RaYzerman19
Go Wings!
A UK rider with a 2013 AS (with ES), mileage 8k, has asked for assistance with a potential design issue. He has not been able to cure a front end shimmy or wobble issue with the normal fixes of checking steering head bearings per FSM, front end assembly, new set of tires, rebalancing, etc. Dealer has only the same recommended fixes. He removed the front wheel and fender, and when the forks are extended, discovered play (any lateral direction) of 1mm on one side and 1.5mm on the other. The dealer did the same to a brand new ES, and got 1.5 & 2mm play. Consultation with Yamaha Tech..... they said the service limit is 4mm.
Note, the FJR ES forks do not have bushings, but rely on the inner and outer fork tube sliding with each other. Comparison was also made to a Super Tenere ES, which has bushings, and the play is not evident. To repeat, this is with front wheel and fender removed, forks extended via the springs. If checked while wheel on ready to ride, the play is not detectable. Makes sense, axle/spacers/wheel is all captured to prevent side to side movement, forks now bound as a pair, and likely weight is too much to overcome easily to detect fore/aft movement.
My thoughts - More info required, i.e., remove the springs (leave oil in, perhaps compensate for no springs by adding oil) so more measurements can be taken at various engagements of the inner and outer tubes. It will be worst when fully extended and likely be progressively smaller as the forks are "compressed". The tubes will ride on a film of oil, as do bushed forks, and perhaps measurements should be taken without oil as well (if it were me, I'd just want to know, plus would like Yamaha Tech to know/check also). There is likely to be more play with no oil. I'm thinking if anyone is due for a tire change soon, perhaps someone would like to investigate further.
Back to the shimmy problem (hands off handlebars), I don't think technically one necessarily follows the other... is this play issue a problem or not, who knows at this point. I'm sure you folks will have some more thoughts........
Note, the FJR ES forks do not have bushings, but rely on the inner and outer fork tube sliding with each other. Comparison was also made to a Super Tenere ES, which has bushings, and the play is not evident. To repeat, this is with front wheel and fender removed, forks extended via the springs. If checked while wheel on ready to ride, the play is not detectable. Makes sense, axle/spacers/wheel is all captured to prevent side to side movement, forks now bound as a pair, and likely weight is too much to overcome easily to detect fore/aft movement.
My thoughts - More info required, i.e., remove the springs (leave oil in, perhaps compensate for no springs by adding oil) so more measurements can be taken at various engagements of the inner and outer tubes. It will be worst when fully extended and likely be progressively smaller as the forks are "compressed". The tubes will ride on a film of oil, as do bushed forks, and perhaps measurements should be taken without oil as well (if it were me, I'd just want to know, plus would like Yamaha Tech to know/check also). There is likely to be more play with no oil. I'm thinking if anyone is due for a tire change soon, perhaps someone would like to investigate further.
Back to the shimmy problem (hands off handlebars), I don't think technically one necessarily follows the other... is this play issue a problem or not, who knows at this point. I'm sure you folks will have some more thoughts........