See those Bird hardtails…

Yep like that – £850 for frame and shock 😀

So how does anti-squat work on a horst link ?

I thought it was mostly done with short link systems and chain tension…

Anti squat is a function/feature of any rear suspension system. Horst, Singlepivot, dual link, whatever.

It’s the propensity of the suspension to extend under power.

Inputs are chain tension and wheel thrust forces, movement of COG, angle of slope, and other things.

Bird frame interesting as seems to have a main pivot position that is in line with chainring, normal for a singlepivot bike, but with a Horst link too.

I will be interested to have a doodle in linkage to see what the graphs look like.

@thisisnotaspoon – the geo on Dirt is actually slightly wrong (my bad but its not that wrong so I wont get them to correct it), the Bird Aeris sizing is:

380 425 445 465 490 mm

or 15.0 16.7 17.5 18.3 19.3 in old money.

And thats with a full spread of ETTs.

So I am with you 100%.

I don’t think many people need bigger than a 19 1/2in frame.
Reverb 150s are 430mm long and have an 80mm min insert!

I don’t think many people need bigger than a 19 1/2in frame.

Ben you doing different colours then?

I don’t think many people need bigger than a 19 1/2in frame.

Oi! I do, with a nice long toptube too 😉

For the love of god do something about your lawn benpinnick.

Good looking bike though.

Oi! I do, with a nice long toptube too

*Interested*

What’s your saddle rail to BB centre dimension?

BenPinnick

@thisisnotaspoon – the geo on Dirt is actually slightly wrong (my bad but its not that wrong so I wont get them to correct it), the Bird Aeris sizing is:

380 425 445 465 490 mm

or 15.0 16.7 17.5 18.3 19.3 in old money.

And thats with a full spread of ETTs.

So I am with you 100%.

Are you the chap I met at the London Bike Show?

yep thats me.

yep thats me

<thumbsupicon>

benpinnick – Member

@thisisnotaspoon – the geo on Dirt is actually slightly wrong (my bad but its not that wrong so I wont get them to correct it)

Not going to tell you how to do your job, but, I’d get it fixed if I was you- there’s tons of us nerds out there that like numbers. It doesn’t make any real difference but we don’t care.

Is the BB drop right?
Jones said this had a really cool BB height, but yours is lower.

Yeah its right brant – its low… not sure whats lower out there but I do know we’ll not be making it any lower any time soon. we run 170 cranks (or 165s) rather than 175 and bashes across the range to keep the pesky rocks in check though.

Good work guys! I’m thinking 170mm cranks make more sense than 175mm for average height riders with the propensity for low BBs on modern geometry. I noticed the geo chart looking strange because the BB height was lower with the 150mm travel but the angles steeper, which is obviously the wrong way around.

Anyone curious about how suspension works, go on linkagedesign.blogspot, use google translate if you dont’ speak Spanish, and try to get your head around the graphs. It’s incredible how different the performance of two 4-bar systems can be, simply through small changes in pivot location. It’s also pretty amazing how a single pivot like an Orange 5 can be made to pedal really well – but you’re restricted with leverage rate and there’s also the issue of lateral rigidity without other linkages.

I’m thinking 170mm cranks make more sense than 175mm for average height riders

Agreed, I ride 170s and am distinctly average, I think Sheldon’s formula put me on about 167mm.

I get no pedal strikes on my Nimble 9 (On my old Blur, with 175s, it was a curse).

This looks smart…. What other colours will it be available in?

I noticed the geo chart looking strange because the BB height was lower with the 150mm travel but the angles steeper, which is obviously the wrong way around.

No, its the right way round – on the Aeris anyhow. The sagged geo (contrary to popular opinion sagging an FS does effect its geo) is what you would expect, but the linkage positions don’t work like most bikes, you are changing the geo so it starts steeper/higher, but ends lower by a touch – more importantly its giving a different shock curve in 140 that 150. 150 is more resistant to bottoming while 140 has a longer ‘sweet spot’ where the shock is very supple in the mid stroke.

This looks smart…. What other colours will it be available in?

Tangerine Orange, Stormtrooper white, Bigfoot blue, Very Lime green and black as the night.

Saw one today at the ukge. Very nice looking too

No, its the right way round – on the Aeris anyhow. The sagged geo (contrary to popular opinion sagging an FS does effect its geo)

Yes, it’s often misunderstood! It looks like the bike sits deeper in its travel at 150mm (30% sag) than at 140mm (21%). Is that due to the leverage curve or does it require changing the shock pressure? Your charts are with 531mm A-C which I guess is with one of the 140mm forks, so they’ll be a bit slacker and taller with the 150mm forks. Geometric navel gazing… 😉 Is it warrantied to 160mm forks?

I spent a while sussing tweaking in my full sus with different pressures and settings front and rear plus three rear axle heights to choose from (Banshee) which affect BB height and angles. I like being able to have a local setting and gnarly uplift setting: A bit steeper and taller suits more twisty and pedally trails whilst lower and slacker suits point it down the hill and hold on trails.

TurnerGuy – Member

Sure I’ve seen him round Swinley.

I will be interested to have a doodle in linkage to see what the graphs look like.

graphs look good.

thumbsup.

Thanks Brant 🙂 I will send you the real deal when I get back home (currently sat in a field… that has wifi 😮 )

The instant centre migration looks to be very clever 🙂

The FS looks really really nice, might look into em if/when I come into enough money.

Right. I just need to be convinced they can be set up to be poppy.

I haven’t liked the Specialized FSRs I’ve tried because they soaked up too much energy for getting air of small trail features. Conversely, the Cotic Rocket was very lively in the same situations.

I’m hopeful that the high pivot point and progressive rate might help.
Obviously a test ride would be ideal.

This is not good. I was happy moving back to hard tails. Then I wished I’d bought a bird hard tail. Now I’m loving the look of the FS. Bums.

I might end up with a flock in a year or two.

I’m hopeful that the high pivot point and progressive rate might help.

you would hope that, being a Bird, it would take flight easily…

Thought I’d just chuck a few photos from around the web here, so that they’re all in one place:

Me likey looky.

Looks like the Aeris rides good too, What Mountain Bike liked it: https://twitter.com/Bird650b/status/514330275820871680/photo/1

Doing a frame only option for less than 900, bit of a challenger for the 650b codeine me thinks.

Those fs are a bit much for the plethora of swinley locals that are lapping them up.

Geo/suspension definitely sounds good for an enduro race machine mind.

Was liking the look if these Bird hardtails the other week, then this full suss pops up, looks good, like what these guys are doing. We need more British manufacturers like this. 😀

Do we know where the Bird frames are made yet?

Might be a toss up between Birds or on one, of which I am suspicious of because the frames are cheeply priced.

Bird are Taiwan at the moment.

Cheers AlexSimon 🙂

AlexSimon – Member
Bird are Taiwan at the moment

Like most bikes, including Santa Cruz. Same factory even I think.

or on one, of which I am suspicious of because the frames are cheeply priced.

Nothing wrong with their frames. The price just reflects lower margins or lower business costs. The 456 models of various forms are some of the toughest frames about. Though nothing is indestructible.