How To Choose Right Mountain Bike Size: A Complete Guide

It is imperative to understand your needs and whatever the bike has to offer before investing in it. Although it may not seem much, the difference the right bike and size can make remains massive.

The importance of the right bike size goes beyond being comfortable; it prevents injuries ranging from back pain to crash risks and having a fulfilling experience while riding with better controls and faster gears. Casual riding might not be of great concern, but the right size is of utmost importance for people looking to fit it into regularity.

But there is no set way to the sizing chart. Many factors like manufacturer’s, height, frame size, etc., play an integral role and demand to be considered. However, there always are options to tune it into that perfect fit manually to some extent. Let us look at some key points you need to keep in mind while choosing your ride.

What are sizing issues?

Before diving into how to choose the right size, let’s look at where the problem lies. Primarily, mountain bikes come in three sizes – S, M, and L, but it isn’t that simple with different brands using different ranges for their sizing guide, causing confusion among many.

There is little consistency in frame size; instead, they are o’en sized by their seat tubes’ length, a traditional method. But, this is faulty as the proper measuring ground is not fixed; some use the top of the seat tube to measure, while others reckon it to be in the middle of where the top and seat tube joins.

The most recent technique used by brands is to use reach figures in place of top or seat tube lengths. Let’s see what reach is.

The Importance Of Reach As Measurements?

As the name suggests, reach is the distance between the top center of the head tube to the bottom bracket axle and is an essential factor in deciding how accessible and comfortable the bike feels. A cramped bike or an overly stretched bike, both are a misfit.

The reach figures are mostly included in a bike’s geometry charts; if not, there is always a manual way to measure. An additional thing to note is that its reach is fixed for any mountain bike, unlike other variable attributes like seat tube length.

A perfect setup of both seat tube length and reach works efficiently in giving the desired comfort. Though, in case of little tuning differences, one can move the saddle up and down to adjust the seat tube length. For e.g., if someone with a smaller height wishes to ride a bike with a bigger reach figure, they can lower the seat tube length to accommodate the difference. This might not be the best adjustment, but it works efficiently in reducing minor faults.

However, it is always smart to consider the reach, seat tube, and top tube length before buying it to prevent further complications.

A Basic Size Guide –

The guides may vary as per the brands, and it is best to choose a perfect size depending on those measurements. Although, to give you an idea, below are some basic guideline for that ideal frame size –

XS – 13in – 14in (152 – 162cm (5’ – 5’ 4’’))
S – 14in – 16in (162 – 170cm (5′ 4″ – 5′ 7″))
M – 16in – 18in (170 – 178cm (5′ 7″ – 5′ 10″))
L – 18in – 20in (178 – 185cm (5′ 10″ – 6′ 1″))
XL – 20in – 22in (185 plus (6’ 1’’ plus))

It is important to note here that this chart is prone to changes at all times and might be subjective to factors like the type of bike ( hybrid or cyclocross, or road).

Choosing The Perfect Ride –

Minor differences and fits can hugely impact the overall experience and feel of your mountain bike. Only a highly experienced biker can tell apart bikes that look precisely the same. We often overlook certain factors ranging from as apparent as the standover to the tire pressure, accommodating ourselves to the bike and not the bike to fit our needs.

The three major and apparent places of contact while riding a bike are – Bars (hands), the Pedals (feet), and the saddle ( the seat ). These three figures are the deciding ground for the experience while also influencing the other functions of the bike like seat angle, etc.

Choosing a bike is one thing, and keeping it in the right setup another. A perfect bike with seamless fit may turn uncomfortable if not fine-tuned from time to time, as regular use may rearrange the initial adjustments. Below are a few crucial factors to keep in mind while buying or fixing a bike and their varying setups –

Standover

The standover is arguably one of the most crucial factors while choosing a bike, but what is it? Standover refers to the distance between the top tube and your crotch. This is while you’re standing in front of the saddle with a leg on each side.

There are two ways to measure the standover. Manually, as you stand as back as possible over the bike, ensure that a minimum space of an inch or two is maintained. Though, in case you are buying it online, you can also check for the geometry chart measurements. Several brands include the standover in their basic guide for easy accessibility, so measure the inside leg and check.

Interestingly, due to the top tube’s varying design and frame shapes, the need for standover distance may fluctuate. In some cases, the standover might not even matter at all.

Crank length

Most brands’ typical crank length is either 170 or 175mm, which is ideal for most riders. But, the cranks might turn out too long for someone with short legs, putting stress over the wrong muscles. Similarly, for people with longer legs, choosing cranks size a little longer than standard is undoubtedly better.

Saddle Height

A perfect saddle size and adjustments can significantly help you out in the focusing strength and balance. The saddle’s ideal length is when your feet are fully extended at the bottom of your pedal stroke, not restricting the flow or knee positioning in any way.

The wrong saddle length can quickly drain you of your energy from maintaining the balance and cautious pedal strokes. You do not want to bend to one side while pedaling, so it is always better to set the saddle height before each ride.

Seat Angle

The saddle and bottom bracket(cranks) are never aligned over one another to avoid your body’s excessive weight to stress over your arms as you lean forward. This is precisely why seat tubes are aligned at an angle to maintain body posture and overall balance while riding.

Since there is generally a set standard to the seat angle, not many alterations are needed.
Other necessary setups include – the top tube length, cleats, foot positioning, reach, and seat tube length.

For Women And Kids
Many brands have come forth with frames and styles to accommodate female body types and kids in recent years. However, many argue that these bikes are more on the unisex front than specifically designed for female riders.
Women have a different body proportion, average height, among other features that suggest the need to modify the frames and geometrical data accordingly. The ‘unisex bikes’ are in general more considerate and accommodating of both genders, especially for men with narrow shoulders and built.

For Women And Kids

Many brands have come forth with frames and styles to accommodate female body types and kids in recent years. However, many argue that these bikes are more on the unisex front than specifically designed for female riders.

Women have a different body proportion, average height, among other features that suggest the need to modify the frames and geometrical data accordingly. The ‘unisex bikes’ are in general more considerate and accommodating of both genders, especially for men with narrow shoulders and built.

Similarly, these accommodations generally revolve around designs with improved safety like easy brakes, among other considerations for kids.

The Downside of Wrong Bike Size

A bike on smooth terrain for once may accommodate the imbalance between a bike and its rider. But, it is an entirely different scenario for mountain bikes as it is typically made for rougher terrain.

The impact of injuries may range from mild aches to severe muscle damage and pains. Listening to your body and consulting doctors for injuries, no matter how minor, is the best to avoid future issues. Another thing is to take a test ride before you finalize buying it.