Hi All,

Does anyone know what tool Tom Oswald use to measure the angle between the head and toptube in this youtube video https://www.youtube.com/watch?v=KIxCdTRkRHo (skip to 3.22 min)?


thx,

Clemens

that's an adjustable drafting triangle. I have one of those from my drafting days

I'm going to have to take care of it, the one I have goes for over $20 nowadays. There are probably better protractors out there for framebuilding, although a good machinists protractor starts to run into $$

Is this the same kind of tool? https://www.hogetex.com/hoekmeter-met-klok.html

I use a Wixey WR300. It's inexpensive and accurate. "Zero" it on one tube, then move it to the intersecting tube to read the angle. Accuracy is ±0.05°

Clemens, yes that is a similar tool and it is probably more accurate and less flexible.

I also use a magnetic level like Scooper, it's very practical. Are you sure the accuracy is 0.05 deg? The resolution is 0.1... Mine (a Fowler) has a resolution of 0.05 but the manual indicates an accuracy of +/- 0.2 deg in "zero-ed" mode.

Oops.

The retailer I bought it from had a data sheet that said accuracy is ±0.05°, but the Wixey website says ±0.1°. That could be interpreted to mean an accuracy to within 0.2°.

that is a machinist's protractor. I am not sure a 49 euro one will work that well for you, but it's a start. You probably want one with a vernier scale

I have a Wixey, you have to be careful with it. They have 2 versions for sale right now. The older one has a reputation for eating batteries.

The problem using a protractor (reguardless of construction) is that the tubes themselves are not straight. I started to use a vernier protractor (machinest's tool, able to measure down to some number of seconds af a degree) a long time ago. But with some tubes the bowing (of the tube) would place the other end 4,5,6+ mms off the c-c point of the other tube. (that's with placing the bow in line with the frame's centerline, as is the usual practice). For mitering the protractor was neat but for setting up the actual tubes not so much. Using the center to center dimensions was a far more accurate method. Yes, this means that the protractor done miter would be ever so slightly off. This is one of the advantages of a jig. The tubes are held so their average centerlines are to spec and the tubes can be mitered to fit. But all this detail won't make the frame any more rideable if all the other work is done well. Andy.

I'll second what Andrew says above. Those little square digital Wixey's etc. will get you in the ballpark, but you'll commonly see variances of several tenths to a half degree across the length of tubes. Paint and decals also get into the mix if you put it on a finished frame. It's great as an aid, but I would never say a frame has a 72.6° head tube because the little cube told me. Customers really like to see drawings with angles to the tenth though.