for them. And yes I know specialised for example guarantee their carbon frames upto 250lbs but there is a difference between unlikely to break and being a nice ride....

Very happy with my steel bike, next best bike is likely to be Titanium.....

I'm 101kg and have been commuting on my carbon frame for 2 years now.
It's done the job fantastically.

rick_chasey

Pretty sure Backstedt broke a lot of carbon wheels in Roubaix.

The race he won was on aluminium boxsets.

http://cozybeehive.blogspot.com/2008/04 ... heels.html

http://www.bustedcarbon.com/2009/09/zip ... ubaix.html

http://trianglecycling.com/threads/on-t ... aix.27733/



Having said this, all the last few winners have been on carbon frames, but I doubt many, if any, were on carbon wheels.

greg66_tri_v2.0

Those are wheels, not frames.

But if we're going off topic, Hincapie broke his alu handlebars in Roubaix a couple of years ago. How many of us are not riding alu bars?

greg66_tri_v2.0

Alu failure at the top of my seatpost a few weeks ago:


The weaved part is CF. Above the weave is (was) a solid piece of cast alu. The shiny silvery surface is where it tore apart. The exposed area was probably a bit smaller than half a regular post it note.

It's an isolated example, with no like for like comparison to a similar CF failure. But it does show that even a thick piece of alu can break.

stuaff

Rick Chasey wrote:

Pretty sure Backstedt broke a lot of carbon wheels in Roubaix.

The race he won was on aluminium boxsets.

http://cozybeehive.blogspot.com/2008/04 ... heels.html

http://www.bustedcarbon.com/2009/09/zip ... ubaix.html

http://trianglecycling.com/threads/on-t ... aix.27733/



Having said this, all the last few winners have been on carbon frames, but I doubt many, if any, were on carbon wheels.

Not so, last year at least: "The majority of the top 10 started and finished on carbon wheels. Garmin-Cervélo’s Johan Van Summeren rode Mavic’s new wheel, dubbed M40 for its 40mm rim height, to victory, while runner-up Fabian Cancellara used Bontrager’s Race XXX Lite climbing wheels, which according to Trek team liaison Ben Coates were stock and not changed in any way to deal with the cobbles." http://www.bikeradar.com/news/article/r ... 011-29868/

I've had two prangs on the Viner, and it's dropped while parked at least three times. It's fine.

tgotb

itboffin wrote:

I have a CF question, is laying up CF the same as fiberglass ?

Yes, with a few minor caveats:
- You don't want to be using polyester resin (not that I'd use poly with glass anyway), stick to epoxy
- Because it's black, it's a bit harder to see whether you've wetted out the carbon properly
- Carbon tends to be available in a wider range of weights and weaves, which gives you a bit more flexibility

For higher-loaded components you want to make an effort to keep the fibre:resin ratio high. Make sure the fibre's properly wetted out, but try to remove any excess resin at the wetting-out stage; easier if you wet out the carbon before applying it. Use peel ply, and if possible it helps to wrap the laminate in something like masking tape (on top of the peel ply) to help compress it and squeeze out excess resin. Wrapping in electrical tape causes all sorts of problems, and is best avoided; vacuum bagging works well (if you have the equipment) but is a pain for tubular things like bike frames, and you can generally get good results without a vacuum.

rjsterry

Greg66 wrote:

Alu failure at the top of my seatpost a few weeks ago:


The weaved part is CF. Above the weave is (was) a solid piece of cast alu. The shiny silvery surface is where it tore apart. The exposed area was probably a bit smaller than half a regular post it note.

It's an isolated example, with no like for like comparison to a similar CF failure. But it does show that even a thick piece of alu can break.

Indeed, everything breaks: steel, alu, CF, Ti and I'm sure even bamboo. It's just down to whether it's engineered right, and has no manufacturing flaws. There *may* be more of a tendency to over engineer in some materials, which might give the impression of greater reliability.

Oh, and 'weaved'? What the hell kind of word is that? Try 'woven'. :P

bails87

Rick Chasey wrote:

Pretty sure Backstedt broke a lot of carbon wheels in Roubaix.

The race he won was on aluminium boxsets.

Having said this, all the last few winners have been on carbon frames, but I doubt many, if any, were on carbon wheels.

MTB again, but
http://www.bikeradar.com/news/article/e ... ls--33221/

They also report that the final prototypes – a single set of rims – incredibly carried Steve Peat through the entire 2011 World Cup season's race runs.

During the 2010 season, the Syndicate’s first on the carbon rims, they replaced 53 wheels, which was down from a reported 180 wheels per season when the team was on alloy. In 2011, the team had to replace just 11 wheels......Over both seasons, ENVE say there wasn’t a single catastrophic failure

.

Stevo_666

Don't worry Bails, they'll catch up with MTB techology eventually :-)

rick_chasey

Stevo 666 wrote:

Don't worry Bails, they'll catch up with MTB techology eventually :-)

Now, the tax thing was bad enough ( ) but this MTB stuff takes the p!ss...

Get out! :P

bails87

Rick Chasey wrote:

Stevo 666 wrote:

Don't worry Bails, they'll catch up with MTB techology eventually :-)

Now, the tax thing was bad enough ( ) but this MTB stuff takes the p!ss...

Get out! :P

rick_chasey

Stevo_666

Rick Chasey wrote:

Stevo 666 wrote:

Don't worry Bails, they'll catch up with MTB techology eventually :-)

Now, the tax thing was bad enough ( ) but this MTB stuff takes the p!ss...

Get out! :P

Good try.

I'll make a Tory-voting mountain biker out of you yet :P

notsoblue

MTB'ers get excited about carbon