Hi All!
My method to correctly fit mudguards and cut the stays to length is a little different, as described here previously. Some years ago, I figured there must be a better, quicker, less frustrating way and developed a method that works quickly and accurately for me.
I use a spacer taped to the tire to set the gap between evenly all the way 'round first. Vinyl tubing is a favorite spacer, though stacks of coins or washers at various points will also work nicely. Once the spacer(s) is (are) taped to the tires with vinyl electrical tape, I then tape the mudguard/fender to the tire over the spacers. Once the appropriate brake is locked with a stout rubber band, the wheel/tire/fender blade remains still and the lot is *so* much easier to work with. Once my tools and supplies are assembled, I can generally install a full set of mudguards evenly and accurately the first time in ~45 minutes. This method also makes it a snap to determine the vertical spacers and bolts needed if the underside of your fork crown and seatstay/chainstay bridges are threaded.
Only then do I dry-fit and size the stays. Since the fender blade is centered over the tire, I can be assured the stays will work if they are of equal length, so I generally only need to size one side, mark it, then remove it and use bolt cutters to cut close, using it as a model to size its mate on the other side. It is necessary to be sure the stay eyes are evenly centered on the dropout bolts or the blade may not be centered evenly over the tire. The cut stay end is then squared and slightly radiused (rounded) using my disc sander. As Dave thoughtfully notes, this prevents heat from the cutting operation from transferring to the plastic fender blade via the cross brace.
Depending on application, I generally do not cut the stay flush with the drawbolt, but allow it to extend a bit in case I later decide to fit fatter (and thus larger diameter) tires or need to make an adjustment in fender clearance -- as I do before venturing out on desert playa; if wet, the playa is sticky and so I require more clearance between 'guard and tire. Same for adding snow clearance as I ride over mountain passes to the high desert.
If the stays extend past the drawbolts, I use vinyl end-caps (available from PB here:
http://ecom1.planetbike.com/7007_9.html ) to prevent getting skewered on the bare stay ends. This happened to me once back in my uni days as I dismounted and upper rear mudguard stays became so deeply embedded in the the side of my knee, I could not finish dismounting alone and had to engage the help of some passersby to hold the bike and lift my knee off the embedded stay. Lots of blood and pale faces ensued in the excitement that followed.
I have capped my stays ever since.
I don't like the safety Seku-Clips used on stays mounted to the fork-end (dropout) eyelets; they are too flexible and allow some rattling and movement to occur on the rough logging roads where I often ride. Thorn places their mounts further up the fork blades to prevent the stay radius from tightening in the event debris is caught under the mudguard -- no safety clips needed. On my non-Thorn bikes, I mount the front stays to my fork's lowrider bosses, accomplishing the same end.
One other tip: I have found the standard drawbolt nuts with 8mm flats do not hold securely in my use on rough roads unless LocTited in place. A far better solution for my needs is/are the polished stainless drawbolt and 10mm nylock nut sets available at reasonable cost from Planet Bike:
http://ecom1.planetbike.com/7006_7.html PB has *all kinds* of nifty spares like stay release tabs, mudflaps
and spare stays that allow one to transfer mudguards from bike to bike without having to buy new mudguards. These spares are my first go-to before I start fabricating and milling things on my own. See:
http://ecom1.planetbike.com/smallparts.html They offer free domestic (US) shipping on all small parts orders; I think it is also free for Canada but am unsure about other countries.
Best,
Dan.
