One last chapter to nerd out on all the little details of the Slacker frame before we launch in a couple of weeks.
The devil is in the details, they say. And at Airdrop we really sweat the details. The Slacker was always designed to not only ride exactly how we wanted and emanate that desired ride characteristic but also to be easy to live with, durable and ultimately be a dependable product that will stand the test of time.
What does that mean though? Well in our eyes that means a bike that’s easy to work on, no crazy one off standards or proprietary parts, a bike that doesn’t let you down and one that just keeps giving.
The Slacker uses a combination hydroformed and extruded, internally and/or externally butted tubes. The profile of those tubes have been carefully considered with durability always being our number one priority. That means the Slacker is no feather weight (full builds come in at 38-39lb without pedals) but can roll with the punches and won’t be getting put down in a hurry.
By using a combination of double and triple butted tubes we are able to not only maintain durability and fatigue resistance but also tune the ride flex to compliment the bike park feel we were aiming for. That means a frame that’s laterally stiff, and rewards for being pushed hard but crucially has degree of compliance to take that edge off.
CNC Machined Parts
As a small-batch producer, we lean into CNC parts heavily. For us setting up forgings and extrusions doesn’t really make sense - the payoffs only come when you're mass producing hundreds or even thousands of units. We tend to CNC from billet. This means our unit costs are pretty high but the quality is second to none.
For the Slacker we really went to town on the CNC. Meaning all the lugs, hardware and dropouts are CNC parts. This isn’t the most cost effective way of producing a frame but it does open up a lot more options with regard to the design and has enabled us to design a series of lugs and tube joints that work together to create a stronger product. Such heavy use of CNC is not normally seen on frames like the Slacker but production cost wasn’t our main priority - delivering the best product possible was. Using CNC so heavily means producing much higher tolerance and ensures part tolerances are always 100% correct, be that bearing seats, axle diameters, tubing joints or bottom bracket & headset faces, its all CNC and its all correct 100% of the time.
Reach Adjust Headset
All Slacker framesets and dual crown builds will come supplied with our own reach adjust headset (the Luxe build has a single-crown fork and therefore uses a tapered headset). This enables any rider using a 1 1/8” straight steerer fork to run the frame in three different reach positions.
The reach headset comprises of two pairs of headset cups. Effectively a pair of centered cups and then a pair of 5mm offset cups. This means dependent on the orientation of the offset cups you can run, centred, +5mm reach or -5mm reach. Having the three positions means riders can really tune the fit and ride characteristic of their bike.
We work with a partner Taiwan to manufacture the headsets. They are one of taiwan's leading CNC producers and make a lot of parts and components for MTB’s premier brands.
The headsets themselves are a no compromise affair. All headset cups are CNC made to ensure a perfect fit every time. We spec a dual sealed, stainless steel angular contact bearing. The upper headset cover comprises of two rubber seals, to keep out the worst of the weather and grime. All headsets also include a starnut and our very own sessions not seconds top cap with stainless bolt.
Universal Derailleur Hanger
For the first time at Airdrop we decided to use the new SRAM UDH mech hanger standard. It's a unified hanger and dropout specification that multiple manufacturers have adopted. This means getting hold of spares should always be a doddle no matter what corner of the world you’re riding in.
If you’re not familiar SRAM’s UDH hanger, it’s not your typical fixed derailleur hanger. The hanger itself is designed to rotate anticlockwise in the event of an impact. And to make all this possible you have to carefully design your dropouts to adhere to SRAM’s specification. The hanger comprises of two parts, hanger and securing bolt, which effectively means the hanger is a floating design. The hanger securing nut uses an opposite thread and contains a captive thread for securing your rear wheel axle. This ensures all threaded parts are replaceable so in the event of a failure there is no damage to the frame and each component can be replaced.
In typical Airdrop fashion we opted not to buy SRAM's own hanger but to manufacture our own (under license from SRAM). Our hanger is made from both alloy and injection moulded composite. The hanger comprises of an alloy shank which contains both the derailleur thread and b-tension limit plate in turn giving the hanger the structure it requires. This is then clad in an injection moulded composite to ensure the hanger can rotate as is designed.
We make our own axles for all our frames. The Slacker axle is designed to suit our 157x12mm dropouts as well as accommodate SRAM’s UDH standard.
The Axle itself is a 190.5mm alloy axle, using a fine m12xp1.0 thread. This finer pitch means more thread contact than previously and eliminates any risk of axles loosening due to vibration. As with all our other axles we use a hollow construction to maintain a respectable weight of 48g. Our axles also have twin hex key fit so in the event one side gets rounded out the axle can still be easily removed. To prevent corrosion all our axles are anodized black and finished with laser logo, denoting the spec and torque specification.
All our frame pivot hardware is CNC alloy components to guarantee excellent tolerances and maintain a respectable weight without compromising on strength.
We always want Airdrop frames to be easy to live with so have designed the frame hardware to be as easy as possible to disassemble. Where possible we use top hot washers to fit the bearings and any additional spacers are substantial enough that they aren’t easily damaged. Our two main pivots use an oversized two-piece axle design to further simplify assembly. And in addition to this all hardware uses either 5,6 or 8mm Hex key fitting, to ensure any developing play can easily be dealt with a the trailside.
One-Piece Rocker Design
At the heart of the Slacker is our one-piece Rocker. Each rocker is individually machined from its own billet. The one piece rocker gives the Slacker its distinctively stiff don’t-hold-back ride feel. And ensures bearing alignment throughout shock movement eliminating any premature bearing wear.
It's worth taking time to appreciate the amount of machine time that goes in to each and every rocker, really it underlines the whole design philosophy of the Slacker. Its definitely a typical to see such large parts CNC’d.
The Slacker uses all 6900 or 6800 series bearings, there are no funky proprietary standards and all are easy to source. As well as over two years testing on the frame bearings, we paid special attention to the bearing load capacities to ensure the bearings will last.
Way back in 2014 when Ed was developing the original Airdrop bike (the Edit v1) a physical head tube badge was in the plan. At that time it was pretty much the peak of carbon mtb frames and there were very few legitimate alloy frames left on the market. And one of the consequences of the shift to carbon was that proper head-tube badges had all but disappeared from mountain bikes in favour of painted-on graphics.
As with so many things in those early days, it proved to be much harder to put into practice than anticipated. And more expensive. It might not seem like such a big hurdle now, but to spend £500 on tooling and then order 1000 head tube badges was too much of a stretch for the long-gone life savings.
All good things come to those who wait, as they say. The Slacker Project was an opportunity to finally nail the head tube badge. Especially because the straight head-tube is much less difficult to work with than a tapered one. So here we are... it only took 8 years!
As usual we went the whole hog, so rather than a flimsy bit of plastic we've got a real alloy head badge with a brushed finish and silver ano to keep it looking fresh. It's a small thing but a nice little finishing touch for the project.
The Big Picture
The frames are complete and they're on the way to the paint shop. We've got a production bike here and we've been producing all the launch content (which we can't wait to show you).
The Slacker Project has a couple more chapters to run until the story is complete; stay tuned for more details on specs, the range, pricing and of course, placing an order.
The Slacker will launch on 26/1/23.
James grew up in Sheffield and Wharncliffe is his local. He spent a few years guiding in NZ but now he's back, helping with all things Airdrop.
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