Hi all,

I know I’ll get flamed for saying this, but I feel I’m more and more reaching the limit of my Bird Aeris AM9′ suspension travel.
Disclaimer: I’m absolutely sure the rider plays a huge part on this and that there are thousands of guys who can out-gnar me on 120mm trail bikes.

Not sure I’m to change, but looked to the market and within my current budget I can see the Transition Sentinel (2018 frames) and the Commencal Meta AM 29.

The Sentinel has more front travel and a slacker HTA than the AM9.

The Meta AM 29 has a lot more travel, 170mm front and I would probably put a -2° angleset. But it’s quite a short bike, 460mm reach for the L and I’m not sure I would fit a XL seat tube.

Does anyone have experience to compare any of these bikes with the AM9? If they don’t feel any “bigger” on descends I guess there’s no point considering a swap.

Any more options?
Thanks

How well tuned are your forks and shock? 150mm at both ends of a 29er should be enough on all but the gnarliest trails.

What kind of trails are you riding?

What is it that the bike is doing/not doing?

Is it the right size?

To reach the limit you are riding it on the wrong terrain, have it set up poorly, have the wrong size or be a **** full on rider.

AM9 rider here, can’t compare to any other longer travel 29ers but can compare to nomad v4/dh bike, the am9 flipping flies through the steep and rough noticeably better than the nomad v4, similar in ability from memory to my previous dh bike.

Harsh, but I think you’re making up excuses.

Considered an Orbea Rallon?

Sometimes a rider and bike just don’t gel and if that’s the case no harm in making a change!

I’ve not ridden the Commencal but as you say it looks a lot shorter than either the Bird or Sentinel so maybe not the best direct comparison.

The Sentinel gets great reviews for descending so would seem like the obvious choice if that is your complete shortlist.

I have a G13 (very long) and a Rallon (shorter, more nimble) and I preferred them both to the Bird AM9 I demoed.

I’m 184 tall riding a L, so 500mm reach which I love.
Running 20% front and 30% rear sags. Rear rebound is 2 clicks from open, front I can’t remember but is according to the RS setup tool.
I could increase fork pressure, but then natural trails would be miserable. I can add some tokens, but I’m not sure if that’s not patching up a symptom and not the cause.

In terms of trails I ride a bit of everything, but tend to ride lots of rocky stuff, generally enduro and some DH tracks. Proper full helmet charging trails

What’s the bike doing? Well imagine to hit a root section or a rock garden at speed and and feeling the suspension, specially the front, repeatedly bottoming out, compromising control

Try getting someone like TF Tuned to sort the front suspension out first before buying a new bike.

Try renting a shockwiz too, should give you an idea of what’s happening with your suspension

Not sure how swapping a 150mm bike for something like a Sentinel with 140mm is going to help.

Maybe just up the fork to 160 and put an angleset in the AM9? They are a big bike anyway. The Sentinel on big, chunky stuff felt to me like it needed more travel in the back, with a slack HA and a 160 fork it encouraged you to ride it like an arse, quite often I found myself hanging on with the back end getting wild.

There arnt many bigger bikes than the AM9.

I don’t think its the bike…

Sounds like it needs a suspension tune or some volume spacers up front to me!
Just my opinion

+1 for giving the fork set-up a bit of attention.

Which model is it?

wow

I just copped a 36 performance eliite fork for my stumpy as the 34 on it just wasnt coping.

Just felt too flexy despite endless tinkering. Having said that it was doing a pretty good job. It was never bottoming out and was trying its best to stay in the midstroke.

I think you need more spacers and more pressure for a start, then see how it copes? It shouldnt be bottoming out over rough terrain.

I can add some tokens, but I’m not sure if that’s not patching up a symptom and not the cause

Tokens are cheaper than a new bike so I think I’d be trying that first!

Skills day

😃😃😃

Thanks for all the answers so far.

To the ones mentioning “excuses” and “it’s not the bike”, that’s why I made the disclaimer in the original post. I’m aware of my limitations and, like I said previously, I’m sure lots and lots of riders can out ride me with way smaller bikes, I’m the first to admit that. But I’m also aware I’m not a complete noob. The trails I was riding yesterday will be a EWS Qualifier in 2019 and I can keep up with reasonable riders on DH bikes.

Anyway, my question was simple. If any of the frame alternatives was to be a “bigger” bike downhill, then great, something to consider. If not (which seems to be the case) then I keep working on the AM9.

Fork is a RS Yari RC (boost, debonair, etc). Would a upgrade to a Lyric cartridge make a big difference? I tried to increase pressure but then I got beat up on rocky natural trails, it’s not the most supple fork to begin with. I think I’ll try to add some tokens.

Not many complaints with the rear suspension, I use full travel all the time but don’t feel any harsh bottoming out. Could use some less pedal kickback but that’s it.

I’d love to change the fork air shaft to 160mm, but Bird says that will void the warranty.
However I’m tempted to try a -1,5º angleset to lower the HA to 64º. Might that calm the front a little?

It sounds like your fork is setup quite hard at 20% sag, but with not enough volume spacers in it to make it rank up. That’s nothing to do with the fault of your bike and it’s not patching up any kind of problem.

What fork have you got on there? If Rockshox Pike / Lyrik has it got the debonair 2019 airspring or luftkappe I’m there?

Edit – Crossed over.

You need to adjust your Yari. How heavy are you if you don’t mind me asking? I’m about 80kgs and with no tokens in the Yari and 30% sag I could t get it to use the last inch of travel as the damper ramped up so hard.

Firstly (and cheapest option), open the fork and see how many tokens you have in there. Maybe try adding 1 or 2 and see if you can then drop a little pressure and set it up with say 25% sag. that may solve your issue.

I doubt there’s a 2019 debonair airshaft in there which can help get the fork moving quicker at the start but allow more pressure to be run so it ramps up better in the midrange.

The charger damper is better – my Yari now has both an rct3 charger and the debonair 2019 shaft and it’s a lot better than before. But I had the opposite issue to you – I couldn’t use all the travel.

For reference it’s on an Aeris 145LT and had 160mm travel. It now effectively has an rct3 Lyrik with the upgrades and is 170mm.

Rockshox tend to blow through their travel imo, this makes them feel good off the top but tend to use the travel to readily for me. A fox 36 tends to sit higher in its travel at the expense of plushnes off the top.

The Yari’s damping might be spiking rather than the fork bottoming out, it’s a while since I rode a RS motion control fork but they did used to sometimes pack down on fast, rugged terrain.

Yes a Charger damper will be better, but is it more economical to snag a bargain fork and flog the Yari?

It really just sounds like a fork set up issue. As said before, add a couple of tokens to improve ramp up and then run at 30% sag.

month on a hardtail will sort you out.

I’d love to change the fork air shaft to 160mm, but Bird says that will void the warranty.

I’d still do it, if the frame fails (I’m pretty sure it wouldn’t) them change back before warranty.

Bikes are fluid, you can’t not do something you want to that could change the performance of the bike just because the brand says so, f that.

I ran my Soul with 150mm forks despite Cotic saying not to, and all on hete saying it’s better at 120mm, because you know what? It worked FOR ME.

I’d still do it, if the frame fails (I’m pretty sure it wouldn’t) them change back before warranty.

Probably best not to mention it on a forum that the owner of the company you are trying to con is pretty active on though eh?

Probably best not to mention it on a forum that the owner of the company is pretty active on though eh?

Only if “Zezaskar” is the OP’s real name.

Sheesh.

Ridiculous that a bike like that isn’t warrantied for a 160mm fork anyway, Bird fella should explain that here if he is reading.

Fork can make a huge difference, went from a Yari to a DT F535 and it totally changed how the front end felt in rough or steep stuff.

To the ones mentioning “excuses” and “it’s not the bike”, that’s why I made the disclaimer in the original post. I’m aware of my limitations and, like I said previously, I’m sure lots and lots of riders can out ride me with way smaller bikes, I’m the first to admit that. But I’m also aware I’m not a complete noob. The trails I was riding yesterday will be a EWS Qualifier in 2019 and I can keep up with reasonable riders on DH bikes.

Are you sure you’ve got the right tool for the job? From this it sounds to me like you need a DH bike. At least on that particular trail. If you’re keeping up with reasonable riders on DH bikes on your trail bike, then you’re obviously more than a reasonable rider and on those particular trails on that particular day you obviously need a DH bike. I’m not sure any other trail bike is going to help you and a degree or so on HA is going to transform the capability of the bike. You’re certainly never going to get a trail bike to perform as well as a DH bike for DH duties no matter how much you faff with your forks and HA.

A trail bike can never be as good as a DH bike on tough DH trails…that’s what DH bikes are for and a trail bike will always be a compromise. Maybe adding a bike to your quiver is the best option…though obviously not the most cost effective. DH bike for the bigger days, and trail bike for the rest of the time.

I’m 86kg butt naked, should be 90 or so kg equipped.

Pretty sure my Yari has debonair, it’s a 2019 model and RS database says so when I search the serial number.

So I’ll install an extra token and put sag at 25%.

Still tempted to try a -1,5º angleset.

On the 160mm fork warranty, I agree that the AM9 should had a 150-160 or 150-170 fork approval, would be more in line with the bike’s propose (it has the geometry and rear end to go with it) and I’m sure many people end up not opting for it out of fear of ending “underbiked”. But, big but, let’s not forget each fork length requires extra validation testing and likely at least homologation extension which comes with an hefty price tag for the manufacturer. It’s a matter of liability. Either that, or the AM9 head area can’t actually mechanically tolerate a longer fork up to legal requirements, which I greatly doubt.
I think I’ll start a petition with other AM9 owners for Bird to approve 160/170 forks…

The aeris 145lt is tested and warrantied for 160/170mm travel forks so there must be some reason why the AM9 isn’t. Maybe Ben will comment at some point if he sees this thread.

At this stage it sounds like you haven’t got the fork setup properly. Just some cheap token tuning sounds like the first port of call though. If you’re not happy with the fork after that then it’s charger damper time. I paid about £230 for the rct3 charger 2 damper I stuck in my Yari. It’s so plush now it’s incredible – and I don’t find it divey. I haven’t played much with the lsc damping adjustment either – think it’s about 4 or 6 clicks from fully open.

Before you go angleset I’d concentrate more on the fork as there’s loads to go at there. As someone else suggested a shockwiz hire period would probably benefit you if you’re not sure what you’re doing with suspension tuning. If you’re running an air shock on the back you could also use it on that to check your settings.

The aeris 145lt is tested and warrantied for 160/170mm travel forks so there must be some reason why the AM9 isn’t

Its a 29er (Aeris is 27.5), so the axle to crown length will be longer, thus providing a longer lever with which to rip your head tube off.

That makes sense then Tom – hadn’t really thought it through. I imagine a 29er with 150mm travel at each end is pretty capable anyway.

Not many complaints with the rear suspension, I use full travel all the time but don’t feel any harsh bottoming out. Could use some less pedal kickback but that’s it.

If the rear is bottoming all the time then that’s not setup well either

Bike Setup Clinics

More travel won’t fix your setup issues. Id look to someone like sprung to get the fork and damper serviced and setup properly. Get a luftkappe for the fork, will make a world of difference.

Put a Charger damper in it. The basic Yari damper isn’t great.

I’ve got a Cane Creek Angleset (which I got from Bird for my Zero AM) that’s little used which I need to sell. That’ll let you try half degree increments in head angle up to -1.5 deg slacker.

FYI the sealed MoCo damper in the Yari causes a lot of spring rate ramp up, so a adding many tokens or a Luftkappe will make the fork too progressive for most riders.

trying to con

Right ye are princess.

Right ye are princess.

What would you call it?

Put a Charger damper in it. The basic Yari damper isn’t great.

I would concur.
My MoCo Yari is a pain – ramps up overly or not sensitive enough. No amount of tokens or pressure faffage have solved it.
Son’s Pike with Charger on the other hand is a noticeable step up in fluidity on small stuff and lack of five, while still not ramping and choking on fast bigger bump’s.
So it’s a +1 on looking at fork set up and damping from me.

Got a Mega 290 earlier this year, I’m 6’2″ with 36″ leg, went for the XL with a 35mm stem.
The bike is fantastic, came from a Capra 27.5 XL, and I never felt really comfortable on the Capra. With the mega it felt instantly comfortable and just right…. Probably fair to say ots the best fitting/feeling bike I have ever had.
Ridden it in lake District, Snowdonia, peaks, calderdale and Alps and it has never felt out of its depth. It always feels in control, the faster it is the better it feels.
The only thing with it is, is it’s harder work on the tighter “bike park” berms. in the Alps my mates are all on m/l 27.5 and found the berms easier and faster, while I struggled a bit more. But when the tracks open up and are more natural and technical I could plow away from them.

If you have steeper and more technical tracks big travel 29ers are great, but if you have mellower less technical trails, then they will be hard work