Originally Posted by hernick

Well, one of the requirements for a singlespeed conversion is to have a frame with horizontal or semi-horizontal dropouts. The Paver frame has vertical dropouts, which cannot be modified for proper singlespeed operation.

To explain, in a multi-speed bike with a rear derailleur, the chain is kept tensioned by the action of the rear derailleur. On all bikes, it is absolutely necessary that the chain be kept tensioned properly, that is, that the chain not be allowed to be slack. A slack chain on a singlespeed bike means that the chain will fall off by itself, which is very bad. Now, to tension the chain without the use of a rear derailleur, you must have a frame with dropouts that are not vertical, so that you can set chain tension by adjusting the position of the rear wheel within the dropouts. In other words, on a frame with horizontal or semi-horizontal dropouts, you can choose the wheelbase of the bike to tension to chain.

There are alternatives that do not apply in your case - the first is to have a special frame with an eccentric bottom bracket and appropriately oversized bottom bracket shell. The Paver frame cannot be modified for this. Another option is to have a wheel with an eccentric rear hub - such a wheel would cost over $200.

Now, there are other options. One is a phantom chainring, which is a bad idea. The other is a magic gearing combination, which is difficult to achieve and has many downsides, including the need for complex, obscure and magical computations and the need for spare parts and tools that may be expensive.

The last option, and in my humble opinion the only viable and affordable (as in free) option for a singlespeed conversion in your case, is to set the rear derailleur limit screws so that the rear derailleur will be frozen in a gear of your choice, disabling the shifter in the process.

Such a configuration would not gain all the advantages of a proper singlespeed. However, your chain will stay a lot cleaner if it does not shift from gear to gear.

If you want the singlespeed experience with that bike, my recommendation would simply be to select a gear and never touch your shifter again. Eventually, your rear derailleur and control cable will rust in place and you'll have achieved a free singlespeed conversion without performing any work. Your chain will stay cleaner and you won't have to worry about the upkeep of your deralleur and shifter.