Bike Size Guide
For kids bike sizes, use the method below. For Adults, refer to the geometry charts below.
The best way to size your rider’s new bike is by Inside Leg measurement, as there is a large spread of leg lengths/heights for each age. This is easy and only takes a few seconds;
- Stand your rider in socks against a wall
- Put a small book between their legs (like a saddle, high as comfortable) and against the wall
- Ask your rider to move away, measure from the top of the book to the floor, using cm or inches.
We list Minimum Inside Leg our kids race bikes (full Geo listed below for Adult bikes) on each product page. We measure from the floor up to the top-tube, in-front of the saddle, then minus 2-4cm for shoes, depending on age...
The chart below lists HUP bikes approx dimensions, when built to a standard spec. Using 650b (on a 700c frame) = 3cm lower standover. Flat bar builds (on a drop bar bike) = suitable for a 5cm shorter rider...
HUP evo:
44cm: Seat Tube 44cm | VTT 50.5cm (49.5cm actual) | Reach 36cm | Stack 51.6cm | HT 100mm | HT Angle 70 degrees
48cm: Seat Tube 48cm | VTT 51.8cm (51cm actual) | Reach 37cm | Stack 51.7cm | HT 105mm | HT Angle 70.5 degrees
50cm: Seat Tube 50cm | VTT 52.3cm | Reach 37.3cm | Stack 53.4cm | HT 120mm | HT Angle 71 degrees
52cm: Seat Tube 52cm | VTT 53.8cm | Reach 37.7cm | Stack 54.5cm | HT 130mm | HT Angle 71.5 degrees
54cm: Seat Tube 54cm | VTT 55cm | Reach 38cm | Stack 55.7cm | HT 140mm | HT Angle 72 degrees
56cm: Seat Tube 56cm | VTT 56.2cm | Reach 38.9cm | Stack 56.5cm | HT 155mm | HT Angle 72 degrees
58cm: Seat Tube 58cm | VTT 57.4cm | Reach 39.5cm | Stack 58.4cm | HT 175mm | HT Angle 72 degrees
Standover (floor to top-tube, in front of saddle): 50cm: 74cm | 52cm: 77cm | 54cm: 80cm | 56cm: 82cm | 58cm: 84cm
HUP evo SL:
44cm: Seat Tube 44cm | VTT 54.5cm (52.3cm actual) | Reach 38.3cm | Stack 54cm | HT 120mm | HT Angle 71 degrees
48cm: Seat Tube 47.3cm | VTT 55.3cm (53.3cm actual) | Reach 38.9cm | Stack 56cm | HT 130mm | HT Angle 72 degrees
HUP straatrace:
Kids Sizes
37cm: Seat Tube 37cm | VTT 49.5cm | Reach 35.3cm | Stack 48.5cm | HT 90mm | HT Angle 70 degrees
44cm: Seat Tube 44cm | VTT 50.5cm | Reach 36.3cm | Stack 49.5cm | HT 100mm | HT Angle 70 degrees
48cm: Seat Tube 48cm | VTT 51.8cm | Reach 38cm | Stack 50.6cm | HT 105mm | HT Angle 72 degrees
Actual Standover (floor to top-tube, just in front of saddle nose): 37cm: 63cm | 44cm: 67cm | 48cm: 71cm
Size Guide (height/inside leg): 37cm: 125cm+ (59-69cm) | 44cm: 138cm+ (64-77cm) | 48cm: 145cm+ (68-78cm)
50cm: Seat Tube 50cm | VTT 52.3cm | Reach 37.3cm | Stack 53.4cm | HT 120mm | HT Angle 71 degrees
52cm: Seat Tube 52cm | VTT 53.8cm | Reach 37.7cm | Stack 54.5cm | HT 130mm | HT Angle 71.5 degrees
54cm: Seat Tube 54cm | VTT 55cm | Reach 38cm | Stack 55.7cm | HT 140mm | HT Angle 72 degrees
56cm: Seat Tube 56cm | VTT 56.2cm | Reach 38.9cm | Stack 56.5cm | HT 155mm | HT Angle 72 degrees
58cm: Seat Tube 58cm | VTT 57.4cm | Reach 39.5cm | Stack 58.4cm | HT 175mm | HT Angle 72 degrees
Standover (floor to top-tube, in front of saddle): 50cm: 74cm | 52cm: 77cm | 54cm: 80cm | 56cm: 82cm | 58cm: 84cm
HUP azure:
Kids Sizes*
37cm: Seat Tube 37cm | VTT 49.5cm | Reach 37.7cm | Stack 47.2cm | HT 90mm | HT Angle 71 degrees
44cm: Seat Tube 44cm | VTT 50.5cm | Reach 38.5cm | Stack 48cm | HT 100mm | HT Angle 71 degrees
48cm: Seat Tube 48cm | VTT 51.8cm | Reach 39.5cm | Stack 49cm | HT 105mm | HT Angle 72 degrees
Standover (floor to top-tube, in front of saddle): 37cm: 63cm | 44cm: 67cm | 48cm: 71cm
Size Guide (height/inside leg): 37cm: 125cm+ (59-69cm) | 44cm: 138cm+ (64-77cm) | 48cm: 145cm+ (68-78cm)
Adult Sizes
50cm: Seat Tube 50cm | VTT 53.1cm | Reach 39.8cm | Stack 50.5cm | HT 110mm | HT Angle 73 degrees
52cm: Seat Tube 52cm | VTT 54.4cm | Reach 40.5cm | Stack 52cm | HT 120mm | HT Angle 75 degrees
Standover (floor to top-tube, in front of saddle): 50cm: 74cm | 52cm: 77cm
HUP xc:
13": Seat Tube 33cm | VTT 53cm | Reach 37.2cm | Stack 57cm | STA 75 deg | HT 9cm | HTA 67 deg | Stays 425mm
15": Seat Tube 37.5cm | VTT 56cm | Reach 40cm | Stack 59cm | STA 75 deg | HT 10cm | HTA 67 deg | Stays 430mm
17": Seat Tube 42.5cm | VTT 60cm | Reach 43cm | Stack 61cm | STA 75 deg | HT 11cm | HTA 67 deg | Stays 430mm
19": Seat Tube 47.5cm | VTT 63cm | Reach 46cm | Stack 61cm | STA 75 deg | HT 11.5cm | HTA 67 deg | Stays 430mm
Actual Standover (floor to top-tube, in front of saddle):
13" (27.5"/100mm): 63cm | 15" (29"/100mm): 68cm | 17"(29"/100mm): 74cm | 19"(29"/100mm): 78cm
Tip: If you size with the saddle slammed, they've no room to move, so (unlike Road/CX) it's better to size down.
Size Guide (height/inside leg):
13": 125cm+ (62cm+) | 15": 145cm+ (66cm+) | 17": 155cm+ (72cm+) | 19": 165cm+ (76cm+)
Dropper Fitment: If you require a dropper post, the riders Inside leg needs to be at least equal to Seat Tube Length + Crank Length + Dropper Travel + 100mm to use the full dropper travel, otherwise only some travel will be useable.
HUP xc20/xc24:
20": Seat Tube 24cm | VTT 45cm | Reach 31cm | Stack 45cm | STA 74 deg | HT 9cm | HTA 66 deg | Stays 340mm
24": Seat Tube 30cm | VTT 49.5cm | Reach 35cm | Stack 53cm | STA 75 deg | HT 10cm | HTA 66 deg | Stays 385mm
Actual Standover (floor to top-tube, in front of saddle):
20" wheels (80mm fork): 53cm | 24" wheels" (100mm fork): 63cm
Tip: If you size with the saddle slammed, they've no room to move, so (unlike Road/CX) it's better to size down.
Size Guide (height/inside leg):
20" wheels: 105cm+ (49cm+) | 24"wheels: 115cm+ (58cm+)
Dropper Fitment: If you require a dropper post, the riders Inside leg needs to be at least equal to Seat Tube Length + Crank Length + Dropper Travel + 100mm to use the full dropper travel, otherwise only some travel will be useable.
HUP air24:
Short: Seat Tube 29cm | VTT 50cm | Reach 34.8cm | STA 73.5 deg | HT 8.5cm | HTA 69 deg | Stays 363mm
Long: Seat Tube 31cm | VTT 54cm | Reach 38.3cm | STA 73.5 deg | HT 10.5cm | HTA 69 deg | Stays 363mm
Actual Standover (floor to top-tube, in front of saddle):
Short: 62cm, Long: 63cm
Size Guide (height/inside leg):
Short: 125cm+ (60cm+), Long: 140cm+ (61cm+)
Component Sizing Guide
Drop Handlebars: match the approx shoulder width for Road, or shoulder width +1 size up for Cyclocross
Flat Handlebars: match the approx width of their press-up position (go narrower for XC, wider for Enduro)
Kids Cranks: take 10% of their height +5mm for crank length (Road & Triathlon cycling) or 10% of their height +10mm for crank length (Off-Road cycling). Example: 1350mm tall rider would choose 140mm for Road bike or 145mm for CX/MTB.
Stems: This isn't an exact science, but generally if the rider is at the lower end of the frameset's growth range, a shorter stem will be correct and vice-versa.
Saddle/Post: Our kids saddle is suited to younger riders and the Youth saddle for older riders (or younger riders Off-Road). Youth, XC and Gravel saddles are all perfect to Adults. We have 2 choices of seat post, inline or rotary, the later is very useful for smaller riders at the lower end of the frameset's growth range being reversible to reduce the bikes effective length.
Kids Clothing Size Guide
Sizing Guide for HUP cycling clothes: Cycling Jerseys, Bib-Shorts and Bib-Tights.
It's best to use Age as a guide, but the Measurements as a rule:
| CHEST | WAIST | HEIGHT | AGE | |
| SIZE 1 | 63-68 | 57-62 | 116-125 | 6-7 |
| SIZE 2 | 69-74 | 63-69 | 126-135 | 7-8 |
| SIZE 3 | 75-80 | 70-75 | 135-143 | 8-9 |
| SIZE 4 | 81-86 | 76-81 | 143-150 | 9-10 |
| SIZE 5 | 87-92 | 82-86 | 151-157 | 11-12 |
| SIZE 6 | 93-98 | 87-92 | 158-163 | 13-14 |