Capecodder

I was advised on another thread to check the bonding at the lugs on a bike I'm going to look at tomorrow and wnt to know if this is a common thing as far as aluminum bike go? The bike is a Miyata Quickcross

I don't own any bikes other tan Cr-Mo and I'm not sure what I should look for, are there any things I should pay close attention to?

Thanks........

ftwelder

Miyata had a pretty good process, pressing and bonding the frame. Trek got it together when they switched from Permabond to Hysol. I am told extreme temperature changes and/or high humidity and salt can accelerate aging. I guess that explains a lot in my case.

531phile 

Back in the early days of aluminum, that was the way lightweight bikes were built. Bikes like the Vitus and Alan had aluminum tubes bonded to aluminum lugs. Some say they flexed like wet noddles other love the way they rode. There's been reports that these frames failed sometimes in drastic ways. Could have been a few bad apples that gave these frame a bad rep in some circles.

These frames are like 25+ years old. I've seen Craigslist ads where the owner wanted to sell his bonded aluminum bike because the seat tube was separating from the bottom bracket shell. I'd make pay close attention to the joints.

I personally wouldn't ride these frames myself. Too scared if you ask me. I'm not sure if the bonding agent was designed to last this long.

Capecodder

Thanks for this info....... Maybe I'll just pass on this bike.

prettyshady

bonded aluminum is not too popular on these forums, but I'l stick up for them since I have a few and enjoy riding them.

They are very light and great for climbing. The larger frames do flex a little under high power or a larger rider, but Sean kelly didn't have a problem in the 1984 milan san remo or paris - Roubaix.

Vitus 979's were made in france and were used by sean kelly. They usually have a 979 sticker on the down tube.




Alan also made bonded aluminum, with a slighly differnt design. Date stamps on the seat tube.



The later models had a smoother design, as below, also with date stamp on seat tube.


I have yet to see one that has separated whiles being riddern and so would trust one as much as others trust carbon fibre. I find them fun to ride on, and very good for climbing.

randyjawa 

I, generally, prefer lugged steel construction, myself and have a few bicycles to back that statement up. However, I absolutely loved the look and ride quality offered by my ALAN, a screwed and glued lugged aluminum bicycle...


I have also owned a Vitus 979 and I really like the ride it offered also, however, the Vitus was too flexible for me and I feared my weight would eventually break the frame set.

Trakhak

I prefer welded aluminum to everything else, including lugged or lugless steel, but I wouldn't hesitate to buy a Miyata aluminum bike that's in good shape overall. A quick couple of searches yielded no reports of Miyata aluminum frame problems.

KonAaron Snake 

There is a bonded ti miyata frame on ebay right now with issues. I'm sure the bike is probably fine, but like 531 said, I'm not trusting my life to glue.

Wogster

You probably do, trust your life to glue, everyday, lots of glues are used in all kinds of places, construction, cars, airplanes. I wouldn't buy a used AL frame, for other reasons, mostly fatigue failure, although bonded and bonded and screwed AL frames are probably better then TIG welded AL in that regard, providing the glue was designed to remain slightly flexible, then the glue will flex instead of forcing the AL to flex. It's also possible if the joints do go off, that the frame can be disassembled and reassembled with new glue, but it would take an experienced frame shop, that knows bonded frames to do that kind of work. Probably cost more then a new steel frame as well.

KonAaron Snake 

I've seen too many frames with bonded lugs that have failed...I actually watched a guy with one of the old Specialized Epics climb as his top tube popped. The local Giant team had the problem at least twice and the rumor was the Techniums did too. Bonded frames scare me...rational or not.

wrk101

+1 I just go with steel frames. OK, I have had a few aluminum Cannondales, but they have all moved on to a new home. For a keeper, I just stick with steel. There are plenty of good steel bikes out there at reasonable cost.

MrEss

All this talk about bonded ALU frames has got me curious -- has anybody ever tried rebuilding one at home? Sounds like fun, but then I like to tinker...

Capecodder

Well not exactly what I wanted to hear, but better to know now than after I bought it. I'll let this one go....... Thanks for the help!

gioscinelli 

Stick with Steel it's Real. As an alternative, go with Titanium, lighter than Aluminum, close to mid range CF and will last for years!

Chombi

Uhmmmm. I thought TI is slightly heavier than Al as an element..........but I do agree that TI's stregnth to weight ratio beats Al easily.

Chombi

Bianchigirll 

what kind of bike? look real close at the joints, and make sure the tubing color is all the same. if there is a small brighter ring near the lug it could mean the tubing is coming loose. check the headtube and BB real close for small cracks. I used to see Vituses with small cracks around the ends where the cups get pressed in. if you see black stains or powder on the luggs or tubes that also could be a sign of something loose.

do we get to see pics even if you don't buy it?

unworthy1

I also am prone to tinker (and then some) but as close as I got was with a friend's ALAN Carbonio frame that had a loose joint: the DT-HT. If the frame had been my size, I was tempted to throw caution to the wind and attempt to re-bond with some super-strong epoxy (Hysol, now a Henkel/LocTite company) that I've used before. It is awesomely strong (in shear and peel strength) but also expensive...and the preparation is crucial. Luckily the frame was too big so it's gone to a new owner who hopefully got it fixed somewhere. There's a outfit in B.C. Canada who repairs Vitus and ALAN frames (for a price): https://www.guywires.com/vitusmain.htm

Chombi

Yes, Guywires is still alive in Canada, but I think in a much smaller scale than they were before. At least emails to them are still responded to, as they did last year to me. As for parts that they used to carry for Vitus frames, the person from Guywires emailed me that they have very limited ("small") parts left in their inventory, and of course, not expecting to get anymore, but he did welcome any inquiries for parts, just in case he still has what a Vitus frame owner might be looking for.

Chombi

RoboIsGod

i've got a bonded aluminum Miyata 1400 and it rides beautifully, even with the original alloy fork! I must say it is a bit flexy, but this does make for a nice ride (maybe not the stiffest). the lug construction is beautiful too.

Fred Smedley

Actually the Miyata is bonded Aluminum and chromemoly. As with any frame a close inspection is in order before buying . That said both of Quickcrosses here are just fine and make a great riding bike due the the steel fork/stays. These are great bikes as are most Miyata's

Wogster

Hey, I didn't say they were perfect, my personal rule, Aluminum or CF, I ain't buying used, I can't afford Ti, so that leaves me with steel. Preferably lugged, brazed steel. You wonder why nobody ever built a lugged, brazed AL frame, some AL alloys can be brazed, although that may not have been the case when those frames were made.

abarth

Ti bonded to Aluminum is bad news, just like steel to aluminum or carbon to aluminum. Aluminum to aluminum...not so bad.

catonec 

my trek mountian bike is bonded aluminum and is holding up fine.

KonAaron Snake 

You'd be amazed at the deals you can find on used ti if you really look.

Kozeemoto

Hello, and this is my 1st post here, sorry for necrobumping but history record corrections should always be welcomed.
I was lead to this thread after reading an earlier on similar topic www_bikeforums_net-classic-vintage-601292-aluminum-revolution-2_html where luckily someone came to correct the record about Alan.

I see some concerns that may fuel myths about aluminum. This here test reveals plenty to destroy myths but does nothing to take always concerns of harshness from welded aluminum frames www_sheldonbrown_com-rinard-frame_fatigue_test_htm The source of the very expensive and scientific study of racing frames at the time (when welded aluminum had already been a refined art and carbon use was still fresh).

I believe one of the fallacies that surround aluminum stories is that it is treated as one thing when alloys are really drastically different between each other and of other metals. So choice of alloy, bonding agent (welding is one of them), and construction technique has a much larger spectrum of variance than the core material itself, in this case aluminum.

There were very few reports of Vitus bonded aluminum failures, and this is probably because they DID flex so much. It is the ultimately rigid frames you should be weary about. Alan just didn't have the finances and networking or marketing technique to make a name in racing, while vitus made a name due to podiums. The vast majority of Alans were sold with different badges, making other manufacturers famous using Alan's frames. The one sad story you rarely hear is how Peugeot (a primary customer of Vitus steel tubing, a competitor to the big names in chrome-moly-steel high performance tubing) attempted to do the same a bit late in the game. I suspect to pressure Vitus for pricing in its supply of steel tubing they made a bike using Pechiney aluminum tubing, a large Al-alloy industry, possibly the largest in Europe at the time, who was also an aircraft supplier. They bonded those frames tugether into lugs using a Pechiney prescribed aerospace technique. Basically they were pressfitted together without much bonding using a temperature controlled pressfitting method where a cold and hot piece would hug each other. What a disaster this was, even though the name of Peugeot and weight of the bicycle were able to carry it in vintage collector's halls. Maybe because so few remained in one piece that became collectable.

The press/screwed/bonded frames were flexy and lightweight riders loved them, such as Sean Kelly. Heavier bigger riders described them as noodle. When the first welded aluminum frames begun to set the new norm they reversed this fame to being to harsh and causing rider fatigue. What could be considered an ultimate weapon as a sprint track bike may be an ultimate disaster as tour racing frame, and what may be a good bike to go bikepacking with may also be too harsh ridden without load and with light rider.

The concerns of frames falling apart, especially lugged frames I believe are unsubstantiated. They never fall apart catastrophically, they begin by alerting the rider of excessive flex and noise. It is uniform carbon construction one should be weary about, but in general they are so overbuilt still that they would stand up with one fork leg, one seat stay, or a cracked chainstay. But you could take the best frame in the world and use a borderline set of bars on it and once they fold, bend or crack, you can nearly kill yourself. It is always the weakest link that gets you and it is not always the frame. Do I dare mention wheels falling apart, like 4 spoke carbon wheels that claimed some podiums?

The study above destroys some myths about Ti too, it is not as perfect as people think and probably more sensitive to construction and design than anything else. One thing it is to admire is the CAAD3 and how it is the only one of 12 frames tested where head-tube and bb flex is close. Question is whether it needs to be or not.

I do miss enjoying an easy ride with steel but I am sold to a variety of aluminum alloys. I just love the stuff and haven't ever had one fail on me.

PS Since I am new and doesn't allow me to post links I replaced some link symbols with dashes, hopefully some can figure it out or run them on a search engine, the one is a local thread, the other is on sheldon's site on frames.