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Posted: Sep 19, 2020 at 13:49 Quote
Ya its cool, I have never seen 1 air shock and 1 coil shock together before.

Posted: Sep 19, 2020 at 16:13 Quote
Respect. You made something and it’s rideable! Now onto the modifications.

Posted: Sep 21, 2020 at 10:09 Quote
theweaz wrote:
What was the design goal with that bike? Is it just to create something that looks cool or does it do something other bikes don’t do right now?

It kinda reminds me of the old huck machines bender used to ride from karpiel.

I didn’t intend this to be a negative comment, I genuinely want to know the design goal, is it meant for urban freeride? Just because you could? Was it inspired by a Brooklyn machine works bike?

Posted: Sep 21, 2020 at 11:31 Quote
JokerT wrote:
@SleepingAwake: That looks awesome, I am really looking forward to see that built and I hope you will share a lot of that building process! Smile

@chasewarner2: I love this design!

Two notes from my side:
1. I think you should consider dropping the upper (chain-)stay 5mm or so. On my HP-Build i did a quite similar degin and do have quite a lot of chain slap due to the low clearance.

2. at your anti squat calculations, did you thake into account, that the gear ratio of the gearbox does alter the chain force and, by doing that change the AS?

R-M-R wrote:
Pivots:
• There is no such thing as overkill on pivot hardware! Large bearings, large axles, large fasteners.
• Bushings are better than rolling-element bearings at low-rotation pivots. I recommend a polymer bushing at the Horst pivot.

Couldn´t agee more. I like to use Max or "V" Bearings that have the maximum count of balls instead of a cage.
I use polymer bushings from IGUS for my Horstlink too, no problems with (too much) play.

Thank you! I saw your design a couple weeks ago when I first found this thread. Awesome build!

1. That is a good point about the chain clearance to the "seatstay" I will look into adjusting that.

2. I didn't and I don't believe the gear ratio in the gearbox will have an effect on the anti-squat. From my understanding of chain forces related to anti-squat its about the change in distance between the two contact points, chain ring & rear cog. With the gearbox those two points of contact are constant therefore the force acting on the chain through the stroke should remain the same in any gear. I find this to be one of the positives of using a gearbox.

I have since done some updating and now switched to using all Enduro MAX LLU, double row bearings at every pivot point.

Posted: Sep 21, 2020 at 16:00 Quote
theweaz wrote:
theweaz wrote:
What was the design goal with that bike? Is it just to create something that looks cool or does it do something other bikes don’t do right now?

It kinda reminds me of the old huck machines bender used to ride from karpiel.

I didn’t intend this to be a negative comment, I genuinely want to know the design goal, is it meant for urban freeride? Just because you could? Was it inspired by a Brooklyn machine works bike?

I really just made it because I wanted to make a frame and the huck bike look is what I like the most.
Didn't really have much of a design goal other than to make something that I could actually ride. I wanted something with two shocks and figured a single pivot would be the simplest thing to make.

Now on to the next one. Which will be even wilder.

Posted: Sep 21, 2020 at 18:21 Quote
Why not try to make an overkill race bike? Haha

Posted: Sep 21, 2020 at 18:36 Quote
laynehip wrote:
even wilder.

Stick with two shocks, but use 'em to create a two-degrees-of-freedom axle path!

Buffalo Composite Designs 2 4 downhill frame.


Or, even better, a linkage fork.

Posted: Sep 21, 2020 at 23:55 Quote
R-M-R wrote:
Stick with two shocks, but use 'em to create a two-degrees-of-freedom axle path!
Would that be as weird to ride as it sounds? I feel like the back would feel kinda vague.

Posted: Sep 22, 2020 at 4:18 Quote
Arnoodles wrote:
R-M-R wrote:
Stick with two shocks, but use 'em to create a two-degrees-of-freedom axle path!
Would that be as weird to ride as it sounds? I feel like the back would feel kinda vague.

Depends how the shocks are setup I imagine, it's always been something I wanted to build and try. I imagine with the proper setup that the back end would feel ridiculously smooth over everything- drops to flat, square edged bumps, you could eat it all up. I had a design that used a leaf spring to allow the main pivot to move a little bit, and I think someone did one 6-10 years ago that wrapped the main pivot in rubber to allow it to float a little bit. Obviously nothing has ever come to market, so there are issues - keeping the rear stiff would be a bit of a challenge.

Posted: Sep 22, 2020 at 7:10 Quote
Arnoodles wrote:
R-M-R wrote:
Stick with two shocks, but use 'em to create a two-degrees-of-freedom axle path!
Would that be as weird to ride as it sounds? I feel like the back would feel kinda vague.

MTBLegend92 wrote:
Depends how the shocks are setup I imagine, it's always been something I wanted to build and try. I imagine with the proper setup that the back end would feel ridiculously smooth over everything- drops to flat, square edged bumps, you could eat it all up. I had a design that used a leaf spring to allow the main pivot to move a little bit, and I think someone did one 6-10 years ago that wrapped the main pivot in rubber to allow it to float a little bit. Obviously nothing has ever come to market, so there are issues - keeping the rear stiff would be a bit of a challenge.

MTBLegend92 is spot on.

Compliance could be better because the axle path is more likely to be aligned with the bump force. Managing anti-squat and chassis stiffness would be challenges, in addition to getting the ideal balance of travel and force between the two suspension systems.

Difficult to say how much each suspension linkage should be allowed to move and how freely. Reduced predictability, within reasonable limits, is a serious problem for top-level riders, less so for good riders, and of little problem for average to below-average riders. This would be a tuning issue: the secondary linkage would be more active for average riders and its activity could be restricted for more demanding riders. Much like linkage forks, little R&D has been done on such systems, so a lot of experimentation would be required to configure them as effectively as simpler, traditional systems.

Posted: Sep 23, 2020 at 6:37 Quote
This could be of use to some people here if you want to try and get fancy with linkages; https://hackaday.com/2020/09/22/linkage-inferring-software-handwaves-away-the-hard-stuff/

Posted: Sep 23, 2020 at 12:56 Quote
Interesting! Looks like it's not available for download yet, though, or did I miss a link somewhere?

Posted: Sep 23, 2020 at 13:54 Quote
R-M-R wrote:
Interesting! Looks like it's not available for download yet, though, or did I miss a link somewhere?

Here's the link to the actual software. https://blog.rectorsquid.com/linkage-mechanism-designer-and-simulator/

Usefulness is meh, was pretty helpful for visualizing linkages in my Mechanisms class in undergrad though.

EDIT: Nvm, didn't realise this appears to be something new, whoops.

Posted: Sep 23, 2020 at 14:00 Quote
Fueniker wrote:
R-M-R wrote:
Interesting! Looks like it's not available for download yet, though, or did I miss a link somewhere?

Here's the link to the actual software. https://blog.rectorsquid.com/linkage-mechanism-designer-and-simulator/

Usefulness is meh, was pretty helpful for visualizing linkages in my Mechanisms class in undergrad though.

EDIT: Nvm, didn't realise this appears to be something new, whoops.

Yes, that's as far as I got. The existing software is interesting, but not what I need. The new software could be tremendously useful, especially for expediting front suspension designs.

Posted: Sep 23, 2020 at 14:10 Quote
Does seem to be at the "we've done the research aren't we clever" stage, I'd hazard a guess that they'll have some functional but not consumer ready software in the bag. They'll presumably be looking for funding to approach a software house to ready it for distribution from my experience of these things.


 
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