Results 4,351 to 4,375 of 13088
Thread: Ask the experts
-
04-30-2021, 10:14 AM #4351
-
04-30-2021, 10:15 AM #4352yelgatgab
- Join Date
- Oct 2002
- Location
- Shadynasty's Jazz Club
- Posts
- 10,248
All this talk about Specialized sucking back in the day, and no mention of how mediocre VPP was? Every new and improved iteration of VPP was the same wonky curve that me and plenty of others didn't like. The latest iteration is pretty good and it's because they went straight progressive like everybody else.
Remind me. We'll send him a red cap and a Speedo.
-
04-30-2021, 10:32 AM #4353Registered User
- Join Date
- Mar 2015
- Posts
- 551
-
04-30-2021, 10:33 AM #4354
Your school is better than mine. I’ll just say that I graduated from one of the Canadian ones.
I did win an award for vehicle dynamics simulation work when I was in college, and then had a brief career in motorsports after graduating, so that’s gotta count for something, right?
The race team’s manager’s daughter actually graduated from Mudd, and that’s the first I’d head of it. She ended up working for Prodrive, but not on the WRC program, alas.
I did get to work alongside the guy who was the former Prodrive crew chief for Colin McRae and Richard Burns when they were winning their Subaru WRC titles.
-
04-30-2021, 10:35 AM #4355pura vida
- Join Date
- Mar 2006
- Location
- The bottom of LCC
- Posts
- 5,750
-
04-30-2021, 10:46 AM #4356
Leverage ratio curve is kind of independent of the linkage design, so it’s a bit of a different topic than has been discussed.
That said, the falling-then-rising rate curve seems like one of those things that seems to work better in theory than in practice. In theory, it should provide nice small bump compliance around the sag point, and then since it ramps up in both extension and compression you should get some additional resistance to both topping out and bottoming out.
-
04-30-2021, 10:48 AM #4357yelgatgab
- Join Date
- Oct 2002
- Location
- Shadynasty's Jazz Club
- Posts
- 10,248
-
04-30-2021, 10:54 AM #4358
-
04-30-2021, 11:04 AM #4359
Leverage ratio has come up, but the conversation started with a discussion of whether Horst Link is any good compared to newer linkage designs, and that’s really looking at how the wheel moves through it’s travel. Shock actuation is separate from that.
You can design to get nearly identical leverage ratio curves regardless of whether you have a Horst Link, single pivot, VPP, etc. it’s quite independent of the linkage layout.
-
04-30-2021, 11:16 AM #4360
I think in the early 00's, shocks and the valving within them were kind of terrible. So suspension designers tried to work around that by building seemingly desirable traits into the suspension design. It sort of worked, but not as well as everyone would have liked. Then shocks got a lot better, but those better shocks were held back by all of the goofy leverage curves since it's really hard to tune a shock properly when the leverage curve has a bunch of inflections. It took until ~2018 for the guys designing the frames and the guys designing the shocks to get on the same page and design frames and shocks that actually work well together.
-
04-30-2021, 11:20 AM #4361
Air shocks, specifically. There have been pretty good coils for a long time, and just to stick with the Santa Cruz example, the V10 has also had a reasonable leverage curve for a long time. All their pedally bikes just had goofy leverage curves, until they went to the lower link-driven shocks. What sucked was when companies made fucked up leverage curves to try to compensate for the fucked up spring curves of older air shocks, and the results were... still fucked up.
-
04-30-2021, 11:22 AM #4362
-
04-30-2021, 11:27 AM #4363
-
04-30-2021, 11:27 AM #4364yelgatgab
- Join Date
- Oct 2002
- Location
- Shadynasty's Jazz Club
- Posts
- 10,248
-
04-30-2021, 11:28 AM #4365
-
04-30-2021, 11:32 AM #4366
That's awesome, you did a senior project.
That explains why you know waaay more than people with the same education (or better) who do this every day.
If only the bicycle world knew about you. Hell today's bikes would be pedaling themselves.
(BTW, mine was from Purdue. No, I don't think I know more than engineers who do this every day, regardless of where they went to school)
It's a shame companies like Specialized employ only stupid people as engineers. If they had just asked you, they could have made this perfect HL and nothing new would have ever been needed.
In fact, the whole industry could save tons of cash by firing all their engineers and just "Ask the Experts" here.
The entire budget could be marketing and TGR.
And yes, my knowledge on suspension design is seat-of-the-pants. But when the engineer tells you this works better. And your experience is that it does, in fact, seem to work better?
Maybe he's not such an idiot after all.
And yet it was miles better than anything else available at the time, even in it's infancy.
VPP was the first design to show the promise of being active AND efficient.
Based (again) on experience. I'd say it's lived up to that promise pretty well.
-
04-30-2021, 11:33 AM #4367
-
04-30-2021, 11:35 AM #4368
-
04-30-2021, 11:42 AM #4369
But isn't that the issue with HL?
It's a tradeoff between active and efficient. By choosing the 75% anti-squat, they were choosing active. Bump that number up for pedaling efficiency and you lose active.
That's why lockouts were always the only option to get both with HLs
-
04-30-2021, 11:50 AM #4370
Things I have learned from this thread:
I was wrong, bring back superD!
Maybe the one race I did was kinda crappy.Forum Cross Pollinator, gratuitously strident
-
04-30-2021, 11:55 AM #4371
-
04-30-2021, 11:57 AM #4372
It is a tradeoff, but it's also a tradeoff on DW link or whatever other design you care to mention. Pick any design you want, and you can choose how you want to balance that tradeoff. Formulating your whole opinion of horst link around how Specialized decided to strike that balance for a long time (which I agree, kinda sucked) is silly.
-
04-30-2021, 12:30 PM #4373
But that's exactly what I'm talking about.
From the bikes I've tested, ML bikes seem to do a whole lot better at giving you your cake and eating it. They go down as well as HLs but, in my experience, as a group, they really do pedal noticeably better. They don't give up anything when the trail gets flat.
And I'm not talking about Specialized. My talking about current model Norcos, Transitions, and Konas.
Regardless of what your suspension theories tell you, ML bikes really do seem to do a far better job with that compromise.
You guys seem to be saying that, regardless of design, all suspension with the right curve and rate will act the same.
Sorry, in my experience, that's just not the case.
-
04-30-2021, 12:34 PM #4374
Like HAB said, it's just a tradeoff. That tradeoff is not design specific.
The older Stumpy's had a ~75% anti-squat, which stayed super active over small bumps, but pedaled fairly terribly. The older Pivots (to name a DW example) had much higher anti-squat numbers but weren't nearly as active.
Mostly, Specialized got ahead of themselves with trying to solve kinematic issues with shock valving. They thought they could get away with low anti-squat numbers if they valved their shocks for additional support. In theory that's not a bad idea. In practice, it didn't work very well. But none of that has anything to do with the HL layout. It just had to do with what the Specialized designers were trying to accomplish. Specialized has since abandoned that approach to suspension designs, much the same way Santa Cruz and Yeti abandoned their prior suspension designs (and by that I mean their kinematics are very different now, even though the basic layout of their linkage is similar).
Edit to add: You specifically named Norco, Transition, and Kona. The Optic, Sentinel, and Process 134 / 153 all have lower anti-squat numbers than your Ripmo. So it's not surprising that they pedal a bit worse. The Ripmo has high-ish anti-squat numbers and (by modern standards) a leverage ratio that's closer to straight linear. That all makes for a bike that's pretty snappy on the pedals. But it's going to be a bit less naturally plush over small chatter, and it's going to rely pretty heavily on the progressiveness of the air can, the high speed valving, and the bottom out bumper to handle bigger hits compared to the Norco.
But wrapping back around to what Cy said, you're conflating your personal preferences with the actual design of the bikes. Just because a given bike doesn't suit your preferences doesn't mean that particular pivot layout is incapable of suiting your preferences. It just means the design of that particular bike had different goals in mind.
-
04-30-2021, 12:35 PM #4375
Bookmarks