Rear disc without top hat adapter or jackshaft


Jan 16, 2016
Hales Corners, WI, USA
Hey guys, I'm asking a question that's been beaten to death over and over, but with a slight twist. I picked up a used (like new) bike at work for relatively cheap, and it has front and rear mechanical (plan to upgrade to hydraulic) disc brakes; is there a way to use a rear disc brake and not have a jackshaft (won't fit) or top hat adapter (expensive to buy, I could make one out of wood if I really needed to)? I was thinking I could reverse the rear wheel (as in putting it in with the disc side on the right and the cassette on the left) and find a way to move the caliper to the right, and figure some way to mount the sprocket to the cassette splines. I could toss a sidepull on the rear, but I'd rather have two disc brakes.


Feb 10, 2013
Southeastern GA
Wood = bad. Don't even try that.

If you flip the wheel, you will lose the ability to pedal the bike. You also lose any forward motion, since the engine would then be trying to turn a reversed freewheel.

You can also buy a hub clamp sprocket adapter for $40 shipped. Not free, but not expensive.

I'd really have to see the bike, close ups of the rear wheel would help the most. If there's frame clearance, you may be able to mount both the sprocket and disc on the same side. If not, you could just use a rim clamp. Honestly, a disc on the back (just my opinion) is more brake than it needs. 80% of your braking is done up front, so a somewhat weaker brake in the rear is acceptable. I'm not advocating losing safety for speed (although it sure sounds that way).

allen standley

Well-Known Member
Oct 22, 2011
Bangor, Maine
I understand this is a multi speed rear wheel you want to use. Light duty spokes...Hmmm. You could save a lot of trouble, maint and money if you considered a rear coaster brake found here.
And a sprocket adapter and sprocket from "Jakes Bikes". But this completely depends on your riding style and situation. I use my bike for back and forth to work and long distance pleasure rides (25 or 30 mi. on nice days). I pedal only to start it... Not for fitness sake. The more complex you make it -- I have found-- the less riding I do. Ya know all that adjusting and repair is ok but after a while, that in itself will nickle and dime ya crazy. If reliability is important keep your front disc and do a coaster brake with strong spokes @ the rear. Check out my album for tips and suggestions. Good luck to you whatever you do!