Hello!
This is Yoshimoto from Circles Tokyo!
It’s been a while since the release of the PBJ, the multi-purpose bike brought to you by SKLAR. It seems many of you are considering it, as we’ve been getting a lot of inquiries in the shop.
While Adam’s design philosophy and the story behind the PBJ’s development were introduced in a previous blog written by Shige-chan, this time we’ve put together a feature to uncover what kind of bike it really is, focusing primarily on its geometry and comparing it to others.
We compared it against the WILDE / Supertramp and the XC hardtail SPECIALIZED / Epic. It turned into quite an interesting deep dive, so please stick with us until the end.
Geometry Comparison
| Specs | PBJ (Size S) | Supertramp (Size S) | Epic (Size M) |
|---|---|---|---|
| Head Angle | 68.5° | 69.5° | 68.5° |
| Seat Tube Angle | 74° | 73.5° | 74° |
| Fork Offset | 52mm | 50mm | 42mm |
| Head Tube Length | 85mm | 130mm | 95mm |
| Top Tube Length | 617mm | 591mm | 604mm |
| Chainstay Length | 432mm (min) | 440mm | 430mm |
| BB Drop | 68mm | 66mm | 63mm |
| Tire Clearance | Max 29×2.6″ | Max 29×2.6″ | 29×2.35″ standard |
Many of you are probably wondering why the SPECIALIZED Epic was brought in for comparison without any clear connection. Looking at the comparison table, what do you think?
It’s surprising how many numbers are nearly identical.
So, let’s look at what kind of bike the PBJ is, bit by bit, based on its geometry!
The rear triangle that produces acceleration and directness
First, I want to personally highlight the chainstay length and seat tube angle.
| Specs | PBJ (Size S) | Supertramp (Size S) | Epic (Size M) |
|---|---|---|---|
| Seat Tube Angle | 74° | 73.5° | 74° |
| Chainstay Length | 432mm (min) | 440mm | 430mm |
| Tire Clearance | Max 29×2.6″ | Max 29×2.6″ | 29×2.35″ standard |
The seat tube angle affects the fore/aft position of the saddle, in other words, where you sit. A smaller angle shifts the center of gravity rearward, creating stability. Also, the frame flexes to soften road vibrations, making the ride more comfortable.
Conversely, a steeper angle shifts the center of gravity forward. This makes it easier to put your weight down and use your thigh muscles, leading to more efficient pedaling.
The length of the rear triangle greatly affects frame rigidity; longer stays offer better comfort, improved riding stability, and particularly allow for stable handling on descents.
On the flip side, shorter stays increase frame rigidity, which makes the ride stiffer, but improves power transfer and acceleration.
As you can see from the comparison table, these two figures are almost identical to the XC bike, the Epic. The chainstay length, in particular, is surprisingly short considering the tire clearance! (Incidentally, a 74° seat tube angle is comparable to a road bike, similar to the SURLY Midnight Special.)
In Japan, where constant steep climbs and descents are unavoidable, pedaling efficiency is extremely important. For gravel climbs where seated pedaling is required, this geometry turns your body weight and quadriceps power into forward momentum!
Handling with a balance of agility and stability
Next, let’s look at the parts that heavily influence handling.
| Specs | PBJ (Size S) | Supertramp (Size S) | Epic (Size M) |
|---|---|---|---|
| Head Angle | 68.5° | 69.5° | 68.5° |
| Fork Offset | 52mm | 50mm | 42mm |
| BB Drop | 68mm | 66mm | 63mm |
Handling is complex with various factors intertwined, so it can’t be compared simply. However, looking at the slacker head angle and lower BB height, you can see it’s a geometry that keeps the center of gravity low, allowing you to trace lines stably on descents. The shortest head tube length among the three models also allows for a more aggressive position, conveying that it’s built to keep your center of gravity low during descents.
Regarding the Epic’s figures, these are for the ROCKSHOX SID that comes stock, so you can custom-build it into an XC bike like the Epic by putting a 100mm front suspension on the PBJ!
With its short rear end, isn't this the perfect geometry for Japan’s narrow and winding trails?
A stoic nature that draws a line from touring bikes
By now, you should have a good image of the PBJ’s personality, right?
Don't be fooled by the cargo cage mounts on the fork or the eyelets for the rear rack and fender. I was tricked by them, too... haha.
The biggest characteristic lies in its stoic geometry. The more I looked into it, the more surprised I was that it’s so close to a racing hardtail—though that makes sense.
Before arriving at this bike, Adam went through a process of:
Hardtail bike
↓
Drop-bar gravel bike with 27.5″ fat tires
↓
Hybrid titanium bike that swallows 29×2.1″ tires
He has built and toured on various bikes.
It seems those experiences are what led to the inspiration for the PBJ!
My own Super Something is the same way, but isn’t building bikes with “geometry that isn’t straightforward” SKLAR’s greatest charm? A design that makes you see the roads you want to ride naturally creates an urge for the rider to head out.
Not only that, but the ability to change the ride feel with the rear slider dropouts is another highlight. Isn’t this truly the best multi-purpose bike created by Adam, who loves MTBs?
Circles Tokyo still has a small amount of stock, so we look forward to hearing from you!
