Mr. Rando's talk on "Geometry"

Geometry refers to the overall dimensions and angles of each part of a frame.

It's the foundation that determines how a bike feels to ride and what kind of riding it's best suited for.

 

This time, we will introduce the details of the Sig. Rando's geometry.

 

The geometry of the Sig. Rando is the result of ideas from our staff member, Ikeda, who has assembled, ridden, used, and enjoyed many bicycles. He thought, "Wouldn't it be even easier to use if it had these specifications!"

When you encounter many bicycles for play, work, and daily use, there are points where you can't help but say, "What a shame!" For example...

・Full fenders can be installed, but your toes hit the tires, making them difficult to use.

・Thick tires can be installed, but a kickstand cannot be attached.

・It looks cool with a classic appearance, but it's difficult to customize...and so on.

 

Of course, we know that nothing in the world is perfect, but we wanted something that was as easy to use, easy to customize, and stress-free as possible. That's how this geometry was born.

 

The Sig. Rando frame is longer front to back, providing stability and comfortable riding.

It's designed to be "easy to use" for carrying luggage, for daily life, and for weekend cycling.

So, what makes it "easy to use"?

We will explain the specific parts by dividing the frame into ① front, ② middle, and ③ rear.

 

① About the front of the frame

The front fork of the Sig. Rando is bent (offset) further forward than a typical bicycle.

This is because we wanted to move the front wheel as far forward as possible.

There are two reasons.

The first reason is to prevent toes from coming into contact with the tires when "thick tires" or "full fenders" are installed.

Thick tires have a large air volume, providing a comfortable ride.

Full fenders are items that protect your body from water and mud splashes.

When these two parts were installed on a bicycle, toe contact often occurred in our previous customization experiences.

We wanted to ensure that the body would not come into contact as much as possible, allowing for a stress-free experience when using the bicycle.

This is the first reason.

The second reason was that we wanted to place the center of gravity of the luggage behind the front wheel axle, not directly above it.

The area in front of the handlebars (above the front wheel) is a very useful place to carry luggage for cycling.

However, if the center of gravity of the luggage is in front of the front wheel's axle, it can make steering difficult and reduce stability.

We wanted to make it easy to use even with a lot of luggage. This is the second reason.

 

② About the center of the frame

The top tube of the Sig. Rando frame is slightly longer (when measured horizontally to the ground) and adopts a sloping design.

For example, for a rider who is 170cm tall, it is about 10mm to 20mm longer than a typical bicycle.

This is because we wanted to create "extra space" for carrying luggage on the bicycle.

There are two reasons.

The first reason is to make bike packing easier.

A wider space is required to attach bags and bottles inside the frame.

Tent poles, hydration packs, and long or heavy tools are stable when placed in the central part of the frame.

Also, it's a common story that once a frame bag is installed, the space becomes too narrow to attach a bottle.

Therefore, the Sig. Rando frame is designed so that bottles can be attached to the lowest position on all sizes, while also securing space for a frame bag.

If the frame is long (the top tube is long), the handlebar position will also be further away.

Therefore, with the Sig. Rando, using a shorter stem than usual will result in a good riding position.

Since the frame is 10-20mm longer than usual, it would be good to use a stem that is 10-20mm shorter.

A shorter stem creates more space in front of the handlebars, allowing you to carry more luggage.

Also, when combined with a front rack, there will be space for your fingers between your hands and the luggage when gripping the handlebars, making the handlebars even easier to use.

When the frame has a sloping design, the seatpost inevitably extends further out.

Large saddlebags are often attached to the seatpost, so this space was crucial for easy bag attachment.

We wanted to secure as much space as possible to make it easy to carry luggage.

This is the first reason.

 

And the second reason was to secure distance between the toes and the tires.

In addition to the front fork section mentioned earlier, this distance was ensured by lengthening the central part of the frame.

 

Another point we want to mention about the design of the central part of the frame is the bottom bracket section.

The Sig. Rando has a slightly higher center of gravity than road bikes or gravel bikes in similar categories.

The reason is to make it easy to use with any of the three wheel sizes: 26 inches, 650B, and 700c.

The Sig. Rando allows for easy swapping of wheel sizes to enjoy customization. 

With a typical BB position, 26-inch wheels have a smaller radius, causing the center of gravity to drop too low, which can lead to a sluggish riding feel.

Additionally, the distance between the pedals and the ground becomes closer, making contact more likely, which is also undesirable.

Therefore, the Sig. Rando's BB is designed to be slightly higher.

With 26 inches, it allows for heavy cargo transport and leisurely city riding.

With 650B, it facilitates enjoyable riding for gravel and bike-packing tours.

With 700c, it allows for swift riding while maintaining easy handling, like a cyclocross bike.

We designed it to enable riding that leverages the characteristics of each wheel size.

 

 

③ About the rear of the frame

The rear part of the Sig. Rando frame (chainstay) is very "long".

This is because we wanted to make the bicycle more practically "usable".

There are two reasons.

The first reason was to prevent heels from hitting the rear pannier bags when installed. 

Even with large pannier bags, your body won't come into contact, allowing you to enjoy cycling stress-free.

The second reason was to make it possible to attach practical items.

Parts indispensable for everyday use, such as full fenders and kickstands.

To install them, it's important to have mounting space.

A dedicated mount for a kickstand is provided in the central part, making it easier to install the stand.

↑Here are the detailed geometries for the Sig. Rando's S, M, and L sizes.

The Sig. Rando frame comes in three sizes: S, M, and L.

S size (height 155-165cm), M size (height 165-175cm), and L size (height 175-180cm) are approximate guides.

The Sig. Rando is available as a frameset and complete bike.

・Frameset ¥129,800

・Complete bike (front single) ¥354,200

・Sig. Rando Shimano GRX Limited Model  ¥442,100

We also offer customization services to fit your desired parts.

If you are considering a purchase, please feel free to contact us.