I was already required to do some weird adapting in order to get disc brakes mounted in the rear. I found a pretty sweet period correct Manitou fork in great shape, titanium springs etc. on eBay and was able to snag it. I was pretty pumped at how things were coming together and then I got the fork, installed it on the bike and then went to mount the brakes on the post mounts...
Disc brake standards have bounced around a bit, and suffered from some experimentation. Especially back in the late 90's early 00's. I knew there was some weirdness back then but I had forgotten about Manitou's random decision to make 68mm post mounts for a few years instead of the now standard 74mm that all brake calipers are machined to. Go to mount the brake...6mm off. #sadtrombone
After a bit of internet'ing I found an adapter to get from the asinine 68mm to 51mm IS and go figure it was machine by the same folks who made the rear adapter I was using. Long story short they were actually out of stock so the folks I ordered it from apparently had the same adapter made by A2Z components and shipped that one instead.
I was on my own with this adapter, no real instructions or description about its intended setup and things got a bit crazy pretty fast. I don't have any calipers that mount directly to 51mm IS so I had to bolt an adapter to the adapter. I'm not sure this is necessarily intended to be used this way. If it was it would have been nice for them to machine in a bit more clearance in a few spots because stuff got REAL tight. So tight that I had to get really weird. Dremel tool weird.
We don't need no stinking clearance!
So in order for me to get the bottom bolt through to mount my second adapter to the 68mm post adapter I had to (in no particular order):
- Find a bolt to mount the 68mm adapter to the fork with the lowest profile head I could find. The head on the standard brake mounting hardware was too big and would not let the second adapter sit low enough. Luckily I found one at the local hardware store that bought me 1-2mm.
- Add an extra washer to the caliper mounting bolt on that side. The standard bolt threads through the adapter just a hare so adding the washer makes the bolt not stick out and bought me another 1mm or so.
- It was still just a bit off so I had to literally Dremel metal off the 51mm IS adapter until it would sit low enough to allow that second bolt to thread through without cross threading.
- I then had to find another special bolt that was shorter so that it wouldn't stick through too far and hit the rotor on the other side.
It took a lot of troubleshooting but it all technically "fits" and feels solid (for the most part). This setup requires you to increase the rotor size to make up the room added by the adapter. So I had to purchase a 180mm rotor as well. I now wish they made a 182 or 183mm rotor.
I might try and mess with some more of those washers to see if I can get some better spacing but the shed was so hot and I had already poured so much time (and sweat) into this that as soon as I rode it around the yard and got it to successfully stop me I called it good for now.
I'll be honest, the sound of this brake 'working' is horrible. Hard to explain in print but I'm sure anyone who rides probably knows what a horrible disc brake sounds like. While it does stop me (on flat ground in my yard) I'm sure that the first thing going through my head at speed on an actual trail will be "I wonder if I'm about to die." Initial testing will have to be done gingerly.
But thats it. You could ride this thing. You might not survive but you can ride it, go forward and then 'stop'...maybe. Partybike doesn't really care about details like that, its mostly about the party.
Rock 'N Roll