Tandem Club Discussion Board
Viking Saratoga - important warning! *LINK*
Posted By: David Walker
Date: 6 September 2008
You might remember that I wrote last year a thread about K and my Viking Saratoga tandem - "The Viking Report". Some of you were quite complimentary about it (many thanks) and I think some readers might even have bought Viking tandems, partly on this recommendation. I have an update, and a SERIOUS WARNING!
We've now had our Saratoga for about 18 months, and have probably done getting on for a thousand miles on it, which will give some idea of our usage. The rest of the time the bike lives in a rather damp garage. We've just come back from three days riding the Sustrans Route One from Berwick to Newcastle, along the Northumbrian coast. Very nice and highly recommended as a trip, fairly flat and very scenic. The only downsides are a couple of bits of the Sustrans route - some grassy fields with virtually no path, which would be tricky in the wet but fine on the Saratoga's 2.3" semi-slick tyres, and a slow twisty navigate through a rough, glass-strewn housing estate in Blyth, in which we got our first ever puncture. If you do Route One, just bypass Blyth.
The tandem is on the whole still great. With an Avid BB7 203mm disc at the front, good braking is now assured. I changed the front bottom bracket to fix an annoying squeak. Once we dropped it on its right side and the Shimano Revoshift twist-shifter broke, so that's been replaced by a SRAM (Shimano compatible) twistgrip which is rather more cultured. Eventually (this bit is techie) I think it would be a good idea to replace the Shimano rear mech with a new SRAM mech and shifter. SRAM's native 1:1 cable pull ought to cope better with the cable stretch over the tandem's length and obviate the need for quite so many overshifts. But on the whole, all good, except:
** IMPORTANT BIT **
On the third morning I applied the brakes as we rolled out of Warkworth and there was no response at all from the back disc. We pulled up and had a look, and it appeared that one of the rear pads was missing! So I took the wheel out and had a further inspection. What had actually happened was that (on one side) the abrasive brake pad had delaminated from the magnetic shoe that it was attached to, sheared off, and just fell out. I took out the remaining bit of shoe and the other pad and checked them. Rust had formed between the shoe and the pad, forcing them apart. On the remaining shoe I was able to separate (break)the shoe and the pad using my fingernail and very little pressure. In addition the inner magnet (which holds the shoe in the brake caliper) had come away with the other shoe, indicating that rust had also damaged the caliper.
I had forgotten to bring spare pads for this brake so we disconnected it and did without. Fortunately we have a third brake (cantilever, stoker-controlled), so still had two working brakes.
Below is a link to two photos of the offending pads. At the bottom are the two shoes, one with the caliper magnet still attached. At the top is the remaining brake pad, which has also begun to crack and disintegrate. The degree of rust penetration can be clearly seen.
These are the Alhonga cable-operated disc brakes, 160f/140r rotors, supplied with our Viking Saratoga tandem bought from Parkers of Bolton in February 2007. I state again that our tandem is stored in a damp garage, which is probably the root of the problem. However, if you have the same bike or the same brakes, for god's sake check the integrity of the things! I hate to think what would have happened if it had been the front brake at 40mph, rather than the rear at 5mph.
** NON-TECHNICAL SUMMARY **
Viking Saratoga / Alhonga Disc Brakes
Rust can and will penetrate into the pads of these brakes, causing INSTANTANEOUS FAILURE. If you have these brakes, check the pads now, and change the brakes as soon as you are able. This is particularly important if your bike is stored in a damp environment.
What I don't know is whether this problem affects ALL disc brakes, or just these. Any ideas?
Ride safe, and sorry to scaremonger!
Photos of the delaminated disc pads
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