The drivetrain (transmission) covers the power of the bike – the Cranks, Chainring, Cassette, Chain, shifters and Bottom Bracket, this is where all the propulsion comes from to drive the bike forward. Where possible we’ve again relied on the miracles of British engineering to drive us forward!
These are the components that are most likely to wear down and need replacing as the journey goes on, so it’s all the more important that these are as tough and hard wearing as possible.
Middleburn cranks and chainrings can be a real pain to get a hold of. For weeks the CRC Middleburn builder had them listed as out of stock. By coincidence, we came across a supplier of them in an LBS – East St Cycles. Although their website is a bit of a shambles, and the cranks and rings took a while to come, come they did in all their Teflon impregnated ceramic coated glory.
The triple chainset (44-32-20) gives an enormous gear range, the smallest allowing us easy (albeit slow) access up the steepest mountain. More information on gearing calculator’s can be found on Sheldon Brown’s Website.
Update from the Road: After 6000km, the cranks are still holding strong. They’ve shifted smoothly and cleanly, with no major problems. Shifting too into the smallest chainring quickly can cause problems, but as long as the limits are set properly then it’s just a case of making sure the changes are strong and confident
The only other issue with the chainring is that the pins that are installed for the “slick-shifting” have on occasion rubbed against the chain when in the smallest sprocket on the cassette. Unsurprisingly though this doesn’t happen too often with a bike as heavy as ours.
Titanium Bottom Bracket Axle (£127)
Once again, something of a last minute change of mind from our Hope Ceramic bottom brackets to the Royce Titaniums.
Complete with titanium end bolts, I was pleasantly surprised by how smooth these were once ridden, despite their tough all-weather capabilities.
Installing them into the Thorn frames caused some problems, because of the dodgy paint job on our frames, but this didn’t really pose a major problem.
Update from the Road: There’s not been much to notice about the BB. It’s been turning happily away, without any issues. We’ve tightened the end bolts occasionally to ensure proper seating on the square taper axle. I haven’t checked on the state of the bearings, but I’ve not yet noticed any grinding or other issues…
Update from the Road: I’ve replaced my first cassette after the 6000km to Damascus – not a bad shelf life from one cassette and one chain. There have been no issues at all with this reliable cassette, other than reaching damascus and having them removed. Bike shops in Syria it would appear do not deal with this type of bike often. But with a bit of ingenuity from local bike mechanics (and a couple of pounds for their services), they soon managed to get them off without a chain whip.
I love the KMC chains, having only bought one originally as an alternative to Shimano’s range for my road bike. Since trying them out, I’ve been really impressed – light, strong, precise shifting, and incredibly easy to fit with their “missing link”.
The X9-L have a titanium nitrade gold coating, for longer lasting wear, and their “bling” golden look is also meant to be less reactive to corrosion and less susceptible to dirt, easier to clean, and harder wearing.
Update from the Road: This chain has lasted the trip to Damascus amazingly well. Although mine broke early on in Stuttgart, that was more down to an earlier sloppy gear change on a steep incline, which bent the chain on one of the links. beyond that though, I haven’t had a single issue. Craig’s chain broke somewhat worse than that in Turkey, but again that was easily fixable with the missing links and spare chain links. With regular (albeit not frequent) cleaning and oiling, this chain definitely lasts the distance. A new chain is on the bike now of course, so hopefully the success should continue through the next few countries.
Ultegra 6600 Medium Cage (£56.24)
Update from the Road: Not much to say – no problems so far!
A wide cage was needed to accommodate the wide tooth range of the Middleburn Chain Rings, and the XT provided this with the benefits of being lightweight while still rigid.
Set up was incredibly easy with clear cable routing, and the gear changing with the friction shifting Dura Ace bar ends is incredibly smooth and precise.
Update from the Road: Smooth shifting. Trimming is easy enough and the cage still looks strong and reliable.