Effective Rim Diameter (ERD) is used to calculate spoke length when preparing to build a wheel. The measurements here are averages based on two measurements (90 degrees apart) of two rims of each type and different hole counts. These are provided as a guide only. Actual required spoke length could vary slightly from those calculated.

• Model 101 700c 30mm toroidal Al rim = 576.3mm
• Model 245 650c smooth Mid-v Tubular = 521mm
• Model 250 25mm deep, (red) Quick-V tubular = 596mm
• Model 255 700c 32mm deep, dimpled Mid-V tubular = 575mm
• Model 280 700c 38mm smooth Mid-v Tubular = 569mm
• Model 285 700c 44mm deep, dimpled Mid-v Tubular = 555mm
• Model 285v4 700c 45mm deep Mid-v Tubular ERD = 555mm
• Model 330 650c 58mm deep, smooth Deep Tubular = 484mm
• Model 360 700c 58mm deep, smooth Deep Tubular = 525mm
• Model 360 700c 58mm deep, dimpled Deep Tubular = 525mm
• Model 360v3 Tubular Firecrest = 525mm
• Model 370 650c smooth Mid-v Clincher = 518mm
• Model 415 700c 38mm deep, smooth mid-v Clincher = 569mm
• Model 417 700c 44mm deep, dimpled mid-v Clincher = 551mm
• Model 420 700c 82mm deep, dimpled Super Deep Tubular = 483mm
• Model 420v4 Tubular Firecrest = 483mm
• Model 460 650c 58mm deep, smooth Deep Clincher = 480mm
• Model 505 700c 58mm deep, smooth Deep Clincher = 529mm
• Model 505 700c 58mm deep, dimpled Deep clincher = 530mm
• Model 520 700c 82mm deep, dimpled Super Deep Clincher = 487mm
• Model 620 700c 108mm deep, dimpled, Extra Deep Tubular = 421mm
• 720 700c 108mm deep, dimpled, Extra Deep Clincher = 423mm
• CSC aluminum rim = 596mm

Spoke lengths used at Zipp in 2011 [xls]