Guide · Bespoke frames
Getting a frame that fits
Start here
Your current bike is the best guide
If you have a bike you like, its numbers tell us more than any size chart. Look up your frame size on the maker's geometry page and note down the reach and stack, plus the head angle, seat angle, chainstay length and BB drop if they're listed.
Only have the top tube length and seat angle? That's fine: we can work reach out from them. Then ask yourself one question: what would I change? A little longer? A little higher at the front? Roomier tyre clearance? That answer is the brief.
In the frame designer, the Compare my bike tab lets you type those numbers in and draws your bike over the new frame, with the differences listed.
The two big numbers
Reach and stack
Reach
How far forward the top of the head tube is from the bottom bracket, measured level. It decides how stretched out or upright you feel. If a bike feels cramped, you want more reach; if you're reaching for the bars, less. As a rule of thumb, 10 mm of reach is about the same as 10 mm of stem length.
Stack
How high the top of the head tube is above the bottom bracket. It decides how high your bars sit. Back or neck ache on long rides often means you want more stack; if the front wheel feels light on climbs or you want a racier position, less.
Reach and stack are better than top tube length because they don't change with the seat angle. They're the numbers we start every design from.
If you don't have a bike to copy
Starting from your body
Measure your height and your inside leg (stand against a wall with a book pushed up firmly between your legs, and measure from the floor to the top of the book). In the designer, the Find my size tab turns those into a starting point: roughly 2 mm more reach for every centimetre of height, and about 6.5 mm more seat tube for every centimetre of inside leg.
It's a start, not an answer. Riding style matters as much as your measurements: someone who races wants a longer, lower position than someone who spends a day on a gravel track with a bag on the bars.
The other numbers
What else is worth a thought
Head angle
Steeper steers quicker and feels lively; slacker feels calmer at speed and on steep descents. Mountain bikes run slacker than gravel and road bikes.
Seat angle
Steeper puts you more over the pedals, which helps on climbs and for a forward riding position.
Chainstay length
Shorter feels playful and keeps the back wheel close; longer is steadier and fits bigger tyres. With 32-inch wheels it also keeps the tyre clear of the seat tube.
BB drop
How far the bottom bracket sits below the axles. More drop is a lower, more stable bike; less drop gives more clearance over rough ground.
Head tube length
Sets how high the bars are, together with stack. A longer head tube is a more upright position without stacking spacers under the stem.
Fork length and offset
A longer fork lifts and slackens the front end, and changes how the bike steers. We keep the head tube length and the front wheel position consistent for you.
Seat tube length
Matters for standover and how much seatpost you need, and for fitting a dropper post. Shorter lets you run a longer dropper.
Tyre clearance
Tell us the biggest tyre you might ever want. It's easy to design room in; impossible to add later.
Wheel size
29-inch, 32-inch, 700c or 26-inch fat bike. The wheel changes the whole front end, so each frame type has its own sizes and limits. See our guide to 32-inch wheels.
Put it together
Design it, then we check it
Open the designer, choose a frame and a size, and change what you like. The drawing is to scale, with the wheels on the ground, and it warns you if a tyre would touch the frame or your heel would hit the chainstay. Send it to us and we go through every number for a frame that rides well before we draw it in CAD for you to approve.
Questions
Frame sizing FAQ
What if I'm between sizes?
That's exactly what bespoke is for. Instead of choosing the nearest size and fixing it with a stem, you choose the reach and stack you want. Most people between sizes want a slightly longer reach with a standard stack, or the reverse, and that's easy to draw.
Can you copy the geometry of a bike I already like?
Yes. Send us the make, model and size, or its reach, stack and angles, and say what you'd change. In the frame designer, the Compare my bike tab draws your numbers over the new frame so you can see the difference.
Do I need a professional bike fit?
No, but if you've had one, send us the numbers and we'll build around them. If not, your current bike and your height and inside leg are a good starting point, and we check every design before we quote.
How long does a bespoke frame take?
About 12 weeks from the day you approve the CAD drawing, and up to three revisions of the drawing are included.
What does it cost?
From £1,999, or £2,199 for mountain, 32-inch gravel and fat bike frames. UK delivery is free, and the options list on the frames page shows what each extra costs.
Can you build the frame into a complete bike?
Yes. We do full builds: tell us the groupset, wheels and finishing kit you want and we'll price it as a complete bike.