GRAVEL / ROAD
A New Model with Old Roots
It might seem strange that a company built on the pursuit of full suspension excellence has chosen to launch a Gravel bike. At Knolly, we have always done things differently. We are not afraid to do the unexpected. Our crew have logged A LOT of hours in the saddle, and despite our diverse backgrounds, the one constant is pretty simple - we are happiest when we are on two wheels. With an entire lineup of new full suspension models designed and heading into production, we shifted focus to a new type of Knolly. One that we wanted to build just for the hell of it. A sign of things to come.
The goal was to design a bike that checks every functionality box while elevating ride quality and experience. We wanted the Cache to be so versatile that it becomes your go-to bike in the shed, ready for any adventure.
The Cache is a passion project and we are very proud of it. It’s our first non–suspension bike and our first product in titanium. Working with titanium is arguably the most difficult material to work with (as opposed to carbon, aluminium or steel), so it was extremely challenging to build this frame.
This of course begs the question: if titanium is such a pain in the ass to work with, why use it?
The simple answer is that neither carbon, aluminum or steel can surpass the ride quality and feel of a well-made titanium frame. Add in the longevity of titanium - completely corrosion resistant and unlimited fatigue cycle - and the value only increases. The Cache will become a legacy bike for any rider that owns one.
So, what does it take to create something new in titanium? With our engineering and ride experience, we knew from the start that the Cache was going to be unique.
We wanted the Cache to be designed different from other titanium bikes on the market and to create something truly new and innovative. We achieved this by not starting with a traditional frame concept and adapting it to gravel. Instead we started from the ground up.
We based the Cache on ultra-modern off-road geometry, featuring a longer front center. Designed to be ridden with a shorter stem, the Cache has the perfect balance of optimal multi-surface handling characteristics and total compliance. We took full control over the design and execution of every aspect of this frame, right down to the tiniest of details.
Yes, we are new to the titanium market space, but we are confident that there is no other bike company working in titanium at this foundational level.
Titanium is a high-end world, and the vast majority of tubesets and machined parts come from a very small group of suppliers: 3, maybe 4 of them. Almost every high-end titanium frame on the market is made from a combination of parts provided from these suppliers.
There are a lot of options, but not an infinite amount. Surprisingly, none of them provided what we wanted for our bike.
The next step was engaging with one of the premium titanium suppliers and presenting them with our design ideas. They gently laughed, and told us that it was almost impossible to do what we wanted - to manipulate titanium tubing like you can with aluminum.
We countered and argued that it could be done and that they were probably the only factory that could do it. We knew it would be extremely difficult, require a bunch of custom tooling and the patience to develop custom tubes.
After numerous discussions, the factory committed and took on the challenge with us. Soon, development began on our custom, multistage tube forming tooling- yes it is as cool as it sounds.
On the Cache, the seat tube is one of the key elements that makes it so unique. We needed this tube to be manipulated because of these four key features:
Tire and fender clearance for relatively short chainstays meant that it needed to be bent.
Vertical compliance that this bend and offset design would provide through the seatpost to the rider.
High torsional stiffness (i.e. high pedalling efficiency and aggressive cornering ability) meant that the tube needed to keep its width.
Fully internal cable routing – without exiting the down tube and re-entering the seat tube - meant that the seat tube needed to be welded fairly far up the down tube.
These last two features required the tube have a significant taper to it, right where it was bent around the rear wheel.
And to top this off, we wanted an elegant shape.
Making tapered tubing in titanium is done quite frequently. Making butted tubing in titanium is done quite frequently. Making formed and bent tubing in titanium is done quite frequently. But, doing all three operations in the same section of tubing is highly non-trivial and will almost always result in unusable cracked and crinkled tubes due to titanium’s propensity to work harden. Fifteen months after our initial discussion with our vendor and four separate production tools later, we had our first successful seat tube samples. This seat-tube is the most difficult tube to manufacture and we’re not aware of anything like it on any other titanium product in the market. Anywhere.
To put it mildly, for a tube that looks so natural and subtle in person, it required a huge amount of work.
This was the most difficult tube to execute, but it is not the only custom tube in the Cache frame. In fact, all seven frame tubes are custom and required completely new or modified production tooling. By completely controlling the shape and thicknesses of our tubing, we were able to not only define the ride characteristics of the Cache, but also incorporate features that are not found on any other titanium frames in the market.
Particular attention was paid to cable routing, allowing for super clean and efficient internal and external options. This is especially obvious in the chainstays where the cross-section changes from a classic oval shape near the BB and tire, to trapezoidal at the dropouts. This was done for two reasons: it increases the weld-able area for the flat mount disc brake mounts next to the non-drive side dropout, and it provides an angled surface for the rear derailleur cable to exit the chain stay slightly away from the frame. It also allows the rear derailleur cable to avoid the chain and naturally goes around the drive side dropout to interface with the rear derailleur.
This level of detail meant the final product was everything we wanted it to be, no sacrifices made. For the rider, it’s a ride experience second to none.
While we know that most Cache customers will no doubt install a rigid fork on their bike, being predominantly a mountain bike company we wanted to ensure that customers who want to be a little more adventurous could install one of the new generation Gravel suspension forks. This meant it was necessary to bend a very large diameter titanium downtube (critical for strength, stiffness and handling) near the headtube. We also bi-ovaled the down tube to both increase its width at the BB (again, better pedaling efficiency and cornering stiffness) and allow room for a custom CNC machined gusset plate for internal cable management.
Our heavily manipulated (tapered and bent) seat stays provide enhanced ride compliance (above titanium’s legendary feel) and also support 45c tire clearance as well as fender mounts. No-nonsense rack mounting incorporates easily accessed M5 seat stay bosses and dropout threads.
For the top tubes, we wanted to maximize front end stiffness under power and when cornering, but still build in compliance around the seat tube area and this meant custom tapers for these tubes. To ensure each frame size delivered the exact ride experience we wanted, we created two separate top tubes and two separate down tubes. We could now mix and match these tubes through the Cache’s seven different frame sizes. For smaller frame sizes, it delivers a smaller diameter, lighter weight tube set. For larger frame sizes, we provide a larger diameter tube set and a mix of the two for the mid sized frames. Using a bunch of fun math, we calculated the exact stiffness profiles that we wanted for both the smaller and larger tube sets and created the diameters and tapers used in all four Cache top and down tubes. This allowed us to tailor the stiffness of the frames and increase overall frame stiffness close to 50% for the largest frame sizes, compared to the smallest frame sizes. To be honest, it’s a bit of an inexact science backed up with a lot of “feels right” testing but we think we nailed it!
The Cache rides like a Knolly and continues our legacy of producing premium bikes that surpass rider expectations. For specs, geometry and pricing: https://www.knollybikes.com/cache