INSTALLED : Top Hat Adapter on Wheel



Hi All,

I finally got a little time today and decided to get the Top Hat Adapter put onto a disc brake wheel to show you what it looks like installed....NOTE: I only had 2 old bolts here at the shop so that is why the sprocket is held onto the Top Hat Adapter with only 2 nuts and bolts instead of 9...The sprocket in the pic is a 34T Race Series Adapter Sprocket (race series means bevel machined off to save weight, adapter sprocket means center hole is 2.15 inches in diameter).

Hope this clears up some questions as to what the install looks like....

NOTES: Recommend using 1/2" bolts with thin heads and thin nuts for better clearance (can file or grind standard parts if needed)....Recommend slightly longer M5 bolts to mount the entire assembly to the disc hub...Use washers (or special disc rotor spacers available at bike shops) to center rotor in relocated disc caliper...Can use old 9 hole metal mounts (HD 9 hole mounts only not standard 9 hole mounts (6MM bolts) or washers to space sprocket closer to spokes if needed....The Top Hat Adapter in the pic has additional lightening holes machined in.....I was just experimenting and trying to lose more weight off the part....I may redesign the lightening holes on the sprockets to be used with the adapters so the circles won't be "cut off" or covered by the Top Hat itself....May make the cutouts "sausage shaped" with the cutouts....just cosmetics mainly....

I'll try tinkering with the spacing and caliper relocation when I get a chance....(The area between the disc rotor and sprocket needs to have enough clearance for caliper to fit in....also add a little clearance for the chain...) but I hope these pics give you an idea of how the Top Hat Adapter works....



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Last edited by a moderator:


Local time
6:42 PM
Jun 19, 2008
Elgin, IL
Here's an idea for you. Make the adapter and the sprocket using the bolt circle pattern from one of the 3 standards for MTB bicycles. Riders could get spares rings on the road if needed and you could sell rings to the MTB/BMX crowd.