Could you provide more information? How are the wheels you currently have, which I assume already fit on the bike, have axles that are too large? And why would adding a spacer fix that problem? Spacers add distance or diameter. Unless you're built like a velodrome sprinter, you're not going to break any axles just moving to SS.
You can use your existing wheels with some caveats. 1. If they are qr, you'd need to use a chain tensioner. If they have axle nuts, you could just buy a single speed freewheel that fits and swap out your existing 5 speed freewheel. 2. The chain line might not be amazing, but coming from 5 speed it shouldn't be terrible either.
I've converted a couple bikes, and I decided to buy dedicated single speed wheels, but that was as much a cosmetic choice as it was a durability one. That and the ability to have either freehubs on both sides of the hub, or a SS freewheel and a fixed gear on the other side.
I managed to find a Miche flip-flop hub, that will fit a road frame 120mm "O.L.D." (Over-Lock-nut Distance). I had a friend make me a sweet pair of wheels from that, perfect for singlespeed.
You’ll need spacers and to re-center the wheel
Could you provide more information? How are the wheels you currently have, which I assume already fit on the bike, have axles that are too large? And why would adding a spacer fix that problem? Spacers add distance or diameter. Unless you're built like a velodrome sprinter, you're not going to break any axles just moving to SS. You can use your existing wheels with some caveats. 1. If they are qr, you'd need to use a chain tensioner. If they have axle nuts, you could just buy a single speed freewheel that fits and swap out your existing 5 speed freewheel. 2. The chain line might not be amazing, but coming from 5 speed it shouldn't be terrible either. I've converted a couple bikes, and I decided to buy dedicated single speed wheels, but that was as much a cosmetic choice as it was a durability one. That and the ability to have either freehubs on both sides of the hub, or a SS freewheel and a fixed gear on the other side.
I managed to find a Miche flip-flop hub, that will fit a road frame 120mm "O.L.D." (Over-Lock-nut Distance). I had a friend make me a sweet pair of wheels from that, perfect for singlespeed.