U.S. Built Custom Bicycles in Titanium and Titanium-Carbon Mix
This page provides the engineering details, math, and data that support every statement we make about Seven's Lion of Spring project.
For the frame specifications, component interfaces, torque settings, and more, visit our Lion of Spring frameset design details page.
Our engineering director has been designing frames and tubesets for more than 30 years; we've learned a few things along the way. Our new LOSO tubeset and frame kit provide numerous benefits and improvements, including:
A dozen hidden engineering features make our Lion's LOSO drivetrain more than 60% stiffer than the average titanium bike's drivetrain. That sounds a bit unbelievable. It's not. Here's why.
We define an "average" titanium frame as one of Seven's center of the bell curve butted titanium framesets. No rider would consider this frame to be flexible or lacking in performance, which means that using Seven as "average" is a more than reasonable baseline.
Drivetrain rigidity is a simple math equation. When you add these factors together, you get more than a 60% stiffness increase. Even with that, we are being conservative in our promises about the Lion.
It all starts with oversized materials that we tune for the bike's requirements:
The Lion's LOSO drivetrain is more than 40% stiffer, on average, than performance carbon road frames we've tested.
Here's how we define this:
Are there carbon frames with stiffer drivetrains than this limited edition frame? Sure, but we have yet to test one.
How can we claim such a stiff drivetrain but also achieve a smooth ride? It's simple, just not easy. We're able to isolate the vertical compliance — the static suspension of the bike — from the frame's lateral stiffness.
Torsional stiffness comes from three engineered factors: drivetrain stiffness in bending and torsion, head tube bending stiffness, and top tube torsional stiffness. We push these elements without creating a harsh ride.
Seven's LOSO tubeset encompasses a lot of what you see on this page — stiffness, control, performance, and size-specific tubing, to name a few.
LOSO stands for Lion of Spring Oversized. We first developed this frame kit for the Lion Limited, so the kit gets the Lion's name.
Here are a few of the benefits of the LOSO frame kit for the Lion Project:
Tubeset innovation history: Seven has been building butted framed bikes for more than 25 years. In fact, Seven's founding engineer, Rob Vandermark, invented the first process for butting titanium tubing more than three decades ago. Those first bikes were ridden by Greg LeMond and his team in the Tour de France. Since then, Rob has developed a number of other titanium butting methods. And every year, we find ways to refine and improve our frame kit designs. Our LOSO frame kit is the latest addition to our butting and design techniques.
Seven's Rider Ready program always incorporates size-specific tubesets. For the Lion LTD project, we have 16 distinct tubesets for the 16 Lion frame sizes.
Tube diameter is only one aspect of Seven's size-specific formula. Baseline wall thickness is also an important factor; we have multiple baseline walls for most tube diameters. We then individually design the tube profile, including wall thickness variation and butt lengths.
Each of the 16 tubesets is entirely different; each rides differently, and provides performance value you can feel.
Seven's Rider Ready designs for the Lion of Spring have size-specific tubesets. That allows us to match the optimal rider weight to the actual size of the bike. Seven's tubeset tailoring techniques include using many tube diameters and numerous butting profiles as frame sizes change.
Seven's rider weight limit recommendation is intended for optimal ride performance. If you, your gear, your hydration system, your saddle bag, etc., combined weigh more than recommended, the bike's performance will be hindered. However, in most cases, the bike will still handle and perform better than any stock bike.
Our weight limit is for the frame alone. Not all of the components we've chosen for this build have a weight limit rating as high as our frames. Check each manufacturer's specifications for safety recommendations and warranty.
| Seven Rider Ready Top tube length, cm[1] |
Ride weight limit, lbs.[2] |
|---|---|
| 49.0 cm | 170 |
| 50.0 | 180 |
| 51.0 | 190 |
| 52.0 | 205 |
| 53.0 | 220 |
| 54.0 | 235 |
| 55.0 | 250 |
| 56.0 | 265 |
| 57.0 | 280 |
| 58.0 | 290 |
| 59.0 | 300 |
| 60.0 | 310 |
| 61.0 | 320 |
| 62.0 | 320 |
| 63.0 | 340 |
| 64.0 | 360 |
Table footnotes:
At least two challenges exist when fitting a modern stock bike:
Fit and control are important stock bike challenges. Seven addresses both concerns with our Rider Ready program through the function of our NineEx Precision Fit.
Using the table below called Fit gaps in popular stock bike sizes, it is easy to see that many frame size gaps exist with stock bikes. To illustrate the challenge, the Size Gap table shows that average performance allroad bikes typically come in four to seven sizes. Conversely, Seven's Lion provides 48 distinct sizes and fit possibilities. That's about 8-fold more specificity for your fit, handling, and performance. Of course, you're only interested in the size you need, not the entire size range.
For example, if a rider wants a 55.0 cm top tube, that person is probably close to "average" size. With three of the four most popular performance carbon bikes (in the size gap table below), the rider can get a frame within 0.3 cm larger or smaller than a 55.0. That's pretty good. However, if the rider wants to size up 1.0 cm because the person needs a bit more handlebar height, the rider is out of luck. If the rider wants to size down by 1.0 cm (maybe for a more aggressive position), only two of these four brands might have this covered.
At best, three of the four brands have potentially two sizes to choose from. That's not bad, but a 55.0 top tube is about as popular and average as can be, so there better be some options for optimizing fit; two is not optimal.
Seven, on the other hand, has nine sizes within about 1.0 cm of a 55.0 top tube. How can that be possible? Seven's Rider Ready designs. They are:
Do nine fit options provide a more accurate fit than two options? Probably. And keep in mind that handlebar height is usually the larger fit challenge with a stock bike. Seven offers nine frame stack heights covering about eight centimeters of height range! We have you covered!
Comparing Seven's 16 Rider Ready geometries to four popular carbon bike offerings.
Two of these brands are known for their sophisticated fit and geometry prowess. One of these brands is among the largest and most respected in the world. These are the representative brands' highest-end allroad models.
| Seven Rider Ready 16 sizes |
Brand A 5 sizes |
Brand B 6 sizes |
Brand C 6 sizes |
Brand D 4 sizes |
|---|---|---|---|---|
| 49.0 cm | ||||
| 50.0 | ||||
| 51.0 | 51.2 | 51.2 | ||
| 52.0 | 51.5 | |||
| 53.0 | 52.7 | 53.2 | ||
| 54.0 | 53.9 | 54.1 | 54.0 | |
| 55.0 | 54.9 | 55.3 | 55.3 | |
| 56.0 | 55.9 | |||
| 57.0 | 56.8 | 56.8 | ||
| 58.0 | 58.2 | 57.5 | ||
| 59.0 | 59.2 | 59.1 | 58.9 | |
| 60.0 | ||||
| 61.0 | 60.7 | 60.8 | ||
| 62.0 | ||||
| 63.0 | ||||
| 64.0 |
The popular measurement "frame reach" is a poor gauge of proper bike fit. The classic "top tube" measurement is much more helpful in determining the right fit of a frameset.
Here are some of the factors that frame reach does not and cannot take into account. All of these are significant facets of a bike's true reach. At its most basic and helpful, reach means the distance from where you sit on the saddle to the grips. Frame reach provides about half of the data needed to determine an ideal riding reach. Meaning it is impossible to get your ideal fit by using frame reach.
In total, the variance could be nearly 30 cm of missed fit accuracy. On average, it's probably about 20 cm, but that's still a lot of reach information for a fitter forego by thinking that frame reach is a measurement of value.
Frame setback is the distance from the bottom bracket plumb line measured along the horizontal line from the head tube top face's axis back to the seat tube axis. Ironically, adding frame reach and frame setback together account for about 95%+ of the frame's effective top tube length; the term everyone used for decades as a measure of bike fit.
Regardless of frame reach's shortcomings, we include the information because it has become a popular industry shorthand for comparing one bike size to another. While the frame reach numbers Seven shows here are accurate, Seven does not take responsibility for an ill-fitting bike if a fitter chooses to rely on the industry's frame reach standards.
So, how does Seven recommend you determine proper frame size for your ideal fit — assuming you are looking at stock geometries? First, work with a professional fitter. Failing that, use frame stack and effective top tube length as a starting point. However, DO NOT order a bike based on this overly simplistic explanation. Go to a bike fitter.
We've built more custom bikes than anyone else in the world, surpassing 30,000 handbuilt framesets. Seven has been building bikes for more than twenty-six years. Seven's lead designer has been building titanium bikes continuously for more years than any other framebuilder ever, at thirty-six years of continuous designing and building. That's 70,000+ frames fabricated. No builder has more custom framebuilding experience than Seven Cycles.
Seven brings to bear all its manufacturing and materials knowledge to deliver the most finely tuned highest quality titanium frames available. This knowledge and heritage go into every frame we craft.
Is there anything more important than having smart, capable humans building your bike? We think not. Therefore, for this project, we've brought together our most experienced builders. Each team of three or four artisans has about 90 years of combined framebuilding experience. If that's not compelling, we don't know what would be.
While working on your frame, your framebuilder works on nothing else. This singular focus creates a better frame with more precise details.
There isn't a single piece of a frame that Seven's designers and engineers don't modify to improve. We don't use any prefab or off-the-shelf parts for any structural elements of our frames. From our dropouts to our head tube, and everything in between, it's all designed in-house.
Having complete control over every piece of the design results in a better-performing bike every time. In-house designs also ensure a more durable and rider-optimized frame.
Our founding team has been building titanium bikes continually longer than any other builders. In fact, Seven's founding engineer developed the first bike-specific 3-2.5 titanium alloy tube specfications and tubesets more than three decades ago. And every year, Seven finds new ways to refine and improve our tubeset designs, dropouts, and all the small parts.
Here are some of the universal defining characteristics of Seven's titanium allroad frames:
Titanium is a misunderstood material. It's most commonly misperceived that titanium frames are flexible or soft. There have been plenty of flexible titanium frames made – especially in the early days of titanium. However, because the material is so tunable and controllable, we can make a titanium frame extremely stiff if the rider desires that. We've built plenty of bikes for world champions and riders over 300 lbs. If you want stiff, titanium may be the ideal material with which to build your frame.
For example, Seven's LOSO frameset has a drivetrain that's 40% stiffer than popular performance carbon frames. About 60% stiffer drivetrain than the average titanium frame. And the LOSO is not our stiffest tubeset!
Just because titanium excels at providing a shock-absorbing ride doesn't mean it has to be plush. If you want your teeth to rattle, we can deliver.
Seven's Rider Ready Program is unique in the cycling world. The Program consists of predetermined frame geometries that fit 98% of riders. We have, on average eight-fold more size options than popular stock bikes for significantly better rider fit. The tubesets and frame kits are also predetermined, size specific, and tailored for the intended use. Each size has been vetted for optimal performance and handling. Each size is ready to build to order.
Seven's Rider Ready program provides a significantly more precise fit and much more tailored performance than any stock bike ever built. This precision results in four areas of riding excellence: Performance, fit, handling, and durability.
Ride faster in four dimensions: Accelerate quicker, climb more easily, descend with more confidence, and corner with more control. We achieve all this through a unique combination of drivetrain stiffness, tubeset tailoring, improved rider fit, and balanced weight distribution. If you want to unpack some of this, read all about our limited edition LOSO (Lion of Spring Oversized) frame kit and our NineEx Precision Fit designs.
Ride farther with more comfort: There are two distinct ways we accomplish this. First, our NineEx Precision Fit means a more accurate and easier fit. Second, Seven's use of titanium and proprietary tube modification creates a smoothness of ride that no other material or design can match. With these factors combined, riders tell us they are able to log higher speeds on longer rides and are fresher after. Remember, comfort is speed.
The average high-end stock bike comes in 4 to 7 sizes. Seven's typical Rider Ready project has at least 40 size offerings — usually 12 to 16 frame sizes, in 2 or 3 fit profiles, with 1 to 3 performance geometries. Seven's NineEx Precision Fit provides each rider 9 sizes to choose from versus about 1.5 size options from a standard production bike.
Seven's 40+ size options provide a much better fit than any stock bike ever made. Better fit means no component compromises. There's no need to change the stem, push the saddle fore or aft, or add or remove spacers from the fork system. These types of alterations degrade the handling and performance of a stock bike's original intent. Remember, perfect fit provides more speed.
Ride with more control and confidence: First, Seven designs all of our titanium frames to isolate drivetrain stiffness from the wheels' smooth tracking over terrain. We add vertical compliance, where it helps with control and handling while maintaining drivetrain and torsional stiffness to maximize watt transfer. Second, our NineEx Precision Fit ensures the best possible weight distribution between your tires' contact patches. Combined, you've got the best handling and controllable bike possible. More confident descending and faster cornering are the results. Remember, control is speed.
Speed and simplicity.
Choose Rider Ready over Seven's custom program if you want to ride sooner. The Lion of Spring is ready to build. For this project, we're able to cut the lead time to about nine weeks, more than 50% faster than our current standard lead time. How? There are no design decisions to make. No rider fit to confirm. Just choose your Rider Ready fit type, kit details, and color palette on these pages. We'll start cutting metal right away.