Fenders
Mounting the cycle fenders to the Miata uprights
Overview
The Exocet kit includes eight fender mounts. Two fender mounts are used in each corner. Once installed, the fiberglass fenders can be mounted by drilling appropriate holes and using polyurethane adhesive to bond them to the fender mounts.
The frontmost fender mount is the one with three bolt holes that replaces the stock brake dust shield. The fender mounts that go on the back of the front corner and the front of the back corner are the same size/design and will bolt to the top caliper bolt. The rearmost fender mount is the one with the slightly longer mounting tab, meat to bolt to the nub on the non-ABS rear upright.
Note 1: Depending on the castings of the Mazda uprights and where you drill your hole in the fender mounting tab, you may need to take an angle grinder and remove a little material from the mounting tab on the fender mount for proper/secure fit.
Note 2: The fender mounts are made out of 1/2″ steel bar and are designed to have enough give to be bent a few degrees as needed for final fitting of the fenders. Once bolted down, you can bend them with your hands with a sizable amount of force.
Note 3: You may want to use a little thread locker on bolts, especially the top caliper bolts.
Note 4: In rare cases, some Miata donors may not have a nub on the rear upright and will require a steel angle bracket to be attached to the upright.
Front corner, front mount
Remove dust shield and replace with bolt on mount. Locking washers are recommended.
Front corner, rear mount
Note the angle and where it fits to be bolted via top caliper bolt.
(Note – the forward mount in this photo is the old style replaced by the new model that bolts to the stock brake dust shield location)
The front mount on the rear corner installs the same way as the one up front – bolts to top caliper bolt)
Rear corner, rear mount
Drill two holes and use bolts with locking washers and/or nylock nuts to secure to the nub in the rear hub.
First hole drilled:
Drilling second hole:
Note 1: You may want to consider grinding or filing the side of the nub flat for a better fit.
Note 2: Be aware of how close you drill the mounting holes to the center of the hub. If you drill the holes too close to the center of the upright you may have to grind down the top of your bolts to make them fit. Example:
In the case that you are using a Miata donor that had ABS, or if you have a Miata that does not have a nub on the rear upright, you may need to fabricate a small steel angle bracket like this:
Attaching the fenders to the mounts
There have been a number of ways builders have approached securing the fiberglass fenders to the steel mounts. The basic concept involves cutting a hole for the 1/2″ diameter bar to support the fender and then securing the bar to the underside of the fiberglass with polyurethane adhesive, P-clips, or welding a small tab to the fender mounts for a larger attachment point.
PU Adhesive Method
This is the classic method first recommended by MEV on the first UK Exocets. Exomotive used this method on XP-1 and we have now had it running for over 3 years on the street and track with fantastic results. This method involves roughing up the surface on the bottom side of the fender to ensure a good bond. We recommend using the highest quality polyurethane adhesives from manufacturers like Loctite, DAP, Liquid Nails, and others. A 10oz tube will cost between $7-15 depending on brand/purchase location. Use a healthy amount of PU adhesive to completely surround the entire 1/2″ bar and continue at least an inch in all directions on the underside of the fiberglass. After application and setting the final position, place a microfiber towel on top of the fender and place a few books or weighted items on top to keep slight pressure during the curing process.
P-Clip Method
Builder Geoff (Steadfast) used these 1/2″ P-clips to grip the bar then used allen-head bolts, metal washers with a rubber washer on the side that contacts the fiberglass, and nylon lock nuts to prevent loosening.
Welded Tab Method
Similar to the P-Clip method, this method involves welding a small tab to the 1/2″ bar to provide a place to bolt the fenders on. If your desire is to be able to run a number of different tire/wheel/offsets, you could consider adding a slot in this mount to allow the fender positions to slide and be set with bolts in the optimal position for the wheel/tire/offset combination selected.
UK Builder JGilbert took this method a step further and fiberglassed small stainless steel plates into the underside of the fenders. Read more on page 21 of his build thread.