Hulsroy's Hustle

I accidently tried a full suspension this weekend. I gotta make one now.

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Have you seen Project 12 Cycleworks' stuff?

Nope. I am fairly new at this. Really only did research last night 😃

Only reason for single pivot design currently is ease of manufacturing. Got to design something I can actually make... Cheaply

Looks quite like my Starling Murmur

Yes. Been looking at the Murmur, swarf single pivot prototype and 44 bikes snakedriver prototypes.

I'll make it more original as I get my head around what's required

exciting !

This is going to be good. How much travel are you wanting from the frame?

I hope so. I bet I am overlooking stuff already tho.

The one I tried is chinese carbon frame with 110mm rear travel and 120mm up front. That felt like plenty squish. I have 100mm Reba forks already and I am tempted to just build the frame around them with 66.6 degree head angle. Then when/if I feel like I need more travel up front that will slacken the head angle. But I just need to draw that up to confirm it will work.
I am very much considering it a prototype. No way I will get it right in the first go

It is. I wish I had the time and money to just play around with sort of shit all day

This could be a challenge! But I have faith in the Hulsroy

I had this as my only mtb before it was stolen - https://www.cotic.co.uk/product/flare1#sizing

It worked for everything from all xc rides through to the Megavalanche - with the 140mm fork it made the head angle 66.5 degrees. Short travel bikes can be very capable with the right geometry.

What wheelsize are you going for?

Ohhh yeah. That is pretty much what I have in mind.

29x2.4" has been good to me so sticking with that

Lets see :-)

I swear I've seen someone build a single pivot mtb using a hollowtech BB as the main pivot bearing. Can't find it for the life of me now but that would be pretty rad here.

That could make sense, but as I have a lathe I am not tooo worried about making a custom press fit bearing solution.
I think the manufacturing side of things is manageable. My main worry is getting the geometry right. There is sooooo much talk and opinions when it comes to test suspension that it is impossible to navigate with 3km of riding experience.

Those are really nice bikes, I wonder if the pivot design could be moded to at foldable bike solution?

Yeah if you mean that the rear end could be detached? I think thats very doable

Good stuff! I have a thing for couplers, rinko etc. The idea of foldable bikes make me dream of Turin-Nice etc...

I am fumbling in the dark. Does anyone know anything about appropiate ratios for single pivot suspensions??

This is where I am at. I get approx. 110mm travel on a 210x50mm shock. Thats a 2.2 ratio (is this waste of 50mm shock??) but I could easily get it higher, I am just not sure I want more. I dont care about weight really, but maybe I should get a smaller shock?? More XC style?
Will I die riding this? I have no idea how it will feel and whether my curves are efficient etc. I am basing this solely on having ridden 110mm travel rear suspension and finding it good.
Does it even make sense with a 1o0mm travel fork to have 110mm rear?

I am having fun learning all this stuff but any advice is very welcome...

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In terms of rear triangle construction I am looking at what I am able to make in my workshop. This is sort of where I am at. Very inspired by 44 Snakedriver but without all the bendy tubes extravangaza (I don't think I need it to get the clearance I want.

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This may just be me, but a 66 ha with a 100 mm travel fork and 110 mm on the rear seems a bit odd? The head angle of a trail bike with the travel of an XC bike? Is that just because that is the fork you have?

Yeah. Which is stupid really. I should get longer forks. Or do shorter travel on the rear. Maybe ille sell the forks I have and get som 120-140mm instead. So discard that for now and let's talk the rear geometry. Is this going to be riding shit?

Have you looked into anti-squat, anti-rise, pedal kickback, etc. to get an idea of how it'll ride? Pretty complicated stuff.

https://enduro-mtb.com/en/mtb-suspension-kinematics/

https://www.singletracks.com/mtb-repair/a-vultures-eye-view-of-mtb-suspension-kinematics/

Starling Murmur vibes, 65.4 deg ht but 140mm travel both ends

I have read about it yes. Bikeradar has a pretty comprehensive article about it which I enjoyed. But it doesn't make any sense to me what do ever as I've never physically experienced any of it.
Maybe I am in over my head here.

What I really should do is just replicate a tried and tested single pivot geometry completely and see how that feels. Basically making a Murmur for myself. Then down the line as my brain grows I can start challenging the concept.

Thanks for the links