This timing chain has been a huge thorn in our backside.

It actually ended up not being the root of the problem at all, but rather, a bent chain ring that was the source of our woes. Because of its slight deviations, the chain would turn for a couple revolutions before hitting the contorted teeth and slipping right off. We hadn't noticed this, but an eagle-eyed Burmese bike mechanic in Mae Sot spotted the problem when we took the bike in desperation to see if they could fix it. He whacked it back into shape with a hammer and all was well.

But because we didn't realise this until a full day after we had bastardised the chain by going to 3 different bike shops in the area and trying to relink it together, it was almost a moot point that we had straightened the ring itself. The chain refused to work properly and most importantly, stay on. Either it was too loose or too tight, and both scenarios caused it to fail. The valiant bike mechanics of Mae Sot did their best, but fettling a tandem was something they just weren't accustomed to, and it beat them all.

It's not as simple as taking two regular KMC chains and looping them together. The one on our tandem is a weird length that requires a half-link to stay taut. And it was this half-link that was confusing the hell out of us. Where did it come from? How did it work?

We were finally advised to go visit a bigger bike shop on the outskirts of Mae Sot (go about 3km farther up the road towards the airport, past Famous Ray's new location - you can't miss it), promised that they knew their way around a tandem. And that's where we finally learned about the eccentric bottom bracket and its role as a chain tensioner. All of a sudden, everything made sense.

With this new knowledge in mind and various bits and bobs sorted, we did a final test run of the bike and prepared to cross the border the next day. But not before enjoying dinner and beer at the Night Market with Bernd and Hilda, a German/Dutch couple we met at T. House who were also planning to cross the border at the same time as us. Their mission: cycling from China back to their home in Holland. They expect it to be a one year endeavour and with three months already behind them, we watched in envy at their tanned, toned selves vs. our pasty wobbly ones.

Well, Jess anyway, as she has been fighting a horrendous cold which struck her the day after we got here. It's basically been a week straight of illness. It's fair to say we're not exactly in the optimum physical condition to embark on a trek like this. But we'll battle through. We always do.

At least there's Thai soap operas. Our favourite over these past couple of days involves an undercover witch trying to convince her pop star boyfriend that she's not actually crazy. We've also developed an affection for the Thai military government's minister of agriculture, who appears on national TV in the evenings lecturing farmers to do as they're told and stop growing so much sugar cane and overworking the land.  

T minus 12 hours...