I’ve purchased 3 British bikes this summer and will be building this winter. 2 are probably from a small Scottish builder and I posted about them here;
New Bike(s) day
After getting the two, I crazily bought a “challenged” Raleigh International because I was on the lookout for one in the first place:
NBD Raleigh International; Why did I do this?

Not knowing much about the pair of semi-custom frames, I wanted to compare them to the more documented specs of the International. i thought they were probably 531 butted, and indeed the green one has 531 butted on the steerer and takes a 27.2mm seatpost. The Chrome one appears older, and a 27.0 was a perfect fit. Weight of the similarly sized International and the green bike were within 50 grams while the slightly smaller chrome bike was just slightly less.
None of these bikes were fit to ride at time of purchase, so I am at a loss as to ride quality. The 74 International is well documented about ride and frame angles and such. It would seem to be slightly more relaxed than my full 531 Trek 700 from 1983. I did try a phone app for angles that was mentioned on this forum, but I didn’t have much luck with it. So with all the frames stripped, I thought to compare them side by side on this rainy day. It was unscientific but still interesting and gave a couple relative clues.









I tried to keep all the bottom brackets at the same height just to give a consistent view when comparing frame angles even though the BBs are different. This was kind of an interesting experiment as one could pick out some subtle differences. The chrome bike surprisingly seemed to have a slightly steeper head tube and perhaps the same seat tube angle. The green frame looks quite interesting with a slightly slacker head tube and seat tube plus about 3/4” of extra wheelbase. It sounds like a cushy ride. Anyhow, it was an interesting comparison and gives me something to go on. I think my brother has some sort of electronic angle finder that I want to use when I can get it and that might be revealing too.

Very cool you're doing this. Interested to see what difference you discern, especially as you build them up.

I use a magnetic digital angle finder like this one:

https://www.amazon.com/Electronic-Pr...dp/B0C1NGVBMS/

Can you show a pic or two of the entire frames straight on from the drive side, rather than at an angle as you do above?

I’m thinking that may be the kind of angle finder I want to get from my brother. As to a straight on pic, it was a bit hard to discern without moving my head back and forth because of perspective. Setup is all taken down, but it was obvious that the green frame was more relaxed.
Reading on the custom British builders of this time mentioned that many liked 72 degree parallel frames which would possibly match the green frame if the International did indeed have 73 degree as is often mentioned. The surprise was the chrome one actually looking slightly steeper at the headtube. Indeed , that one measured 1/8” longer in the top tube despite being 1/2” shorter in the seat tube. I find all this geometry stuff to be interesting even though I ride slow enough that it isn’t a big deal. I kinda like the low trail handling too.

The nice young man at the store assured me my new cell phone would have that feature.

I tried one of those apps and have it loaded on my phone still. It didn’t seem very easy to use, especially when getting into the shorter headtube on the chrome bike. On that one I kept getting like 76 degrees or more on the HT which I didn’t think would be correct except after an accident which didn’t seem to be the case. Operator error I concluded as I guess I am a Neanderthal with tech stuff. Kinda surprising how the International is listed as biased toward touring but still has a shorter wheelbase that these and not really relaxed angles. The geometry of the green one intrigues me most. I’m sure I will have to use a seatpost without setback so as to accommodate my usual riding position. My knees complain a bit if I’m too far back relative to the bottom bracket. All useful info no matter how one approaches it.

those phone angle apps are not that granular.

get the forks installed and use the same set of wheels on a common level plane to reverse engineer angles, BB drop and wheelbase is my suggestion.

I have one of these and it works well. The base is magnetic and there is a v-shaped groove so it sits on a round tube properly.
It can also tell you the difference between two angles, in case you r top tube isn't level, e.g.

Amazon, Lowes, Home Despot all have them.

Klein angle finder

I've used the $5 Horror Freight angle finder for years.

I did this with a few frames once- a pipe through the bottom bracket and the forks on the deck. Bottom bracket drop made a big difference in the way the frames lined up (or not). It was easy to see slight differences in the angle of the seat tube and headset but unless the front and rear dropouts are at the same level for any given frame, you don't know if the difference is tube angle or rotation from the BB drop.

I see what you did. When I had the dowel installed somewhat lining up the BBs, I knew that the height was different for each. That is why I tried to also get the top tubes level assuming that that was going to be indicative of how they would set once built up. I figured then I was looking at frames with tubes parallel to the ground and was close to eyeballing the same relative frame angles. The forks weren’t really needed I guessed. Not super scientific but I was just looking for comparisons on a rainy day. Out for a nice ride tomorrow.