Originally Posted by
stapfam
This was cured with the OPEN system where any expansion of the fluid would return to the master cyclinder and NOT apply the brakes.
No, it didn't cure the problem... at least for tandems. It simply make it far less likely to happen.
Even an open system could be over-heated to the point where the fluid expanded beyond the capacity of the master cylinder under a variety of different scenarios:
1. The system had too much fluid to begin with (very common)
2. The DOT brake fluid was old and lost it's heat resistance (also common)
3. Plain and simple over-use of the brakes (easy to do on asphalt)
Originally Posted by
stapfam
And if using an effective disc brake system on a Tandem- I would suggest a bolt through system for the front wheel. Never had a problem with the QR- but I do not fancy taking a chance on the front wheel pulling out.
A bit off topic, but yes... if you (a) use a fork that wasn't originally designed for use with a front disc brake, or (b) that is poorly designed, or (c) that has been modified to remove any lawyer lips or other skewer retention features, or (d) uses silly lightweight skewers, or (e) put a massive rotor & downhill disc caliper on a fork that was not designed for use with a massive rotor, or (f) never bother to check or even know how tightly a QR skewer should be tensioned then you could find yourself at risk of a front wheel ejection.
No offense, while I understand what happened in the various documented front wheel ejections, it wasn't exactly an epidemic within the tandem community. Moreover, for as long as Cannondale has been selling it's dual-disc equipped tandems and as many of them as there are on the road I've never heard of a single front wheel ejection. Outside of Cannondale, I have heard of one or two front disc / road tandem wheel ejections but as already noted, they were custom one-off bikes that used forks never intended for use with a disc that had disc tabs added on and no lawyer lips or other similar features. Moreover, the wheels pulled out at very low speeds which also suggests the skewers weren't all that tight either.
Now, that said, for an OFF-ROAD TANDEM, a solid front axle is almost essential if you want to have full control over your steering. There's just too much torque steer on suspension forks when you're driving the front wheel through ruts and the like... regardless of what type of brake system you're using.