I knew I would be getting large wheels even before I owned a YZ85. I googled specs and read forums to find out that a 16” rear tire fits the small wheel swing arm. Here are the parts needed to do this conversion. I also listed the parts which are optional.
Parts needed:
19”x1.40” front rim, 32 holes - Excel GBK404 $160
19” 70/100-19 front tube - Yamaha 942-27192-92-00 / Kenda Tuff Tube
19” front rim band - Yamaha 943-27191-11-00 $5
19” front spoke set - Excel XS0-41197 / Yamaha 4LB-25104-00-00 $80
19” front tire - 70/100-19 42M $50
16”x1.85” rear rim, 32 holes - Excel DDK404 $130
16” rear tube - Yamaha 942-09160-03-00 / Kenda Tuff Tube $15
16” rear rim band - Yamaha 943-30160-58-00 $5
16” rear spoke set - Excel XS0-41167 / Yamaha 4LB-25304-00-00 $75
16” rear tire - 90/100-16 52M
longer chain - Yamaha 9Y5-81971-21-00 or Pro Taper PT428MX
chain master link - Yamaha 946-81970-01-00
14T front sprocket
52T rear sprocket
Optional:
large wheel swing arm - Yamaha 4LB-22110-01-00
swing arm bearing kit - Yamaha 933-17217-46-00
longer rear brake line - Yamaha 999-99030-68-00
front hub
front hub bearings
rear hub
rear hub bearings
For riders of all sizes, the YZ85 with the bigger wheels should be a taller but more stable ride.