Like anyone with an interest in bikes I am often told of the benefits of a singlespeed bike. I actually own one already in the form of a street/park BMX but while that excels in its natural habitat it is of little use around town or for trails. Luckily a few weekends ago I was able to experience singlespeed mountain biking and I'd like to share my experiences. The best part about this is it cost me nothing due to some cunning mechanical tricks. Read the following in all seriousness as a how-to guide:
1: First, you need a mountain bike, with gears. Now the key to this entire method is the state of your rear derailleur. To test whether this method is compatible, simply shift to the largest sprocket at the rear and then gently hold the pulley cage and attempt to push it in towards the spokes. Of course a properly functional mech is designed to resist this very movement and it will prove difficult. What you need is a 6 year old mech that, while once good, has been abused to the point where the pivots are now more like very wobbly bushings that allow masses of sideways travel of the cage. Such a mech will inevitably struggle to maintain indexing and will make gear changes unpredictable at best and dangerous at worst. No competent mechanic or cyclist would run a mech in such a terrible state for years of course. But let's say you keep spending your money on other shiny new trinkets and the replacement of the mech gets put in the I'll-get-round-to-it-soon category along with repacking hubs and headsets. So, hypothetically, if you were silly enough to run this alleged worn mech in the larger sprockets it might just decide to knock itself inwards towards the spokes under certain circumstances.
2: While I have anecdotal reports that this method can work even on quite smooth streets for best results you need to find somewhere rough. Very rough. Imagine the worst, most jarring potholed Edinburgh street, and then multiply it by 10. Imagine a bunch of large granite blocks laid out in a manner that would be suicide to attempt to ride over at any great speed. Imagine this line of rocks stretches for 27 km. What would we call such a monstrosity? The 7Stanes Dalbeattie red route. Countless souls have assumed that the nice hardpacked red routes at Glentress would be replicated here but how wrong they were. And there can be no cheating on a full suspension bike either. Short travel aluminium hardtail it is. You think an alu frame is bad for transmitting vibration on road? You don't know the half of it.
Dalbeattie red route. At a different time of year. A while ago while I had a different mountain bike. Also one of the smoothest bits. It does capture the essential grimness of mountain biking in the tail end of winter though.
3: Finally, you need something to diminish your normal ability to reason. If you were running the mech described in part 1 you might think you could get away with it as long as you shifted to the small sprockets such that the cage has ample clearance from the spokes when the trail becomes rough. If you religiously done this on every necessary occasion you could indeed drag yet more life out of the gears. But, suppose it's 25C, the middle of the day under a baking sun and you have already done one and half loops of the 27km trail. By this point were it not for the large supply of water from the mighty camelbak you would have succumbed to heatstroke long ago. Luckily you are still alive but beginning to wish you weren't. The bonk is not far away, the water is running low, every muscle in your body is screaming for mercy. There's just one more descent left until you can finish just past the halfway point round the second loop. Quick mental checklist: seat down, suspension unlocked, front mech shifted to middle ring....yep, that's all I need to do.
4: If you have followed so far then I congratulate you. With the preparations in place (hey didn't we miss something from the descent checklist?) all you need to do now is wait. Simply blast down the rock garden as normal.
CLUNK BASH WALLOP!!!
Hey, what was that?
Why did I feel the cranks jerk?
Why does the back wheel suddenly feel strange?
Why is the chain loose?
What is that thing my bike is dragging along the ground?
Oh, that's what:
Some foolish people when converting to singlespeed waste seconds taking off the mech by unscrewing it. Hah! Look, it's been done for me with no effort. Sure you still need to take off the cable but a penny saved is a penny earned...or something.
With the heavy inefficient mech out the picture now you can work the magic of the singlespeed drivetrain. Luckily you have a chaintool with you:
That looks good.
Now maybe there's some issues with it not being a 'proper' singlespeed conversion and not strictly being able to pedal as such but it gets you to the nearest road while looking stylish:
There may be some other points of contention about the suitability of this method. You have traded off using the spokes to remove the mech against needing to retrue the now buckled wheel. Should you want to go back to a mech there will be some additional costs:
New mech: £25
New mech hanger: £10
New gear cable: £4
Successfully completing a mtb rite of passage, namely wrangling your way off a trail with a busted drivetrain: Priceless
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