ArgoMan

Hi all. In my search for an appropriate aluminum frame for a CRIT bike, I'm seeing several older aluminum frames (my preferred material) with carbon seat stays. I was unaware that some manufacturers built frames in this way. I imagine for the eight savings. But are these decent frames? Does the combination of carbon with aluminum at the seat stay cause problems over time? I watched a video on YouTube where an English gentleman who repairs carbon frames - he is obvioulsy an expert on all things carbon - was critical of combining carbon with anything aluminum. So, I thought I'd throw a query onto this forum to see what you experts think: is a good aluminum frame with carbon seat stays a wise investment? Or should I be weary? Thank you!

Trakhak

A few manufacturers offered aluminum frames with carbon seat stays back around 2005 to 2008, approximately. The claimed advantage, at least from what I remember reading, was that the inserted carbon sections would absorb road shock better than full-length aluminum. I suspect it would take a very sensitive instrument to detect any difference. A BS detector, on the other hand . . . .

I also read a suggestion that the real advantage was that it simplified the building process for constructing rear triangles for the various different sizes of a frame model.

There have been a few first-hand reports of the epoxy failing at the joins, so that's something to take into consideration.

In any event, bikes with inserted carbon stays vanished from manufacturers' catalogs almost as quickly as they arrived. Maybe because word spread that there was no performance or comfort advantage for the rider, maybe because manufacturers were having to replace frames under warranty at rates above their comfort level.

msu2001la

This was common on higher end bikes in the early-mid 2000's. There were also bikes in that era that that had carbon tubes on the main frame triangle, but still connected with aluminum lugs at the bottom bracket, head tube, etc.

I'm not sure there's anything inherently concerning about this. There are current bikes on the market that still combine aluminum and carbon on forks/steerers. I think bike manufacturers moved on from combining carbon/aluminum on frames because they figured out pretty quickly how to build the whole thing out of carbon.

msu2001la

My memory of the timeframe might be a bit off. Looks like there were lugged carbon bikes in the early-mid 90's.

ArgoMan

There were definitely lugged carbon frames in the early years. I believe that's how the who carbon thing started out. The carbon top tubes, seat stays, and such were lugged into light aluminum. Wasn't Kestrel a pioneer in that field?

So, regarding my initial inquiry, I guess my main concern is whether older aluminum frames with carbon seat stays are SAFE nowadays to race at higher speeds, under some stress.

Thanks again!

Broctoon

I worked briefly at a company that produced carbon tubes for Trek frames. We didn't assemble the frames, just made the tubes. There were round tubes for the main frame triangle as well as shaped pieces for the seat stays and chain stays.

The company made other products as well, such as antenna masts and windsurfer masts. They were trying to launch a line of snowboards at the time. But the Trek contract was their biggest money maker.

I enjoyed my time there and learned a lot, although it didn't develop into a career for me.

I still have a few carbon pieces from them. When a part did not pass QC inspection for whatever reason, it would be scrapped, and I got permission to take some of these home.

msu2001la

Carbon itself doesn't "wear out" over time, so the age is irrelevant in terms of structural integrity. I also don't recall inherent issues with the jointing of carbon/aluminum that caused failures, but someone with more expertise than me could weigh in on that topic. The main concern I'd have with any used bike (especially carbon) is ensuring that there is no damage. If it were me, I'd have a qualified shop inspect the bike before racing it. I'd recommend doing this for any bike regardless of age and material.

I think your main challenge with bikes from this era will be the extremely narrow tire clearances.

tomato coupe

My wife had an aluminum Orbea with a carbon rear triangle and carbon fork. It was a nice bike for its day.

ArgoMan

Ah, tire clearance. I like running 28's. I'm wondering if most of the Italian frames, pre-2010 (post 1998) will allow that? Bianchi's in particular.

datlas 

Likely depends on model and even rim width. But likely may only go to 25.

Eric F 

In some cases, your limitation might be the brakes rather than the frame or fork. I can't get a 28mm tire on my #1 road bike because there isn't enough clearance under the arch of the rear brake caliper (Campy Record).

bruce19

I have a Masi Gran Criterium S (2005 or so) and it is AL with CF fork, seat stays and chain stays. it's a size 58 with Dura Ace 10 sp and it weighs a little over 17 lbs w/Speedplay pedals. I love this bike but unfortunately it is too big for me. I ride a 55 w/55TT. It was a present to me from my GF so I've kept it.

Oldguyonoldbike

I have never owned a Bianchi, but I do have three Italian racing bikes from that time period (1995, 2001, 2008) and none of them will take anything close to a 28. Only one of them will even take 25s.

merlinextraligh

Carbon fiber composites absolutely can fatigue and degrade over time. https://velo.outsideonline.com/road/...iber-fatigue/#

its not only the carbon fiber, but the matrix, and also how the carbon fiber was joined.

Most notable and catastrophic example is the titan sub that likely weakened and failed with repeated stresses.

I wouldn’t necessarily shy away from an older carbon frame, but that said, why buy an older technology, that proved to have no real advantages, and has the potential to have problems from joining the two different materials, and at this point may be just worn out. Unless someone was giving it to me, I’d look at a newer all aluminum frame that can be had pretty cheap, or all carbon for a bit more money.

Brazosbynemo

I have a 2009 or 2010 Salsa Mamasita mountain bike with carbon seat stays. The connection point between the carbon and aluminum is painted over and totally seamless to where I can’t tell exactly where the two materials connect. If there was an issue I figured it would be easy to see as the paint would crack at the connection. I had the bike on the bike stand over the weekend washing it and it looks like new. No indication of any issues. This bike has not been abused but it is a mountain bike and takes more abuse than a road bike. As long as the frame was built properly it should not be a worry. I admit when I bought this bike I thought it was a cool feature but had the same concerns as you. Not so worried about it now given the age and the super hot TX summers in the garage.

jaxgtr

I picked up a used 2006 Cannondale Six13 which had a carbon top tube, downtube and seat tube attached to Alum lugs. It was a nice bike, but It was just a bit too big no matter what I did, I could not make it fit, so I sold it and got a CAAD9, which was a much better fit. I actually found the CAAD9 a better riding bike than the Six13, the Carbon really did not reduce the road buzz that much, so to me it was all hype. I never had any issues with the joints where the carbon\lugs met, but I only owned the bike for about 18 months.

tFUnK

Neither? My friend once had an alloy frame with carbon seat stays (an Orbea model) and it was a very smooth riding bike, but from an "investment perspective" - which I interpret as worthy of upgrading over time, I'd look for something more modern (wider tire clearance if you care about that sort of thing). That said I also wouldn't be wary about buying/riding one.

Since you're looking for a crit bike, I'd focus on frame geometry/handling characteristics and there really is plenty out there, vintage/used or modern, that will meet your needs. My perception is that alloy frames with carbon seat stays were designed for all-day comfort and not necessarily for crit racing, but that's just my perception.

urbanknight

This is my understanding as well, and I have had one such frame in the past. My son's current bike is that type as well. I really don't think I would be able to tell you which material (or combination thereof) I'm riding if I was somehow made to ride blindfolded and couldn't touch the material.

To the OP, chances are this frame is very outdated, and for that reason I wouldn't consider it a top choice for building any kind of racing bike. That doesn't mean it won't work as one though. As for the materials as a consideration alone, six of one/half dozen of the other.

BMC_Kid 

My mid-90s Quattro Assi Team, aluminum with carbon seat stays. I got it and then promptly bought the blue QA Easton Elite behind it in the second photo which I rode all the time. A few years after that I got the QA Titanium and divided the mileage between the two but also put miles on other bikes (all steel) I had at the time and others to come over the years. I think I put only a few hundred miles on the Team with carbon seat stays. When my brother comes to town it used to be the only bike of mine that he could make fit since it was a compact frame. The QA Elite rode nicer even without carbon seat stays but that it probably due to the oversized tubing the Team has. It is too stiff for my liking, look at those chain stays! And when I got the Titanium frame, it ended up being even more comfortable.

audiomagnate

I love my 2009 Cannondale Six 5 with its carbon rear triangle and fork. I've got around 7,000 miles on it and it ride in all types of weather. I don't see any reason to upgrade.

Bob Dopolina 

This was an economic compromise for a while. Then aluminum and carbon both evolved to a point where it no longer made sense (from a manufacturing standpoint) to continue mixing them. You could make a very good alloy frame that was as light as low-end carbon but less expensive and then make a full-carbon frame that was lighter than alloy but more expensive. So that's what manufacturers did.

Russ Roth

My wife has a trek pilot aluminum with carbon stays and fork from around 2007, bought it for her knowing the ride quality vs cost at the time. I'd ridden a trek 2300 the year before they came out with carbon stays and were full aluminum, the bike was very rigid and I found it unsafe on bumpy corners, the next year's carbon stay 2300 was significantly better at riding through curves. However, cannondale at the same time was producing a very lively full aluminum frame that handled worlds better, and trek only ran the carbon stays a couple more years before going back to full aluminum frames that handled just as well as the carbon stayed version. Personally, unless you're finding one that's been through the wringer and has a wornout drivetrain, I'd have no qualms about racing one.

My Carrera from 2008 has no problems with 25c tires on velocity A23 rims, I suspect 28c would fit but don't usually run that big of a tire.

daviddavieboy

Colnago built bikes with carbon tubes bonded to carbon lugs for a time (thinking c40) in the 2000s. There were some pro riders that had fully custom geometry with a carbon bike.

I am using 28s on a 2002 master with a flash fork and 11 speed SR but I only have a couple mm in clearance. The SR brakes had no trouble clearing the tire as long as the release was used on the brake lever.

hose

it was a thing like someone else wrote from 2004-2008

Thanks for giving me a reason to repost this nice bike!