Considering a homemade build

[BLACKvoodoo]

I have been using the Linkage X3 Demo software for the suspension. It works really well, allowing you to start with an existing design (Like Giant's NRS for example) and then modify to your heart's content.  It even calculates leverage ratios and chain growth numbers.

 

I have already finalised my new large link suspension.

 

FS6-R4 Susp LHS.jpg

Can you animate this ? 

[popcorn_skollie]

I must be a new kind of stupid. I still can't figure it out.

I mean. In theory I understand the concept. 

But I need to see those diagrams animate to understand the differences in arc and leverage.

Just can't seem to play them out in my mind. 

[nolipoli]

Can you animate this ? 

Hmmm, I'll have to play a little to figure out how to do it. My CAD package doesn't have animation built in.

 

Maybe I can take snapshots at close intervals along its travel.

[Burner]

burner - off topic, but on the topic of jigging and cars - 442 IRS design - have you any experience in it, and if so could you PM me? Shot.

 

As for the build - really lekker to see hoiw it's progressing in the design phases. 

 

Any particular reason you went for a design where the compression is driven from both ends, as opposed to a full floater type design (trek etc) where the shock is driven from one end and the other end (chainstay extension) goes with it at a lower rate of movement?

I designed and built some sports car kits called xO500 and xO400, and two single seater formula cars. I havent decided on going for a specific suspension design yet, I'm still open to ideas while I'm in research/concept phase. I like the trek's feel as I had 2 fuels and have a session 88

 

I'm battling to wrap my head around this too.

 

Disclaimer: Everything I'm about to say comes from a point of pure ignorance.

Still battling to understand the different systems and the pros and cons of each.

 

Anyways if I understand you correctly you are talking about the rocker looking like its actually part of the seat stay and not pivoting off it?

ie: http://i.imgur.com/M7rY2Gr.jpg

Someone needs to ELI5 this for me.

Explain it like I'm 5

There should be a pivot there, my model is incomplete and still open to change since starting the thread I've been reading so much more info.

 

What I was hoping to achieve by having the shock compress at both ends is as follows:

 

1. Relatively long shock stroke compared to suspension travel (57mm vs. 100mm). This gives the shock better control over the suspension action.

 

2. The geometry of my linkages was designed to ramp up the leverage significantly which will offer a plush start and very firm finish to the suspension travel. This will resist bottoming out on bigger hits.

 

3. By having both bottom and top of the shock mounted to linkages instead of the frame, it avoids the requirement for more mounting plates on the front triangle, simplifying the looks as well as the manufacturing process.

Makes sense although the way Pyga and Trek makes use of the travel makes it feel endless. My Fuel 9.9 felt like it had 130-140mm and more controlled then my Teocali that was a 145mm rear travel frame.  Popcorn_skollie, the new commencals has this concept

 

For me the biggest issue is time. My old man has a workshop with a manual lathe and milling machine, that I used to be quite comfortable on, and he also has a MIG and a TIG welder. My TIG welding was basic at my peak, and I am seriously concerned about whether I can actually do a decent job on this project.

 

I suspect what I will have to do it make up the parts and then hire someone to weld them together for me. I am sure I can find a few peeps that would be interested.

sounds like you are well geared

 

 

 

This does not work for me because I am running a very short chainstay for a 650b (420mm) in conjunction with a straight, uninterrupted seat tube (for when you want to jump the bike). I needed better control over where the wheel ended up. 

Have you ridden something similar to this? I'd like to feel how this will handle

[Burner]

I'm battling to wrap my head around this too.

 

Disclaimer: Everything I'm about to say comes from a point of pure ignorance.

Still battling to understand the different systems and the pros and cons of each.

 

Anyways if I understand you correctly you are talking about the rocker looking like its actually part of the seat stay and not pivoting off it?

ie: http://i.imgur.com/M7rY2Gr.jpg

Someone needs to ELI5 this for me.

Explain it like I'm 5

The evo link also stiffens up the rear. But as nolipoli said earlier, the single pivot path compromises the seat tube if you want a shortened rear end

[BLACKvoodoo]

The evo link also stiffens up the rear. But as nolipoli said earlier, the single pivot path compromises the seat tube if you want a shortened rear end

So the top pivots around forward and down , but then the the bottom also pivots down away from the force? 

Not sure if this will work, whats going to stop the whole system from 'bottoming out' 

 

This is what I think it should look like but please correct me if I'm wrong

[Captain Fastbastard Mayhem]

So the top pivots around forward and down , but then the the bottom also pivots down away from the force? 

Not sure if this will work, whats going to stop the whole system from 'bottoming out' 

sus.jpg

this is exactly how Trek & PYGA & a few others have their suspension designs

 

Top rocker moves faster than the bottom one, and there are limitations in the design of the system itself to limit movement - the system requires the shock to be able to move - if there were no more shock travel left in the system, it wouldn't move any more. That's your bottom-out prevention - the shock's max travel. 

 

http://d3udhci353hstj.cloudfront.net/2012/07/PygaCU.jpg

[Burner]

I see BH is also incorporating a split pivot and floating shock, and I've just read good reviews about it. So there must be some synchronous wizardry happening between the rear split pivot and floating shock that works really well together. My personal experience is that it tracks well. I'd still like to try the commencal/mondraker type floating setup and see how that feels and compare the two.

 

Does anyone here have experience riding both the trek/pyga floating suspension vs the commencal/mondraker type?

[Burner]

I haven't been able to give this post attention recently with my increasing work load but there has been some progress... even if it's baby steps.

 

I've decided to commit to a carbon frame for this build. The reason being that its going to be hard to make what I want and keep the weight down in Steel. So I've acquired another cnc,slightly bigger than my current machine and perfectly sized for the seat stays etc.

 

I've also refined my custom 31t narrow wide chain ring design to work with my 11-36 cassette and I can't wait to cut it and test it out. I started on a stem as well, used billet aluminium but it still feels a bit heavy. Will try to get the weight down a bit more and post some progress pics soon.

[Tubehunter]

Looking forward to ppics of this process!

[Burner]

I've been neglecting this post for a while now because of work mostly. The design process is still progressing and I'll be uploading some of the work soon. On a side note, I've been trying to finish up this drift trike project to make more time for the mtb project.

[popcorn_skollie]

You such a tease. When you gonna let me drive that thing.

[Blackheart]

Been following this for a while now.

I've had experience with designing in composites and am looking forward to seeing your progress.

As an ex racing driver, I've also done my share of destroying composites too...

 

I think this suspension design is well worth looking at.

I used to ride one of these, and it just about worked the best of any system i've ridden over the years. The quick release at the top shock mount allows the shock to be repositioned in the top rocker arm which slackens (or steepens) both head and seat angle, and increases available suspension travel. It didn't seem to affect the rate of the damping or compression either.

 

Having no chain stay makes it super quiet too.

 

Good luck and keep us posted.

 

 

 

 

[Burner]

Been following this for a while now.

I've had experience with designing in composites and am looking forward to seeing your progress.

As an ex racing driver, I've also done my share of destroying composites too...

 

I think this suspension design is well worth looking at.

I used to ride one of these, and it just about worked the best of any system i've ridden over the years. The quick release at the top shock mount allows the shock to be repositioned in the top rocker arm which slackens (or steepens) both head and seat angle, and increases available suspension travel. It didn't seem to affect the rate of the damping or compression either.

 

Having no chain stay makes it super quiet too.

 

Good luck and keep us posted.

I've got one of these completely dismantled at home. There are so many good reviews on this system that it's worth looking into. I'll check it out, thanks.

 

Popcorn skollie, you'll get a ride soon enough. We just making a die for the custom pvc pipe size to fit our wheels

[Burner]

The design has changed a bit due to a few minor reasons. This is the design I've decided to go with. It's based on the DW link with at the rear. Shock length is 200mm eye to eye and short chainstays to make it very active. Seat tube is 31.8mm at 78 degrees, a long reach top tube and a 1.5inch headtube at 64.5 degree. Rear travel is 150mm and the fork must be 160mm.

 

The frame will be contructed out of bi-directional carbon and aluminium inserts for pivots and BB. No place for any front derraileur. I'll pop it into CAD soon to see to results

[popcorn_skollie]

The design has changed a bit due to a few minor reasons. This is the design I've decided to go with. It's based on the DW link with at the rear. Shock length is 200mm eye to eye and short chainstays to make it very active. Seat tube is 31.8mm at 78 degrees, a long reach top tube and a 1.5inch headtube at 64.5 degree. Rear travel is 150mm and the fork must be 160mm.

 

The frame will be contructed out of bi-directional carbon and aluminium inserts for pivots and BB. No place for any front derraileur. I'll pop it into CAD soon to see to results

Awesome. with animation?