Since last building my Soma I've had the chance to build up another steel tourer and in doing so learnt some lessons in spec'ing a touring bike. I've since made a few changes to my Soma and learnt a little more about it. The changes are a mix of functional and aesthetic mixed in with value. Not all of them wholly necessary but given my bike is my hobby, I couldn't resist.
I originally stumbled across the most ideal (for me!) gearing ratio when re-building my Genesis Croix De Fer back in 2012. At the front 26/36/48T and at the rear 11-28T. I've since adjusted this slightly and now prefer a slightly smaller largest chainring (26/36/46T) which means a smaller jump in ratio from middle to top. And also an 11-30T rear cassette. 11-28T is just about perfect, but sometimes hard to find, and often expensive. I've since found a Shimano HG51 11-30T 8-speed cassette for £16 from Spa Cycles. Being 8-speed it's perfect for a Shimergo set up and at £16 is great value. It's 140g heavier than my Ultegra cassette, but that's weight I'm willing to add on. Or at £1 cheaper (£15) the SRAM 8spd PG830 which only weighs 80g more than the Ultegra is probably an even better choice.
In terms of gear inches a 26/36/46T with 11-30T gives me as low as 23 inches and as high as 112 inches. This is enough to get me up the steepest of hill (fully loaded) and also cycle as fast as I'd like (on day rides).
Hollow Tech 2 vs Square Taper
While I do like my Hollow Tech 2 chainsets I think I'm beginning to prefer square taper once again. The XT M785 28/40T chainset at £140 was fantastic, but more than I should have spent. The Deore 26/36/48T chainset at around £50-60 offers great value. However, I have now opted for a 26/36/46T Stronglight Impact (£60) on a Shimano UN55 bottom bracket (£16). Even better value is Spa Cycle's XD-2 28/38/48T chainset at £35. Both the Deore and Stronglight options add around 300g over the XT chainset.
The advantage of using a square taper bottom bracket is firstly that they last longer, but also that I can easily change the width should I switch between a road or MTB chainline. Also from an aesthetic point of view, it looks far more at home on a steel bike than the more rugged Shimano MTB chainsets. The main advantage of HT2 is that I can remove the chainset just using an allen key tool, but that's something I'm willing to lose.
It wasn't until recently that I noticed both my Soma Double Cross and Genesis Croix De Fer have quite a tight fit in terms of where the wheel sits. Once you put mudguards on, it leaves very little space to fit a front mech. In fact with some front mechs I found the swing-arm would press against the mudguard it was so close to the seat tube. Another 5mm and I'd be fine. It's just something to consider when buying a frame. Both my Soma and Croix De Fer have a 425mm chainstay length. Ideally 430-460mm would have been better, but it is possible to get away with 420mm or 425mm (as found on many cross-trail bikes). Something like a Surly Long Haul Trucker would be ideal in terms of wheelbase.
I've always picked 170mm crank length (due to an article I read a long time back about it being my ideal size). My Croix De Fer came with 175mm cranks, and it wasn't until trying them again that I noticed how much more I preferred 170mm cranks. I like cycling at high cadence (spinning) so shorter cranks suit me. It'd be nice to try 165mm cranks, but I don't think I'll ever have the chance. The StrongLight Impact chainset offers much more selection (especially for smaller people) in terms of crank length compared to anything Shimano has. Another positive for choosing it.
I'd never used downtube shifters, but upon fitting them I found them very easy to fit and use. The smoothness of shifting and simplicity of them are great. In terms of a cheap, lightweight build, they're perfect. It makes for a far cleaner set up too (less cable length needed). What they lack though is convenience.
The other advantage is that they left you use linear pull brakes, such as the Tektro RL520's. These are cheaply priced, and let you run full size v-brakes which are far easy to set up than mini v-brakes. They also brake better and have plenty of clearance.
One thing I did discover, is that my Soma Double Cross, despite having downtube bosses, doesn't have a standard square base (on the boss). This is where the lever cover locks against to stop it spinning/sliding around as you use the levers. Unfortunately the Double Cross has a base, but it has rounded edges and corners so the lever cover can't lock onto it properly. Using curved covers means the levers can be mounted, but it's still a big negative (for me) against the Soma Double Cross frame.
While I enjoy my downtube shifters, for now I've decided to stick to my Ergoshifters. They're more convenient and work perfectly with the 8-speed cassette (mentioned earlier in the post).
The Retro Look
Not really a touring related point, but I do like my bike to look its best. I've been switching a few parts around on my bike and going for a more black with chrome, retro look. One thing I found was many modern parts come anodized and often look dull. The Stronglight Impact chainset or Tektro RX5 brakes are two good examples.
I spent some time with grit 400/800/1200/2000 sand paper, and sanded off the anodized finish to get down to the metal. Starting with 400 to get the worst off, and working towards 2000 until the parts where shining. Then I finished it off with some metal polish.
Mudguards, Tyres and Weight
For the sake of 500g, it's worth fitting mudguards. I used to think they didn't look as "cool" but if done correctly give a nice retro look. The amount of crud they keep off you and your bike makes a huge difference.
For tyres, I run 25C Continental Gator Skins when I want something quick. But these days that's not very often. My tyre of choice is a 28C or 32C Schwalbe Marathon Supreme tyre. It offers a good amount of comfort without affecting speed too much. They're also nice and light at around 350g per tyre.
Regarding weight, I still like to fuss over weight, but not at the cost of convenience or value. The mudguards and tyres add around 1kg to the bike but it's worth it. The 8-speed SRAM cassette is around 100g heavier, but at only £15 it's too good to pass up.