Though you can go out and buy a ready made "Single Speed" bicycle, these days, at just about any local bicycle shop anywhere, this discussion is about "Single Speed" bicycles, that have been converted from old "Ten Speeds".  The conversion methods, suggested, are those, that I use myself.  The procedures, offered for converting, an old "Ten Speed" to a "Single Speed", are designed with the ordinary person's lack of facility, resources and training issues, in mind.  In other words, let's build our first "Single Speed" road bicycle on a budget, without really knowing what we are doing, and, in a place that is often used for eating.  But first, why bother?

The "Ten Speed" bicycle, converted to "Single Speed" design, is an exercise in functional and aesthetic simplicity.  The modified bicycle, with its absence of a transmission, coupled with the simplified appearance of a converted crank set, suggests the one thing that vintage road bicycles are remembered for - lightness.  The result of "Single Speed" conversion will be a lighter bicycle, simply because some of the parts will have been removed.  Additionally, a converted "Single Speed" looks light.  The bicycle will feel light, when ridden, and that light feel will be complimented with simplicity.  Simplicity?

The "user friendly" nature of the bicycle soars.  Your hands need never leave the handlebars, dramatically increasing the safety factor, when considering vintage road bicycle use.  Increasing a bicycle's opportunity to be ridden safely, earns big points in today's modern, and often times, unforgiving traffic.  And, to me, there is an additional advantage, connected to the inability to change gears, and a factor that will become an endearing quality of its own.  Just pedal, steer and brake.  Removing the transmission will help to connect you and the bike.  You want to go fast, pedal faster.  Its up to you, not the transmission.

Said another way, the converted "Single Speed" bicycle is almost perfect as a city bike.  Light to carry, both indoors and out.  Ride just means go, turn and stop.  Easy to pedal, going up hill or down.  And it goes just as fast as you can go.  Kinds starting to sound like a Dr. Zeus (not the bicycle) story.

If you convert an old "Ten Speed" to "Single Speed" design yourself, the cost will be minimal.  Though there is one building situation, that might prove to be beyond the capabilities of some people, the bulk of a "Single Speed" conversion is a very straight forward, "take off and put some back on" task.  The one situation, that might prove to be beyond some people's reach, is the converting of the rear wheel.  But don't despair.  The rear wheel modifications are not as mysterious, as one might think.

One of the nice things, about building a decent old "Single Speed", is that you do not have to start with a top of the line frame set, to begin with.  There are a host of lesser frame sets, be they department store or of local bike shop origin, that will serve as a great place to begin building a bicycle.  Bicycles like the Sekine SHC270, reeking of vintage appeal, and capable of offering a great around town ride.  Bicycles, that were well enough made, to stand a thirty some year test of time, and resurface to meet new needs, once again.  And bicycles, that can often be had for little, or no cash outlay.

However, not just any old "Ten Speed" will work for a "Single Speed" build.  There are certain features, that need to be present on a vintage frame set, before conversion becomes viable.

First and foremost, look for long horizontal rear drops.  The drops are the places where the rear wheel axle is supported, in the bicycle frame set.  The long horizontal drop will allow for forward and aft adjustment, of the rear wheel position.  And, this forward and aft adjustment opportunity, is absolutely necessary to have in order to adjust drive chain slack.

Normally, the rear derailleur will help to keep a bicycle's drive chain properly tensioned (actually there should be no tension on a drive chain at all - there should always be a bit of slack).  However, once the rear derailleur is removed, only the position of the rear wheel will serve to set the drive chain's slack.  The further the wheel is positioned towards the rear of the bicycle, the less slack there will be in the chain.  And, of course, the closer to the front of the bicycle, the looser the chain will be.

Some rear drops are horizontal, but shorter, in the adjustment range.  These drops will work for a "SS" build, however, fitting the chain, and achieving proper adjustment, might be a problem.  I compensate for this by trying different front sprocket tooth counts.  Sometimes, changing a front sprocket will make it possible to get the chain adjustment right.  Sometimes, proper adjustment will be impossible to achieve, with a shorter horizontal drop.  For this reason, try to avoid the shorter rear drop, when selecting a frame set for a "Single Speed" project.

And another thing to consider is the rear drop that has the built in derailleur hanger.  The integral derailleur hanger looks out of place on a "Single Speed" bicycle.  With no need for a rear derailleur, the hanger is left - well - hanging.  Unfortunately, the integral derailleur hanger is normally found on forged drop-outs and the forged drop, all other things being equal, is considerably stronger than its lesser cousin, the stamped drop.

Needless to say, the better quality tubing, the better the ride will be.  That said, do not turn your nose up at bicycles made from high tensile tubing.  These tube sets, though a bit heavier than their more sophisticated siblings, are more than adequate when it comes to frame selection for the "Single Speed" bicycle.

The high tensile tube set steel bicycle will be, considerably, more available than will be the top of the liners, that we would all like to have.  Secondly, the chances of finding a lesser frame set, in really nice condition, is greatly enhanced.  So, if you happen to run across a near mint condition, mid seventies, department store "Pricewasrightatthetime" "Ten Speed", consider the possibility.  Or, how about that scratched all to heck Peugeot frame set, some guy said you could have,  if you wanted it.  Since you are not going to restore anyway, a paint job, in a design of your choosing, might as well be in order.  Either of these two opportunities has potential.

The next thing to look for, should not be there.  Braze-ons!  Try to find a bicycle without shifter braze-ons.  These horribly practical items look to be horribly out of place on a "Single Speed" or "Fixed Gear" build.  With no shift levers to hang on these brazed on brackets, they just sit out their in all their not so beautiful glory.  An eyesore, to say the least.  So why not look for a frame set that lacks such unnecessary adornments.  A clean down tube is a good feature to look for when selecting what frame set to use for your "SS" project.

Some bicycles, particularly the older ones, will not have built in derailleur cable guides attached to the bottom bracket.  Once again, the look is cleaner and, I might add, cleaning maintenance will be much easier.  Initially, the bottom bracket cable guide was a clamp-on affair.  With the coming of braze-ons, and the manufacturing costs reduced, through their use, other areas of a frame set fell under the bean counter's, and clever engineer's eye.  The, already mentioned, clamp-on rear derailleur chain stay braze-on was hardly obtrusive, however; the same bicycle might well have a set of guides brazed onto the bottom bracket.  This, to me, was an exercise in stupid!  Sure they worked but at what cost.  Unsightly, awkward to clean and allowing for wear to the bicycle's frame set itself.

There is one other braze-on, to consider, but the consideration is minor, when compared to either an integral derailleur hanger or shifter braze-ons.  The rear derailleur cable guide, usually permanently attacked to the drive side chain stay, is also an eyesore, but only a minor one.  Older frame sets will often not have this particular, welded on, cable guide.  Since there will be no rear derailleur to deal with, there is no need for this rear guide.  With that in mind, take note of the frame set, to see if the braze-on is there.  If so, so what, but if not, the build will be that much cleaner looking, in the end.

The next thing to consider is the bottom bracket type.  Is it cottered or tapered?  Though it can certainly be done, I do not recommend trying to use a cottered crank system, to build a "Single Speed" road bicycle.  The cottered crank set is antiquated, to say the very least, difficult to properly remove/install and will be very difficult to convert to "SS" design.  With this in mind, seek a tapered shaft bottom bracket, if you can, but do not disqualify a potential "Single Speed", candidate just because of the type of bottom bracket installed.  A bottom bracket can be changed, but doing so will add cost, and confusion, to the project.

Virtually everything else becomes an "I like it" or "I don't like it" choice.  The handlebars choice.  Saddle choice.  Brake style choice.  Wheel size, pedals, freewheel tooth count, crank tooth count and other things like that, are all decisions that you can make, before you start the build, or even as you go.  You can even decide to paint the bicycle, if the present paint is cosmetically challenged, or simply not to your liking.

And these choices are one of the nice things about converting an old "Ten Speed" to your "Single Speed".  Since the entire effort is an exercise, in customizing a bicycle exactly to your liking, your creativity is the only thing holding you back, from doing exactly what you want, unless you are like me.  In my case, how much moola I have, in my pocket, also helps me decide what I get to include, and not include, in a "Single Speed" conversion.  My personal city bike "Single Speed" cost me about twenty bucks and it is a treat to ride around town.

With the frame selected, the time to plan on component choice becomes the issue.  And, component choice will almost be a non-issue for most people.  Simply throw away what is not required (front derailleur, rear derailleur, shifters and all associated cables and brackets).  Part of the drive chain will also disappear and one of the crank rings will join the lost links.  With what is left, you can get busy building your own "Single Speed" vintage road bicycle.