Blog 08-06-23

Turf Zone – ArnistonBing

With the single speed Harley Quinn project finally complete and my delight at finding that I actually love single speed turfing/cycling, or turfling, to coin a new term, I’ve started another single speed project. The main aim of the project is to create a lightweight minimalist single speed bike dedicated to off-road turfing, for those zones in muddy places such as around Dalhousie castle, Newbattle abbey woods and Dalkeith country park. And the bike I’m going to use is my trusty 2012 vintage Surly Ogre.

I did look into other options, keeping in mind one key factor, that of weight. I want to try and keep the overall weight of the finished bicycle as low as practical. For comparison, here’s the approximate weights of the other bikes. All the bikes were “naked”, no racks, mudguards, etc. Note, I suspect the accuracy of our bathroom scales leaves a lot to be desired.

  • Harley Quinn, single speed, 12.20kg
  • Surly Ogre, 8-speed hub gear, 15.80kg
  • Surly Pugsley, 8-speed hub gear, 17.50kg

Initial thoughts were to source another Genesis Day One Reynolds 853 frame but they are no longer in production. There was one on eBay for £500 and I was tempted but noted that the maximum tyre size is about 35 mm, and I wanted larger tyres for off-road, so not really suitable. I even considered going very slightly crazy and looked at carbon fibre frames with one from Ribble catching my eye at a whopping £1700.00. Add another £1000.00 or more for all the other components and it’s a heap of cash. Mind you, could end up with a bike weighing in at around 8.0kg or less. The frame and forks only weigh a paltry 1.60kg!

So, it seemed sensible, if you could call it that, to use the Surly Ogre. I just don’t have enough space in the shed for more than three bikes. Mechanically, not too much work to convert the Surly Ogre to single speed. Main task is to swap the Shimano Alfine 8-speed hub gear on the rear wheel for a single speed hub. Luckily, I already have a Surly Ultra New single speed hub in the parts store, left over from when the Ogre was once a single speed! This will save about 1.50 to 2.0kg of weight. Nice! I’ll be using BG Cycles at Portobello again for the wheel build and I also need to have the front wheel trued as it has a slight wobble.

Still on mechanicals, the handlebars will be exchanged for a set of standard riser bars, and the chain guard will also be removed, if possible. As will the rear rack, frame bag and handlebar bag as I want as minimalist as practical. I’m actually getting used to wearing a small rucksack and may return the frame and handlebars bags I’ve ordered for the Harley Quinn. I have a set of Schwalbe Marathon Tour MTB tyres in the attic which I was thinking of using but at 1275g each they are on the heavy side. Plenty other makes out there weighing 400 to 500g.

Another, very important decision I have to make is the size of the rear freewheel, or the number of teeth on the freewheel. This will determine the final gear ratio. The existing front chainring is a 34T and I want a lower ratio than the 1:2 (16T/32T) on Harley Quinn. I have a 20T freewheel in the parts store, so may try that. Some other options I’m considering.

  • 34T front/20T freewheel, giving a ratio of 1:1.70
  • 34T front/19T freewheel, giving a ratio of 1:1.79
  • 34T front/18T freewheel, giving a ratio of 1:1.89

I’ve already stripped down the Ogre frame ready for paint stripping. Yes, it’s going to get the same, or very similar, paint job as Harley Quinn, same bright fluro colours but probably a slightly different design. I’m think asymmetric on the wheels! Not quite decided exactly what but plenty time for that. One thing I’ll need to do is construct something to support the wheels for painting.

Now, all this has me thinking about the Surly Pugsley fat bike and some big questions. Could I go single speed? Will a single speed fat bike be rideable? Is this a totally nuts idea? Research online shows that other fat bikers have successfully converted their fat bikes to single speed and the key factors here is, as mentioned above, gear ratio. It seems that very low rations are essential, with something like a 30T chainring and a 22T freewheel being a good compromise, giving 1:1.36. Of course, Pugsley would also get the fancy paint job as well. But that’s all for the future. More soon.

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