What Bike Frame Size Do I Need

Riding a bike that doesn't fit is no fun. It's uncomfortable and yous adventure injury from being too cramped or too stretched out, but knowing what size cycle y'all should buy tin be a fleck of a minefield. So here's some advice to assistance you find the right size road bike.

Finding the right bike starts with the frame shape — traditional, semi-compact or compact — and size.

Two wheel models of the same stated size can also result in very unlike positions, so it's well worth reading up on the key numbers that bear on road cycle geometry, what they mean, and how they affect fit and handling to ensure you're buying the best road bike for your needs.

Getting a good fit means more than just having the right size frame. It besides means your bike fits at all the chief contact points: saddle, handlebars and pedals. Have a read of our guide to finding the perfect route bike position.

Beyond the master contact points, standover is also important. Y'all need to be able to place both feet apartment on the floor with at to the lowest degree a centimetre or so to spare at your crotch when standing astride the summit tube.

Of course, nosotros're non all the same shape and size, so use the information beneath as both a starting point and a guide. Once you've found the right size cycle and got your position close, you can make smaller adjustments to fine-tune the fit. You'll be able to get bike fit advice in person from a wheel store.

Nosotros likewise recommend taking whatever bikes yous are considering buying for a test ride to gauge how they feel in action. You want to brand sure yous're comfortable on a bike and check its treatment.

You'll also desire to brand sure there's enough range of aligning for you to tweak the fit one time you've bought the bike. Once over again, a reputable bike shop should be able to offer impartial advice, and you can also read our guide on how to buy a cycle.

Manufacturers' size guidelines

Frame sizes can vary significantly from one manufacturer to another.

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The simplest way to decide what size bicycle to get for is to use the guidelines bicycle manufacturers typically provide, which correlate diverse superlative ranges with unlike wheel sizes.

Still, as we've already alluded to, at that place are no standard sizes between the bike manufacturers. Each volition have its ain arroyo to bike blueprint, so it's useful to take an overall understanding of bicycle geometry.

How one make sizes its bikes may be very dissimilar from some other, so don't assume one model has the same fit as another, even if the stated size is seemingly the aforementioned.

Yous'll normally detect the frame size on the seat tube. Many route bicycle brands use seat tube length to size their frames. Watch out, however – how ane brand sizes its bikes may be unlike to another.

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Many manufacturers size road bikes past seat tube length (or a nominal seat tube length that imagines the bikes has a horizontal top tube, even if it doesn't), whereas mountain bikes are ordinarily sized as Southward, M, L etc. That's also a system used for some road bikes too. Disruptive, eh?

Almost bike makers volition as well quote stack and reach figures for their bikes because they are a useful way of comparing bike sizes and geometry between brands.

The advantage of using these figures is they are independent of frame angles – 2 different frames might have two different top tube lengths, but the same reach, with a divergence in angles making up the difference.

Many manufacturers size route bikes by seat tube length.

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If you're planning to buy a bike on the internet, it'south even more important to make sure that you've got your size correct. Many spider web-sales brands will suggest a bike size based on your superlative and a few other measurements.

That might exist fine if your build is pretty average and y'all're in the middle of a suggested height range, but if you're an outlier, we'd strongly recommend a wheel fit and a test ride to make certain that you purchase the correct size.

Some road brands use S, M, L etc to size their bikes.

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Beefcake of the bicycle frame

Bike manufacturers will normally list the measurements for each chemical element of a cycle'southward geometry, so knowing what each measurement refers to is the first step.

Employ the diagram below to help you identify the unlike tubes used on the frame of a road bike.

Seat tube length is often used to denote size, but top tube length is the more important number for establishing the right fit.

However, it'due south also worth noting that two top tube lengths may be quoted on a cycle's geometry chart: the length of the tube itself and the effective meridian tube, which concerns bikes that accept a sloping top tube (road bikes with a semi-compact or compact geometry).

We'll take a closer look at that next.

This diagram shows the various tubes that brand up a road bicycle.

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Frame geometries: traditional, semi-meaty and compact

In that location are three main geometries of frame to consider when ownership your commencement bike: traditional, semi-compact and compact.

Traditional bike frame

Traditional route bikes with a horizontal top tube that runs parallel to the footing are now rare.

Raleigh

Traditional frames are characterised by a pinnacle tube that runs parallel to the basis. There is a reduced space when continuing over the bike, though, and so sizing can be more critical hither.

Traditional frames were pop in the past, as you'd expect, merely it'southward much more mutual to see compact or semi-meaty frames on the latest bikes.

Meaty wheel frames

The Behemothic TCR, now in its ninth-generation, revolutionised route cycle geometry with the introduction of a compact frame shape and sloping top tube.

Behemothic

Meaty geometry frames are characterised past a sloping superlative tube, shorter wheelbase and smaller rear triangle of the frame. The result is more than standover clearance than a traditional geometry frame and possibly a stiffer, more than responsive ride.

Behemothic introduced the meaty frame shape with the launch of the TCR (which stands for Total Compact Road), and compact or semi-compact designs are at present ubiquitous across the latest road bikes.

With the sloping tiptop tube, wait to see an actress two to three inches of seatpost showing when compared to traditional bikes with a horizontal peak tube.

Semi-compact cycle frames

Semi-compact frame shapes, as seen here on the Rose Pro SL, are also popular.

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Semi-meaty geometry is similar to a compact with the only difference being that the sloping angle of the top tube is non as great, so the standover clearance is reduced and the effective summit tube distance is slightly longer.

The difference between a semi-compact and compact frame volition often be quite subtle, though.

Elevation tube length

Meridian tube length is a fundamental sizing measure – but beware, there's more than one way to mensurate a acme tube.

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The most important consideration to make as you decide which frame to go for is the effective top tube length: the distance from the head tube to the seatpost on a cycle with a sloping elevation tube, or simply the length of the top tube on a road cycle with traditional geometry.

If the tiptop tube is besides long, y'all'll exist overreaching to the handlebars, and your riding position will probable be more than aggressive, which could be uncomfortable on longer rides.

If y'all're looking for a more comfortable riding position then you may wish to go for a shorter effective top tube length.

Route wheel size chart

Use the chart beneath for a rough guide on the frame size to go for. Once more, we'd emphasise that this is a guide and should be used every bit a starting bespeak. If you're unsure, seek farther communication from your local bike store.

Tweaking the bike fit

In one case you have the right size frame, you can start to fine-tune the fit, including handlebar height, stalk length and lever position.

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Once you lot've decided on your frame size you can fine-melody your bike fit.

The next disquisitional adjustment to make is setting the bar and saddle height. Nosotros've got guides to adjusting handlebar height and setting the correct saddle meridian.

You may also want to adjust or change the stalk length because that can as well affect your attain – how far you are reaching forward to the handlebars – and besides the handling and functioning of the bike.

Further tweaks tin can include adjusting the fore/aft position and tilt of your saddle, the angle of your handlebars and the distance to the brake levers. If the handlebar shape isn't right for you, you lot may want to consider upgrading.

Cleats can be rotated to enable the shoes to be fixed at a position that's comfortable to you

Cleat position has a big bear upon on your overall fit on the wheel.

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Don't forget about your pedals either. If you're using clipless pedals, the position of your cleats can have a large touch on your overall comfort on the bike.

Many of these changes can be made in a skillful bike shop, though a bicycle fit is as well worth its weight in gilded if you really desire to punch-in your position. As part of a bike plumbing fixtures session, wheel fit experts will get yous riding on a fixed trainer to cheque your bike position and ensure everything fits you perfectly.

Women who have opted for a unisex bike may find our guide to the most common adjustments to make bikes more female-friendly useful, while nosotros as well have a guide to women's bike sizes.