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7000 series can absolutely be welded. All of Knolly's bikes are 7000 series and I can confirm they are definitely welded, great piece of kit too
I've only welded with an old Hobart flux core, but Knolly's site says "we use a 6066 series hydroformed aluminum alloy tubing. It's the most advanced weldable tubing alloy available".
I just received tubes to make a couple of dozen frames. I plan on taking deposits/preorders toward the end of this month.
I think 7005 is a less expensive weldable alloy, as it doesn't need to be heat treated post-weld. 6061 is a better option but needs heat treatment.
7075 is more than just a little stronger than most Al alloys, typically 525 MPa vs 290 for 6061. So less stress per unit force applied and better fatigue life, especially without the complication and inconsistency of welding.
Like most here I've had a several Al frame failures, always from fatigue at a weld. Bonding is better and more consistent once you have a design and process that works, but that isn't trivial.
Hey Primoz!
How many HP bikes is this now, like 32 or something?
Pretty friggin cool!
7005 (or 7020, the EU equivalent of 7005) can, 7075 for all intents and purposes no. A higher ultimate strength limit will also make it more fatigue resistant. Stiffness wise it's basically no difference between the two.
For brazing you need enough surface area for the two parts to be joined, so you might as well glue the tubes in the lugs and be done with it.
7005 also needs to be heat treated, but it's cooled in air, 6000 series needs to be cooled in oil and thus requires a more complex heat treatment equipment. 6000 is more easily weldable though, so that's a benefit of it.
There will likely be more HP trail bikes for a few years, just like with through headset routing, if it turns out to be a flop, it will take another product cycle to clear then out (4ish years from now).
7005 is way more expensive than 6061, limited in tube sizes and much more costly when working with billet for machined parts. The advantage is the ease of aging/heat treating.
For the same design and same loading, stress is the same for the two materials assuming no deflection. Modulus of elasticity is the same for all intents and purposes so when you consider deflection as well it’s still pretty much the same. S-N curve is the quick and easy way to visualize fatigue. For the same stress, 7075 can handle significantly more cycles. This graph is something I found really quick so no idea how accurate it is, but conveys the point. Traced lines for stress that would cause failure in 10^4 cycles in 6061. Would require about 10^5.6 cycles for 7075 to fail under the same stress. So same part same application but 7075 instead of 6061 would last almost 40x as many cycles.
In my mind, usage of 7075 is about what it lets you do with the design. For some things the reality is it doesn’t let you do much other than take a part that’s already overbuilt and make it way overbuilt. On the other hand there are parts such as our DHX2 MX eyelet that wouldn’t be possible in 6061.
If you're stiffness limited 7075 is mostly a marketing point. Making a C section crankarm (more or less most modern cranks that are forged and/or machined) out of 7075 and thining it out to achieve the possible limits will probably just make it more noodly. Making a handlebar out of 7075 vs. 6000 series and modifying it to achieve the same fatigue limit will make it more flexy as well but this might be a lot more beneficial than crank arms.
So is the new Fox fork chassis incoming imminently? This is a GMBN journalist.
There's a new Fox fork chassis? I thought it was all internal changes for the 38. Unless this is for a 36?
Seems like MY24 is internal changes only (at least from what can be seen in the parts specs on the Fox site).
MY25 may be more extensive.
If they're testing with journalists, must mean the announcement and reviews are imminent?
I haven’t been keeping tabs lately but I’d only heard it was internal updates. I’m asking if/how we know there’s a new chassis
It's their 50th anniversary... Good excuse to do something...
Race Face with 3 upcoming releases...
https://www.raceface.com/pages/the-new-carbon-era
Likely ERA wheels/rims, handlebars and maybe something unexpected.
Some of the factory riders are riding non-Kashima forks which as it was pointed out earlier happened last right before the 38 was released.
In the IG post, the entire fork is blurred out on each bike.
Wow there’s a ride-4 chip!
Dang that’s a sweet looking Nomad
The man on the left has his top of the fork showing. Says Kashima on it.
I meant that in races, riders like Remi and Richie have been running non-Kashima current-model forks. I think the reason these forks are blurred out is because they're the new chassis.
Looks like Kashima lowers too
Excited for what comes of it. Love my Era cranks, and I've been looking for a reason to replace my Spank stem.
Why the switch to VPP? Thats a big move from Horst (which I prefer)
This looks incredible. Bravo rocky.
Wonder if its just a normal vpp or they're are a bunch of funky flip chips etc.
Nice EndurMegaMaditude!
It looks like it's using their Ride4 chip at the forward shock mount, and is also using reach adjust headset cup/chips.
It's definitely funky. Adjustable for wheel size, lower pivot is concentric with the bottom bracket and drives the shock. Also includes in-frame storage and has some nice details like good access to the high speed rebound on Fox shocks from the non-drive side.
Chassis are censored because, colors.