To put it on a trainer or make it a bike? Trek Catalog from 1992 https://www.retrobike.co.uk/threads/1992-trek-8900.330139/ https://www.pinkbike.com/buysell/3009707/ https://www.mtbr.com/threads/spindle-size-for-1992-trek-8900.1149571/ https://www.ebay.com/itm/314437469349?hash=item4935ef04a5:g:9n8AAOSw9olkCPxK http://www.vintage-trek.com/Trek-Fisher-Klein-Lemond/1992specmanualTrek.pdf