Greetings, I've ridden a (~1977) 23 1/2" Raleigh Professional since I bought it new. It fits me pretty good. Now I want to compare it to a new fangled bike and am searching for the frame geometry details. Anyone know where I can find Raleigh frame geometry?
Thanks,
Sherbornpeddler

If the frame is in your possession, how about measuring it yourself? You need a tape measure for tube lengths and a protractor for angles.

Neal

Welcome to the forum.

In regard to your question, I would start with www.retroraleighs.com first. The site has historical information for most Raleigh models as well as catalogs from the 1960's up through 1979. Most of what I know about my 1978 Raleigh Competition GS I learned from this site.

Good luck.

I don't think they recorded the geometry of the frames. Things like fork angle or wheel base. I think nlerner's right. I think you are going to have to do your home work on this one. Good luck in your quest.

The link below has the frame angles for the 1978 model. I think yours should be the same. That should at least get you started.

FYI. The information is at the bottom of the comparison chart near the end of the page.

https://www.retroraleighs.com/professional.html

I think it is really unlikely that a 23.5in frame will have the same geometry as the 21.5in whose geometry is listed. The larger frame is likely to have a shallower seat tube angle and maybe a slightly steeper head angle - the only real way to find out what your frame's geometry is, is to measure it. Making a half scale or ideally a full scale drawing of the frame will help to ensure you get it it accurate as measuring frame angles with a protractor in incredibly difficult. However by doing a drawing you can see if what you measured actually all adds up. Altenatively a local framebuilder could check it on his jig...

Hilary

To measure the angles on my frames I've used some of my carpenter's tools - a T-Bevel and a speed square. The t-bevel rests on the inside of the ST angle easily, you have do a little finagling for the HT angle.

Thanks folks,
I'm a newbie, on the case and will report back.

You could take pictures of the bike directly from the side, draw a base line across the bottoms of the tires, and then use a square, straight edge and protractor to measure the angle right on the photo. You'd probably need an 8" by 10" to get it accurate.

Tried the 8x10 photo method is still too small and probably camera angle my acuracy is insufficient. I need resolution of 1 degree and can't get less than 2 or 3 degrees.
I'll try direct measurement, high school geometry and carpenter tools directly on the frame.

Sherbornpeddler,

Ralieghs are like most bike boom bikes. They just didn't publish frame geometry data.

We'd very much like to get the Ralieghs documented on the Bike Geometry Project spreadsheet. Bad news is that we'll have to rely on volunteers taking a half hour or so to measure their frames and then rely on those measurements as approximations to the design specs (variations in manufacturing and measuring). The good news volunteers have submitted ideas on how to measure the frames and we've posted it here:
https://home.comcast.net/~pinnah/dirt...t.html#measure

If you want to measure up your frame, you can PM me or send me mail at pinnah at comcast dot net. We'll record it in the spreadsheet so others can benifit.

Many thanks!

-Dave

Hilary is correct, a full scale drawing would help, I go a bit further, set in a set of wheels without tires, as tires are not perfect and I use a CAD program to check the geometry for truthfulness, quicker than a drawing. A number of cheap CAD programs out there, cheaper than buying drafting tools even.

Having sold Raleigh's long ago, there is a transition point somewhere in the mid 70's where the geometry did change, and frames of different size seat tubes shared a top tube length, great for a rider wanting to sit up more upright and not reach as much, not so good to get a typical fit. We guessed it just made for faster production, less parts, less to rejig.

Later they even sent over the Nuovo Record cranksets with chainguards fitted... big brother was watching and had to protect the masses with too much money and no sense.

I've contacted Pinnah and will give it my best.