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rhodefab Added a reply to Can You Fine-Tune Frame Stiffness With Just Bolt-On Bridges?
3/17/2025 8:22pm In other words the swing arm looks like a triangulated structure. If you are looking for stiffness, I'd look at the main pivot or the bolt on drop outs
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rhodefab Added a reply to Can You Fine-Tune Frame Stiffness With Just Bolt-On Bridges?
3/17/2025 8:10pm Hey Joe, I'm not sure the motion you're trying to fix is coming from the swingarm.
rhodefab Added a reply to Can You Fine-Tune Frame Stiffness With Just Bolt-On Bridges?
3/15/2025 6:05pm And hey @Ryan Burney I looked back and noticed you were working with 6061, 7075 should give a different result.
TEAMROBOT Liked a reply to forum topic Can You Fine-Tune Frame Stiffness With Just Bolt-On Bridges?
3/15/2025 5:34pm
I've learned a ton about welding, rivets, and metalurgy from these answers, but I'm still wondering: aren't you gonna increase the failure rate at welds by inducing additional flex in a welded aluminum structure?
This forum topic has 52 replies.
rhodefab Added a reply to Can You Fine-Tune Frame Stiffness With Just Bolt-On Bridges?
3/15/2025 4:09pm It's not that you won't, just that the stresses should be below the fatigue limit at the weldment. A well designed joint is important, a quick transition from thick to thin in an area that sees high forces might be bad if it relies on the weld joint.
rhodefab Added a reply to Can You Fine-Tune Frame Stiffness With Just Bolt-On Bridges?
3/15/2025 3:50pm I'll only speak to "boats" but riveted construction is usually limited to small jon boats (12-14' length) using thin gauge sheetmetal (1.5mm or so) construction. Welding requires higher skill and a slower manufacturing speed. Rivets are quick and low skill in comparison. That said, most small boats for rougher water use are welded these days. The type of aluminum used...
Ryan Burney Liked a forum topic Can You Fine-Tune Frame Stiffness With Just Bolt-On Bridges?
3/14/2025 11:05am
We’ve reached a point where bike geometry is pretty dialed for most rider sizes. Reach and chainstay lengths adjust, and brands like Cannondale even implement size-specific kinematics. The next frontier in frame chassis design seems to be ensuring that both large and small riders experience the right frame compliance for their weight and, beyond that, that every rider has a bike that behaves to their preference. Some riders want to plow, others need the chatter to be calmed down, and some just want to pop and play and have an exhilarating ride on their local blue trail, like a track...
This forum topic has 52 replies.
sspomer Liked a forum topic The BMX Thread
3/14/2025 10:28am
Because it's the best and long overdue here.
This forum topic has 41 replies.
ebruner Liked a reply to forum topic MTB Tech Rumors and Innovation
2/25/2025 12:38pm
TLDR: More volts = more betterer for design, and battery requirements, but not a huge impact to the end user if the design is done right. Complicated question and answer. There isn't a massive reason to favor a 48v system over a 36v system. The biggest advantage to a higher voltage system is within the formula/equation for current/watts/amps. Said another way... Amps = Watts / Volts. Here is an example... Assuming 750w power request/output by the motor. 750 watts / 48 volts = 15.6 amps 750 watts / 36 volts = 20.8 amps Batteries are generally more efficient the less...
This forum topic has 30444 replies.
rhodefab Added a reply to MTB Tech Rumors and Innovation
2/20/2025 5:27pm That's an interesting cross section. What say @Ryan Burney
rhodefab Added a reply to MTB Frame Compliance Analysis & Discussion
1/19/2025 3:20pm Ti Cycles sells an ovalized 1.75x.035 tandem tube that might work for ya. https://www.ticycles.com/ticycletubes/main-tube-ovalized-4130-tandem-bo…
synBike Liked a reply to forum topic The Mountain Bike Bearing Discussion
1/6/2025 12:25pm
Designed for an OEM pre-covid so ancient history. Still do a bit of custom linkage work for various people. Using a split clamp chainstay like the Orbea Rallon (and many steel bikes) with the below bearing layout is pretty much perfect. The main axle would be torqued to basically finger tight and then locked using the split clamp. Ideally the main frame bore would be bored from 1 side and then retaining rings used to seat the bearings. This ensures concentricity as cheaply as possible (very hard to do machining from two sides). You could also use a undercut endmill...
This forum topic has 53 replies.
Dave_Camp Liked a reply to forum topic Shock servicing at home
12/8/2024 6:17pm
We used to normal bleed everything at rockshox in the shop. A wet bench/vice setup would be ideal. Somewhere you can spill a bunch of oil and not worry about it. This is what we had- Cookie pan under the vice and seal it up, get a drain fitting and hose and run that to a 5 gal bucket on the floor. You can then just build and dump oil out on the vice with no cleanup.
This forum topic has 91 replies.
rhodefab Added a reply to Shock servicing at home
12/7/2024 7:01pm A Good set of digital calipers like Mitutoyo, Starrett etc. A 0"-1" micrometer is nice to have as well. A hand dyno is another piece that's usually needed just to check functionality. A compressed nitrogen tank with the appropriate regulator and valving is another piece to consider.
Rimpact Components Liked a reply to forum topic Tuned Mass Dampers and Mountain Bikes
11/16/2024 11:41pm
Actually very similar to the approach that Downamics talks about using in their Instagram post above. We recorded data from a range of different rides on varying bikes and trails. Merged the data and cleaned it up a little. We used a fast Fourier transform to order the data in a most to least occurrences fashion. Drew conclusions from this and then selected a specific trail that had a range of different speeds, features and conditions in one lap, the kind that, if you were to set up your suspension on, it would yield a solid ball park set up...
This forum topic has 182 replies.
rhodefab Added a reply to MTB Frame Compliance Analysis & Discussion
11/11/2024 1:42pm That's a good point about short link 4 bar. Does adding the corresponding upper link (and it's additional bearings) help or hinder the desired compliance in flex or roll? To bring you back to Dak's bike
Ryan Burney Liked a reply to forum topic MTB Frame Compliance Analysis & Discussion
11/11/2024 1:32pm
Haha, fair! I think going to extremes in examples helps illustrate points, so you'll see me slipping into that mode a lot so my apologies in advance. Let's compare a single pivot to a short link 4 bar and just look at the chain stay and its stiffness: A typical single pivot has a set of main pivot bearings between the bottom bracket and the rear axle. A short link 4-bar, on the other hand, has two sets of bearings at the link near the bottom bracket. Having two sets of bearings between the bottom bracket and the rear axle...
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rhodefab Added a reply to MTB Frame Compliance Analysis & Discussion
11/11/2024 1:19pm Let's not use a hardtail as an example, we're working with full suspension bikes 😉
rhodefab Added a reply to MTB Frame Compliance Analysis & Discussion
11/11/2024 12:12pm I think various links used to connect the rear axle to the main frame need to be accounted for. Horst links, short link 4 bar and direct single pivot designs all have different loadings at the joint. Is it common practice to consider them rigid but articulating joints?
carlinojoevideo Liked a reply to forum topic Stiffness versus Compliance
10/17/2024 5:11pm
I think we could figure out some type of compliance scale based on these factors below. Rider weight: 125lb more compliance needed. 250lb less compliance needed. Rider ability: Beginner rider could use a softer setup. Pro rider could push a stiffer setup harder. Riding style: Playful park rider could use a stiffer setup(but not always). Downhill/enduro smashing into rocks and off chamber could use a softer setup. Dirt type (grip): Dry dirt/hardpack could use more compliance for extra grip. Tacky dirt, clay, loam can run stiffer setup.
This forum topic has 37 replies.
