June 9, 2025

Restoring my Peugeot PX-10 - Wheels

These came new with sew-ups mounted on 700C wheels. Back then 700C clincher wheels were unheard of.

My bike came with 27 inch clincher rims. I ran sewups for a while. They were fun, but I eventually decided they were more trouble than they were worth and sold those wheels.

Now the question is putting 700C clincher wheels on the bike.

You may or may not want to use wheels that use a cassette. The cassette will be too wide and require the frame to be spread.

At first I thought that spreading the frame was something I absolutely wanted to avoid. But after giving it more consideration, I went ahead with it (see below). It only needs to go from 126mm to 130mm. A change of 4mm! They call doing this "cold setting" a frame and it is only recommended for a steel frame (and the PX10 is a steel frame!).

700C wheels that use a freewheel are available and would avoid the cold setting.

Tire sizes

700C is 622mm (24.5 inches).
27 inch is 630mm -- just a bit bigger, so you would fight to mount a 700C tire.

The idea is that a tire mounted on a 700C rim would be 700mm in diameter, but of course this varies with the tire. The idea with a 27 inch rim, is that the tire ends up 27 inchs in diameter (686mm).

Cold setting

I asked a bike shop to do this, but then discovered that they did not. The wheel was just pushed into the frame, which has enough spring to let it fit. The trouble with this is fixing flats in the field. Getting the wheel out is no big deal, but getting it back in requires a fight using prying tools (like a big screwdriver).

So I tackled this myself. I got a 12 inch long piece of 5/16-18 threaded rod. (I actually had this laying around), 3 nuts and 3 big washers. I used 2 nuts and washers to clamp the rod to one side of the frame, and the other nut and washer to "push" the frame to a bigger size.

I measured the frame spacing as 4.94 inches (125.5 mm) when I started.
I measure my wheel as 5.15 inches (130 mm).
I did the expansion in stages, as follows: 

Expand to 5.50 inches -- measure 4.93 when relaxed.
Expand to 5.75 inches -- measure 4.94 when relaxed.
Expand to 6.00 inches -- measure 4.97 when relaxed.
Expand to 6.25 inches -- measure 5.05 when relaxed.
Expand to 6.50 inches -- measure 5.04 when relaxed.
Expand to 6.75 inches -- measure 5.23 when relaxed.
The final dimension of 5.23 (132.8 mm) is perhaps bigger than I wanted, but works just fine and allows the wheel to be inserted easily. The quick release has no trouble compressing the 2mm required.

Also it is quite possible that the metal will relax and close up after some time. At any rate, this seems to have worked out just fine.

Have any comments? Questions? Drop me a line!

Tom's bike pages / tom@mmto.org