quemazon

I just upgraded our 2002 Arriva to a rear disc brake. I decided to cobble the parts together myself instead of purchasing a kit, and I wanted to document the parts and process in case anyone else is trying to do the same.

Parts:
$25 A2Z AD-PMR Rear Disc Brake Adaptor. Ebay
$75 TRP HY/RD Post Mount Cable Actuated Hydraulic Disc Brake Caliper w/o Rotor. Ebay
$8 Bicycle Bike Freewheel Threaded Hubs Disk Disc Brake Rotor 6 Bolt Flange Adapter 44MM/48MM. Amazon
$51 Shimano XT Brake Disc (SM-RT86L) IceTech 203 mm Rotor w/6 Bolts. Ebay
$0 Cone washers from old brake pads



A few notes on the install:
- The two screws that come with the a2z adapter are a little too long and bottomed-out in the frame mount. I cut them to size with a dremel.
- There was an offset of about 2-3mm between the caliper and disc. I used a couple of fat aluminum washers to move the caliper in-line with the disc.
- The post mount that came with the Hy/Rd worked fine
- The Hy/Rd is setup for longer-throw levers that are the new standard. There is a simple modification for older levers that appears to be approved by TRP: - The cone washers really helped in getting everything lined up.
- Because this is a pre-2004 Santana, it uses 203mm rotors instead of 10" Santana standard. That suits me just fine.

My wife and I just got back from our first ride with this setup, and it was pretty great! The stopping power is moderately better than with the rear V's. I'm pretty certain I could lock up the rear if I really laid into it. We had a 2000' descent with an average grade of about 7%, but some areas approaching 10-12%. At the bottom the front rim was warm to the touch, but not hot. The rear disc was hot probably enough to burn my finger, but I only tapped it lightly.

Darth Lefty 

Fascinating. No luck for my old Burley which only has the Arai tab

There was a "Hacks and Bodges" adapter on GMBN a week ago that was carbon fiber wrapped around the steel frame.

merlinextraligh

Just installed a TRP hybrid, and am very impressed. After some adjustment and bedding in, it's very powerful. I can lock the rear wheel using only the rear brake easily, and more importantly, modulate short of that.

The Bengal cable actuated brake it replaced, would bottom the brake lever well before it came close to locking the wheel

quemazon

Interesting. What did you do to bed it in? Are you using the stock brake pads? Did you use compressionless housing? Also did you do the throw adjustment as mention in the video?

merlinextraligh

stock brake pads.

Not running compression less housing, although i'm thinking of going to it just for a little insurance.

Only set up I did was follow the instructions, and then a number of hard stops to bed in the pads.

I can see the logic of adjusting the cable pull angle, however, for us and Dura Ace levers we haven't found it necessary so far.

rocknrollin

the upgrade looks great!
I just purchased a 2008 Santana Arriva and was planning to upgrade it to hydraulic discs.
I looked up the freewheel 6 bolt adapter, and I find two sizes to choose from: 44 and 48mm.
Which one did you install? And is it a hadley hub?


I will still need to wait a bit until the tandem will be delivered and I can do measurements. I hope that the fact that its post 2004 and has the hayes mount moved forward will not complicate things.

Joint Venture

You can get an adaptor to accommodate the 10” disc. I bought mine from Precision Tandems. We upgraded our former 2001 Santana with it. If you do move up to the larger rotor, get the Santana Gen 4 rotor, not the Gen 3! This setup had spectacular braking!!

IPassGas

It is great you have provided detailed information on the installation and should be useful for others. Disc brakes are the norm now, but I have never understood the infatuation with disc brakes on touring bikes and especially on tandems. The tandem load is far greater than single bikes and so it is not about locking the brakes, but about dissipating energy. The drum was ideal for this, and anyways, we could "lock" the drum brake on our older Santana. Unfortunately, Santana long back veered into the disk brake world for marketing. The result is the strange looking huge diameter discs.

CaliTexan

Hmmm. I have a 1998 Sovereign. It originally came with the first gen Santana hydraulic disc. That thing was really a high-maintenance flop. But, there was no replacement for it and there is no provision on the frame for any kind of rear rim brake. And the frame being aluminum, there was no real retrofit possible.

So, I was stuck with it until the WinZip brake came along. Bud's in Claremont did the first factory refit of a WinZip to the old hydraulic brake system on my bike. It works, with a BPB helper up front. It uses the original Santana disc. But at the time, no other brake would work, because of the location of the caliper attachment bracket.

Fast forward to 2019: I would sure like to put a modern brake like a TRP on it. Has anyone tried to do that yet?

rocknrollin

Thanks for the tip!
I hope to be able to use one of hopes floating disc rotors. It has excellent reviews, supposedly great heat dissipation, and the largest model comes in 225 mm (just one inch smaller than the 10" santana). I would't mind the Santana either and i might not have a chice in the end, but the major downsize is its royal price (180 $ vs. 60 $ for the hope rotor).

I think in particular for tandems and touring bikes any improvement in braking power is welcome.
We just started tandem touring this summer, hauling 185 kg of total weight for 2 weeks. We have Magura HS33 hydraulic rim brakea which are great without the panniers, but the stopping distance is significantly increased with the luggage and water. We had many stretches with secluded turns and sharp corners along our tour, which required us to slow down a lot so we could bring the bike to stand in case of an incoming car. This can be quite exhausting after a while.
Apart from being more fun and safe, stronger disc brakes would also increase the comfort by saving energy and time. I'm curious to try the drum brake that will come on our second hand Arriva, but with regards to comfort I think I'd prefer 2 strong brakes to a 3 brake setup.

Regarding the safety of hydraulic disc brakes, i was recently reading about the Rennstahl 853 e-bike which has been tested and certified for 185kg. So it should be possible to get them safe enough for a tandem.

Chancy

[QUOTE=rocknrollin;21218172]Thanks for the tip!
I hope to be able to use one of hopes floating disc rotors. It has excellent reviews, supposedly great heat dissipation, and the largest model comes in 225 mm (just one inch smaller than the 10" santana). I would't mind the Santana either and i might not have a chice in the end, but the major downsize is its royal price (180 $ vs. 60 $ for the hope rotor). QUOTE]
Rocknrollin,

Have a look at post #13 for a lower priced 10" rotor that looks be be identical to Santana's Gen4 rotor for less $$. We have a Santana Beyond that I may upgrade to this rotor.

Tailwinds,
Charlie
2016 S&S Santana Beyond

Chancy

Sorry,

Here's the link I mentioned. The rotor is in post #13

https://www.bikeforums.net/tandem-cy...ke-rotors.html

-Charlie

rocknrollin

Thanks!
That one should do the job.

Leisesturm

Agreed. For touring and tandem use the ability to lock a wheel is NOT useful. Especially at the rear. A locked rear wheel is not doing any useful ******ing of forward speed. A locked front wheel is even worse. The capacity of a drum brake to absorb the steady heat input of a controlled descent and the same capacity ot a 203mm or larger rear (or front!) disk to do the same is of great benefit. Still, it is probably less hassle to just buy a more modern used tandem than to try and upgrade a Santana Arriva. The stock brakes on an Arriva work about as well as anything else. With good pads on the Canti's and the stock Arai drum brake there isn't much else to be done. There is a mystique that disc brakes have that makes riders want them but the only way that makes sense is to buy a bike that is designed to use them. Front AND rear.

IPassGas

On our old santana, the arai drum took us down many mountain passes loaded with camping gear. We never questioned the ability of the drum to keep speed in check. Our new tandem has 2 rim brakes and a 200 rear disc. These are insufficient for mountain passes and we must stop to cool brakes. The drum afforded an extra measure of safety.

Leisesturm

As I understand it, a larger diam. rear disc like yours, used as a drag brake, can be heated until glowing red hot, using the right rotors and pads. You may be unecessarily cautious. My earlier point was that if one already owns an Arriva it is bike enough (as you prove) in stock form. However, someone buying a bike today will probably be presented with a 203mm disc drag brake without asking, and this too will probably be enough for the majority of teams.

IPassGas

"red hot" I do not believe. Certain hydraulic/disc combinations can dissipate heat better, but then you risk fluid boil, soft pads or disc warp. I am not a fan of hydraulics when touring in the middle of nowhere. I agree that the team weight/amount of loaded gear/terrain are all relevant in choice of braking. Lightweight teams need not be as concerned.