Carbon fiber frame questions

[TheArchitect]

I've started thinking of the next bike purchase and reading up on the options. Most of the ones I'm drawn to have carbon frames, which at first I was like "woo-hoo" light and sexy tech! Then I started reading more stories than I'd like about cracked frames, spontaneous collapse, etc and now I'm spooked on carbon. I understand a carbon frame cracking after a big crash but I'm seeing anecdotal stories about carbon frame damage from chain drops, bikes falling over hitting curbs and simple bangs on the frame. That kind of stuff certainly happens to me and Ellen on occasion so I have a few questions.

1. Is what I'm reading just a case of the negative stuff getting posted online more than the positive stuff or is it a real concern?
2. Are some manufacturers better than others with CF quality and durability? My LBS carries Specialized, Trek and Giant so I've been looking at those but can/will look at other brands if they're better.
3. We ride on rail trails mostly (compacted stone dust and pavement) but are thinking of expanding to rougher gravel surfaces. Would you be less concerned with CF if riding only on paved and stone dust?

Thanks!

 

[scott43]

CF is incredibly strong and if treated well I wouldn't worry if buying from one of the three mfgs you mentioned. Surface doesn't matter. Having said that... Crash damage is different than steel frames.. especially depending on location. Some CF frames have very thin seat stays. If you crash and nick one of those on concrete rocks etc, you need to be very careful and visually inspect the damage. In some areas there is very little CF to absorb impact damage. Other places there is a more generous safety margin. It's really a magical material for building bike frames, so many opportunities to save weight and tune ride quality.

If you're worried and clumsy, there are still great alu and steel options. And far more reasonably priced.

 

[crosscountry]

Is what I'm reading just a case of the negative stuff getting posted online more than the positive stuff or is it a real concern?

Yep!

These days, the majority of the bikes I'm seeing in my club rides are carbon fiber. I haven't really heard too many such stories. My own road bike is carbon fiber from 2005. I take it on dirt roads plenty often. For that matter, my gravel bike has a carbon fiber fork. It's from 2009 and still going strong.

* the road you ride really doesn't matter, as the road shocks are absorbed by the tires and wheels. And for that matter, there're wheels made of carbon fiber! That should give you an idea how much abuse carbon fiber can handle.

Are some manufacturers better than others with CF quality and durability?

I don't believe so. As long as you don't buy some unheard of brand with no track record of products on the market.

 

[scott43]

CF warranties are usually 5 or 10 years only. I believe this is primarily because the mfg can't have control of crashes, maintenance and inspections. Some CF mfgs have stated the is really no practical lifespan for their parts. Easton is a good example. Still, knicks and subsequent cracks happen but it's unrelated to mfg, more improper use. Many people were just used to steel where you could run a bike over with a car and if you could live with it being bent as a dog's hind leg, it'd still go fifty years!

 

[Tom K.]

Generally unfounded worries, but from the description of your riding, the extra pound of an aluminum frame is no big deal, and it may give you confidence.

The "rub" is that it's often tough to find an aluminum-framed bike with higher end components.

 

[wooglin]

Just keep it out of full sunlight and you’ll be fine.

 

[crosscountry]

Just keep it out of full sunlight and you’ll be fine.

Missing a wink?

 

[Wilhelmson]

I haven't broken mine yet and it has taken some abuse, including a big crash and a few small ones.

 

[cantunamunch]

2. Are some manufacturers better than others with CF quality and durability? My LBS carries Specialized, Trek and Giant so I've been looking at those but can/will look at other brands if they're better.

Go ride all of them. Buy the one that fits best. I'm not kidding. All of those reviews are complete horsesh*t if you wind up on a bike that doesn't fit your body right.

Don't upsell yourself. Don't read reviews until you've pre-formed opinions. Test ride with a completely open mind. Test ride naturally.

The key to getting your moneys' worth out of a carbon fiber frame is to ride. Ride lots. Ride more than that. Now do what you just did over again.

The worst thing you can do in todays' bike market is to buy a bike and *not* ride it. That goes double for CF frames.

 

[cantunamunch]

1. Is what I'm reading just a case of the negative stuff getting posted online more than the positive stuff or is it a real concern?

30 years ago, even 20 years ago there was such a thing as 'general' concern about carbon fiber. Resins have been updated, layups have been updated, materials prep on all the other things that go into a frame other than the CF has been updated.

Most current concerns are due to brands getting a hair up their bum and doing something weird and marketably proprietary at the seatpost/headset/bottom bracket (even pro bikes get this, witness Cervelo's seatpost issues) or due to quality control failures at problem areas (bottom brackets, tube joins, through drillings like at water bottle bolts, and clamps), which also happen all the way up to the top of the market.

Forget about all that, and see if you can't ride the bike into the ground during the warranty period.

 

[TheArchitect]

Thanks for all of the replies!

CF is incredibly strong and if treated well I wouldn't worry if buying from one of the three mfgs you mentioned. Surface doesn't matter. Having said that... Crash damage is different than steel frames.. especially depending on location. Some CF frames have very thin seat stays. If you crash and nick one of those on concrete rocks etc, you need to be very careful and visually inspect the damage. In some areas there is very little CF to absorb impact damage. Other places there is a more generous safety margin. It's really a magical material for building bike frames, so many opportunities to save weight and tune ride quality.

If you're worried and clumsy, there are still great alu and steel options. And far more reasonably priced.

I'm not particularly clumsy but my wife can be (we'd both be upgrading). She might be more comfortable with aluminum. After I've done enough reading I'll know if I'm worried enough to restrict myself to aluminum or steel.

Yep!

These days, the majority of the bikes I'm seeing in my club rides are carbon fiber. I haven't really heard too many such stories. My own road bike is carbon fiber from 2005. I take it on dirt roads plenty often. For that matter, my gravel bike has a carbon fiber fork. It's from 2009 and still going strong.

* the road you ride really doesn't matter, as the road shocks are absorbed by the tires and wheels. And for that matter, there're wheels made of carbon fiber! That should give you an idea how much abuse carbon fiber can handle.


I don't believe so. As long as you don't buy some unheard of brand with no track record of products on the market.

Good info. I'd never buy an unknown brand for something like this.

Generally unfounded worries, but from the description of your riding, the extra pound of an aluminum frame is no big deal, and it may give you confidence.

The "rub" is that it's often tough to find an aluminum-framed bike with higher end components.

That IS the rub I'm coming across. I'm not looking at CF bikes for the extra weight savings, nice as it is. It's the higher quality components and features offered that I want and it seems like to get those you end up with CF options.

Just keep it out of full sunlight and you’ll be fine.

Should I avoid garlic as well? (I do know about the UV degradation from YT videos)

Go ride all of them. Buy the one that fits best. I'm not kidding. All of those reviews are complete horsesh*t if you wind up on a bike that doesn't fit your body right.

Don't upsell yourself. Don't read reviews until you've pre-formed opinions. Test ride with a completely open mind. Test ride naturally.

The key to getting your moneys' worth out of a carbon fiber frame is to ride. Ride lots. Ride more than that. Now do what you just did over again.

The worst thing you can do in todays' bike market is to buy a bike and *not* ride it. That goes double for CF frames.

Absolutely. My LBS is Landrys here in MA and they offer a good selection of bikes as well as fitting services. I plan to work with them to get the right bike fit.

 

[cantunamunch]

3. We ride on rail trails mostly (compacted stone dust and pavement) but are thinking of expanding to rougher gravel surfaces. Would you be less concerned with CF if riding only on paved and stone dust?

Thanks!

Part of the fit issue, especially if you're both smaller riders, will be what wheel size and what tires you will be able to fit. Rougher gravel will be much much nicer for you if you can fit wider tires. Wider tires weigh more and take more effort to get to speed because of that.

Flint chips, granite shards and random creekbed quartz will pound the living daylights out of you unless you can go wide and low pressure - but that will change how the bike feels on pavement. Bikes with longer rears do well on flattish sandy or muddy terrain, but tend to not climb sandy slopes well. Bikes with longer fronts will feel sluggish or retarded on paved flats - but will make you feel much more secure descending a gravelly drainage path or punching through a creekbed.

 

[TheArchitect]

Part of the fit issue, especially if you're both smaller riders, will be what wheel size and what tires you will be able to fit. Rougher gravel will be much much nicer for you if you can fit wider tires.

Yeah, that's true. We both have Sirrus X 3.0 bikes that can take a larger tire. I imagine we'll keep those and these will be in addition but who knows. In any case, you make a good point about the wheels and tires so I'll keep that in mind.

 

[cantunamunch]

Yeah, that's true. We both have Sirrus X 3.0 bikes that can take a larger tire.

Those are relatively upright and relatively slack. You're keeping those for short rough days, maybe hacking the tire, wheel, fork to suit the task?

I imagine we'll keep those and these will be in addition but who knows. In any case, you make a good point about the wheels and tires so I'll keep that in mind.

If you're keeping those, I'd suggest you forget tire size and get something closer to road or all-road geo. Something that will let you sustain 20mph+ on pavement and stay out of headwinds. And that will be noticeably lighter, zippier, more aero, more playful than your Sirrus. Use the X 3.0s on rough stuff.

 

[Tom K.]

That IS the rub I'm coming across. I'm not looking at CF bikes for the extra weight savings, nice as it is. It's the higher quality components and features offered that I want and it seems like to get those you end up with CF options.

Absolutely. My LBS is Landrys here in MA and they offer a good selection of bikes as well as fitting services. I plan to work with them to get the right bike fit.

A truly good LBS would work with you at time of purchase to swap out select components on an Al bike for better ones, giving a reasonable credit for the "takeoffs".

Market for takeoff stuff isn't quite what it was a year ago, but it's worth asking!

 

[cantunamunch]

A truly good LBS would work with you at time of purchase to swap out select components on an Al bike for better ones, giving a reasonable credit for the "takeoffs".

Out of curiosity, what would *you* upgrade on something like a Domane Al5?

 

[scott43]

Out of curiosity, what would *you* upgrade on something like a Domane Al5?

I wasn't going to mention it.. but since you brought it up... Most of my gripes were fit related. Unless you're chasing the weight weenie title, it's a pretty decent bunch o parts... However, people who do less than 1000kms a year pay $10k for a bike. So....

 

[cantunamunch]

I wasn't going to mention it.. but since you brought it up... Most of my gripes were fit related. Unless you're chasing the weight weenie title, it's a pretty decent bunch o parts... However, people who do less than 1000kms a year pay $10k for a bike. So....

That was kinda my point ... of the three brands mentioned, Giant are the standout for pushing CF down to the bottom-level Defy frames, and Contend (alloy) parts choices are meh. I think one can totally get a decent, seriously rideable, bunch of parts on alloy Domanes, on alloy Allez Sprint Comps, on alloy Checkpoint ALRs.

 

[scott43]

And really if you're blowing cash, get a Rodriguez steel and spec Dura ace. That'll be $6k.. and really nice.

 

[Lauren]

1. Is what I'm reading just a case of the negative stuff getting posted online more than the positive stuff or is it a real concern?
2. Are some manufacturers better than others with CF quality and durability? My LBS carries Specialized, Trek and Giant so I've been looking at those but can/will look at other brands if they're better.
3. We ride on rail trails mostly (compacted stone dust and pavement) but are thinking of expanding to rougher gravel surfaces. Would you be less concerned with CF if riding only on paved and stone dust?

I've been riding a carbon fiber frame for the past 4 seasons...no complaints, and no plans to go back to aluminum. I had very similar concerns when I first bought CF. Got a good deal that I couldn't pass up, so went for it. No regrets...and I've put my bike (and my body) through a number of rough crashes. Most bikes come with pretty solid warranties if you buy new (I know Santa Cruz offers lifetime warranties from manufacturing defects and have heard that it's a pretty liberal policy...I haven't managed to break their frame so haven't tested it out for myself). I'm sure all the big brands offer warranties of some sort to back up their quality.

I'm no weight weenie but enjoy the perks of a lightweight bike...both on the trails and putting the bike on the car rack.