# Drum to disk brake adapter?



## mahuan! (Nov 23, 2010)

I have an old Santana Rio that I am converting into a real MTB, and I'm getting the rear brakes sorted out. I had a rear brake tab welded on, and now I'm looking at the hub issue. 

Before I fork out a bunch of money on a new rear wheel, I'm wondering where I can find a thread-on adapter to run disk brakes. The original (140mm) Sueuze hub came threaded to for an Arai drum/drag brake. Where can I find a screw-on donut adapter to run 6-bolt brakes?

An upgraded hub/rim would be nice, but I think it may be a good idea to test the effect of earnest off-road riding before dropping a bunch of cash on Chris King or Phil Wood hubs, etc.


----------



## PMK (Oct 12, 2004)

DT sells the screw on disc adapter. 

PK


----------



## banks (Feb 2, 2004)

My off road Specy Deja Tu has Avid Speed Dial brake levers, Avid Arch Rival calipers and Salsa boosters and have not needed much more brakes. We ride Monarch Crest, Rainbow trails, etc in Chaffee County, Salida Colorado. Brake Therapy can do a canti stud hub mounted disk caliper adapter.


----------



## JokerW (Nov 5, 2004)

I didn't have much luck with finding an adapter, readily available anyways, so I made my own.
(I work at a metal fab job shop.)

I found a picture of one on the interweb, and copied the general idea.
I lasercut the blank(s) from 1/4" stainless, and then tapped the rotor bolt holes. That was all pretty easy. Tapping the threads for the hub proved to be a little more challenging. To tap the adapter, I used a bottom bracket thread tap from my LBS. The trick was trying to get the threads perpendicular to the surface of the plate.
I ended up laser cutting some more blanks with the center hole oversized. I then bolted the larger blanks to the part blank. I was able to "guide" the tap through the larger blanks, and keep the tap perpendicular to the adapter plate itself.
It was pretty much a pain in the rear.
If you can buy one, I'd go that route









I also had to add the caliper mount to our old KHS frame. This was actually pretty easy compared to making the rotor adapter.









.


----------



## ostwandlager (Oct 24, 2010)

oh mei Gott...


----------



## XC Mike (Sep 26, 2004)

Anybody find one or have a link for one?
Joker you selling these yet??


----------



## malaclemys (Oct 22, 2010)

W/guidance from PMK I swapped the axle and adapter on a 140mm Hugi to convert it to a 145. All I did was call DT and talk to an engineer. They were super helpful and accommodating. The parts were cheap too. The axle job was simple and the re-dish straight forward. I was warned by the engineer that sometimes the threads on the hub get buggered by the set screw on the adapter. Keep in mind if you are parked facing uphill the adapter could conceivably unscrew unless there is a setscrew. I am not really sure it would happen though. The adapters come in two thicknesses depending on the spacing desired. I did find a link to the part in the UK but you get the gist.


----------



## JokerW (Nov 5, 2004)

I didn't put a set screw in mine. 
At only a 1/4" thick, not much meat there to work with. 
I believe that most of the production adapters are thicker, up to 1/2".
I'll have to check and see if it loosens up. But I guess to tighten it, roll the bike forward and apply the brakes?
I don't plan on making any to sell, for all the time/work involved, I'd rather go riding


----------



## Stevoo (Mar 9, 2007)

Just a tip for future tapping jobs. Obviously the first choice is to use a mill or a drill press to keep the tap perpendicular. If you do not have that go old school. Make a tapping block. Kind of a catch 22 as you need a mill or a lathe to make that though. A tapping block is a simple chunk of metal that has a hole or multiple holes of different sizes that are drilled nice and perpendicular. These are not tapped but just really close clearance holes for the tap. They are just big enough to guide the tap and keep it nice and straight. Simple and effective.

As mentioned by a previous poster you can just buy the adapter as well. I have converted a number of bikes and bought one from Santana and some others from Precision Tandems.


----------



## XC Mike (Sep 26, 2004)

Stevoo said:


> Just a tip for future tapping jobs. Obviously the first choice is to use a mill or a drill press to keep the tap perpendicular. If you do not have that go old school. Make a tapping block. Kind of a catch 22 as you need a mill or a lathe to make that though. A tapping block is a simple chunk of metal that has a hole or multiple holes of different sizes that are drilled nice and perpendicular. These are not tapped but just really close clearance holes for the tap. They are just big enough to guide the tap and keep it nice and straight. Simple and effective.
> 
> As mentioned by a previous poster you can just buy the adapter as well. I have converted a number of bikes and bought one from Santana and some others from Precision Tandems.


Stevoo You are the Man :thumbsup:
I just talked to Steve @ Santana and they do make these in a 13mm and 17mm thickness do you know what thickness you went with?

Here is from Precision Tandems

HUB ADAPTERS HUB ADAPTERS DISC ADAPTERS donut rotor adapters 
Measure from inside of the disc mount on the frame to the threaded 
shoulder on the hub, near the spokes, in millimeters. 
Provide this measurement when placing your order, 
along with the brand of hub and tandem. 
We will then know which hub adapter to send you.

DISC BRAKE WHEEL ADAPTERS HUB ADAPTERS DISC ADAPTERS donut 
Disc Brake Hub Adapter addition shim, 3mm for Cannondales - Cannondale spacer $20.00 
Disc Brake Hub Adapter / Disc Donut 6 Bolt design ~13mm Hub adapter $50.00 
Disc Brake Hub Adapter / Disc Donut 6 Bolt design ~15mm Hub adapter $60.00 
Disc Brake Hub Adapter / Disc Donut 6 Bolt design ~17mm Hub adapter $50.00 
Disc Brake Hub Adapter / Disc Donut 6 Bolt design ~20mm Hub adapter $75.00


----------



## malaclemys (Oct 22, 2010)

That 3mm shim for Cannondales suddenly makes a lot of sense. For some odd reason the inside of the mount is machined down and the caliper sites too far outboard. I shimmed my caliper rather than the rotor so I could use any wheel.


----------



## XC Mike (Sep 26, 2004)

malaclemys said:


> That 3mm shim for Cannondales suddenly makes a lot of sense. For some odd reason the inside of the mount is machined down and the caliper sites too far outboard. I shimmed my caliper rather than the rotor so I could use any wheel.


malaclemys can you post a picture or two so that I can see what you have


----------



## malaclemys (Oct 22, 2010)

Let me start by saying this is on our road tandem but I think all the older Cannondale frames are like this. You can see how the inside of the dropout/brake boss has been machine to make it thinner. See the bit toward the top of the dropout where it is radiused? It is even unpainted like it went through a milling machine after final assembly and paint. At least the face that the brake mount is touching is unpaitned. This moved the position of entire caliper and mount too far outboard to align properly w/the disc. No amount of adjusting would make up for this. There is standard distance from the centerline for the disc, much like a cassette. That is why I had to change the adpater from the one used on the 140mm configuration. Obviously you could set it up anyway you want but don't expect to grab someone else's wheel and throw it in there. Rather than using spacers to move the rotor outboard I used spacers to move the caliper inboard. Interestingly I had to add the the exact amount that was removed from the frame.

As an aside you can also see how thick the threaded adapter for a 145mm Dt/Hugi is and where the setscrew is located.


----------



## PMK (Oct 12, 2004)

FWIW, around the beginning of disc brakes there were a few standard before it sorted out.

Cannondale had their own standard that was the same as IS but with a caliper mount further outboard.

Cannondale / Coda also made their own brakes for a while.

Additionally, Magura beat Shimano and the others to the punch and early Magura and Cannondale have the same standard. Shimano came in shortly after and as you can imagine, everything sort of followed that.

Shimming the caliper inboard is common and well proven. BTW, this all started in 99.

PK


----------



## sopris (Nov 10, 2008)

*Union - Hugi*

Will any of these adapters you're all discussing work on my Union Hugi hub? Does anyone know what type of mount my hub has? Thanks!

**I tried to post pics in this thread but the system said I needed more posts to do so.**

Perhaps this link to my gallery will work?

Nope...I'll remove the http and try again...

forums.mtbr.com/members/sopris/albums/hugi-union/

Thanks!


----------

