Cook Bros. Racing Technical Update

June 21, 1995
Subject: Inner Chainring Choices for Cook Bros. Cranks

When choosing an inner chainring for Cook Bros. cranksets, it is imperative to use one that has counterbored bolt holes.

Non-counterbored chainrings prevent the inner chainring bolts from sufficiently threading into the spyder (CBR, RSR and RS models) or crankarm (E Cranks only). Under this condition, the inner chainring bolts may pull out from the spyder/crankarm, causing the rider to lose control of the bike and seriously injure him/herself.

For example, Avitar, Bike-Pro, Quality Bicycle, and some other American made chainrings are not counterbored and should not be used with the Cook Bros. cranks.

Some examples of acceptable inner chainrings are Cook Bros., Action Tec, Shimano, Profile, and Real Design.

Additionally, using inner chainring bolts and spacers other than those provided with your Cook Bros. crankset will void your warranty. For more information, refer to crankset's instruction sheet.

Questions? Feel free to contact us at 805-343-2700, 8:00 am - 4:30pm Pacific Time, Monday through Friday for additional technical support.