Carbon Fiber vs Aluminun frame for MTB

[Altaf]

Carbon Fiber vs Aluminum frame for MTB

I've got an itch for a new hardtail MTB and have been doing some window shopping lately. I've typically owned my bikes 5-10 years and plan on doing so with my next purchase as well. I don't do any jumps or crazy stunts, my typical ride is technical single tracks with roots, rocks (not boulders), and lots of hills (up and down), about 5 miles in all. I also do a long flat dirt trail that's about 30 miles round trip so comfort is also important. Oh, and I'm 6', 190 lbs but I'll drop to 180 once I start riding again.

I did get to take a brief test ride on a 2009 GT Zaskar Expert (26") and really liked the way it fit and rode. I went to GT's web site found the same bike in a carbon fiber model - GT Zaskar Carbon Expert.

Performance sells both bikes with the carbon model costing a few hundred dollars more. The Performance bike shop I went to didn't have a carbon bike in stock and I've got no experience with riding or owning a carbon frame. Besides the potential weight savings and costing more, what are the pro/cons of going fiber vs aluminum? Is it worth purchasing the fiber model in this case? As far as I can tell the components on both bikes are exactly the same (Shimano SLX), the difference is just the frame.

To throw in another option, GT also makes a Zaskar 9r Pro, which as the name implies is a 29" but with Shimano XT components. This is an aluminum frame and costs a couple hundred more than the carbon model I referred to earlier.

If the consensus here is to go with an aluminum frame, my next question will be should I pay $600 more and go for 29" XT components over 26" SLX components? I did get to ride a 29r though not this exact one, but I"ll wait for some responses before this thread becomes a 26" vs 29" topic. Oh and in case it matters, in the GT brand I fit a Large in the 26" frame and a Medium in the 9r frame.

GT Zaskar Expert (aluminum) $1300

GT Zaskar Carbon Expert $1700

GT Zaskar 9r Pro (aluminum) $1900

 

[cary]

My two cents:

1) For the price difference go with the Carbon Fiber, it will provide more dampening on the trail, is slightly lighter, and as durable as the aluminum.

2) In regards to the SLX v. XT, there is not $600 difference between those two lines of components. What I would be much more interested in is does the more expensive bike come with better wheels and/or fork?

3) 26 v. 29er- Very much a personal preference thing. Given you are looking for a hardtail, the 29er is a very good option as they tend to eat up trail chatter better.

Have you looked at and considered a full suspension bike? The 4-5" bikes pedal nearly as well as hardtails and offer a much more comfortable ride and less fatigue, even on no so technical terrain.

 

[Altaf]

Zaskar Carbon / Expert
Fork: Rock Shox RECON RACE, 100mm of travel, 7050 al steerer, Air sprung with rebound damping and motion control
Mavic CrossRide Disc for Centerlock, with straight pull bladed spokes, QRM sealed bearing hubs, 24 holes front and rear

Zaskar 29r Pro
Fork:FOX 32 RL for 29 inch wheels with 100mm of travel, rebound adjust and lock out
Rims: Shimano XT centerlock hubs with DT swiss Champion spokes and Mavic TN-719 welded rim for 29'r

I've not been a fan of full suspension bikes except when I'm going down hill and having my bike being tossed around like a salad. I know I could gain some benefits with going full suspension but don't like the additional weight and complexity.

 

[GREENPEA]

Carbon on the Mountain scares me. I hard impact to the frame can show no signs of damage on the outside but can compromise the entire frame. And then your are just asking for trouble.

And before you say that you wont crash...they call it an accident for a reason.

Carbon is an amazing material but it has it limitations. If you raced extensively then it would worth the money but you would be replacing the bike every year maybe 2 years at the max.

Whats the warranty on the frame? Whats the weight difference between them?

Which one whispers in your ear at night to ride the s*** out of her? In the end that's usually how I end up choosing a new mistress.

 

[Altaf]

I think GT offers a [STRIKE]lifetime[/STRIKE] 5 year warranty on their frames but I will have to confirm that. I know I will crash or fall on occasion, that comes with riding. How much lighter carbon is I have no idea. I love the appearance of carbon and would be willing to buy it for looks alone if I were a millionaire. This is a long term commitment so it's more of a wife than a mistress but I like the way you're thinking.

 

[cary]

Carbon on the Mountain scares me. I hard impact to the frame can show no signs of damage on the outside but can compromise the entire frame. And then your are just asking for trouble.

And before you say that you wont crash...they call it an accident for a reason.

Carbon is an amazing material but it has it limitations. If you raced extensively then it would worth the money but you would be replacing the bike every year maybe 2 years at the max.

You better tell all the guys that have been riding carbon frames for 5+ years that they should have broken already. Carbon has been well proven in MTB applications for years now. It has no fatigue limit like aluminum and any crash that would break a carbon frame would also destroy and aluminum frame. Carbon frames have been sold for years now by Ibis, Trek, Giant, Specialized, and a plethora of others. Go take a look on MTBR and you will see the guys actually riding them have had very few problems.

 

[Altaf]

Scratch the lifetime warranty, GT is stating 5 years on the frame.

 

[cary]

Zaskar Carbon / Expert
Fork: Rock Shox RECON RACE, 100mm of travel, 7050 al steerer, Air sprung with rebound damping and motion control
Mavic CrossRide Disc for Centerlock, with straight pull bladed spokes, QRM sealed bearing hubs, 24 holes front and rear

Zaskar 29r Pro
Fork:FOX 32 RL for 29 inch wheels with 100mm of travel, rebound adjust and lock out
Rims: Shimano XT centerlock hubs with DT swiss Champion spokes and Mavic TN-719 welded rim for 29'r

I've not been a fan of full suspension bikes except when I'm going down hill and having my bike being tossed around like a salad. I know I could gain some benefits with going full suspension but don't like the additional weight and complexity.

The fork on the 29er is a better fork. The Rockshox equivalent of the Fox Float is the Reba, the Recon is a definite step down. Wheels, are about equal.

 

[beaufort-fj60]

I had a 1993 Cadex CFM-2... I was like riding a super stiff bouncing ball

 

[mcewan13]

Lex,
I tell everyone to ride 'em all and let the right rig find you. Since you're comparing two different frame materials, I'd strongly suggest finding a carbon bike or two to demo and then go revisit the AL version at performance. They will feel different and that's what matters on the trail. ...esp, in technical riding where you need the bike to be an extension of your intuition.
26 vs 29? Again, ride 'em back-to-back. They feel different. You're tall enough that you won't have to worry about toe-overlap issues like I do on 29ers.

I've gotta ask; why GT and why Performance? I've never been a fan of GT myself, but I got a chance to spend a whole day on a demo 2010 carbon one last summer at MBO. It was light and responsive, but I didn't give it another thought as I handed it back at the end of the day. It felt Trek-ish to me. ...and I'm not a fan of them either. I know Performance is based in NC and I'm guessing they're stronger -and therefore more service oriented- in your neck of the woods. Out here, they are the wal-mart of bike shops. If you're just trying to get a good spec for a good value , there are plenty of good online options - speedgoat, pricepoint and bikesdirect to name a few.

hth,
.matthew

 

[Altaf]

The fork on the 29er is a better fork. The Rockshox equivalent of the Fox Float is the Reba, the Recon is a definite step down. Wheels, are about equal.

Thanks, I had no idea but when I googled the products I see a huge price difference between the Fox and Rockshox.

Lex,
I've gotta ask; why GT and why Performance?

I'm trying to ride several bikes, several times before I drop any cash. I've ridden Trek, Gary Fisher, and GT so far. The Trek did not fit me well and I didn't like the ride much so that's out of consideration. The Gary Fisher was decent and fit pretty good so I may go back at check them out. The Zaskar 26" fit nicely and was very responsive but they didn't have a 29" Zaskar to compare to.

You're right about Performance being the dominant shop in the DC area. If I go GT, Performance is my only option locally. With their free adjustments for life, generous return policy and decent sale prices, I can't really say anything negative about them. My concern with buying online is not having the ability to test ride the bike before hand and having to pay full price for adjustments, trading parts, etc. I can't imagine buying a bike that looks great online and rolling the dice on fitment. I'd have to pay someone to assemble, disassemble, and ship. That would be a couple of hundred down the drain.

I'm open to other brands and models for sure but I'm just getting started and have been out of the loop for a few years now. I stumbled upon BikesDirect.com which seems like a bargain but I'm not familiar with their models.

 

[GREENPEA]

You better tell all the guys that have been riding carbon frames for 5+ years that they should have broken already. Carbon has been well proven in MTB applications for years now. It has no fatigue limit like aluminum and any crash that would break a carbon frame would also destroy and aluminum frame. Carbon frames have been sold for years now by Ibis, Trek, Giant, Specialized, and a plethora of others. Go take a look on MTBR and you will see the guys actually riding them have had very few problems.

I'm not saying that carbon is not great. It will last a very long time if properly cared for. It will not fatigue any faster than any of the other materials. But it is less impact resistant.

I would try and get frame weights, I looked on the site but didn't have anything at first glance. I doubt the weight savings is significant.

But again, ride them all and buy the ones that your heart calls to. Nothing worse than going with the safe choice only to wish your were riding something else.

 

[BreckenridgeCruiser]

I like to ride hard and sometimes have to drop (or throw) the bike. Carbon scares me. I have a trek fuel with the rear carbon triangle (front is the last year of aluminum). My buddy who is a bike mech caught a crack before it caused an issue with the ride. Cost a bit to get it replaced, but was well worth it.

That story is to cite the issues with carbon. Even pedal wear can eventually weaken the chainstays enough to be a risk. Yes, racers use carbon all of the time, but they also gets bikes every year. I don't

When my fuel gives up the ghost (I am goibg to build it into a single ) I am looking for a titanium or even steel. Yes, it costs more, but the plush nature and, more importantly, the ability to go though milions of flexes make them better materials in my mind. Just ask me about the 1975 Tommasini road bike I ride with all original campy super record that weighs 22 pounds. It rides almost as smoothly as my litespeed!

 

[cary]

Thanks, I had no idea but when I googled the products I see a huge price difference between the Fox and Rockshox.



I'm trying to ride several bikes, several times before I drop any cash. I've ridden Trek, Gary Fisher, and GT so far. The Trek did not fit me well and I didn't like the ride much so that's out of consideration. The Gary Fisher was decent and fit pretty good so I may go back at check them out. The Zaskar 26" fit nicely and was very responsive but they didn't have a 29" Zaskar to compare to.

You're right about Performance being the dominant shop in the DC area. If I go GT, Performance is my only option locally. With their free adjustments for life, generous return policy and decent sale prices, I can't really say anything negative about them. My concern with buying online is not having the ability to test ride the bike before hand and having to pay full price for adjustments, trading parts, etc. I can't imagine buying a bike that looks great online and rolling the dice on fitment. I'd have to pay someone to assemble, disassemble, and ship. That would be a couple of hundred down the drain.

I'm open to other brands and models for sure but I'm just getting started and have been out of the loop for a few years now. I stumbled upon BikesDirect.com which seems like a bargain but I'm not familiar with their models.

I wasn't going to get into the Performance issue but since it was brought up, I will throw in my two cents. While performance has decent accessories at good prices and good prices on the bikes they carry, their selection is very limited. Don't get too enamored with their "lifetime" free adjustments, most of their mechanics are not very good. The ones that are, quickly move to independent shops.

Bikes direct has some great deals. You will have to do final assembly of the bike yourself, but it is not hard. I would strongly encourage you to learn to do your own maintenance and repairs on your bike. It is easy and in most cases you will do a better job. Park tool has excellent free instructions on their website on how to do virtually any repair. In my case, I do all my own work outside of building wheels (go to Mike Garcia or Mountain High Cyclery for that) or rebuilding suspension (that is what Push Industries is for).

I would caution you about buying mail order if you are not positive on what fits you in bikes. For example, I know that I like a 24" effective top tube with a 73 degree seat tube and about 5" of headtube. If I go to a frame with a 72 degree seat tube, I need to go to a 24.4" toptube. Without knowing what really fits you, and how geometry affects your fit, you will be hit and miss on the fit from a mail order bike. That said, most shops spend so little time setting up a bike to fit you right on a test ride, that they are in many respects useless.

I would strongly suggest you do the following for each test ride, if a shop doesn't want to spend the few minutes this takes, go find another shop.

1) Make sure the tire pressures are the same on each bike you ride, for a demo ride 35 psi is a good place.

2) Take your own tape measure and make sure that every saddle is set to the same height for each bike you ride. Use the LeMond method (search it on the internet) to establish your starting saddle height. The same bike will feel very different with the seat moved up or down an inch.

3) Also check to see that the saddle is set level (no huge nose up or down) and in a similar position on the rails for each bike you test (remember to compensate for a setback post v. a straight post).

4) Make sure the saddle to bar drop is the same for each bike you test. For starters, 0-1" of drop is about right.

5) Is the fork sag set properly? Make them set it with 25% sag.

Now that you have done all of that, you can actually get a decent idea of how each bike feels and what you like or don't like. Without spending the 5 minutes to set up each bike you test like I suggested you are just shooting in the dark to feel the differences. Is it a pain, yes. It will also get you a bike you will like to ride for years to come.

At your pricepoint, here is what I would be looking at:

http://fisherbikes.com/bike/model/x-caliber

http://jamisbikes.com/usa/thebikes/hardtails/dragon/10_dragoncomp.html


http://www.bikesdirect.com/products/motobecane/fpti_09x.htm

http://www.pricepoint.com/detail/19835-018_SETRB9-3-Parts-47-Bikes/Sette-Razzo-29er-Bike.htm

http://www.pricepoint.com/detail/19...47-Bikes/Sette-Morph-Carbon-Mountain-Bike.htm

http://www.bikesdirect.com/products/motobecane/fly_TeamTI_29_2010.htm

 

[carboncycles]

I'm in the same camp with the carbon guys - it has its place such as road bikes and certain components. But for me, I'd rather have a titanium frame - sorry that's not the question you asked. Btw, to me, carbon feels listless and almost dead, and my experience with aluminum has spanned the gamut from extremely stiff where your teeth hurt to noodlish because the main tube walls were so thin.

 

[mcewan13]

+1 on everything Cary's sayin. If you can wrench on an old LC, bicycles are a breeze.

 

[Altaf]

Good stuff Cary, none of the bike shops I've been to have been that thorough. You're talking about a whole different level of fitment. I don't know if I'd be able to tell the difference between a couple of degrees of geometrical change but maybe I would.

So bike shops are supposed to measure all my limbs to determine what bike fits me best? It's been "stand over the bike and see how far it is from your crotch" to gauge the fit so far. I've got a couple of shops to go to today so I'll find out if there's a difference.

Haven't even looked at titanium bikes but doing some quick searches it appears to be a great option. I checked a few brands (GT, Sette, Gary Fisher, Specialized, Jamis) and none offered titanium, only carbon. Bikes Direct Motobecane does offer titanium (thanks for the links).

Why are most brands (I've looked at) going carbon and not titanium?

 

[mcewan13]

TI prices fluctuate a lot & carbon's becoming the industry trend bc now that the Taiwanese factories have figured out how to replicate the high-quality layups, their costs are dropping enough to make reliable carbon bikes available for 3k and up.

I'd lay serious odds that we are going to see a major shakeup in the industry in the next few years. Taiwan makes 90+% of the bikes for all the major industry brands and many of the better qualified factories are peeking out from the OEM curtain and displaying their own brands. I've had six or so companies in the last year contact us, nosing around what it will take to get into the US market.

Lex, if you're interested in BikesDirect, you can find the backstory w/ a little google action. The short story is that they are a Tx bricks-and-mortar bike shop that opened an online presence. Rather than trying to compete w/ all the other online offerings, they went a diff. route. They licensed a couple defunct brand names - Motobecane being the most known - and contracted w/ a couple asian factories to applied their new brands too the factories' catalog frames. So the deal is, a consumer gets NO cs but gets a free frame for the cost of the parts kit. ...and it's likely the same frame that a major player was charging big bucks for just 2-3 years prior. No affiliation; just interested in them enough myself that I did the research.

To get a proper fit, you have to find a shop that's selling high end bikes or find a custom builder. Serotta had a national fitment class that all Serotta dealers had to send their people too, so that's a good start. If you tell them that you just want the fit, not the Serotta, it will run you $75-$200.

 

[carboncycles]

mcewan, can you further elaborate on the shakeup part? Are you suggesting a carbon-only industry across the board and that Taiwan makers are about to pinch most of the domestic and Euro markets?

 

[mcewan13]

Not exactly, steel will always be real. ...and some would argue more sustainable both for the rider and for the industry at large. ...and tin cans (AL) will always be cheaper. All I'm saying is that carbon has come of age as a frame material for mtb. Hell, Lopes is winning DH races on carbon.

The shake up is going to come of the Asian companies vying for a greater piece of the consumer dollar by concentrating on their own brands rather than soley doing OEM work for big US/EU brands. Giant and Merida set the stage years ago and there's now a running joke in Taichung about "Giant University" because so many of the heads of the smaller up & comers are ex-Giant execs. ...similar situation to the apparel scene here in Portland growing out of Nike roots. Overall, it's a good thing for consumers.