So I recently tested the new Bird Aeris One20 and the review is here. Once I handed that back, I was given the bigger, burlier brother, the One45 and went to the Surrey Hills to put it through its paces. Simply put, at the end of the day, I didn’t want to give this bike back.

Before I get too carried away, let’s talk about the bike. At 6’1” and 87kg, I currently ride a large original (now retro?) Aeris, but opted for the ML (medium long) version of the new bike. The reason for this is due to an increased top tube length (630mm) and wheelbase (1230mm), effectively sitting me in a similar position to my current ride. Measurements are below, these can also be found on the Bird website:


The demo bike came with 150mm RockShox Yari forks and a metric Deluxe RT3 shock with 145mm travel. I ran the suspension at 30% and 20% sag respectively, opting for a slightly stiffer rear for the terrain I was heading to. Like the One20, it was equipped with SRAM GX 1×11 drivetrain and guide r brakes. The wheels were slightly wider DT Swiss M1700’s, with the same Maxxis DHF/HR2 combo I tried the day before. This time though, I ran the rear at 23psi and the front at 20psi. Again, a mighty Mudhugger Shorty was on standby to keep any mud and slop from my face.

The weight was around 30lbs, so a like for like with my current bike and this was evident the second I sat on the bike; I felt instantly at ease with it. The bike has been totally redesigned around metric sizing and boost spacing, but it felt familiar, which is a huge plus when you only have a day to form an opinion!


It was another cold Winters day, so the ground was frozen with some iced over areas to contend with. I set out and after what is usually a brutal climb out of the Walking Bottom car park up a super steep 13-15% incline, I still had air in my lungs; this bike genuinely climbs like a hardtail with zero feeling of pedal bob… from then, I knew it was going to be a fun day out. I hit Proper Bo to get the measure of the bike and the power was instant. Snaking through the small turns and ruts, the small double and drop on this trail felt like nothing.

Due to it’s steep seat tube angle (440mm), the One45 felt long and slack when attacking the descents but put the saddle up for a killer climb and it shortens up, allowing you to really put the power down and stomp uphill in record time. It’s like Optimus Prime’s wet dream, a transformer of epic proportions.


I figured it was time to try a bigger trail. Thick & Creamy on Pitch Hill had a hold over me this time last year with its 2 sizeable drops and a crazily steep, tight chute as the entrance. I’d nailed it a few months back, but on the One45, I breezed through and it genuinely made the drops there feel like I was hopping off a kerb. The landings were so smooth and the bike soaked up everything with more to give. Granted it’s not carbon, but when the One45 is released in March with its ultra-stiff chassis and tidy design (and bottle cage mounts!), it may have Nomads and Capras squirming a little uncomfortably in their seats.

Thick & Creamy done, I gave Thicker & Creamier a go next. Another crazy steep entrance gives way to loamy turns and fast bombholes. However, there was a monster puddle in one of these, which I tried riding around, only to eat dirt. After a nice soft landing and a little chuckle to myself, I was back up and finished the end of the run with its nice step up before leading out to the road and a nice climb back to the top.

The Surrey Hills is great, too, with an abundance of trails and friendly riders. I bumped into a film crew from Fly Creative and a guy called Phil, chatted to them for a while, then saw Joe Williams of Physio 1 to 1. Check him out here if you’re in need of a top class physio! Here’s a couple of close ups:



Taking so many pictures, riding like a bat out of hell and laughing like a mental case made me hungry, so I set my sights for the Peaslake village store, via the renovated Captain Clunk. When I say renovated, I mean ruined. It’s been tamed down massively and wasn’t anywhere near as challenging as it once was. A huge shame, but there’s still a vast network of trails to keep every level of rider entertained.

Whilst I was tucking into a red velvet cupcake and slurping coffee to refuel courtesy of the ever lovely ladies at the store, a few Trek staffers rocked up on some of their 2017 demo models, so we had a chat about the Aeris and their Remedy and EX models before I set off for round 2 and my old favourites on Holmbury Hill; Yoghurt Pots and Barry knows best.


Consistently, the One45 climbed like a trooper, making light work of the Radnor Road climb. With sore legs, I hammered through Yoghurts as best as I could and then flew down BKB as if I had sprouted wings. I did pick up some PR’s earlier in the day (including climbs), which is testament to the bike. The Surrey Hills is a place I’ve been riding for so long and riding this bike breathed new life into very familiar trails, rejuvenating my love for some that had become a little stale over the years.

Massive thanks to Bird for the demo. The One45 drops in March and you can pre-order yours here. As with the One20, a huge range of sizing and a fully custom bike builder means there will be an Aeris One45 for you. Colours are delightful too; lime green, the tangerine orange model I tested and my favourite of course; stealth black. Frame prices start from a wallet friendly £900, so this is set to be another outstanding value for money machine.

I absolutely love my current Aeris and I’m sure it’ll go on for a long time yet. However, when it’s time to change, the One45 will be at the top of my list. The One20 is superb, but from the second I slung my leg over the One45, I felt at home; one with nature and metal, with nothing but zen thoughts of shredding epic trails in my mind.


I’ve been trying to pick out a flaw or a negative point, but after sleeping on it, I honestly have nothing bad to say about this bike. To sum it up, imagine if you will, that Hercules and Icarus had a baby. Their lovechild would be an Aeris One45. Immensely strong, stiff and solid, yet light as a feather when climbing and faster than me at an all you can eat buffet.

It’s a most welcome addition to their line up and is simply an outstanding successor to the Mk1 and Mk1.5 Aeris models.

The Aeris is dead; long live the Aeris.


Ian @ Stealth Riders

Note – This is my own review and all opinions are mine. I was not paid or asked to do this, I just wanted to share my views in the hope it may help you out if you’re in the market for a new bike. The ride I did can be seen on Relive right here. I’ve also included a video full of sketchy riding, crap angles and a little stack from my day out:


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26 thoughts to “Bird Aeris One45 review

  • Pingback: Bird Aeris One20 review | STEALTH RIDERS

  • Cookie

    Another brilliant write up…. Glad you left the Oh natural bin off….Bird 1 : Ian 0

    • stealthriders

      Thank you! Haha yeah, had to leave it in!

  • adrian

    Really nice review, the bike obviously generates smiles judging by the tone. Did you come across any steeper hills on your travels ? I’m seriously considering one of these but the steep climbs here are 30+%.

    • stealthriders

      Thanks Adrian, it’s a superb bike for sure. There were a few shorter steeper climbs, stick it in 1st and you’ll be fine buddy. I’m a southerner, we don’t do proper hills around here haha!

  • Justin Hobbs

    Hi,great review.. the bike you rode was fitted with the Deluxe shock,do you think it needed the Super Deluxe?

    • stealthriders

      Thanks Justin, appreciate it!

      As far as I’m concerned, the Deluxe was more than capable of anything I can ride, so for me, no. However, I currently have the Rt3 debonair so it was a similar comparison to that and haven’t tried the Super Deluxe, but if you ride hard and like the big stuff, the Super Deluxe is definitely worth considering mate. Hope that helps!

      • Justin Hobbs

        Cool, thanks

  • Dylan Miles

    Just demo-ed this back to back at Cwmcarn with the One20. Was hoping it would be really heavy cycling up hill so I could clearly pick a preferable bike. But it was brilliant! Felt no more difficult than it’s shorter travel brother.

    Which leaves me in a pickle – which one to choose. I’ll be riding Blues and Reds at local places like Bike Park Wales and Afan. Would the One20 soon find itself out of its depth on more rocky descents? What do you think? Cheers

    • stealthriders

      Hah, it’s a tough call considering the 145 climbs so well! Personally I would opt for the 145, as I’d rather always be over biked than under biked! Reds at BPW would be more fun on the 145 in my opinion mate, but I’m sure you’ll be happy with either!

      • Dylan Miles

        Thanks mate. I suppose that’s the thing – ‘reds would be more fun on the One45’. Most reviews of bikes like the One20 or Whyte T-130 say it can handle anything….but they never actually say which would be BEST. My bro has a Whyte T-160 and struggles uphill, but the One45 seemed like a doddle 🙂

        • stealthriders

          Agreed, I’ve tried the Whyte G160 and found it harder to climb than the 145.

      • Cameron

        Great review, it’s certainly left me with something to think about for my current bike purchase predicament. Interesting comments about the comparison to the G160. I demo’d the G160 and T130 back to back and also felt convinced I would not like the G160 but I had exactly the same sentiment that it climbed just as well as the T130 so why wouldn’t you have more bike and more versatility.
        You say the 145 climbs better than the G160, how does it descend in comparison?
        What other bikes in this Spec/price point have you ridden and how does the 145 compare. i.e. Jeffsy 27, Canyon Spectral, Airdrop edit…

        • stealthriders

          Descending was quite similar, although I felt more comfortable on the 145.. maybe it’s because I have the ‘old’ Aeris, but saying that, I had a lot of Marin’s back in the day when Jon Whyte designed their quad link (although times change of course!).

          I’ve tried the Spectral, Strive and owned a Nerve, have only tried the Capra (AL and CF though) rather than the Jeffsy and haven’t tried and Edit yet. Others would be the Marin Mount Vision, a few Pivots and a DMR bolt, then a SC nomad but that’s waaay more pricey!

          Out of all of them, the 145 still felt the best to me, it came across as more solid and railed on the descents for sure. The Nomad and CF Capra were up there too, but they’re twice the money!

          Hope that helps pal?

      • Cameron

        It definitely helps! Your review has convinced me enough to request a demo. Hopefully get out on one in the next couple of weeks. Thanks

        • stealthriders

          Glad to hear it bud, I’m sure you won’t be disappointed and please let me know how you get on with the demo! All the best!

  • Pete

    I’m seriously looking at getting one of these in the summer. It’s kind of a toss up between the 125 or an Airdrop Edit v2, I think it’ll be the Bird though due to the awesome warranty! How was the sizing? I am 6ft dead on and was gonna go the large, did you try a large too? How was the ML, I like the idea of lower stand over and a 170 dropper. Bit concerned the large might be a bit of a barge with its 506mm reach!!

    • stealthriders

      Definitely worth a demo if you can Pete, as although I’m just over 6’1″, body shapes are totally different! I sat on a Large and it felt a bit too long for me, so the ML was spot on as I also like to have a bit of give with standover and I was fine with a 150 dropper if I’m honest! At just over 6′, I think you’d feel comfy on an ML but trying one out is the best way forward.

      I can’t comment on the Edit, as I’ve not tried one… I seriously need to as it’s clear that it’s a main contender with the 145!

      The ML was a beast! I’m currently pondering making the switch from the original Aeris but trying to justify the cost when my current bike works perfectly haha!

      • Justin Hobbs

        My buddy has the Airdrop v.1, it’s an amazing ride, with that new dB coil. It’s only fault,to me, was a very high seattube, but he loves it! Looks​ nice in Grey too!

        • stealthriders

          Good to know! Those DB shocks are unreal! I agree too, the grey is lovely!

  • Pete

    That shoulda read 145 btw!!

  • Sune

    Have you had a chance to compare it with a On-One codeine 27.5? I’m​ thinking about which I’m going to go with. Hope you can help.

    • stealthriders

      Hey Sune,

      I’ve only had a very quick ride on a Codeine, so it’s a tough comparison. The Codeine did feel a bit more upright, whereas the Aeris felt slacker and a bit more planted if that helps. Sorry I can’t really give anything more! The Codeine was fun to ride but I didn’t spend enough time on it (it was a mates) to give a fair review. Cheers!

  • Stephen Jewson

    I’m stuck between getting one of these the aeris 120 or the whyte t130, which would you choose out of the three? I’m leaning towards a bird but my lbs is a whyte stockist.

    • stealthriders

      If it was me, I’d got with the 145 for sure. However, if you can demo them all, it’s definitely worth trying as what’s right for me, isn’t necessarily right for you! The 145 is an absolute weapon though, soaks up the descents whilst climbing like a goat 🙂

      • Stephen Jewson

        Thanks, I’ll have to get in touch with Ben and sort a demo out of the birds.

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