I am also considering a Surly Troll frame and fork, build myself with Rohloff hub, disc brakes, with chain and full enclosing guard to tkeep crud out. But I emailed SJS about a Rohloff wheel build and they told me I need an axle plate £22 even with horizontal drops out and a solid axle with traditional nuts as QR cannot be used according to SJS. What you think MacB? It's either orange (last year), aubergine purple or black for the frame colour.
I'm not a fan of the Surly options for hub gears the only one I rated was the Crosscheck with horizontals and rim brakes. Two of my sons have Karate Monkeys with derailleurs which are great bikes. But I did experiment with putting a Rohloff on one to see how it would fair as an allround tourer. You instantly run into issues with the disc brakes and mudguards for wheel removal and the orientation of the OEM2 axle plate adds complexity as well. The rear caliper mount is slotted to move with the wheel but it means you have to be pretty precise with alignment to avoid rubbing. It is improved on later KMs and the Troll etc as earlier models you actually had to loosen the disc brake caliper to remove the wheel in some positions.
That's not to say it doesn't work very well for some it really depends on the level of faff you can/will tolerate. For me the rohloff attraction was immediately diminished by the need for the OEM2 plate and having to go to a nutted axle. So I decided that if I'd shelled out the dosh on a rohloff then I wanted to maximise the benefit and needed a frame appropriate to this. I would actually rather use vertical dropouts and a tensioner than go back to using track ends with a hub gear.
My personal preference would be a swing style vertical dropout, my frames have the Paragon Machineworks Rockers which places the disc caliper between the stays and allows normal rack and guard fittings. Salsa do production frames with their Swing dropouts and with either sort you can opt for a rohloff specific dropout to accommodate the OEM plate. The Salsa ones place the disc caliper on the seatstay as do most of the sliding dropouts which would be my next choice. After that it would be a toss up between vertical dropouts and tensioner or vertical dropouts and eccentric bottom bracket. But mainly because I have an irrational dislike of an EBB. My final choices would be horizontal dropouts and lastly track ends.
I know Shand cycles offer the rocker dropouts as a build option and they have a reputation, though pricetag to match, that I would trust for any sort of build. I did look at seeing if I could modify a Surly to the different dropouts but it worked out to more than it was worth. If you wanted to supply the dropouts yourself I reckon you could get a frame done for about £700 all in but can't see it being much less.
I use Wheelcraft in Scotland for my wheelbuilds and Big Al there is extremely helpful and will advise and keep costs down for you. If I was buying a Surly frame for a Rohloff then I'd go for a LHT disc version and use an OEM2 plate with a chain tensioner or one of the mini EBBs that fit a standard size shell. I have the LHT disc forks on one bike and they are very nice.
For a custom frame or an off the peg that can come with rohloff dropouts there's Shand, Roberts, Dave Yates, Mercian, Argos, Bob Jackson and plenty of others - most of their rohloff offerings will be standard sliding dropouts or EBBs but I'd imagine they could build with a different style of dropout if requested, I know Dave Yates would.
But if you invest in a good wheelbuild via somewhere like Wheelcraft, I opt for a tandem strength build, then the wheelset(especially if disc brake) could outlive several frames. I reckon you could do that, build up the Troll and see how you like it. A Troll frame would be fairly easy to shift on if you decide on a change at a later date.
