# Carbon Fiber Weight Limit



## damnilocano (Feb 10, 2010)

I've been doing some research on my next bike. Does anyone know what the weight limit would be for a carbon fiber frame? I weigh about 250 and getting back on the bike for weight loss.

I was looking at the Look 566 as one of my top choices. I emailed them but no reply.


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## waterobert (Nov 24, 2009)

I think they are good for 220 lb, so you need to lose 30 lb asap. I don't think that frame would brake under your weight, but I wouldn't ride it over bumpy roads.LOL


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## terbennett (Apr 1, 2006)

Good question! That's something that remains to be seen. My understanding is that many bike teams recommend not racing on carbon frames if you're over 175-180 lbs. They claim that the frames might not be able to handle the larger crit rider. I'm not a carbon fanatic but I still question that to some degree. I have a riding buddy that rides a 2009 Trek Madone 5.2 and he's 255 lbs. The frame hasn't failed on him. On the other hand, another riding buddy of mine (from the same riding group) had a 2008 Cannondale Synapse and had to have the frame replaced last year because it was cracking on the seat tube. He's 245 lbs. One of my Felts is a carbon bike and I haven't had any problems with it. However, I don't ride it as much as my other bikes either. Jim Felt said in an interview that the the new AR bike was designed with Garmin team's Magnus in mind. He's over 200 lbs and is a major powerhouse. Larger riders are just as capable of accomplishing the same feats. We just dish out more power doing it. You should check out Bike Forums.net Clydesdale forum. That's the forum for bigger riders. I'm not trying to promote them but you're a Clydesdale so it would be best to get info from as other Clydesdales. No manufacturer or anyone else can give you as accurate info as other Clydes that ride.


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## damnilocano (Feb 10, 2010)

Thanks for the information, terbennet. I'm still in the researching and weight loss phase so not looking to add to the stable anytime soon... and I don't have the money for it, yet.


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## Argentius (Aug 26, 2004)

It's really, really hard to put a SPECIFIC weight limit on stuff -- how can I phrase this? 

There are 200 lb riders that ride like 150 lbs, and there are 200 lb riders that ride like 300 lbs.

Given enough determination, you can break anything.

There are a LOT of riders your weight, riding carbon frames, with no problems. Many bike companies, the ones I know well included, don't publish SPECIFIC weight limits -- it ends up being sticking your neck out there for little benefit, because of what I mention above, among other things.

All things considered, I would probably lean towards a metal bike -- though you can make them break as well, they're often tougher, and when they start to crack, it is a lot more obvious externally.

If you go carbon, I do think a lugged bike or monocoque instead of a direct-connect one is a good idea, but that's just my personal opinion -- it feels like when direct connect bikes that I have seen fail, they do so fairly dramatically.


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## medimond (Apr 26, 2009)

A 250 lbs rider will provide an increase stresses in the bike frame than a 170 lbs rider, regardless on how you ride. Increasing the weight may have a significant impact on the fatigue life of the item, which is based upon the stress level imparted. If you increase the stress enough (but not overstress the item) you can end up with low cycle fatigue event.

It has always been a mystery to me how they can design bikes for 140-150 lbs people and 200+ lbs people. Either the bike bike is going to be way too stiff or soft and flexible like a noodle. 

Go ride multiple bikes, if a bike feels pretty stiff, that "may" be a indication that it would be capable of supporting your weight. 

I cannot see any benefit for a company to state a weight limit on a bike, but I can see some possible negative impacts. You might want to look into higher spoke wheels as most bikes come with fairly low spoke wheels, this may be more of a problem than the frame.

Oh ... I've also been eying the 566, doesn't that come in a UL or some other designation for heavier riders?


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## Mel Erickson (Feb 3, 2004)

damnilocano said:


> I've been doing some research on my next bike. Does anyone know what the weight limit would be for a carbon fiber frame? I weigh about 250 and getting back on the bike for weight loss.
> 
> I was looking at the Look 566 as one of my top choices. I emailed them but no reply.



I don't see them going much below 700 grams.


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## fallzboater (Feb 16, 2003)

medimond said:


> It has always been a mystery to me how they can design bikes for 140-150 lbs people and 200+ lbs people. Either the bike bike is going to be way too stiff or soft and flexible like a noodle.


They can't, really. Any frame will absolutely be compromised for riders well outside the design average weight range. Back in the lugged steel frame days, the tubes were all the same OD, but there were several different wall thicknesses to choose from, so you could buy a 57 in say, SL, SLX, or SP. I would hope that with most carbon frames, the mfg's are at least using heavier layups for the larger sizes, but I don't know if that's the case. I'm 6'3" and 195 and recently scored a used custom carbon Parlee that was built for an even heavier rider (their XL tubing), which works out great for me since I like very solid handling for 50+ mph mountain descents. I'm sure that one built with their lighter SL tubes would not give me the same confidence. My other bike is a Tarmac SL Pro, which is extremely stiff in the front end, so much so that I can't imagine lighter riders enjoying it (that'd be a good bike at 250 lb). If you're an outlier in size or weight, all you can really do is try a lot of different bikes, or go custom.


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## edwin headwind (Aug 23, 2004)

I'm 6'2", 212# & ride a Cervelo RS. This frame was recommended by my LBS & it's plenty stiff with no bottom bracket flex that I experience with my steel LeMond. I think the days of carbon fiber bikes being for lighter weight riders are long gone. pound for pound a carbon fiber bike with oversize tubing is going to be much stronger than a comparable steel frame.


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## Dave Hickey (Jan 27, 2002)

There is nothing about carbon fiber's properties that dictates a weight limit. Certain steel and aluminum bikes also have weight limits

You are on the right track contacting manufacturers about what they recommend for their frames.....and BTW, their recommendation will be based upon what their lawyers tell them so you can probably add and 20lbs to what they say and be fine..


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## Truckasaurus (Jan 10, 2010)

The 2010 Cannondale handbook states 275 lbs max for any rider on a carbon frame such as the Six Carbon.


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## Dajianshan (Jul 15, 2007)

I am just curious... why only CF? At 250lbs it seems the bike material and weight wouldn't matter that much.


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## Peanya (Jun 12, 2008)

Argentius said:


> There are 200 lb riders that ride like 150 lbs, and there are 200 lb riders that ride like 300 lbs.


I think you phrased it perfectly. Iin my line of work, I see examples of this every day. Same goes with cars too.


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## IAmCosmo (Jul 26, 2005)

Before I bought my Tarmac, I talked to the Specialized sales rep for about 15 minutes. One of the first things I asked him was if there was a weight limit (I was 270ish at the time). He said that there was no weight limit on their frame or fork. He said that they couldn't warranty the wheels, but would warranty the frame/fork no questions asked no matter how the bike was used.


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## damnilocano (Feb 10, 2010)

What does UL mean?

I do have high spoke wheels (36H Mavic Open Pro, Ultegra for the rear and a Neuvation M28 Aero3 up front).

And to the other post about why I'm looking for a CF, I'm still doing research and a lot of people have been recommending the 566.

Thanks for all the information! This is helping my weight loss motivation. By the looks of it, I'll be looking into a 2010 model when the 2011's come out.


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## fastev (Jan 4, 2010)

IAmCosmo said:


> Before I bought my Tarmac, I talked to the Specialized sales rep for about 15 minutes. One of the first things I asked him was if there was a weight limit (I was 270ish at the time). He said that there was no weight limit on their frame or fork. He said that they couldn't warranty the wheels, but would warranty the frame/fork no questions asked no matter how the bike was used.



Agreed. They (Specialized) gives a weight limit on carbon accessories-- seatpost, stem, bars, cranks I think of 250lbs. As stated above, however, no limit and no warranty issues for frame and forks. I'm 205lbs and have zero issues with my Roubaix SL, no discernible flex; it provides a great ride. I'd never use a carbon bar or stem, and I think I'll be changing my carbon S-Works post for a Thomson, but other than that I love the ride.


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## zriggle (Apr 16, 2008)

damnilocano said:


> What does UL mean?


Ultra Light


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## Jwiffle (Mar 18, 2005)

I think most manufacturer's carbon bikes would hold your weight, at least as far as the frame goes. I know that Giant and several others state there is no weight limit on their bikes. Mainly, you'll want to upgrade stock wheels to something burlier.


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## Hooben (Aug 22, 2004)

I'm 225 and weight testing my Giant TCR Advanced. No problems after a year and 3K miles. Just go buy one and let the guys in the shop tell you the line about how carbon is stronger than steel and aluminum, yet flexible. This while the manual tells you to inspect the frame for cracks after every ride.


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## desmond88 (Feb 19, 2010)

zriggle said:


> Ultra Light


 argh, you beat me to it!


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## laxcheeks (Jan 6, 2006)

*CR1 Weight limits*

Just got my 2010 Scott CR1 and in the users maunal it states that the frame weight limit is 275 lbs.


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## estone2 (Sep 25, 2005)

medimond said:


> A 250 lbs rider will provide an increase stresses in the bike frame than a 170 lbs rider, regardless on how you ride.


Er, 250 pound rider who rides around the potholes. 150 pound rider who rides through them and bunny hops curbs.

Somebody who knows how to wheelie (and set the bike down) versus somebody who knows how to get the front wheel in the air, then slams down the front wheel.

There's more to it than just rider weight, there's rider style. It's a combination of forces.

OP: Different frames, different limits. Carbon may be fine, steel may be better, aluminum may be better, titanium may be better, or... whatever. Most big guys favor steel and Ti, but that's personal preference, not frame limit. Look at the weight limit for each frame on a 1-by-1 basis.


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## BooBah (Aug 16, 2009)

It's not just about the material, it's how it's used and therefore depends on the frame in question. There would be steel, titanium and aluminum frames that couldn't handle your weight as well.


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## wedge962005 (Jan 4, 2010)

The Carbon itself changes from frame to frame and company to company. You cannot put a limit on all of them equally. Some frames, like my old Fuji, just can't take as much stress. It was fine with me when I weighed 260 but when I got to 240 with a lot more muscle to use it started bending a lot. I haven't cracked it but I know I could if I went all out. My wife is a mechanical engineer who works directly with CF for military applications. She said to tell you that if you are really concerned, get it down to 2-3 frames and then call the manufacturing sites and talk to an engineer. That is what we did in choosing my new bike.

Good luck with the weight loss, I'm 50 lbs down and loving the bike for it.


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## voodooguy (Aug 18, 2007)

I rode a Scattante CFR Race for over two years at 250 - 265 pounds w/o any problems on the carbon frame or the fork. The only thing that went on the bike over the years is: seat post bolt (replaced w/ Thomson) and just before I upgraded, I developed a small crack in the stock Shimano wheels (16/20 spokes). 
Now I am riding a Cervelo RS, am still at 250+ and it is just wonderful. I wrote Cervelo and asked this very same question. The response was there is no weight limit on their frames; tested beyond tolerance etc. They did say however, the difference is in the wheel set and the other bike components; those would likely be the first to fail. I have alloy post, stem and bars and ride 32/32 spoke alloy DT wheels on DT 240s hubs. Rides like a dream. Good luck!


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