Custom Sizing Made Easy

Building frames for myself over the past few years, I’ve managed to get the correct size for myself by iteration.  However, you don’t have this luxury and need to get the correct size and geometry on the first attempt.  This causes a great deal of ‘brainpain’ for some of my customers!

Starling Cycles offers: head angle, reach, seat tube length and head tube length options.  I’ll discuss each of these in turn and try to make the job of picking your ideal geometry as easy as possible.

Head Angle

Current fashion is for slack head angles.  However, this is great if you’re a good rider and can control the bike, but the less able among us might appreciate something slightly steeper. 

With each model I will give my head angle recommendation based upon my riding experience of the bike.  For example, for the Swoop Enduro race frame I recommend 66°.  My test bikes are 65°, this is great for the magazine riders who ride everyday.  But for myself, with my “fastest of the duffers” speed, 66° feel better. 


Reach is the dimension from bottom bracket (your feet), to the top of the head tube (your hands -ish).  This is quite a hard thing to measure.  However, measuring the length of the downtube of a bike is much easier, from BB centre to headtube/downtube centreline intersection.

So, if you’re not sure what reach you want.  Measure the downtube of your existing bike.  Then let me know if that feels good; or whether you want it longer (fashionable now) or shorter (fashionable 5 years ago).  I can then work out the reach from this dimension.  Fork length may have a slight impact on this, but if you let me know what you have on your existing bike, we can sort this out.

Seat Tube Length

Measure your existing seat position (from top of seatpost) at full extension.  Reduce this value by 350mm, i.e. the typical post extension from frame.  Job done! 

Head Tube Length

By default, frames come with a 120mm headtube. 

If you like your bars high, or are tall, you may want to increase this.  Although, for aesthetics reasons, too long may make the frame look a bit gate like. 

If you like them low, or are perhaps running a 29er front wheel, you may want it shorter.  However, 110mm is the shortest I can comfortably go.