TandemGeek

Road tandems will chew up tires and chains twice as fast as a personal/regular bike which, if you think about it, makes sense. A tandem carries nearly twice as much weight propelled by nearly twice as much power. Therefore, more attention to wear inspections and lubrication is required.

Tandems are also more prone to flat tires, either via pinch flats or punctures that wouldn't have penetrated a personal bikes tire due to the significantly higher passenger load that a tandem carries. You can also create tire failures by riding the brakes on long descents to the point where the rim is heated up enough to cause a tire to "blow off" the rim.

The cross-over crankset, timing chain, and eccentric (that would be the aluminum cylinder that holds the captain's bottom bracket and that facilitates adjusting the slack in the timing chain) are also unique to tandems and introduce an extra element of mechanical complexity, albeit one that's easily mastered as the basic level. You can, if you like, delve into the fine points of timing ring alignment, out-of-round corrections, and ring rotation to extend the life of the chain rings, but it suffices to say it's a relatively simple design and adjusting the eccentric is easily mastered as well.

The drive train itself can be a bit finicky in that you'll find yourself trying to shift under higher chain loads. In these instances, it is your technique that will require attention; easing off on pedal pressure when you shift the front timing rings as well as anticipating and shifting into the small/granny/alpine or taller sprockets as you approach climbs or steepening ascents.

Anyway, you get the point. Tandems are a bit more demanding of your attention given the added complexity of the extra hardware, loads, and power generated by a second rider. If you're a competent bike mechanic, all of the nuances can be mastered. Although, one thing that mechanics who don't work on tandems often times miss the boat on and that home mechanics will be confounded by is the need to have a second rider on the tandem for fine tuning adjustments to the shifting, chasing creaks, squeaks, and the like. For example, older, and even newer but less rigid tandems often times flex enough under very heavy loads to cause rear derailleur shifts -- not all that uncommon even for some regular bikes. But, until you identify that root cause, it can drive you nuts. Test riding alone often times just doesn't stress the tandems enough to recreate those problems, just as having a load on the chain will often times eliminate a noise/interference problem or create one.

FWIW: Our tandems have never seen the inside of a bike shop except to have threads chased on a cross-threaded eccentric and I can't think of any special tools need to do work on a tandem that you wouldn't need to accomplish the same task on a regular bike.