Sizing guide

Getting the fit right

The sizing recommendations for Starling frames are given in the geometry charts on their respective pages.

These are what I recommend. Don’t be tempted to try and be fashionable and size up to a bike that’s too big for you.

But if you are a little confused, or would like to compare to your current bike, watch the video and then read the information below.


Effective Top Tube

Bikes have grown longer recently. Reach and wheelbase have lengthened.

This is good for bike stability and something Starling Cycles has pushed since day one.

Luckily, our bodies can easily accommodate this lengthening when stood up on the pedals.

But when seated it is harder to accommodate a bike length increase. So to counter this longer reach, seat tube angles have got steeper (be careful of some manufacturers who haven’t quite worked this out yet!). What we end up in is a position where to size a bike for the rider, the reach becomes less important, and the old measurement of effective top tube reverts to being the best to use.

Effective top tube (horizontal length from top of head tube to seat post) isn’t perfect, it doesn’t take into account saddle height, bar height, stem length and bar roll. But it’s pretty good. And with saddle and bar changes you can get something that fits you.

So in summary, long reach and wheelbase is good for bike performance, but not really a ‘ergonomic’ sizing measurement. Effective top tube is what you should be comparing when looking for a bike to fit you.

Seat Tube Length

An easy one. We just need to understand the pedalling height of your saddle, and the dropper you intend to use.

Measure your existing pedalling seat position at full extension; from saddle rails to centre of BB. For example, my measurement is 740mm.

You then need to compare this measurement by the extension of your chosen dropper, for example a 160mm BikeYoke dropper has a minimum extension of 202mm, and a maximum extension of 334mm.

For a large sized frame, seat tube is 440mm. Considering my saddle height, 740mm, minus minimum extension, 202mm, we have 538mm, so 98mm of post showing, all good.

For 740mm, minus maximum extension, 334mm, we have 406mm, so with a 440mm seat tube, we will not exceed maximum insertion.

Custom Sized Mountain Bike Frames

We’ll work with you to create the bike of your dreams with completely bespoke geometry, travel, paint and graphics. You’ll create a bike like no other that’s designed to perfectly match you, your style and your trails.

Our UK-made, custom frames allow you to choose reachseat tube lengthhead tube lengthhead angle and fork length. We can also customise travel to create short, mid or long travel setups.

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