New Bike day and first ride: Bird Aether 9c

What a pain in the arse!

My Burgtec chainring did the same thing with Eagle. Drove me nuts. XX1 drivetrain sounding like my beat to sh1t box groupset.

That’s weird on the Eagle drivetrain – I think their x sync 2 rings are ace.

My XT 12 speed has always been noisier and harder to shift. It was parotcuslrlt bad with the Shimano chain on there – better with xx1.

Prompted by the OPs last update, I’ve just thoroughly cleaned my 9C for its winter ‘off-season’ and thought I’d drop the last of my thoughts here.

I will use it over winter, but I find much of the benefit of an FS in my local riding conditions disappears as the ground gets overly soft, grip diminishes and speeds drop. It will mostly be reserved for big days in the hills and trips to trail centres where the going remains good throughout the wet season.

My fundamental views of the bike have not changed from my previous posts, but I have nearly 800km on it now (its not been the best summer for riding) and I’ve lived with it longer.

1. Its been easy to live with and has shown no foibles and just got on with the job.

2. I seem to need slightly more torque on the pivot bolts than recommended to stop the creaking. They seem to be tolerate the higher torque and all has been well since a single adjustment. Same is true of the rear axle. I’m 90kg maybe its got something to do with that, or maybe my lifeline torque wrench is out of calibration.

3. Not the bike per-se, but tuning the X2 had me at my wits end. This is entirely my fault, since I tried to tune it without iterating. My advice is go and iterate it properly and make time to specifically do this. The quality of the trail you do it on is paramount. Never have I huffed and puffed so much with suspension tuning.

Despite my self inflicted frustrations I’ve managed to eliminate the taught, slightly hooky-uppy feeling from the back end without making it feel gooshy. It now ‘just works’ right the way through its travel until you run out. It feels like classic, well tuned horst link suspension, which I have always loved.

4. Occasional chain tug on the pedals can be felt coasting on roughish sections. It’s not noticeable in the faster, rougher chaos because there’s too much going on

5. Cable guiding under the BB still has me pulling a face. Its functional, but messy and I’m always slightly nervous about it. Better if it was like Ibis do on their FS’s IMO.

6. Mud shelf behind the BB formed by the wishbone for the chain stays. Minor niggle tbh.

7. Down tube belly armour is pretty battered already. It’s got multiple, deep cuts. Rubber could do with being a bit harder/denser of having a more durable surface skin. It doesnt quite reach the edge of the down tube either, and since the frame itself is box section here, there is some minor damage to the edges of the frame from thrown up rocks and the odd technical dismount.

Pretty much, thats it. It’s a decent bike for riding. There are plenty of bikes with superior finishing and detailing. Thats not to say it’s low quality because it isn’t – this is a bike for riding and its not ‘cheaply made’. It loses nothing to the Turners, Oranges and Banshees I’ve had prior in terms of ride quality, losing out only in the carpark wankathon when the latest colourways, equipment and brand names are important.

For the money I’d happily buy another.

Useful that, thanks. Still gagging to get a go on one, hope fully not long!

@Scienceofficer Thanks for the additional feedback. How have your bearings held up?

I have just now replaced the frame bearings at the top link. In doing so I found the chainstay / link bearing bolt had broken at the clevis 😢

I want an A9 now I’ve decided. Previously been anti 29er but it’s clearly the way forward for the bike industry and I had a little go on a SC Tallboy about a month back and it didn’t feel sluggish or boring like a previous 29er I had a go on did (albeit I pb’d a trail on it anyway despite the suspension being too soft).

Bloody things are out of stock now aren’t they – probably will go A9 alloy on cost grounds although I wouldn’t have minded the lower weight carbon model. I have an A7 at the moment so apart from wheels and fork everything should transfer straight over.

On the lookout for a medium sized model……

Bearings appear to be fine. I packed mine with stodgy grease prior to the build to protect against water ingress and there doesnt appear to be significant wear from use either.

My shock linkage clevis bolt did fail early on and as I’ve said, the torque on the pivot bolts seems to need a bit more than specified to stop them creaking.

@Scienceofficer Thanks. Did you say before that you had broken a bolt? If so I missed it.

Somewhere on here.

Yep, mine is excactly the same. Did you get a new one from Bird? I’ve filled in a form for warranty, again. I should probably tell them about the shock bolt too

I just emailed them that picture and asked for another one, which they were kind enough to supply. I then knackered the new one by not realising my life-line torque wrench doesn’t do torque in reverse!

My shock bolt is fine.

Hiya,

last bit on this page:

Bird FAQ

step two is the key bit (well apart from needing a left hand reading torque wrench) and use torque / grease details on the frame data sheet.

Easy to do though, not managed it on my own Bird (yet), but did snap one on a friends as forgot to do step 2.

and yes sticky/stiff/seized bearings on my 9a and my mates 9c but Bird did sort under warranty – they are pretty good like that.

I wonder if the bores are perhaps a bit tight for the bearings and compressing them a little – fitting bearings into my 9A – much tighter than when i did this on my older AM9.

Tight bores can and do compress a bearing. If they’re too tight, a perfectly good bearing out of the bike can feel notchy when pressed in.

I’ve spent more than one evening honing bearing seats in aluminiun FS frames over the years to make them super-smooth. Sometime it made a difference to feel and bearing longevity, sometimes it didn’t, but at least you can tell when they’re notchy from wear if they’re smooth from new.

Yep I guess this is the weakest link.
Also the bearings are something everyone should keep an eye on. I had to change all the linkage bearings after couple of months of summer riding (stored inside). Those were totally rusted and stuck.

Maybe the 9C has some different hardware (assume it comes out of a different factory to the alloy bikes) or it interacts differently with the carbon frame? I’ve had 2 alloy Bird bikes and it’s been the best hardware suspension wise on full suss bikes I’ve had.

Bearings lasted ages on my Aeris 145LT – less time on my Aether 7 where I’ve dragged it through a lot of mud. Lasted about 18 months on the A7 before I decided to change them – they weren’t completely ruined but a few were beginning to get a bit notchy. I haven’t jet washed my bikes – and tend to let the mud dry then brush off as much as I can to save water going everywhere.

The main pivot bearing on my 9C was seized solid and rusty from new. The others weren’t great. I just swapped them all out for Enduro BO. I checked my mates AM9 and they were fine, need to get around to checking another friends 9C when I next see him. Love the 9C, just crappy bearings.

Oh yeah, the collet bolts can be tricky blighters too.

Those standard bearings sound an absolute shocker – presumably not got enough grease in and must have been somewhere damp to rust solid from new. Were Bird not all over that sorting it out for you?

Some bearings on my 9 were seized solid after just late-spring & summer, others notchy. Bird sorted me out.

Are the pivot bolts aluminium or steel? I bought a 2nd hand 145 and snapped the alu one after a few rides, I bought a replacement and it was steel so I assume Bird were aware they were a weak point

I never bothered Bird about the bearings, it was easier to sort out myself.

For the record, I disassembled all my pivots prior to the build on my 9C specifically to charge all the bearings with grease.

They were all factory fresh standard cage bearings and free of rust. Of course, because they are standard industrial supply bearings, they were also greased with just enough for high rev running, and would rust fairly quickly in a typical UK mtb riding/cleaning environment without the top up.

When they do go, I’ll replace them with Max complement bearings for extra strength/running duration.

I’ve just finished changing the bearings for the second time in less than a year. This bike does get some pretty rough treatment, but I’d like a bit better longevity than that. The Enduro BO bearings haven’t lasted noticeably better than the originals. I’ll be trying stainless max compliment bearings next time.
I have broken a second pivot bolt, again at the bottom of the link / top of chainstay. The replacement from Bird is slightly different. On the old setup the inner expansion bolt the wedge taper went all the way to the threads. On the new one it steps in a bit. Photo on Insta here:
https://www.instagram.com/p/Cc3Wn5TMRVS/?igshid=YmMyMTA2M2Y=

And the serviced Fox DPX2 has a horrible rattle sound, which apparently may be the glide ring in the damper, so that’s going back to the service centre. 😤

Timely, because Wednesday saw me blow the 4th pivot axle in the same location. It’s the rocker link/seat stay pivot. Whats a kicker its that they’re presently out of stock.

Last time, I took the bike to Bird for them to look at, they changed the axle to a collet with a different taper, but it’s lasted the least amount of time.

Further investigations by them after I drop the bike to them next week. I hope they find the cause because its not fit for purpose if it breaks pivot hardware every month.

I can’t deny it isn’t a pain in the arse to drive it to them, or be without a bike in good riding weather, but they’re treating me fairly and its appreciated.

In the meantime, all my bearings are ok with the exception of the Horst link bearings, which were a touch rusty, but not so bad they couldn’t be saved with more grease.

That’s really odd – they’ve used what seems to be the same hardware for years on the Aeris 120/145/ aether 7 / AM9. Maybe it’s a problem with your specific frame that’s putting more pressure on them. Hopefully they find the problem and fix it permanently for you quickly!

Yeah. Apparently they’re only failing on the 9c. The alu Aether 9 is fine.

That’s rough, and especially with them being out of stock. Are they just letting go in normal riding or in a big impact? I’ve been lucky so far with mine, so I’ll hope for the best (although I broke a spoke at 9am this morning, on this glorious bank holiday weekend, so my luck isn’t looking great 😂)

That is very frustrating. I wonder if the extra stiffness of the carbon frame is increasing the peak loads or transmitting a load in an unexpected direction or if it’s a case of misalignment?

@scienceofficer thank you for the reply.
I’ve not really noticed a particular event that causes it to break. Just ‘something’ feels wrong, and I find it when checking. Please keep us updated on how you get on.

@joebristol I am surprised that the other bikes use the same. I would have hoped that if that was the case then they would invest in some better quality parts, as the ones I get are not very well finished with sharp edges etc.

Afternoon.

I thought I’d pop my head in.

That broken pivot bolt is now replaced with a steel one which seems to have solved the problem entirely.

Cool. I hope they’ve made had a few made, and that I get one next time.

I understand from Dan that they had a batch made.

Bird are now advertising that they have Aether 9c back in stock, so could be time for an update after my year and a half with the bike.

Firstly, and most importantly, I haven’t had any further broken bolts or failed bearings. I did find that the main pivot bolt was cross-threaded, which was probably my fault during reassembly. In my defence I would say (again) that the pivot hardware isn’t great, but I won’t repeat the complaints I mentioned before.

The big change I have made on the bike is suspension setup. The newly serviced (and quiet!) DPX2 shock has given me the confidence to go to a lower pressure and an extra volume spacer. At 90kg I am running 0.40in3 grey spacer, 220psi for 31% sag, and rebound 7 clicks from full closed. The lower pressure does make the rear suspension a little more active under pedalling effort. I do reach for the platform switch slightly more often, but not so much that it’s essential. Like this it only bottoms on the biggest fastest bikepark hits, and rarely in enduro style trail riding.

Overall I am loving the handling and performance of the bike. The handling is a great mix of stable and lively. It regularly encourages speeds through chunky sections. It has a taught handling feel and stiff front end that can hit lines at speed with addictive precision. I do wonder how it would feel with a different shock, maybe even a coil. At high speed it can feel a bit skippy, which I think is worse with the DPX2 than with the RS Deluxe Select+.

I came to this bike after many years of riding only hardtails. I wanted a bike that didn’t completely isolate me from the trail and still required and active riding style. It has fitted that brief very well. However now my confidence and speed is up I am wondering if actually I would prefer something with a bit more travel. The Aether 9c chassis is stiff and strong, and is well matched to a burly build kit. The downside of that is that the overall weight is so similar to a bike with longer travel. I was very tempted by Bird’s new Aeris 9, but I think I’ll be holding on for something a bit lighter than that. Certainly there are very few frame only options that can compete with the value offered by the Aether 9c.

@Scienceofficer I would be very eager to hear your comparisons with a Geometron. That is one of few bikes that have such a long reach and front centre, but the chainstay length is very different.

That is going to be difficult because I don’t have a Geome-long, although yesterday my mate pulled the trigger on one, he’s 5 inches shorter and 25kg lighter, so not sure that would be fair anyway…

I can compare it to the Ripmo I sold it for if you like?

I can compare an Aether 7 to a Transitional Sentinel if that helps – but more travel but not full on enduro. Both mine are alloy but there’s a carbon Sentinel that’s quite a bit lighter than the alloy one I have.

I find it’s very nearly as playful as the Aether (which had a dhx2 coil / lyrik) – both are size medium with a very similar reach figure. The Sentinel is just a bit more of everything – you can get away with more daft lines and it seems to have more grip climbing too (might be the 650b to 29er wheel size difference I guess).

When I ride steeper angled bikes now / shorter travel they feel more harsh – my mate’s v3 carbon Santa Cruz 5010 almost feels like a hardtail in comparison.

I had a quick go on a carbon mullet NP Mega a few weeks back. It had 38’s and an ext coil – that made the sentinel feel quite poppy and playful – the Nukeproof was more plush. At the time my sentinel had a 160mm lyrik ultimate and the standard fox float x on the back. I’m flipping backwards and forwards between the float x and a Cane Creek coil that I’m slightly struggling with setup on / spring rates.

I’d imagine the Sentinel is quite similar to the Bird AM9 tbh – just with a slacker head angle.

TBH I’d not have described my A9C as playful. Handling wise it was kinda middle of the road and became more stable at speed. It certainly didn’t sharpen up at slow speeds.

I’ve re read some of this thread and I think I’ve gone off the idea of the 9C since the alloy 9 looks so nice. As stated somewhere above the alloy version seems to be really lightweight for what it is and the carbon quite stout so it’s not like there’s a huge weight advantage for the extra money.

They now have Formula Mod shocks available as an option on the website. Seems like a bargain compared to most other stuff out there.

I wouldn’t buy a 9c over a 9a for the weight, since the difference isn’t that much, but I would for the looks, stiffness, and bottle space.

I agree with that you say about it, the00. It’s a fun bike and great mix of lively and stable.

My XL frame is up for sale now if anyone whishes to get in touch