We firmly believe that a fast fit and stable handling should not be mutually exclusive. Because, why should they?

Ever since the development of the True Grit gravel bike (back in 2016) we’ve been itching to use our learnings from that project to make a “new-school-fast” road bike. When developing the True Grit we dived deep to gain understanding of the physics of drop-bar bike geometry and dynamics. We questioned what had been done by others, why they did it that way, and eventually: How it could be improved upon.

A key driver behind Lauf coming out with the True Grit gravel bike was that we felt like nervous handling (steep head angle, short trail) was holding them back when riding on-the-edge. To validate our hypothesis, we made (and rode) a variable head angle bike prototype, re-visited the fundamental physics of bicycles and... any chance we got, questioned bike engineers/designers and journalists on road and gravel geometries.

The main question we asked ourselves, and others, was: Why do road and gravel bikes have such steep head angles? Generally, we got these two answers:

1. Because that’s how road bikes have always been, and
2. Because that makes them feel fast.

Needless to say, we weren’t convinced by these arguments. We believed that in order to go fast, a bike should be stable. This way the rider can put down more power efficiently, and go faster confidently. Sure, there were (and are) bikes out there that emphasize stable handling. But... stable handling is generally paired with slower endurance bikes with a taller/relaxed fit of the rider. While faster-fit road bikes are being differentiated from endurance bikes by less stable steering, in an effort to make them feel faster.

Road cycling is unquestionably the most conservative segment of cycling. It is often as much about tradition and feel, as it is about the science of going fast. Frankly, this made road bikes all the more exciting to us at Lauf. Where there is tradition and conservatism, there tend to be opportunities.

We suspect more road bikes will follow and introduce stable geometries on fast-fit road bikes. Because: When you are stable and confident, you can ride faster. Period.

The second big revelation that led to the creation of Úthald was when we realized how much comfort/compliance/suspension we were able to integrate into our latest (and greatest) gravel bike frame, Seigla. Without resorting to pivots or moving parts, that would bring complexity, maintenance and excess weight.

We immediately realized that our findings from the Seigla gravel bike eventually had to be put to work on a road bike as well. On a road bike the benefits shine even brighter, as road bikes cannot rely to the same degree on big tires for compliance.

Sure, compliance has been done on road bikes, but not like we do on Úthald. To be completely honest, a lot of bike frames that claim to be “compliant” really aren’t. They just might be “X% more compliant” than the outgoing iteration of that same bike, which perhaps wasn’t that compliant at all. While on Úthald we achieve compliance of the same magnitude as others needed pivots to achieve.

The sag from a 75kg/165lbs person sitting on the saddle of a medium Úthald is ~4.5mm, measured in a direction straight towards the rear hub. This means that when you hit that nasty pothole you could easily see travel around 15mm! Which again, is pretty much the same benefit you’d get from a heavier pivot-based gravel bike system (from a certain competitor).

Skeptics will say: “This won’t matter anyway, as all the compliance comes from the tires, and not the frame”. We don’t blame them, as usually this holds true. However, if we compare the Úthald frame compliance directly to tires... Úthald’s 15mm of compliance are actually in the ball-park of what a 20-23mm wide road bike tire can provide (when pushed close to a “snake-bite”). So, effectively we’re giving you comparable compliance to a 20-23mm tire, in addition to the compliance you get from the tire you are actually riding. That’s not nothing!

Here’s the best part though: We do all this on a fast-fit road bike. Because, why wouldn’t we? We know that a smoother ride translates to a faster ride*. So, why should only slower riders get the speed benefits of compliance/suspension?

*even if it might feel slower/calmer.

ICE’d

In the Lauf dictionary ICE stands for: Integrated Compliance Engineering.

There is an old saying in Icelandic “don’t cross a river for water” (“ekki sækja vatnið yfir lækinn”). When there is an opportunity to do something simple, don’t make it complicated!

ICE’d in the front

Many choose carbon handlebars over aluminum ones to get that extra compliance (flex). With the Road Smoothie handlebar we took things further. Our novel use of impact resistant high-end glass fibers in the central portion of the Smoothie Road translates into greatly improved ride quality. Without links, pivots, extra structures or proprietary standards.

ICE’d in the back

Our pivot-free rear suspension works through the combined effect of these 5 properties:

1. The slim rear-portion of the top tube transforms the top tube / seat tube junction to a virtual pivot. The use of a standard seat clamp is critical for this function, as it avoids the added bulk of a wedge seat clamp that would “lock” the virtual pivot.
2. The vertically slim seatstays allow the required twist up/down.
3. The dropped seatstays channel the ground force so it bends the seat tube (since 1. and 2. above permit), resulting in a back/down movement of the saddle, along with a little dose of rear axle travel to go with it.
4. The offset and tilted seat tube doesn’t just provide tire clearance, it translates into a (more desirable) more downward suspension path for the saddle. Note that the rearwards portion of seatpost flex doesn’t add comfort, it is the downwards component that counts.
5. A good amount of exposed seatpost, giving the required lever arm towards the virtual pivot (ST/TT junction).

Here is a video showing the ICE’d in the back function (on the Seigla gravel bike).

It is remarkable how we have spent decades wrapping our heads around the fact that wider tires can actually make us faster.

It is only logical though, as our built-in speed sensors (ears, eyes and sensory nerves) immediately interpret a harsh/unstable ride as a fast one. When there is a lot of “stuff” going on, a lot of “action”, we must be going fast?

When you think about it... this speed perception paradox didn’t start to crumble until we had widespread use of power meters*. Suddenly we had tools to quantify speed vs. input, and gradually tire widths started climbing up.

This (slow) journey towards the optimum is not quite done yet.** Despite data suggesting wider tires being faster, widths have generally only come up by a millimeter or two between bike generations. Even then, fast-fit road bikes have largely been left out, still having their wheels stuck in the speed perception paradox.

Let’s stop wasting time. Let’s start riding faster.

Úthald comes on 32mm tires, and supports up to 35mm. For speed!

*Úthald comes with a power meter on all builds, so go ahead and do all the data crunching you can wrap your head around!

**Your optimum tire width depends on your power, weight, riding surface, riding type, and preference. It’s always a tradeoff between a wider tire’s:

• a. Lower rolling resistance, improved grip/cornering and increased comfort (enabling higher power output), vs.
• b. Increased air resistance.

No one should claim that a certain tire width is “the best”, it’s not that simple. But, what we at Lauf will claim is this: The vast majority of road cyclists would be faster if they had a bit wider tires.

First, let’s establish one thing: Stability in the front is more beneficial than at the back. It’s at the front where you really can get into trouble. Be it an unexpected pothole or a sharp/fast turn, it’s at the front where stability is crucial.

We design the chainstays to give you the maximal sense of involvement. So... we can then turn around and inject more stability to the front, while keeping the bike engaging.

How short are they? As short as possible*: 405mm.

*SRAM drivetrains do not support shorter chainstays than 405mm, and our desired tire clearance of 35mm wouldn’t either.

It was a bit off-trend when we initially did this on our True Grit gravel bike back in 2017. But we felt it was the sensible thing to do. Minimal hassle and minimal creaking.

6 years later, threaded bottom brackets are becoming the industry standard again. They just work!

We dislike complicated and/or rattle-prone routing, so all Lauf bikes (gravel, and now road) have full length tunnels built into the frame to make sure the right things pop out in the right places and nothing rattles.

However, the luxury of tunneled routing isn’t entirely “free”. The tunnels don’t weigh nothing. So, realizing that we would only ever build our Úthald with wireless shifting we decided to optimize it for SRAM AXS and wireless-cockpit Shimano Di2. We spent no extra grams* on shifting tunnels that generally wouldn’t be used.

*That cost would have been somewhere close to 50g

Cable routing became an interesting topic by the coffee machine at our office (and in Iceland we drink a lot of coffee!). Most brands have been moving to fully internal through-the-headset routing lately, so we had to ask ourselves: Should we?

For us, the fundamental question became: Does fully internal routing provide benefits that outweigh its downsides?

We dove into all the literature we could find on the topic, and our findings were:

Fully internal routing...

• ...does not give you the marginal aero advantage that some would like you to believe. Especially on wireless-shifting-only bikes such as Úthald.*
• ...can be a pain to work on.
• ...can be expensive to have worked on.
• ...gets in the way of quick fit-adjustments that can make you faster through substantial aero- or comfort improvements.
• ...can make traveling with your bike a hassle.

Hence, our conclusion was that fully internal routing is mostly an aesthetics thing, best served to cyclists that find it difficult looking at brake hoses entering bike frames. So, we opted out!

However, it might make you a happier cyclist to know that Úthald has full-length tunnels in its fork and frame to guide its brake hoses. This prevents rattle and makes maintenance as easy as possible.

*At Lauf we have yet to see a study that shows any non-negligible speed advantage to fully internal cable routing on a road bike. The studies that are out there show extremely marginal gains. Despite generally being set up to amplify potential benefits (often to sell a new bike that has fully internal routing), i.e.:

1. Testing done with 4 cables (i.e. non-wireless shifting), rather than 2 as seen on modern wirelessly shifting high-end road bikes.
2. Neglect the required larger frontal area of a fully internally routed bike frame (to house a larger upper headset bearing, the head tube needs to be bigger).
3. Testing done without a rider on the bike. This is a simplification that skews the results, exaggerating the drag of the cables. Including a rider would lessen the system overall drag addition caused by an object upstream of the rider, as a given air molecule pulled along by the cables is likely going to hit the rider at a lesser speed than what it otherwise would have done. Not including a rider in testing is incorrectly assuming that air pulled along by cables would never have gone on to affect the rider.
4. Testing is generally done at unrealistic speeds, without attempts to explain how misleading that is. Power required to sustain a certain speed against the wind grows to the power of 3. So, if we assume someone claimed 1W saved at 45km/h (which, based on publicly available testing, is likely going to be close to what they should be able to claim when factoring in 1.-3. from above) then the savings become:
   a. At 35km/h (TT-style, no-drafting) = 0.47W and
   b. At 25km/h (TT-style, no-drafting) = 0.17W.
5. It skews results further to focus on TT riding values (while usually selling non-TT bikes), where any aero benefits are greatly exaggerated compared to road riding where riders frequently draft other riders. So, even the (miniscule) W numbers put forth in 4. (above) are an exaggeration of road bike reality.

Do you still think internal routing is worth it?

Úthald is not a single-dimension optimisation exercise. Generally, you cannot optimize one thing without other aspects suffering. All-in optimising for weight means you sacrifice qualities such as robustness and aero-shapes (no matter what marketing might tell you). Sure, for a major-brand to sell a given bike frame, it has to pass a series of load, stiffness and fatigue tests. However, fully optimizing for weight means you design your bike exactly according to that test criteria, while neglecting other real-world loads and impacts.

We like to achieve our low frame and fork weights through smart shaping* and layup design, combined with good manufacturing methods. Rather than using more brittle high-modulus or intermediate-modulus carbon fibers.

Yes, we are boasting about exclusively using “normal” carbon fiber in our products!

By doing so, we are rejecting shortcuts to lower frame weights. Higher modulus carbon makes it easier to pass compulsory fatigue tests and hit stiffness targets, as microcracks don’t develop as much in/around the stiffer fibers. The stiffer fibers effectively “lock” frame members from flex. This would however demand sacrifices we’re not ready to make. Impact resistance of higher modulus fibers is far (not just a bit) worse than for standard modulus carbon. Plus, the stiffer fibers can make a bike feel overly harsh.

We believe a fast road bike should not just be light, it should also be robust and aerodynamic.

*Refraining from aesthetics-driven sharp edges, because carbon fibers strongly "dislike" sharp bends (which results in a higher risk of failure, and/or higher weight as the inefficient shape has to be made up for with extra fibers). And, refraining from aesthetics-driven or pseudo-function kinks or bends, where a straighter "column" would carry a load more effectively.

Aero matters. A lot.

The by far biggest variable is the rider himself, and his position on the bike.

However, this doesn’t mean that aero should be disregarded when designing a frame/fork. But it does imply that a good fast-fit road bike frame/fork should seek a balance of ease-of-changing-your-fit, with the bike itself being aero, light and compliant.

To make the fastest bike possible, we reach for the lowest hanging “aero-fruits”. Hence, we focus our aero-efforts on the front part of the bike where the airflow is still laminar (while drag further back on the bike in turbulent air is much less significant).

On the Úthald frame, the head tube and top-part of the down tube are kept slim and deep, and gently taper inwards towards the back. Keeping laminar air attached further back, resulting in a smaller wake behind them. Extending the head tube to the back, rather than the front, also helps reinforcing the junction between top tube and down tube. This aero shaping therefore brings a minimal weight disadvantage.

Further down, the down tube grows wider. Providing some shelter for water bottles, and increased bottom bracket stiffness.

Although less important this far back on the bike, we do make the seatstays slim and drop them far down on the seat tube, giving some further aero-benefits. However, we also do this as that design is at the core of ICE.

We chose to go with a standard 27.2mm round seatpost, to prioritize robustness/serviceability and at the same time having a cross-section shallow enough to support our ICE design (while a deeper, faster-looking, shape would have killed that compliance).

The Úthald fork was shaped to combine strength and aero-gains. The slightly deep shape also “happens to be'' an effective shape for structural strength. Go deeper, and it results in a weight increase of the “web” (fork sides) between the load bearing leading and trailing edges of the fork. Go shallower and you get a reduced “I-beam-effect” and therefore the leading and trailing edges of the fork require more material

We chased low weight through shaping and manufacturing methods, while we chose to invest some grams in: Frame compliance (ICE’d), frame robustness (IRM), aero head tube and down tube, tire clearance, and full-length hose tunnels.

Where does this leave us? How light is Úthald?

985g for a fully painted M frame*

365g for a fully painted fork*

270g for a Road Smoothie ICE’d handlebar, 40cm*

*Average weights, without hardware (through-axles, front- and rear derailleur hangers, bottle cage screws and seat-clamp). Fork is weighed with the steerer cut to fit an M frame with 35mm of headset spacers. Note that some other brands quote frames without paint. Paint, in our experience, accounts for somewhere around 130g of our frame weights and 20g of our fork weights.

When comparing apples to apples, are any framesets lighter than Úthald?