The Aether 7 is the newest model from British mountain bike direct-sales brand Bird. Replacing the old Aeris 120/120LT, this new bike has 130mm of rear wheel travel with a 140mm fork up front and rolls on 27.5” wheels. The geometry is right on the money if you want a thoroughly modern short travel trail bike.
Bird has been direct selling mountain bikes since it launched in 2013 from its base near Swinley Forest in South East England, with a focus on creating bikes with progressive geometry that offer a great value for the price.
Bird Aether 7• Frame: aluminum
• Wheel size:27.5"
• Travel: 130mm R; 140mm F
• Head angle: 65º
• Size: S, M, ML, L, XL
• Price as shown: £2,918
• Builds: £2,035 to £5,100
• Weight: 31.09lb (14.09kg) size large w/o pedals
•
www.bird.bike The goal with the Aether was to develop “an aggressive, hard-hitting and fun short travel trail bike” to replace the Aeris 120, and while there are some shared features, namely the tubeset, the geometry and suspension design have been totally refreshed to meet the demands of the current market for bikes that are short on travel but big on capability.
Because Bird sells bikes directly through its website, it can offer seriously good value for money and it compares well to the likes of Canyon and YT. The bike shown here costs £2,918 with a SRAM GX Eagle groupset with Guide RE brakes, RockShox Pike Ultimate and Deluxe Ultimate suspension, DT Swiss 1900 wheels with Maxxis rubber and RaceFace handlebar and stem. There are other builds available and you can personalise your own bike through the company’s website, as well as buying a frameset.
Bird ships complete bikes to the EU, USA and Canada, and only frames everywhere else. For US prices you just need to subtract 20% VAT, so a £3,000 bike works out to $3,273 USD after the VAT is removed and the currency is converted. There will be import taxes into the US as well which vary by state, as well as shipping to take into account.
Frame Details Bird has stuck to the tried-and-tested four-bar suspension design it been using since the company was founded, so the overall look is familiar to other models in the range. The 210x55 metric shock is anchored to the top tube and driven by a short linkage with self-locking collets used on the pivot axles. Travel is 130mm and it’s designed to work with a 140mm travel fork.
It’s a 6066-T6 aluminum frame with a choice of three colours, and external gear cable and brake hose routing with internal dropper post routing. The frame has been designed around 1x drivetrains, with a bolt-on ISCG05 chain guide mount and 73mm threaded bottom bracket shell.
Out back is a Boost 148x12mm SRAM Maxle thru-axle with a 160mm post brake mount and there’s clearance for up to 2.6” tires. Frame weight is a claimed 3kg without shock for a medium. There’s also space for a water bottle but space is tight under the shock.
While it might look the same as the old Aeris, the suspension has been refined with a focus improving the kinematics to ensure it offers a fun and poppy ride. We’ll let Bird designer Dan Hodge take us through the changes:
“The suspension is a refinement of our four-bar system that I have been developing since we launched the company. Over time we have gradually tweaked the amount of anti-squat and rising rate in the system to where we are today. In particular, this bike has quite a lot of rising rate (or progression) in the linkage for a bike of this travel class, which results in a poppy feel when you do want to get it airborne. Achieving that fun feeling when riding drove a lot of the design of this bike – we all ride bikes to have fun, right? The anti-squat is similar to our other frames in that it is designed to be run with the shock fully open all of the time, but I made some small refinements to the anti-squat for this frame as well, in order to balance the pedalling efficiency against the pedal kickback over rough terrain,” he explains.
Geometry Bird is no stranger to progressive geometry. Relatively long and slack geometry has been the norm since the launch of the Aeris 145 in 2017, so people familiar with the brand won’t find any huge surprises in the geometry chart. The new Aether is available in five sizes from S to XL, with an ML splitting the M and L sizes which is an interesting decision and offers a wider range of fit options.
The head angle comes in at 65-degrees and the virtual seat tube angle is 76-degrees across the board, with 425mm chainstays and 325mm bottom bracket height. To keep the steering reasonably nimble the fork offset is 37mm. The reach ranges from 432mm on the small to 527mm on the XL, with the size L getting a 504mm reach. The seat tube has been kept short so you can run a longer dropper post.
Bird designer Dan Hodge explains the reasons for the geometry numbers were aimed at providing good stability at higher speeds but balanced against a requirement to offer fun and nimble handling.
“We settled on a 76 degree virtual seat angle as it gives a good weight distribution when climbing, plus the extra reach and wheelbase boost stability when the speed picks up,” explains Dan. “I wanted the bike to feel as fun as possible, which meant it had to have chainstays as short as possible without impacting the seat tube position. This resulted in the super short (for a full suspension bike) 425mm chainstays. The head angle was driven by a lot of testing (both with prototype frames and anglesets), and also the widespread availability of 37mm short offset forks. We felt that 65 degrees combined with 37mm offset forks gave a nice balance of downhill stability but also a feeling of quick steering which improves responsiveness.”
I’ve been able to get a number of decent rides on the new Aether, at the launch day in South Wales and for a couple of weeks afterwards, as I was able to hold onto it so I could get a solid understanding of the new bike.
My first ride on the new Aether was as the popular Cwmcarn trail centre in South Wales, where the new bike was presented in its various guises. Setting the bike up was a breeze, with 30% of sag in the rear shock the recommended air pressure, about 80psi, in the Pike Ultimate. I had to up the saddle height, rotate the bars a touch, and I was ready to hit the trail.
My test bike was specced out with a SRAM GX Eagle groupset and four-pot Guide RE brakes, a RockShox Deluxe Ultimate shock and new Pike Ultimate fork. Rolling stock comprised DT Swiss XM 1900 wheels with Maxxis High Roller II and Minion DHF 3C tyre pairing, and finishing kit was a RaceFace Affect 35 handlebar and stem and Fabric saddle atop Bird’s own-brand dropper post. The new Pike Ultimate is an impressive bit of kit, silky smooth, lovely sensitivity and ample progression to ensure full travel is achievable without bogging down mid-stroke.
Like most trail centres, the Cafall trail starts with some solid climbing, ideal for warming the lungs and getting acquainted with the new bike. It’s a cliche I know, but I did feel right at home on the bike within a few switchbacks. There’s minimal suspension movement when you’re spinning up a smoother climb, and on the steeper climbs littered with rocks, the rear suspension pushes the Maxxis tire into the ground for maximum traction. I’ve been riding some bikes recently where I feel I have to flick that little switch every-time I roll into a climb, so to not have to worry about it on the Aether was hugely appreciated, and it’s nice to have one less thing to worry about. Instead, I can just concentrate on riding.
The length of the bike is apparent from the get-go, but I didn’t find it unmanageable. I felt balanced and centred on the bike with a comfortable position for spinning up the climbs and on longer rides, while that agility you want from a short travel bike was present for those times when you’re not hustling along a super tech trail.
On the descents, the Aether 7 is a blast. The geometry makes it feel calm and planted at speed and the suspension is smooth, sensitive to the smaller ripples and loading up nicely on bigger impacts. It’s a lot of fun in the rough stuff and when dropping into a techy trail. The short 37mm offset fork, as used by a few other bike brands, helps to deliver good high-speed stability when smashing through rocks and roots, while on flatter trails it ensures the Aether is agile and nimble through the corners. Weight and drag from the Maxxis tires aside, it doesn't feel sluggish on linking trails and offers that all-round performance you want from a short travel trail bike. It’s strong everywhere.
The suspension offers plenty of support on big impacts, I never noticed the extreme being reached, and it has that zesty liveliness that Bird intended when it designed this new bike. It strikes a good balance of big hit capability with poppy fun on smoother trails. The geometry lets you go fast and the suspension can keep up and cope with everything you can hit it with.
It’s clear this is a long bike. It’s longer than many other size large bikes and even a fair few XL bikes, but the size range is fairly wide so there should be a size for most people. So the reach on this large size bike is long, but it’s not unmanageable. From looking at the geometry chart I might have picked the ML, but I’m glad I was given a size L and before the end of the ride I was really happy with the size and fit.
Short travel and long and slack geometry are not two things that have traditionally gone together, but in recent years they have been a solid bunch of bikes that have shown that the right geometry and sorted short travel works damn well. Just check out the Norco Optic in the recent Field Test. Like that bike, the Aether 7 doesn’t quite climb like a cross-country bike, but it’s more than capable and it’s playful and fast when it comes to descending.
It just lets you have fun, and for me the limits of this combination are more approachable than some bigger travel enduro bikes which need a big dose of guts to wring the best out of them.
Plus their customer service is the best I’ve come across. Highly recommend them and their bikes
Seems fair, carry on.
Well this old midget-legged person is happy there are now bikes a decent length that I can actually run a dropper on. Poor old Boosting will just have to stick to the mere 90% of bikes made with him in mind.
Thanks very much. I will.
This is what I have gathered from 10ish reviews of bikes with short fork offset. Why do you need more stability on bikes that are already super long and stable?
geometrygeeks.bike/bike/bird-aether-7-2020
Which is probably because the stack is fairly low. You are losing roughly 4mm of reach for each 10mm you have to raise your grip height with spacers or riserbars.
Spacers will shorten the reach as the stem moves up & back on the angled steering axis. Riser bars only go up, though; they do not move back on an axis as they get taller (unless you roll them back, but that’s a different story).
Long story short, cockpits are way more complicated that people give them credit for, and it's very hard to change one value without affecting others.
Perhaps a better way to phrase it is to say that for a given reach, differences in stack effectively change the reach by ~40% of the difference in stack.
Gloss Powder Not Pink/Acid Yellow
Gloss Powder BigFoot Blue/White
Link to readable geometry sheet..
"but it’s more than capable and it’s playful and fast when it comes to descending."
"It just lets you have fun"
But PB says short-travel 29ers are the only all-around choice!