8 – FRAME AND FORK ALIGNMENT AND DAMAGE 8 – 9 FORK-BLADE-ALIGNMENT PROCEDURE Even when symptoms indicate that there is need to correct only width error or only centering error, a procedure should be used that corrects both. The rea- son for this is that if only one type of error exists it is likely that the other error will be created while cor- recting the original error. The following procedure is designed to correct both types of error simultaneously. The procedure is based on the assumption that any width or centering error of more than 1mm would create a tracking problems or wheel-fit problem. If, after correcting a centering error, the remaining width error creates no additional symptom(s) (check by installing and removing wheel), then there would be no point in correcting any re- maining width error. In addition to centering error and width error, fork blades can have a fore-and-aft error. This type of error exists if one dropout is further forward compared to the fork crown than the other dropout. Although there would be no negative symptoms if a fore-and-aft error existed without centering or width errors, the existence of a fore-and-aft error can make the wheel appear misaligned to the rider when it is not. It is also inconsistent with good mechanical tech- nique to have the fork out and in the jig to align the width and centering errors, but ignore the fore-and-aft error. Finally, looking for fore-and-aft error can help iden- tify a fork that has been damaged in a crash or ship- ping. It is normal to see a fore-and-aft error of up to about 2mm. If significantly more error than this is seen, then it is likely that the fork is damaged. The fork should be inspected thoroughly before proceed- ing further. PREPARATIONS 1.   [ ] Use appropriate procedures/worksheets to remove fork from bike. In the next step, front-hub-over-locknut width is measured with calipers and recorded. It is not neces- sary, but would be handy if the calipers were locked at this setting until step #16 is completed. Over-locknut width 8.14  Measure front-hub-over-locknut width with calipers. 2.   [ ] Measure front-hub-over-locknut width (front-hub locknut width: _________mm). Align and secure fork in jig The Park FCG-1 has three interchangeable clamp- ing blocks for 1", 1–1/8", and 1–1/4" fork columns. The older Park FT-4 fits 1" only, and the VAR 478 fits all sizes without changing blocks. NOTE: Skip step 3 unless using a Park FCG-1. 3.   [ ] Secure correct block inside Park FCG-1 (skip if using Park FT-4). Depending on the brand and model of fork jig used in the next step, it is possible to insert the fork column too far into the jig. This is not possible with the Park FCG-1, but with the other models make sure that the clamp of the jig does not go on the fat portion at the base of the fork column, or on the fork-crown race. Do not secure the clamp at this time. It will be secured in step #8. 4.   [ ] Slip fork column into jig until crown race or fork-column base is against, but not inside, jig clamp. Do not secure clamp now! In the next two steps, the sliding gauge is set so that it can be used to align the fork in the jig before securing the jig clamp. The sliding gauge is positioned above the fork blades just below the point they join the fork crown (or where the blades begin curving in- ward, if the fork is a unicrown style). The sliding gauge must be secured on the main bar before bringing it down against the fork blades in step #7. 5.   [ ] Move sliding gauge to position that will con- tact fork blades just below fork crown. 6.   [ ] Secure sliding gauge. 7.   [ ] Swing main bar down until sliding gauge is firmly against both fork blades. With the sliding gauge positioned and secure, and the fork still loose in the clamp, applying pressure down on the main bar will automatically bring the