Human specific geometry

 

 

Because Knolly frames feature a continuous seat tube they allow for a full range of seat heights: on many other frames, the seat tube is either bent or interrupted by the shock allowing only a restricted range of seat heights (this problem is exasperated as frame sizes become smaller). Our frames feature both a continuous seat tube as well as a low “dropped seat height” - meaning the seat actually travels forward and out of the way - which allows riders of all sizes to get farther back on the bike when the terrain demands it. 

For taller riders -  The ability to run the latest dropper posts is mandatory in order to achieve proper climbing height, and still be able to drop it down low(175-200mm). Running these posts (with long insertion depths) is impossible on interrupted/bent seat tube designs. In fact, Knolly is one of very few bikes that can actually run the latest 200mm dropper posts. Our seat tube angle is optimized to make sure the rider is in a very effective pedaling position while climbing with the added benefit that the top tube length effectively grows when the seat is raised which allows the rider to have increased reach when necessary (without placing the rider "behind the bike").  

 

For smaller riders - Frame fit is an absolutely critical part of the purchasing process. Proper stack-height and stand-over measurements can be a make-or-break proposition. Add a longer shock into the mix, and most frames start getting too tall to continue the conversation. One of the side benefits of Knolly's Fourby4 design is the ability to accommodate smaller riders, even with up to 170-200mm of rear suspension travel. This keeps the shock mounted low which means we can drop our top tubes for better stand-over clearance. It also means the center of mass on the frame is low and that equates to exceptional handling in technical terrain. Smaller riders can run a 150mm dropper post on our bikes due to the low stand-over height and straight seat tube. 

Geometry - Is the single most important factor that determines how a bike is going to ride. A simple 1 degree difference in headtube angle can make the difference between feeling ‘sketchy’ or confident. We design all of our bikes to make the rider’s position on the bike a source of confidence, since when you’re feeling confident, you’re having fun. All Knolly models provide a comfortable, confident ride by utilizing a few key concepts:

Standover height - We design all models in all sizes to have very low standover measurements. This helps the rider feel ‘in the bike’ instead of ‘on top of the bike’. Low standover also helps with cornering and maneuvering, allowing the rider to lean the bike over while maintaining proper center of gravity.

The 'Attack Position' - This is the position you assume when you are out of the saddle and ready to descend. This must be a position of total balance, where the rider can shift weight in any direction equally, and manipulate the bike as terrain and obstacles dictate. Proper balance is achieved in design by having reach measurements that coincide with the total length of the bike. This puts the rider in the middle over the bike, feeling confident.

 

Front end stack height - Another key to proper geometry. All Knolly models feature very short headtubes, which keeps the front end stack height as low as possible. This allows the rider to get over the front wheel, which is a key to proper traction and balance. This concept’s importance becomes magnified when the wheel size starts to grow. The headtube on our 27.5 models are among the shortest in the industry, ensuring that the rider can still get over the front of that taller wheel. Short headtubes also allow for longer travel forks that won’t throw intended geometry out of balance.

Chainstay length - This is a highly debatable topic. It seems very trendy these days to have chainstays that are as short as possible. Here at Knolly we focus on balance. We design each model with stability and predictability as top priorities for all types of terrain. So depending on the model, you’ll see a chainstay length that will be appropriate for maneuvering and stability at high speeds.

 

So when you combine some of the industry's lowest stand-over heights (on all frame sizes) with our continuous seat tube, and our 'way-before-it-was-cool' long/low geometry, the Knolly simply feels right... 

The ethos of Knolly’s frame designs is to allow the rider to transition effectively between a highly efficient pedaling position and the “attack position” required for aggressive riding (and be comfortable anywhere in between). The key feature allowing this seamless transition is the offset straight seat-tube, which positions the saddle in an efficient & comfortable climbing position, then moves the saddle downward and forward in the dropped position. Knolly pioneered this technology back in the early 2000’s, and it’s now becoming the de facto way to design most modern mountain bikes. This design element is critical in allowing maximum rear wheel travel while keeping rear suspension elements and the rear wheel away from the seat tube under full compression.

Offset Straight seat-tube advantages are:

+The actual seat-tube location can be designed so that the bike has a steep effective seat position when pedaling and / or climbing (74.5°– 75.5° effective seat tube angle). (The blue dotted line running from the BB to the seat in the illustration below)

+ The saddle not only lowers, but moves forward when dropped, allowing more room to maneuver above and behind the bike (The red dotted lines in the illustration below).

+ The longest possible dropper posts will fit into the frame because the seat-tube is straight and

uninterrupted: many of our frames will support 175mm and even 200mm dropper posts. It’s commonplace for our smaller riders (5’1” – 5’2” in height) to be able to use 150mm dropper posts in their frames. (The green dotted line in the illustration below)

+ No possibility of rear wheel / rear suspension elements colliding with the seat tube / saddle under full compression.

+ Amazing stand-over clearance.

Effective Top Tube explained. 

The definition of Effective Top Tube (ETT) length and how it compares to the traditional Actual Top Tube (ATT) measurement can be confusing.  Almost all modern full suspension mountain bikes use an ETT because conventional seat-tube locations do not integrate well with today's modern bike geometries. This is why Reach and Stack measurements have become more relevant in the industry. When deciding on bike fit: ETT, Stack and Reach are the best measurements to use.  

 

Some notes on ETT vs ATT:

+Our ETT and ATT are designed to intersect with the saddle at normal pedaling height : this ensures that the ETT accurately represents the ATT when pedaling.  Given that the angle between the ETT and ATT is typically well under 10 degrees, the saddle position won't deviate far from the theoretical for riders who are slightly above or below the ETT / ATT intersection point (this is illustrated by the blue and green dotted lines as they converge near the rails of the saddle).

+It is difficult to accurately measure the ETT with a tape measure: this measurement is designed into the frame which is then manufactured accordingly (illustrated by the horizontal blue line "A' above).

+Many riders measure the ATT ("B" in the illustration above) and become concerned that they've purchased a frame that is too small for them.  However, the ATT will always measure 1.0 - 1.5" (25-40mm) shorter than the ETT for Knolly frame models.

+If a bike is sized correctly no rider will position their saddle any where near the horizontal line drawn between the seat-tube (post) and the center of the head tube (the horizontal blue line "B" in the image above). In fact most riders saddles are significantly higher than this line so the ATT is not a good indication of top tube length. 

+The difference between ATT and ETT will vary slightly between frame model and size.

+We measure our effective top tube lengths off a line that extends from the center of the BB at roughly a 74° angle (image is not the engineering drawing so it is just a representation). (This is the blue line running from the BB to the seat in the image above).   ​

+The higher your saddle is, the closer it gets to this line. You can see in the image above that the center of the saddle intersects this ETT blue line.

Sizing help

In an effort to help you find the right frame size we reached out to our Knation of riders and asked them these three questions: How tall are you? What is your inseam? What size Knolly do you ride?

The data below is from real riders, human beings that actually ride our product, so it is a great reference point to help you chose a frame size. Of course this is still just a guide but this is a great example for those riders that fall right in between sizes. Now you can see what other riders have chosen. 

Rider Height

Rider Inseam

Frame Size

5'2

5'2

5'3

5'3

5'4

5'4

5'5

5'5

5'6

27.5

28

28

29

29

30

30

31

30

S

S

S

S

S

S

S

S

S

31

29

30

30

31

30

31

31

5'6

5'7

5'7

5'8

5'8

5'9

5'9

5'10

M

M

M

M

M

M

M

5'10

5'11

5'11

6'0

6'0

6'1

6'1

6'2

6'2

31

30

31

31

32

32

33

33

34

L

L

L

L

L

L

L

L

L

6'3

6'3

6'4

6'4

6'5

6'5

33

34

34

35

35

36

XL

XL

XL

XL

XL

XL

Sizing help

When we were developing our Cache we took advantage of the variety of riders we have in the company and Noels knowledge of how to fit a human on a bike. What we realized is that for Gravel bikes if you don't offer more than 5 sizes, every size you offer is a compromise.

 

We don't like compromises so we opted for 7 sizes and when you take into account the size of the frame, and the flexibility in cockpit set up, we know that our bikes are going to fit really well. 

© Knolly Bikes. 604-324-6635. Burnaby BC, Canada

 

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