New Bike day and first ride: Bird Aether 9c

Bird Aether 9c size XL gloss black. Most parts moved over from my Cotic SolarisMax.
Gloss black finish is intriguing… you can see the patterns and swirls of the fibre beneath the gloss, but lots of different layers and pieces all catch the light a bit different, so it’s quite a random finish. The aesthetics for me are ok, but might be a bit head-doing for some. Matches nicely to the gloss black of the forks and brakes. The gloss Invisiframe kit is probably unnecessary as I think this finish will prove quite hardwearing, and should respond well to a polish once a year.

The build wasn’t all plain sailing:
The Chris King headset doesn’t fit so well, as the top cup is quite deeply cut in the frame. I needed to use some spacers from the toolbox.
The cable routing is within tubes glued inside the frame, with a Y to allow the rear brake to be fitted to the left or right side of the bars. Generally it’s pretty good, but the rear mech cable and rear brake cable go under the BB, where a fair bit of slack is required to loop around at suspension bottom out. The cables aren’t so snug in the tubes, so I have added a couple of cables ties to stop that excess being pulled up to the bars. The rear brake hose also needs some slack to allow for the chainstay and seatstay to open up through suspension compression. Here there is a small bolted clamp to keep the hose in place.
The front face of the ISCG mount is only just proud of the swingarm. I added a couple of washers to add a little clearance.
The 37mm seatclamp is not so common. I don’t like the bulky hope design, but found one from Nukeproof in the right colour.

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If I decided to go 29er instead of 650b for my full suss this would be very high on the list – in this colour too. Looks great!

Currently on an Aether 7 so a similar aim to be a decent all rounder with relatively short chainstays to keep it playful.

How does it ride – and any idea what it weighs?

Those are build notes! You’ve made no reference to the first ride or how it behaves at all.

Nevertheless your build notes are useful, since I have one of these hanging in the garage being slowly built.

How tall are you if that’s an XL?

Spent more time building it than riding it… I guess ride impressions to follow because all I know so far is saddle was a bit high, fork needed a token, and shock a little less rebound. It’s my first full-sus in a while, so it will take some adjustment and time to get used to. It wasn’t a huge difference from my Cotic. The shorter stays weren’t immediately off-putting. The lower BB was noticable (especially when getting wet feet riding through puddles). I have the bars 20mm higher, and will experiment with that a bit.
Weight is 31lbs according to the bathroom scales.

Lovely. Are you selling the solaris max?  Dibs!

Thats a good weight if accurate.

Mine is a ML and I think my build will come out heavier – I’m expecting 32-33lbs.

I was expecting these to generally be a bit lighter than my Aether 7…..which weighs 32lbs in its current build. That’s Lyriks / Code R’s / bashguide / XT 12 speed – although wearing carbon X1 GXP cranks / Hope hubs with XM481 rims / carbon handlebars / 180mm OneUp dropper. Size medium.

I think I’d read the C frame was 300g lighter than the A frame and mine has a reasonably heavy build. If I swapped to Pikes and lighter wheels I can easily dip below 31lbs. Just the like and a lighter front wheel (off my other bike) hit 31lbs pretty much bang on.

I’m tempted to get a Pike Ultimate and a set of light hubs and carbon rims when I have a bit of cash to spend to get close to 30lbs.

Spent more time building it than riding it

First ride looks a bit more comprehensive than a spin down the local singletrack… Nice!!

My Solaris was about 29lbs, but with lighter tyres, and all other parts were moved across, so 30-31lbs sounds about right for mine. I acknowledge that bathroom scales will not give a very accurate measurement. I didn’t have any good scales for weighing the bare frame.

I’m 6’3″ and have the saddle at 82-84cm from BB centre to top.

I was expecting these to generally be a bit lighter than my Aether 7

Its not an especially light carbon frame and its a 29er. (Nor is it especially heavy either). By the time you’re wearing proper rubber it all mounts up. I reckon on adding 1.5 to 2lbs to a comparably specced 29er over 27.5.

If I swapped to Pikes and lighter wheels I can easily dip below 31lbs.

I’m sure, but I weight 92kg. My 36 is both stiffer and better performing than my old Pike, even though its roughly 200g heavier, its more appropriate to my mass and case-use. I’ve chased weight in the past and all it got me was expensive repair bills and frequent replacement parts.

My Solaris was about 29lbs

My Kingdom Ti vendetta is 32lbs😬

Fair – I’m 82kgs with aspirations to be a bit lighter than I am and furiously turbo training to try and help achieve that right now!

If the 9C frame is circa 300g lighter than A version then there’s 0.66 of a lb saving. That’s about the same as going Lyrik to Pike.

Guess it depends what tyres you’re running too – so far I’ve got away with exo casing Maxxis / equivalent in other tyre brands. DD casings quickly up the overall weight.

The 2.6 Mary on the front is snakeskin and has proven quite durable. On the rear I have a 2.5 DD DHF which I am trying without an insert. I am finding exo isn’t strong enough, even with an insert, and Exo+ not noticeably better. I think I need to be more careful with making sure pressures are correct (high enough).

I completed mine yesterday, so here are a couple of pics.

Its an ML and I’m 182cm. I’ve deliberated chosen this instead of the L because amongst it’s other duties it will spend a fair amount of time on tight natural singletrack. In contrast to the OPs weight, ‘Scienceofficer’s luggage scales of truth’ put the weight of mine at 33.5lbs.

It looks like the seat tube angle is still a little on the slack side specifically on the XL size, I have an Aeris 145 and the sta is one of my only complaints.

It looks slacker on the XL doesn’t it.

According to the tech docs the effective SA should be steeper than the ML. Actual SA is quite slack at 72 on the ML, and effective SA jumps forwards by 5 degrees. It felt ‘about the same’ as my hardtail , which has 76.5 actual.

@Scienceofficer

Had a chance to test your 9c out yet? Any initial thoughts?

Also, anyone know why none of the mtb magazines/websites have reviewed this yet? Perhaps I missed them.

My circumstances are that I have 1 fox 36 to share between two bikes presently.

I took the Aether on a single 8.5km shakedown ride before I put the forks back on my hardtail until Easter. Because mud.

My very initial impressions are as follows.

It’s stiffer than my V2 prime was. This contributes to it feeling lighter and easier to turn, even though its only a lb lighter. The Prime v2 has the same rear travel but a 150mm fork vs 140 on the Aether 9C. So there is some consideration for that.

One the flat, pedalling is no better than the Prime, but uphill, it has more pep and pedals better, yet maintains traction. Its feels more like a trail bike than an enduro crusher. Descending seemed fine. Possibly the frame rate is a slightly too progressive for my personal tastes, but I bought a float X2 to compensate for that If I need to, although I’ve not done anything more with the shock except set approximate sag and fox recommendations.

So, yeah, positive first impressions, mostly centred around personal preference stuff. I can tell you that my seat was too low, brake levers and dropper/shifter needed tweaking, as did saddle angle, plus my bars were a little off. Still work to do with the rear suspension though. The Fox recommendations felt too damped in both compression and rebound, and I need to take a spacer out of the air spring to reduce the overall progressivity.

At Easter I’ll get the forks back on and run some further tweaks before commenting further.

@Scienceofficer : nice setup, like it a lot.

If you liked the build notes, you’ll love the de-bugging report!

I’ve done a few rides now, including chunky trails in Wales and Ticino. I’ve done just over a hundred miles in total, and 9,300m of descending, assisted by a couple uplifts.

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Front tyre: 2.6 Magic Mary SS is now a couple of years old, and starting to show it’s age. It’s done sterling service and will be replaced with a 2.6 DHF Exo. I’m don’t have high hopes for this tyre… but it’s what I have so I shall use it.
Rear tyre: 2.5 DHF DD was killed in action. Running 25psi and no insert I still managed to snakebite the bead. I will not miss this tyre. I have fitted a 2.35 Hans Dampf SG which rolls faster, has better grip for climbing, and I haven’t noticed a rim strike yet at 25psi.
Forks: RS Pike Ultimate 150mm have been ace. I started with 80psi, same as I used with the forks on my hardtail (140mm Pike RCT3). I think with rear suspension I don’t ride the front as hard, so I have settled with 70psi and one token, and performance has been excellent. RS recommend 90psi for my weight.
CK Headset: No issues despite tricky install
Brakes: Formula Cura 4 have been good. Plenty of power, solid lever feels good. A completely different feel to my previous Sram brakes, and still learning the precision required to modulate them.
Gears: Chain started to skip in one gear, and shifting wasn’t very good. A new mech and cassette were on the cards. And then I smashed a jockey wheel, so it was a done deal. I now have a 52t cassette (!).

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Rear shock: The Fox DPX2 needs 200psi for me to achieve 30% sag, which felt like quite a high pressure, although obviously a long way from maximum. With this setup the suspension is active yet progressive. I haven’t even been able to get in to the last 15% of travel. I have used the climb switch because it’s there, and it does change the feel of seated climbing.
For comparison I have also tried a RS Deluxe Select+, which needed 170psi for 26% sag. In open mode this setup felt more taught and responsive to power input then the Fox. It matches the bike nicely, climbing well and offering good control on the lumpy downhills too. I have also been able to get deeper in to the travel. I will refit the Fox and try more pressure/less sag to match this feel. I will open the shock just to check that there is no volume spacer in there.
I think the bike is designed to run more like 25% sag, so I should aim for that in the setup.

Frame: Frustrating rattle on chunky trails traced to internal cable routing tubes inside the frame. The tubes are glued in place inside the frame; the one for the dropper cable secured in the bottom of the downtube, but it then does a bend up in to the seat tube. For this portion it is unsecured. This length was rattling. With some fishing I was able to tie down the tube to the BB shell, which has helped a great deal.

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Ride:
My Solaris is a great technical climber, the kind of bike that makes you try crazy steep technical stuff just to see if you can clean it. Now with a good rear tyre the Bird is showing itself to be even more capable. Some people might assume that it would be hampered by the short chainstays when it gets very steep, but this is just a non-issue. Although my feet are closer to the rear axle, my COG is further forward. And the low BB grants excellent stability.
Actually the low BB is the most noticeable aspect of this bike in comparison to my Solaris. I suffer pedal and crank strikes all over the shop and I will have to adjust my riding technique accordingly. The BB is a similar height to that of recent Specialized bikes, so nothing insane, but certainly on the lower side of the spectrum, and in sagged position a good 30mm or so lower than my hardtail. The Aether 9c is billed as an ultimate trail centre bike, and the chunky trails I have been riding are the polar opposite to groomed ribbons of singletrack. With level pedals this bike can blast through a rock garden with confidence… but it will take some practice in remembering the low BB when I need to pedal. The bike feels nicely balanced and I am enjoying getting to know the bike and getting up to speed with suspension. The low BB makes a positive impact on slow speed stability.
Head angle feels a touch steeper than my hardtail, despite what the numbers may say. There is less steering flop too.

Just popped open the DPX2 shock and found a huge blue volume spacer which will be adding considerably to the progressive feel. I will whip this out and start again on the set-up at 25% sag. All a good excuse for another ride soon.

This is all music to my ears since my 9c will see a darn sight more ungroomed chunder than trail centres.

Especially pleased to hear about your have-a-go-Henry remarks re: technical climbs, because I resemble that remark and adopt the same attitude on my hardtail.

Currently resisting the urge to steal my forks from the HT. Easter is only just around the corner now.

Whilst Ive been waiting, I did look in the X2′ air spring and found 3 out of four spacers in there. Given the frame rate is progressive to 130% I’ve removed 2 and will report back after the next shakedown.

Interesting notes about the progressive rear end, I’m building up a 9a and have a cane creek double barrel air to pop on – think I will be taking out the volume spacer of I encounter any issues…

Its something I factored into shock choice. With an X2, DB air or similar, you have a wider range of air spring tuning than a little trail shock because they’ve got more volume, so if I don’t like the progressivity, I can pull a bit of it out of the system with no ill effects.

In theory.

Proof of the pudding will be over Easter I guess!

DPX2 back in place without spacers and 235psi for 25% sag. Keen to try it now and see what difference it makes. I enjoyed the bottomless feel of the initial set up, but I’d like to use more of the travel.

I’m amazed at the difference in pressure required between the RS and the Fox.

You must be about the same weight as me for those pressures. I do recall Bird Cycles Ben saying the DPX was quite a high pressure shock on one of the other Bird threads. On shakedown I was about 200psi at 35% but the ramp up was stealing about 20% at the other end – that said, it wasn’t a very big or gnarly shakedown so I was unlikely to go deep into the travel anyway.

I demoed the 9c and had a quiet a few peddle strikes. I’ve now bought a 9A but with the fork at 150 rather than 140. Don’t seem to have many pedal strikes. Maybe it’s because of the slightly raised BB or because I’ve got used to it, who knows probably a bit of both.

I went 150 fork on my Aether 7 and it feels really good. I don’t think I’d want the BB any lower, my confidence on steeper lines and jumps and drops has gone up another notch.

Low BB is a consideration for sure. Sagged BB drop is 81mm – my HT is 60mm drop.

I run my fork at 140mm on the HT and was planning to switch it straight across, but if pedal strikes are a problem I have a 150mm airspring waiting in the wings.

My actual measured BB height, with 150mm fork, 2.6 front tyre, 2.35 rear; is 330mm static, and something like 300mm sagged.

The low BB height is a feature of the bike. It was one of the points of the geometry I was keen to experience. Because it is quite noticeably different from my previous bike it is something I have commented upon. Of course there are compromises with the design decision to have a low BB, but for now I am just becoming aware of how to adjust my riding a little. It’s a feature that might be easier to manage with shorter cranks, or on smoother trails.

I’ve also been thinking about the air shock pressure. Of coarse a shock with a larger air volume will require a higher pressure to achieve the same sag, which must account for the difference between the two shocks I have tried. And the benefit of the larger air volume is greater ability to tune the spring rate.

My actual measured BB height, with 150mm fork, 2.6 front tyre, 2.35 rear; is 330mm static, and something like 300mm sagged.

Thats low, but its not really mega low. I’m sure it will be fine.

I have gone with a 140mm fork initially, but can alway adjust to 150mm (formula Selva R). Have some 170mm cranks, but being 6’4″ don’t think I would want to go shorter

Just have to wait for brakes and wheels to build it up!

When do you expect to complete it Sam?

Hopefully get a ride in May, really depends how long the hope e4’s take to arrive!

Coming from my Banshee Spitfire to my new 9C I have noticed a few extra pedal strikes which isn’t surprising. You soon get used to it and after a while its not even an issue. The bike is great and capable of just about any trail, I think the marketing about smashing trail centres is misleading and potentially damages the bikes image. 110 miles in and to me it seems like the perfect hard-hitting FS 29er trail bike, the limitations to its capabilities are with my abilities and gonad size.

However there’s some significant creaking coming from somewhere around the pivot areas which I’m not happy about and haven’t had time to try and diagnose yet. Think I’ll contact Bird direct to see if they’ve got any ideas or heard of it elsewhere

Hmmm.

I’ve had the pivots apart before I built it to pack the bearings and understand how the fixings work. The collet recesses were bare, dry carbon. I’d look there first.

Those of you who aren’t sure about the progression rate have you seen that bird sell an alternative linkage that modifies that.

Are you certain that applies to the new Aether 9?

There is a “triple R” linkage available for the Aether 7, which is also compatible with the Aeris AM9 & 120. On the Aether 7 it changes the progression from 35% to 30%, so a very slight change. The Aether 9 has, I think, 30% already.
Biggest eye opener for me is that the triple R link is available in purple 🤣

My shakedown ride yesterday with no volume spacer saw me reach full travel. I’ll do another couple of rides before maybe thinking about trying with a small spacer.

Ah yeah, sorry read am9 as a9.

Would love it if there was the option to have the standard linkage in colour like Nicolai do. Orange linkage and orange cable guides on the gloss raw would look great.