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-   Clydesdales/Athenas (200+ lb / 91+ kg) (http://www.bikeforums.net/clydesdales-athenas-200-lb-91-kg/)
-   -   Too big for carbon? (http://www.bikeforums.net/clydesdales-athenas-200-lb-91-kg/553000-too-big-carbon.html)

priorat 06-17-09 08:50 PM

Too big for carbon?
 
I've been riding the heck out of my Felt z90 the last three months, and have dropped from 295 to 275. The bike is great for what it is, but I'm starting to ride more aggressive now, and can really feel the aluminum buzz more than I want. I knew the z90 was an entry-level bike when I bought it, but I didn't expect to ride as much as I have, or to want to upgrade this fast either. Well, I bought my 9-year old son a 2008 Fuji Ace kids road bike the other day (he loves it, and is already fast!), and the bike shop had a 2008 Fuji Team Pro on closeout for $1600, and I think I can get them to go lower than that. Full carbon frame with Ultegra group and Dura-Ace rear. A friend of mine recommended that I buy the bike I see myself riding a year from now, not the one that I see myself riding next week.

So here's the million dollar question: Am I too heavy for carbon right now? I've searched for opinions on carbon frame weight limits and haven't found much. Any thoughts here? Thanks!

Mr. Beanz 06-17-09 09:09 PM

I've heard lots of no poblem posts on this issue. But a rider on a Socal roum ride just ate it the other da on a Cannondale 6/1 on Saturday. Stil in the hosptial with bleeding on the brain and two borken hands. He was at the front when the rider behind him saw him go down for no reason. They both ate it. Reports say the guy's bike just snapped into 3 pieces.

Not sure of all the details and prolly never will be. Maybe he had crashed it befoe and thougt it was fine? Did it just vaproize? Scary thought cause the guy is only about 180'ish. Seen other similar stories on other forums.

Once a frame is crashed, it might not be detectable but can fail in an instant under stress. I'd worry too much about dumping a carbon frame if I had one. No way would I buy one on ebay.:eek:

I've snapped an aluminum frame about 1 year ago. The free replacement is 3/4 carbon and I worry about it. I'm 230 ish

JoelS 06-17-09 09:16 PM

I have a CF bike, but then I'm a lightweight now. To be honest, I'm not gonna get another. I'm just not that impressed with the ride. It's very neutral feeling, and rather "dead". I prefer riding my steel bike, it has a more lively feel. Might get Ti next or another steel.

That said, it's great for a rain bike. So that's what I use it for.

bigfred 06-17-09 09:26 PM

I'll be interested to hear the responses to this.

jimblairo 06-17-09 09:34 PM

I ride a Specialized Roubaix 64cm and weigh 240-250. I'm confident the big frame can take my weight but I upgraded the wheel set.

mkadam68 06-17-09 09:41 PM

This comes up now and again. It's a cycling (urban) myth.

What Beanz said: yeah, CF can fail catastrophically. But of course, so can aluminum.

Now, CF is plenty strong for you. I ride a CF frame & so do plenty of other big clydes like me. And these are racer-dudes (like me). I've ridden it since my days at 320-lbs. Currently, I weigh-in around 250+. I ride centuries. I ride epic 10,000+ foot centuries. I ride consecutive 55-minute criteriums. I commute to work on it. Day-in, day-out. Year 'round. I put on about 9,000+ miles per year (had it for 2-1/2 years). I crashed once when my crank broke (aluminum Ultegra, btw). That was 8,000+ miles ago. It does creak, but I think that may be the pedal spindles, not the frame.

Overall: extremely satisfied with its comfort and strength.

For us big guys, the issue is: wheels.

cohophysh 06-17-09 11:08 PM

If you want to be sure, just call the manufacture and ask. Kestrel carbon bikes are tested up to 400 lbs for example.

biffstephens 06-17-09 11:13 PM

I bought a carbon Giant because of there warranty..rode that from 270 to 250....a few years....bought a Kuota....rode it for a few years more....

I am 200 now and am going aluminum....CF is fine...just get the right CF bike...

sstorkel 06-17-09 11:14 PM

I ride a carbon fiber bike and have no problems trusting it. Knowing what I know about aluminum and fatigue limits, I'd never trust an aluminum road frame... even if it didn't ride like a jackhammer.

Bone Head 06-18-09 03:14 AM

I'm 240-250 ish. I ride a Giant OCR Limited (CF) with 20/24 spoke wheels -- no problems.

Wogster 06-18-09 06:10 AM

Quote:

Originally Posted by priorat (Post 9121038)
I've been riding the heck out of my Felt z90 the last three months, and have dropped from 295 to 275. The bike is great for what it is, but I'm starting to ride more aggressive now, and can really feel the aluminum buzz more than I want. I knew the z90 was an entry-level bike when I bought it, but I didn't expect to ride as much as I have, or to want to upgrade this fast either. Well, I bought my 9-year old son a 2008 Fuji Ace kids road bike the other day (he loves it, and is already fast!), and the bike shop had a 2008 Fuji Team Pro on closeout for $1600, and I think I can get them to go lower than that. Full carbon frame with Ultegra group and Dura-Ace rear. A friend of mine recommended that I buy the bike I see myself riding a year from now, not the one that I see myself riding next week.

So here's the million dollar question: Am I too heavy for carbon right now? I've searched for opinions on carbon frame weight limits and haven't found much. Any thoughts here? Thanks!

Bikes that have weight limits, will have warnings of that weight limit all over them, because if a bicycle has say a 250lb weight limit, and the company does not warn you of it, they are still liable if it fails due to you being over that limit.

Carbon Ffbre reinforced plastic is amazingly strong stuff, they use it in building fighter aircraft. Now one issue with it, if you crash, the frame needs to be inspected for damage, because if some of the fibres have been damaged, it loses some of it's strength, which can lead to a cascade type catastrophic failure over a very short period of time.

This is why you never buy a used CF bike, you never know when it's been dumped. It's also not recommended to buy a used AL bike, because they have a limited life span, due to stress fractures from repeated flexing. Steel frames on the other hand, if you don't let them get rusted, can last a long time, there are steel framed bikes that are over a century old, that can still be ridden (although most are museum pieces now), lots of steel bikes that first saw the road in the early 1960's that are still on the road. Ti is also quite durable, expensive, but durable.

The road buzz problem with Aluminum is usually because your striving for the rock hard tire, try a 10PSI lower tire pressure, and see if that helps.

lambo_vt 06-18-09 07:08 AM

Quote:

Originally Posted by sstorkel (Post 9121712)
I ride a carbon fiber bike and have no problems trusting it. Knowing what I know about aluminum and fatigue limits, I'd never trust an aluminum road frame... even if it didn't ride like a jackhammer.

Do you know anything about fracture toughness in composite structures? Fatigue strength of aluminum is just as relevant, which is to say hardly at all.

Also, ride quality doesn't come from frame material.

rcaddell 06-18-09 07:41 AM

Interesting topic. I am currently looking into a Cannondale Quick3 which has carbon rear and carbon forks. I weigh in at about 225lbs.

The Big Wheel 06-18-09 07:49 AM

i think you're too heavy for the CF, i would wait till i go to about 200 LBS before making the purchase.

CliftonGK1 06-18-09 09:43 AM

One of the shop guys at Woodinville Bicycle is 230 and hammers on a Specialized Tarmac full carbon with carbon cranks, bars, seatpost and Ksyrium SL wheels. I picked his bike up yesterday and it weighs less than a gnat fart, but he's never had any problems with it.

StanSeven 06-18-09 09:55 AM

Quote:

Originally Posted by JoelS (Post 9121194)
I have a CF bike, but then I'm a lightweight now. To be honest, I'm not gonna get another. I'm just not that impressed with the ride. It's very neutral feeling, and rather "dead". I prefer riding my steel bike, it has a more lively feel. Might get Ti next or another steel.

That said, it's great for a rain bike. So that's what I use it for
.

The CF ride feel varies considerably between different bikes. That "dead" feel exists with some and not with others. My CF is very stiff and much more responsive feeling that either my Ti or steel bikes. Someone should test ride a number of bikes to see what they like.

Isabelle's Dad 06-18-09 12:24 PM

From one big bot to another
 
I have a Cannondale Sysapse Carbon SL1 with a Mavic Ksyrium SL wheelset and I weigh 270lbs. When I bought the bike my light weight friends cringed at the thought of what was going to happen when I hit my first bump. I have hit it, over and over. I did get a flat on the rear tire, but no rim damage.

I wouldn't worry about it.

zp295 06-18-09 12:50 PM

I ride a full Carbon Tarmac Sworks 2007 Never had an issue I'm 218.

prxmid 06-18-09 01:18 PM

Quote:

Originally Posted by Isabelle's Dad (Post 9124888)
I have a Cannondale Sysapse Carbon SL1 with a Mavic Ksyrium SL wheelset and I weigh 270lbs. When I bought the bike my light weight friends cringed at the thought of what was going to happen when I hit my first bump. I have hit it, over and over. I did get a flat on the rear tire, but no rim damage.

I wouldn't worry about it.

+1 Same bike , same experience, 255lbs

Love the bike, no issues with wheels or frame

Stickney 06-18-09 01:49 PM

Well, even if you don't choose to go with a carbon frame, let me know how your search goes for finding a road bike that doesn't come with a carbon fork.

Carbon is everywhere now, and despite the rather horrific internet stories (some documented), carbon is being used daily by people of all shapes and sizes (on roads/trails of all manner of upkeep).

That said, I am 260 lbs, I have a carbon fork, I do wait with anticipation occasionally as I assume it will fail catastrophically. It hasn't yet. In all likliehood (knock on wood), it won't. I have pondered replacing it, but there are pretty minimal options modern steel or TI road forks on the market.

youcoming 06-18-09 02:28 PM

Also, ride quality doesn't come from frame material.[/QUOTE]

I hear this so many times and also from the same people who say carbon will snap in th ecold. I tried many bikes including some that where made by same builders one carbon and one aluminum and there is a difference in ride quality same as there is a difference in materials. Some carbon will ride harsher than alum but some carbon will be really plush and some are a perfect combo. By the way I ride full carbon at 220 and have no fears.

lambo_vt 06-18-09 02:39 PM

Quote:

Originally Posted by youcoming (Post 9125851)
I hear this so many times and also from the same people who say carbon will snap in th ecold. I tried many bikes including some that where made by same builders one carbon and one aluminum and there is a difference in ride quality same as there is a difference in materials. Some carbon will ride harsher than alum but some carbon will be really plush and some are a perfect combo. By the way I ride full carbon at 220 and have no fears.

It's true. Stiffness comes from geometry moreso than material. You can have a harsh steel frame just as easily as a whippy aluminum or carbon, etc.

Now, controlling for weight tends to differentiate materials a bit, but in general Carbon Frame A with XYZ Wheels and IJK Tires is not necessarily a smoother ride than Aluminum Frame B with ABC Wheels and EFG Tires...

youcoming 06-18-09 02:51 PM

Quote:

Originally Posted by lambo_vt (Post 9125933)
It's true. Stiffness comes from geometry moreso than material. You can have a harsh steel frame just as easily as a whippy aluminum or carbon, etc.

Now, controlling for weight tends to differentiate materials a bit, but in general Carbon Frame A with XYZ Wheels and IJK Tires is not necessarily a smoother ride than Aluminum Frame B with ABC Wheels and EFG Tires...

All I know is I can take my wheels off my harsh riding aluminum frame, swap out the wheels from my smooth riding carbon frame and I still have a harsh riding aluminum frame and a smooth riding carbon frame.

lambo_vt 06-18-09 02:52 PM

Quote:

Originally Posted by youcoming (Post 9126002)
All I know is I can take my wheels off my harsh riding aluminum frame, swap out the wheels from my smooth riding carbon frame and I still have a harsh riding aluminum frame and a smooth riding carbon frame.

That's because they're different frames. What's your point?

Edit: That is to say, just because your carbon frame is smoother than your aluminum doesn't mean that's because one is carbon and one is aluminum.

As a counterexample, I'd guess that a Cannondale touring bike is smoother than a Tarmac SL2.

Bone Head 06-18-09 02:54 PM

Just a thought:
If CF is such a hazard (fails catastrophically & w/out warning), why haven't I seen any commercials on TV from those "Personal Injury" Law Firms wanting to sue the bike manufacturers just like the drug companies???? Surely the P.I. lawyers know easy money when they see it... :innocent:


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