MadMechanic

I tried to find a post on this but no results when searched.

I have been looking at TrEK bikes and they list one of their alloys as "Alpha Gold Aluminum." I even emailed Trek and asked them what exactly does that mean other than shaping....I want to know what grade....like 6061 or 7075.

Anyone know what grade Trek's Alpha Gold Aluminum is?

Any owners of some Alpha Gold Aluminum?

opinions?

-thanks

samburger

Based on the bikes it comes on, I would guess 6061. Let us know if you hear back from Trek, I couldn't find sh*t about it on Google.

dminor 

So far I have found the older iterations of Trek's Alpha aluminums:

White (base series): Straight-gauge 6061
Black: (mid-range): shaped and butted 6061
Red: (premium): Shaped and butted heat-treated 7075 that at least used to be supplied by Easton.

Nearest I can figure (from a 2011 Gary Fisher model and other interwebs mining) is that Gold is shaped and butted 6061-T6 much like Black; silver is straight-gauge 6061, much like White. If I'm wrong, someone please correct me.

SlimRider

I've been on this Trek road before with their in-house trade names etc.

Look at an aluminum bike, as just an aluminum bike. The best aluminum is heat-treated 7075 aluminum. The worse is the non-heat treated 7075 aluminum. The middle ground workhorse aluminum of the bicycle industry is 6061 aluminum.

For some reason Trek is very stupid about explaining which bike is made of which specific material. They just tell you that it's gold, black, red, or silver.... SHEESH!

PS.

I think that the Alpha Gold is of the heat-treated 7075 variety.

sk0tt

Do you mean 7005? I didn't think you could weld 7075.

MadMechanic

Trek actually replied to me with the following when I asked about the Alpha gold:

Hello,

Thanks for writing in. Molding and shaping of the tube-sets are what will differentiate the various levels, the material being utilized for it is a 6000 series 6061 tube. Please let us know if you have any further questions.

Best,

Andrew Pajak | Trek Bicycle Corporation | Technical Service Representative
_____________________________________________________________________________

Ive been looking at an aluminum 29'er but I am kinda on the fence about 6061 vs 7075.

MadMechanic

Im not sure to be honest, The ACCESS bikes call themselves 7075 and are welded.

dminor 

7075 is generally considered an "unweldable" alloy for laymen, because of its tendency for the welds to form cracks during and after welding and because the base metal around the weld becomes susceptible to corrosion. It is done but in very specialized applications (https://www.lincolnelectric.ca/knowle...nt/alumfaq.asp). I think Trek was using Alpha Red 7075 in their carbon/aluminum bonded frames, so it was not requiring welding.

merlin55

more likely 7005 than 7075. I've tried TIG welding 7075 bike parts (old campy road pedals with alloy cages) and the part cracks at the junction of the bead and the part....just saying

dminor 

^^ More than likely. Just looked up the '11 Session 88, which is listed by Trek as being made from Alpha red and it is most definitely a welded frame.

MadMechanic

I have been narrowing down my decision for a good entry level bike under or at $1000 new. I have looked at TreK, Cannondale, AccESS, GT, Specialized, Scott, Giant, etc.. I went out today to all of the local shops to examine and ride some of these and to figure out what size and what brand im going to blow my load of $ on.

Armed with my collective knowledge and advice over the past months... and my personal mechanical inspection/quality check, I have come to the conclusion that I will most likely be buying the 2012 Specialized Rockhopper29, 19". Not because of customer service and Not by anyone's persuasion...but only because I feel like the bike + the company is pretty solid.

As we were talking about in this thread, TREK uses 6000 series AL, but I have come to find that 6000 series is basically the industry standard under $1500, and has proven its strength over quite a few years. As for the ACCESS bike.......I have found that Performance Bicycle is kind of an outlet for B-grade bikes. Interesting because they do carry some nice bikes... but the reputation is vague. I had looked into an ACCESS bike because for the money the components were pretty sweet and they listed their frame as a "7075" Aluminum. Check their website specs......clearly says 7075.....I go to the store and the TAG on the rack holding an access raptor says exactly this: "6061 Aluminum Frame".........I get to looking over the bike and the sticker on THE FRAME says this: "7005 aluminum series"..................Which is it? ACCESSS seems to be a blip on the frame radar. People say they are good and etc... but without a company name and reputation behind it...who the F* is access other than a chinese tyrant company making people tig these frames with no ventalation?

In conclusion, If you ride any of these bikes...they will carry you.. All of these bikes will carry you just fine to a certain extent. The Rockhopper I have pretty much decided on...it does have a lower quality crank, drivetrain, fork, and shifters.... But I do believe it has the best made frame out of the 900$ range. One of the things that sold me on this frame was the fact that specialized adds a connecting member across the rear tubes on the left side to form an extra triangle near the caliper mount. I feel like Specialized understands the forming and the engineering of angular strength a bit better. I like to see things overbuilt and I feel like this frame dominates the others in its price range. Maybe not the other vital parts, but they are cheaply upgradeable minus the cost of the tools I am going to have to buy.

MadMechanic

Scroll down, This is the model im probably gonna dump $950 on Monday.