Sutherland’s Handbook For Bicycle Mechanics (3rd Edition)
Date: 07/11/2009
Views: 261
Headset - 03
HEADSET:
MAVIC 310 (modified) - threaded headset - 1" (25.4 mm) x 24 TPI English / Italian thread - high strength Duralumin (aluminum alloy) construction - Clear anodized finish (...removed and polished to high luster) - 1/8" or 3.175 mm ball bearings with nylon retainers (...44 count total at 22 each upper and lower) - aluminum alloy upper and lower bearing cups with stainless steel race inserts - 26.4 mm stainless steel crown race - aluminum alloy top lock nut - C.N.D. (...Couche Noir Dure) hardened anodized locking washer - model 310 ... [Introduced for model year 1984, the MAVIC 310 headset was essentially a refinement of the original model 300 which had first appeared back in late 1978 (...both the 300 and 310 models were available in 1984 and 1985 with the 300 being deleted commencing with model year 1986 and the 310 continuing production until being superseded itself by the model 305 in 1989), and one which cost three times as much at retail than its predecessor. While the exterior form of the 300 and 310 models are nearly identical, significant differences can be found internally - the former being based upon an ingenious wholly integrated design of J.P.R. origin which utilized fewer parts, loose ball bearings, and (...unfortunately) aluminum alloy races which wore out far too quickly, whereas the latter incorporated precision stainless steel bearings housed in plastic retainers along with pressed and hardened stainless steel bearing races - a combination which resulted in considerable more durability. It is worth noting that both the 300 and 310 models of MAVIC headsets require specialized wrenches (...MAVIC part numbers 671 and 672 for the backyard mechanic or their 674 and 675 tools for commercial / professional use) in order to install or remove them without inflicting unnecessary damage (...albeit usually only cosmetic in nature). This is one of the major reasons why it can be so difficult to find a used version of these headsets today that has not been marred and/or scarred inasmuch as proper MAVIC tools or clones thereof are generally not easily acquired nor are they commonly found at your typical bicycle repair shop.]