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flag BungedUP
O+
Posted: Sep 26, 2012 at 17:48 Quote
jonbikes wrote:
I'm quite familiar with method of welding on paper, just not in a practical sense. Went over it in the two year welding program I took.

Would you figure a 60xx series tubing would do for a task like this or should I choose between 60 and 70xx based on the heat treating and aging methods available to me.

If you can find someone to do the heat treating of 6061, and properly quench the frame, knowing how to tame the warping that may occur during this step, then it's fine. 6061 will require solution heat treating, as well as aging. On the other hand, 70xx can be purchased in a heat treated state, that only requires artificial aging through a much simpler heat treating operation after welding. Most small builders have to use 70xx tubing for frames as it is the only material that can be reasonably cost effective to heat treat on a small scale.
flag jonbikes
Posted: Sep 26, 2012 at 21:49 Quote
Ok, I will get ahold of my buddy and see what the deal is as far as what he can do and then go from there.
flag TyranT21
Posted: Sep 27, 2012 at 21:54 Quote
Been kicking around some frme ideas, Does anyone know how to locate the actual pivot point in a VPP or similar system?

Thanks
flag sherbet
Posted: Sep 27, 2012 at 21:56 Quote
TyranT21 wrote:
Been kicking around some frme ideas, Does anyone know how to locate the actual pivot point in a VPP or similar system?

Thanks

Said point changes position. Axle path is an S.
flag TyranT21
Posted: Sep 27, 2012 at 23:36 Quote
is that the same with DW and Maestro? I thought it just put the pivot somewhere in the front triangle, but obviously wrong..
flag mozz
Posted: Sep 28, 2012 at 1:02 Quote
sherbet wrote:
TyranT21 wrote:
Been kicking around some frme ideas, Does anyone know how to locate the actual pivot point in a VPP or similar system?

Thanks

Said point changes position. Axle path is an S.

Wrong thread really, we've been trying to avoid suspension discussions on this thread and concentrating on the manufacturing process and other design features.

There is a suspension tech thread set up to avoid taking this thread off topic, as suspension design really derails this thread from its intention.

Sus tech thread. https://www.pinkbike.com/forum/listcomments/?threadid=128070
flag chazdog
Posted: Sep 28, 2012 at 4:51 Quote
mozz wrote:
sherbet wrote:
TyranT21 wrote:
Been kicking around some frme ideas, Does anyone know how to locate the actual pivot point in a VPP or similar system?

Thanks

Said point changes position. Axle path is an S.

Wrong thread really, we've been trying to avoid suspension discussions on this thread and concentrating on the manufacturing process and other design features.

There is a suspension tech thread set up to avoid taking this thread off topic, as suspension design really derails this thread from its intention.

Sus tech thread. https://www.pinkbike.com/forum/listcomments/?threadid=128070

axle path also isnt 's shaped', that was a lie, even santa cruz have admitted it...
flag airmiller44
O+
Posted: Sep 28, 2012 at 7:12 Quote
chazdog wrote:
mozz wrote:
sherbet wrote:


Said point changes position. Axle path is an S.

Wrong thread really, we've been trying to avoid suspension discussions on this thread and concentrating on the manufacturing process and other design features.

There is a suspension tech thread set up to avoid taking this thread off topic, as suspension design really derails this thread from its intention.

Sus tech thread. https://www.pinkbike.com/forum/listcomments/?threadid=128070

axle path also isnt 's shaped', that was a lie, even santa cruz have admitted it...

i can take a bunch of frames of the movement but its really just going to be an arch
flag TyranT21
Posted: Sep 28, 2012 at 16:28 Quote
Ok thanks I will take it elsewhere.
flag Spicy-Mike
Posted: Sep 30, 2012 at 23:49 Quote
jonbikes wrote:
I'm quite familiar with method of welding on paper, just not in a practical sense. Went over it in the two year welding program I took.

Would you figure a 60xx series tubing would do for a task like this or should I choose between 60 and 70xx based on the heat treating and aging methods available to me.

Great bike man. I cannot specifically answer the question with me actually physically using Aluminum to build a whole frame. But, I will try to give you some insight onto what materials to use and which types of Aluminum offer what. Hopefully this helps and saves you some researching!

1) 6061 / (6069) Aluminum -- Major Alloys, Magnesium + Silicon:
- Most ALU bikes are made of this.
- Generally weakest out of the 3 common ALU alloys mixes in terms of raw Strength Yield; 2024 (2nd), 6061 (3rd), 7k (1st) Series.
- Exclude 2024 (Copper Based), it is much more susceptible to corrosion out of the 3 and must go through additional steps to prevent corrosion (still used in Aircraft structures). Unseen in the Bike Industry.
- However, with Heat-Treatment/Artificially Aging, which is T6, it becomes significantly stronger. --- Must.
- 6061 is best because the flexibility and ease of Welding. It's cheap, strong (heat-treated), corrosion resistant, fatigue resistant, scrap-able, and easy to form + weld.
- Santa Cruz uses a "new" 6069 Aluminum which is another variant. 6069 has increased scrap-ability (reusing shavings/etc that can be combined with other 6k Series alloys), fatigue resistance, and elongation (stretch/flex, a GOOD thing).

>> 6061 must be welded with a filler alloy, I choose one for you that's purely intended for "safety applications" -4643-. Online, you'll see that other filler alloys are chosen or recommended, but, they don't mention those Filler Alloys are NOT heat-treatable. Remember, that after you weld a 6061T6 frame, areas around the welds will lose strength by up to 80%, therefore, you must heat treat them again. But, if your Filler Allot isn't heat treatable....then it won't get any strength back. Yaddidamean?

= I would go with 6061-6069 Aluminum. Cheaper, easier to weld/bend/design, scrap-able (if applicable to melt), good elongation properties, corrosion resistant (as most ALU's), very strong after doing a Temper6 Rating (heat treat+artificial aging).

7K+ ALU Series -- Major Alloy, Zinc:
- Strongest ALU blend of the 3 Alloys. However, 7005 itself is only slightly stronger than 6061 comparing by Ultimate Tensile Strength. (By 5k PSI)
- 7005 seems to be the most common ALU Blend out of the different types of 7K series such as, 7005, 7050, 7075.
- 7005 will be stronger than 6061 by having a higher strength yield. However, the 7K series is suppose to be more "brittle" compared to the little more flexible/flexy 6061 ALU. (This may NOT be the case with 7005).
- 7005 ALU SLIGHTLY exceeds most aspects of 6061 ALU, including fatigue strength (by a fair amount). However, 7K series is known to be harder to weld and bit more costly depending on the actual 7K series alloy.
- Still retains corrosion resistance, like most ALU's.

>> In the end, 7005 is VERY similar to 6061 ALU, but has very slightly better characteristics in multiple categories. Yet, the problem or drawback is that 7005 will be harder to weld, design, etc, and therefore cost more.

= You either get a cheaper, more common, easier to weld Alloy that can be manipulated to create a BETTER design or the 7005 ALU which is a great material but is harder to find in that respect and may be more complicated to design or weld, which in the end will cost more money. Remember, that 6061/6069 Frame @ final T6 rating with a decent design will be able to withstand more force/abuse than anyone can physically do to it on any given single situation. Sure, you can break it in one sitting, but that'll require you to break your own bones first or even die before the frame breaks.

TBH, I would stick to Steel. ALU is all Bike-Industry hype. ALU is inherently weak, generally speaking, plus with welding, it's easy to fail due to the design limits with it. Nowadays Steel Technology allows much more strength but still maintaining a weight close-same to ALU. Corrosion is no longer a problem too, if simple proper steps are taken. You never see "old"/grandpa time ALU bikes, but you see tons of Steel ones...I like ALU, but bike makers are making them too weak. They need more "safety" features/designs.

Message if you end up designing a bike out of ALU. I can show you some designs Big Grin
flag jonbikes
Posted: Oct 1, 2012 at 10:13 Quote
Thanks for the info mate!

Turns out I can get both 60xx and 70xx heat treated and aged no problem.

One of the main reasons that I am considering alu for this build is the ability to machine every part that is going to need a bearing. I am going to do some more R&D on steel joints concerning pivots/bearings; this was one major downfall with my original desing. It wasn't catastrophic but I doubt it could have survived a full season without the pivots failing.
flag Spicy-Mike
Posted: Oct 1, 2012 at 14:57 Quote
Thanks guys. Nice, I'm happy you took interest! All the reading/compiling went to some good haha. Anything to help you with your bike man. Always happy to see ppl making sick bikes...If I could, I would start my own bike frames.

And I want to say I didn't mean ALU was a totally terrible material. It does have its great benefits but in order to get there it obviously has to go through certain criteria's and met certain design characteristics. I feel like the bike industry is NOT adhering to those rules as much in today's time and therefore giving me an impression of much weaker bikes that won't last many load cycles/durability.

Go for it man, machining is a huge part. 7005 is good for a small increase of raw strength (3-5% better in some categories vs. 6061), but, perhaps 6061 would be much better to start first?? I'm not sure if there would be a very huge difference. I'll send over the links comparing the 2 alloys, and you can see for your self.

6061-T6 >
http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061t6

7005-T6 >
http://www.matweb.com/search/datasheet.aspx?matguid=34c308934f7a4be589a80ecbee94406e&ckck=1

As you can see, 7005 has very similar properties to 6061. Oddly enough, 7005 has a better elongation/stretch than 6061 which is NOT notable for the 7K series (I would still assume 7005 shares similar traits to other 7K+ alloys, since they are all in the end main alloyed with Zinc). Also, 7005 is a tiny bit more dense.
flag madm3chanic
Posted: Oct 1, 2012 at 16:27 Quote
7000 series are a bit of a shit to machine- they chatter and chip, swarth comes off in flakes rather than coils. and it stinks like fish when you angle grind it...wierd.
strong but.
flag Spicy-Mike
Posted: Oct 1, 2012 at 16:45 Quote
^ There you go. The ole chip and brittle. And the fish thing...never heard of that haha.

 


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