AUSTIN - I made some drivetrain changes on the Surly Troll: replacing the single-speed drivetrain with a 1x10 drivetrain, which also includes a return to the 50mm wide Surly Rabbit Hole rims and familiar 26 x 2.5 Extra Terrestrial tires.
If I could have more than one mountain bike or touring bike (or whatever the Toll is), then one of those bikes – or that other bike – would definitely be a single speed. Even with the recent advances in derailleur-driven multi-gear drivetrains, a single speed is still lighter and simpler.
Practicality dictated that I have a bike that I can ride more easily over more terrain, carrying shit easier. Some of this came from my Great Divide run where I was faced with hills that redefined my idea of “uphill,” often climbing for what seemed like days. Many of those hills involved me pushing the bike when I really should have been able to ride up.
Also, with 1x11 becoming more common, it wasn’t difficult to find 10 speed parts on sale.
This is the setup:
• DT Swiss 240s rear hub, with DT Swiss steel RWS skewer (a steel freehub body will eventually arrive)
• Surly Rabbit Hole 26” green rims (safety orange & reflective tape rim tape, split-tube tubeless with Orange Seal)
• Shimano XT M786 GS 10-speed rear derailleur
• Shimano XT CS-M771 10-speed 11-36 cassette
• Microshift 10-speed thumb shifter
• Orange Jagwire full-length shifter cable
• Shimano Zee M640 cranks 165mm (using existing stainless steel Phil Wood bottom bracket)
• Wolftooth 104 BCD Drop-Stop stainless steel 30t chainring
My concerns about the extra chain needed for the gears rattling and bouncing around with the derailleur were proven to be beyond false.
This setup is as solid and quiet as a single speed.
Modern derailleurs with their clutch mechanisms (I assume SRAM and Campagnolo have something similar), combined with the various “narrow-wide” chainrings keep things moving smoothly and quietly, with the added benefit of negating front derailleurs or chain-retention devices.
I understand for most of you, a multi-gear drivetrain is normal; for me it’s a bit of a novelty, and a change that, so far, I welcome.
It’s as if more of the world opened: I can pedal quickly around city streets, smoothly through sand, easily up 45-degree inclines (with 2 gears to go still!).
I can think back to some of those grinding hills of the Great Divide or long pavement stretches wondering how much better it would have been. Some of that I’ll repeat when I return to the GDMTBR, starting in Whitefish (taking Amtrak from Portland).
The Surly Extra Terrestrial tires have a wider profile on the 50mm Rabbit Hole rims, compared to the narrower profile on the 33mm DT Swiss FR570 rims. This wider, flatter profile puts more rubber on the ground and seems to give a more stable ride. I generally keep them inflated to about 2 bar, which seems to make a nice compromise between being soft enough for unpaved surfaces, and hard enough to roll quickly. If I were to undertake an off-pavement tour or some sort of long ride away from pavement, I would go with 1 bar in each.
I employed the now common split-tube method of tubeless conversion, which is also knows as the “ghetto” method.
I found a 20” Schwalbe No. 7 tube to be ideal for this size rim and are of high quality overall. Mounting the front tire was curiously much easier than the rear, for which I had to struggle.
I used the split tube method straight away with the front, adding a safety orange and reflective fabric tape with an orange Surly rim strip over that.
I tried a few methods for getting the rear tire to mount and had no luck until I just started all over again and tried the split-tube again, leaving more extra tube outside of the tire when it eventually worked.
One odd thing that kept happening with the rear was when I deflated it – either to add sealant or change something with the mounting – the tire beads would squeeze together, wrinkling the fabric tape (and Gorilla tape, when I was using it). That problem stopped when the bead finally made the reassuring pop sound as the tire inflated.
I had to resolve a chainline by moving a 2mm spacer from the non-drive side of the bottom bracket to the other. The chainring has a 2mm offset to make up for it being smaller than the spider arms of the crank. It may take an additional 2mm spacer to align the chain better, but it seems to be good for now.
In subsequent posts (which you’ll no doubt read before this one, given how they display) I’ll go in to more detail about this setup and some different approaches to carrying gear. I have some short trips to nearby state parks in mind, as well as my usual local rides.