General Cycling Discussion - Aluminum or not?

After reading some of the replies on the “Road Cycling” section it seems that most people would choose a steel frame over aluminum. Yes, it’s a bit heavier but much more durable and provide a more comfortable ride. While looking at some of the new mountain bikes I couldn’t find one bike with the steel frame. If durability seems such a big issue in road cycling, without drops and big hits, then why would anyone use an aluminum frame for a mountain bike?

That's a very interesting question. Many of the bike makers, particularly the major ones, concentrate their products in the aluminum market. about 80% of their MTBs are made of aluminum, while only a few are steel. The steel MTBs also don't share the optimized racing geometry that aluminum bikes have.

They solved the suspension problem with FS aluminum bikes.

My friend's Trek 8000 has taken more than 10 years of tough trail riding and still going strong. I have a Trek 7000 preowned and it feels solid. They're both aluminum HTs.

Originally posted by Chi
. The steel MTBs also don't share the optimized racing geometry that aluminum bikes have.
I would guess that aluminum is easier to form in to odd shapes of modern FS MTBs frames then steel.

I think it is because of full suspension designs, weight, it's cheaper, and more people ride MTB, so companies definetly want to go cheaper, and MTB riders(I'm just guessing) replace their bikes more often...

All of my bikes have been commuter models. My first was a tank, steel with metal rods instead of cables for the brakes. I traded that in for a lighter weight steel frame and traded that one in for an aluminum frame.

It's a joy to bike with a lighter bike. If you're going to bike long distances, why tear yourself up, wear yourself out, by pushing extra weight.

I'm not a fanatic and my commuter is probably much heavier than the cheapest racing bike, but ónce you go from a heavier bike to a lighter bike, you don't want to go back.

It's all about weight.

The fact that MTB's are aluminium is proof that they are strong enough for road riding. The only down side to an aluminium road bike is a slightly harsher ride than steel. Most people couldn't tell the difference in a double-blind test. MTB's don't have be to concerned with a harsh ride because they have suspension. I don't know of any racing MTB's that are steel.

CHEERS.

Mark

Originally posted by fubar5
I think it is because of full suspension designs, weight, it's cheaper, and more people ride MTB, so companies definetly want to go cheaper, and MTB riders(I'm just guessing) replace their bikes more often...

Not cheaper. Aluminum is more expensive per weight as compared to steel.

I agree with Dutchy, despite everyone's opinions about a different ride quality, I've ridden steel and aluminum within the last month, and I can tell you this: the only difference I could tell was the weight. Vibration-wise, same thing. The steel may "feel" more stable only because it's heavier.

The geometry has as much to do with the ride, how stiff it is and the feel of the road vibration as much as anything. What I mean by the geometry is not just the angles, but how they actualy build the frame.. just being aluminum does not necessary make it a harsh ride or steel less harsh, there are ALOT of variables involved.

There are a number of good steel MTB frames available. Bianchi makes a couple. Jamis, Rocky Mountain, Scapin, to name a few others. They are primarily at the higher end of things, due to cost. Notice that Trek has gone to graphite composite, but only on their highest end offerings.

Most inexpensive MTBs and road bikes (under $1000) are made in Asia, in any event. Once those guys are set up for mass production the the price drops dramatically (just like the shoe markers). The result is that once one of the bigger guys starts using a material, be it steel or aluminum, it becomes less expensive to have a frame made out of the selected material. While all materials have their supporters/detractors, it is mainly economics that drives what is offered. From their end it is a business, even if we forget that.

If you're interested in checking out a steel bike with racing geometry, check out www.gunnarbikes.com. All handmade in the USA by the same folks that make Waterfords. If you time it right you can even get some of the awesome PPG Waterford paint jobs as specials of the month at no charge.

Hi,
I have owned both Mtn and road Alu bikes. I would consider an Alu Mtn bike, but never another road bike. The difference is the suspension. You also asked about durability. In an unsuspended bike, you need the bike to bend a little to absorb shock. Add suspension, and you don't need that quality. Alu doesn't like to bend.
Mtn and road bikes are different animals, and you're post asked why problems in the road world didn't seem to be a problem in the Mtn world. They used to be. I loved my Alu Mtn bike, but eventually the frame died. I had added a front shock, but that didn't prevent a crack from developing in the bottom bracket.

these things go in cycles (pun intended) steel was all the rage then Al came along and everything was Al. Then developements in steel made it an attractive metal to build with again. then carbon forks came on the market...carbon seat posts, etc. ---> then as these accessories became more affordable they smoothed out the perceived harshness..

i notice that the true love affairs that riders have with their bikes are usually riding steel or carbon or titanium. don't get me wrong...there are people who like their Al bikes.... but there usually isn't that love affair with them that the other materials enjoy.

people look to the pro's. they went from steel to Al briefly. now what do they ride? and as the Ti's and CF's become more affordable, Al with fade more and more.

some manufacturers have even disguised their Al bikes, passing them off as Scandium (Merckx) which is really Al?!

My opinion is that with a suspended (front or full) mountain bike, harshness via frame material is not as much of an issue. Therefore, why not go with a lighter, and generally more popular material? :D

I'm a steel-favorer for almost all bikes, but many of the rear swingarms, rockers, and other rear suspension pieces have shapes that work best to make out of aluminum. On road bikes, the frame members themselves work with the tires to provide the suspension.

I personally have a steel frame. It has a lifetime warranty on it. It just came to my mind that aluminum manufacturers could also provide lifetime warranty, but I have never owned any aluminum frames so I wouldn’t know. Does your Al frame come with lifetime warranty? If so then there would be no problem of buying one, if broken the factory would just replace it with a new one, rite?:confused:


One more thing. Which aluminum alloy is the strongest in bike frame building?

Trek offers a lifetime warranty on their aluminum frames. Alpha series and up. I dunno about any other mfrs.

Originally posted by RiPHRaPH

i notice that the true love affairs that riders have with their bikes are usually riding steel or carbon or titanium. don't get me wrong...there are people who like their Al bikes.... but there usually isn't that love affair with them that the other materials enjoy.

Where do you get this data from? What sources? How do you gauge this?

Chuvak; they are not going to honor your lifetime warranty if it breaks due to abuse, which would be the likely cause of failure in a mtb anyway.

I agree with LATE; I think that AL is used in mtb extensively these days is to lighten the bike up as much as possible before adding on the heavy suspension and wheel parts. But also as LATE indicated you will sacrifice durability for less weight, but if your racing that's ok.

See VeloNews Buyers Guide page 42 called Metal Shop 101 for more info on other frame materials but I quoted the AL section in part below:

As anyone familiar with beer cans can tell you, AL is softer land less stiff than steel. AL is easy to draw and form into shapes, easy to machine, and relatively easy to weld. Its density is about a third of steel and half of TI, so it is not hard to build a light bike with it. It will oxidize, and should be painted powder coated or anodized to prevent corrosion, but it does not rust away rapidly.

AL has downsides, too. Its tensile (breaking) strength, yield (bending) strength and elongation (the % of its length it can stretched before it’s unable to return to its original shape) are far less than those of high strength steel and TI alloys. AL is more vulnerable in a crash. AL has no fatigue limit, a property that steel possesses, often expressed as a % of its tensile strength. Below this limit, the material can be cycled indefinitely without breaking. This means that AL can be less predictable than steel as to when it will fail after long use.

Back to our beer can: compare a can of beer to a can of olives and it’s apparent that the AL container has much less stiffness than a steel can of similar thickness and diameter. Yet many AL bikes feel stiff. Why? It’s because AL’s density is so low; tubes can be made large and thick for stiffness and light weight.

VeloNews also agrees that the lightest parts may not be the best. (last sentence of last paragraph of metal shop 101 article).

Specialized and Cannondale also offer lifetime warranties on their frames, while Raleigh and Diamondback offer a 5 year warranty.

Lets see,masi speciale premio,all ultegra.Fuji marsellie,all ultegra.Scattante R853,all ultegra.Specialized allez comp cr-mo 18/27,all ultegra.Cervelo super prodigy,all ultegra,all under $2000,between 19 and 21 pounds and,oh,all steel bikes with carbon forks.Theres a few to choose from.Boy i really like the cervelo and fuji and lemond.