Anything that is stuck or seized in a frame is bad news. It is even more bad news when the wall thickness of the frame tubing is extremely thin. Reynolds 753 tubing of this type has a wall thickness less than 1mm. The frame top tube and down tube is double butted which means that the centre section of the tube is thinner than the 2 ends of the tube. This makes a lighter tube while retaining strength at the ends where it is required. A seat tube is single butted, with the butted (thicker end) at the bottom bracket.
The measurements in ‘mm’ of this 753 seat tube is 0.7/0.5
I bought this frame with a seized seatpin. That probably wasn’t a great idea but I was confident I could remove it Not only was it seized, it was also snapped off flush with the top of the tube with nothing remaining of the seatpin on the outside of the frame. Seatpins are typically made from an alloy/aluminium material and it is common for the alloy pin to seize in the steel tube of the frame. Using the correct grease can prevent this. Moving the seatpin occasionally can also prevent this. Unfortunately, once most people position their seatpins at the correct height, they seldom move them again. Several years later, when they need to remove it, they will find that the pin is stuck!
The remains of the pin stuck in my frame was strange because it appeared to be made from a very hard plastic with a steel insert for strength. I would normally use the part of the seatpin sticking out of the frame by clamping it in a secure vice and twisting the frame as leverage to hopefully break the bond between the pin and the tube. I couldn’t do that in this instance.
With a little bit of time and patience, together with a hacksaw blade, selection of drill bits, a 6mm chisel and large hammer, the remains of the seatpin were removed. You need a steady hand to cut through the steel insert and through the plastic towards the frame tube. Because the frame tube wall is so thin, you need to be precise and careful and listen to the noise the blade makes while cutting to make sure you don’t get too close to the frame and accidentally cut through or damage the tube.
The theory is to cut a couple of slots into the seatpin from the centre outwards towards the frame and to start collapsing the seatpin in on itself. There was 5 inches of seatpin stuck in this frame and as you can see from the image below, it took a lot of cutting to get it out.
It’s difficult to measure the internal diameter of a seat tube that is 30 years old especially when it has had a bit of abuse from the removal of the pin. The top of the seat lug and tube is often not perfectly circular. I know this frame should be 27.2mm and I have an old 2 bolt Campagnolo Record 27.2 seatpin that I intend to use. A lot of people get hung up on the correct size of seatpin in 753 frames. From the research I’ve done with other frames I own, the earlier metric 753 tubing used 27.0 and 26.8mm seatpins. The later imperial 753 (like this one) uses 27.2 and 27.4mm – some frames and seatpins don’t conform to this because of a combination of seatpin and seat tube tolerances. You cannot be sure what has happened to a frame during it’s life time – you don’t know how accurate it was when made, how many times has it been filed or reamed
I measured my 27.2 seat pin and received various readings depending on where I measured, proving my point about tolerances.
The very first thing you should do when you remove a seized seatpin is clean the internal surface of the tube. You can use a round file to do this or a piece of emery cloth (if you can get that far down the tube), or you can use a reamer. In this example, I’m not using a reamer to increase the diameter of the tube, I’m simply using it to clean any burrs or edges and any built up corrosion from the inner surface of the tube.
Just adjust the reamer to a diameter of 27.2mm, apply some cutting fluid and rotate it into the tube. When you use a reamer, or any facing tool, you should only rotate in the cutting direction. When you have rotated the reamer as far as you can, remove the reamer by pulling upwards but continuing to rotate in the direction of the cutter.
I’ve wanted to weigh this frame properly since I acquired it just to prove that it was 753 and that the story I was given when I bought it had some substance to it. You can’t tell much from the external appearance and measurements of a frame to help confirm the type of tubing. There is however, a definite difference in the weight between Reynolds 531C and Reynolds 753R which were the two main types of Reynolds tubing used at the time this frame was built. Depending on gauge and frame size, a 753 frame will weigh less than 2000 grams. The Reynolds literature of the time shows approx weights…
According to this, my frame should weigh approx 1800 grams.
As you can see from the scales, it is approximately the 1800 I was expecting. I already have a 57cm metric 753 frame/fork weighing in at 1645 grams/639 grams – this new frame is larger at 58.5 cms, a slightly different gauge 753 and has additional braze-ons such as the multiple eyes on the front and rear dropouts. Because of this, I’m confident that this is Reynolds 753.
After giving the frame a good clean to remove the oil and grease, you can see things like the pinned lug construction and perfectly cut and finished tubes through the BB shell that show some of the quality craftsmanship, skill and finishing that make these frames so sought after.
The frame and paint condition isn’t great but it is still good. There is some paint chipping in places especially the right side chain stay; but it is still solid and usable and I’m very much looking forward to building it back into a bike. With some cleaning, waxing and polishing, it doesn’t look too bad.
