Andrew R Stewart 

I am seeking any real numbers WRT Raleigh Professional frame geometry to help me design a frame I will make. Specifically the early/mid 1970s versions with fastback seat stays and the full sloping crown.

I recently finished a French influenced frame/fork and am planning my next project. I have had a few tube sets in my stash for decades along with a collection of fittings and it's time to do something with them. Here's a link to the Framebuilders thread I started on that frame. P - Bike Forums

I have owned a few Pros over the years but never got around to measuring them but always was drawn to the aesthetics of the stay treatment and the minimal lines of the crown. It is this that I wish to follow with my project. This frame won't be for any specific rider, not a custom build in that sense. I'm also not trying to make a replica, details will reflect 50 years of gained knowledge and my mechanical preferences. Still I want to be as true to the vibe that I can be.

If you have some data about frame geometry of these iconic bikes please let me know. Andy

repechage

Don't copy them too much.
iconic in styling, yes.
longer rear triangle than you might recall but shorter than the International. 415mm?
I recall 70mm of drop.
normal reach brake calipers
126mm spacing
avoid that seat lug bolt style and threading.
use a nicer bottom bracket shell.

just build a good frame with "the look" and paint it in Blue Mink and silver

Prowler 

Sounds like you’re interested in the MK IV. I believe that run ended in the Sept of 1976 when Worksop shut down for the annual “vacation” and retooled for the following year’s model, in this case the MK V which changed several things. My Pro was made in August 76 so is one of the last of the MK IVs. Let me know what details/measurements you would like. My frame is a 58cm c-c and I only do metric. Inches are for lumber and cinder blocks.

It would be inadequate gratitude for the wisdom and knowledge you’ve posted here for a long time. Thanks.

T-Mar

Here's the specification sheet from a Bike World Magazine road test of a 1972 Raleigh Pro. It includes partial geometry measurements.

Andrew R Stewart 

Prowler- Yes, the Mk IV is my ideal target. The dimensions I am looking for are the usual center to center of the seat tube, top tube, chain stays and if possible angles and rake/trail. I've done some searching for numbers for a while in my planning but Raleigh did a poor job at putting out any back in that day. I have a vague memory of an on line discussion about this quite a few years ago and was hoping whoever was apart of that might have saved the discussions and step forward.

I have had 3 Pros (and a couple of Internationals). Two were Mk IVs IIRC and one was a Mk5 (which admittedly rode nicer IMO). Only the MkV was bought new from Geo. Rennies Bicycle Shop, where I was working. My boss told a story of when he and the partner visited the Raleigh factory (back when that sort of thing was encouraged by Raleigh) and he asked the guide about the geometry. The response was it was determined by what lug set they picked out of the pile that day. A non answer and made no sense but as an example of how close to the chest Raleigh was with some info.

Thanks for the help. Andy

75lechamp 

Andy, you might recall that I have one of your old MkIVs, which is a '74 21 1/2" CTT frame, one of my favorite bikes. I will try to get some dimensions for you shortly, but in the meantime here is a pic....




Andy
Arvada CO USA

Road Fan

Given the date, my guess is this isn't a Mark IV. Plus, it looks like Raleigh reports front-end geo the same way they did in the adverts for my 1952 Rudge (were the Professionals built at Nottingham?). The way I read the front end specs: Wheel radius is 333mm, assuming skinny tubulars. Fork offset is 2 ⅜ inches, or 60.3 mm, and angle is 73 degrees. So trail by the standard formula or online calculators is 38.75 mm. This is close to the value on my 1952 Rudge, surprisingly! Its wheelbase is more in the range of 43 inches, maybe more.

guy153

I actually have an old Raleigh frame because reasons. Don't know if it's a "Pro" but I'll go and have a look and take some measurements.

Road Fan

After finding my old Rudge, I'm kind of fascinated by older Raleighs at the top end. Would you share the geo numbers you receive? When I got a Super Course Mk 1 (1973) frame/fork (available and still not built!) I measured it up and found it was very close an International of similar vintage in front end geometry and in chainstay length.

Also, having worked for Ford Motor Company when I first transitioned from the space industry to the auto industry, I found the company to play many speciications VERY close to the chest. But in the '40s and '50s, and seemingly even into the 1970s, Raleigh was surprisingly open at least about publishing a reference set of specifications. Can't say how close they are to "true" for every frame and every size variant, but they were willing to build at least a little footstool to stand on, in public press! The data I've seen for my Rudge all comes from the Raleigh advertising and the magazine reviews reproduced by Peter Kohler in his "On the Drops" blogs.

guy153

I think mine might be more of a touring bike, and it might be even older than the 1970s. It's 531 so though pretty nice.

Here are the numbers:

Head angle: 73.5 degrees
Seat angle: 71 degrees
Fork offset: 82mm
BB drop: 61.5mm
Chainstay length: 453mm
TT length: 580mm
ST length: 565mm
HT length: 160mm
Rear dropout spacing: 123mm

Interesting design of fork that looks actually quite sketchy: the legs are just mitred and somehow brazed onto a tube that forms the crown. But it's not a big fillet braze. Just a sort of capillary-action type deal. The writing on the side of the DT looks like it says "LENTON". Going to google for that...

UPDATE: I think is a 1958 Raleigh Grand Prix Super 7 in Polychromatic Silver Grey!

https://www.sheldonbrown.com/retroraleighs/lenton-kohler.html

retroman57 

I have a MK IV in 25" size. Happy to measure if this is of any use to you.

bwilli88 

While not a Raleigh, here are a couple of nice fast back seat lugs.

Geoffrey Butler


British Witcomb

Andrew R Stewart 

The issue I have with the two "fastback" types shown is that the stays are along either side of the binder slot. When tightening the binder bolt the stays will be bent/flexed toward each other. Not what I would call being a slick design, having more stress on the bolt and the stays. The Raleigh's design places the stays against the seat tube below the binder slot. So no stays are harmed when the post is secured in place. Andy

USAZorro

I think that this is a case where "size matters". I think that the distance between wheels is pretty constant across the sizes. If the head and seat tube angles were the same, all sizes would have the same top tube length (which couldn't possibly be the case).

Yes, I am making assumptions, but finding the same model in the same size is going to give the most accurate information.

edit: It would still be a good exercise in documenting the information for possible compilation, even if it doesn't answer Andrew's exact question.

Prowler 

My recollections were correct: when I first got my Mk IV, almost 10 years ago, I took it all apart for a frame up overhaul. Had all winter to do it so I nerded out and measured everything as well, and wrote it down (yikes wadda nerd). So, again, serial number says August of 1976:
ST = 58cm c-c. 59cm c-t
TT = 57cm c-c
HT = 16.5cm
Steerer tube = 20.3cm (I think that includes to bottom of tube in the fork crown, not sure)
chain stays = 43cm from center of BB to center of dropout slot
Chain stay diameter 23mm at BB, 12mm at DO
Wheel base = 101.5cm (rear axle at rear of DO slot)
ST and HT angles both 73deg
Fork rake 4.7cm
Trail 6cm
BB height 26.5
BB width = 68mm
Rear spacing 125mm
I'm lead to believe that this bike is 11 tubes Reynolds 531 ( if you count each fork leg seperately)

I recall spending a lot of time on this stuff BUT, if something seems out of place let me know and I'll remeasure, as long as I can without taking the bike apart.

BTW: Your postings on front fork alignment have been very helpful. I've solved some annoying problems. Cheers


Springsteen: "Your aint a beauty but, hey, you're alright". Oh yes, those are Bocama long point professional HT lugs. Whatever was handy at the end of the production run. I like them a lot.

bulgie 

Those Raleigh "thimble" crowns aren't a tube really, or should I say not just a tube. They're a piece of flat sheetmetal stamped to shape, bent around and welded, but they incorporate plugs that go down into the blades. A pair of secondary round bits that could be called tubes are also inserted inside this primary piece of bent sheetmetal, so the part of the crown that looks tubular is a double layer.

Genius really, super strong and lightweight. In a sense, no crown could be stronger, since if you stress the fork to failure it will always be the blades that bend. The crown and the braze joint are both way stronger than the blades, so there's no sense in making a crown (or braze) stronger than that. For pure engineering excellence, I'd take this over the massive sand-cast crown on the Pro for sure. The thimble crown is superior in every way except maybe style (de gustibus). Though the old bikie in me still loves the Pro crown because that's what I grew up lusting after.

Pic scraped from the web somewhere, I forget where, sorry):



I think we're seeing the nail they drove through a drilled hole to pin the blade to the crown during brazing. Brazing might have been partly or completely automated — yes even way back then — with brass pieces inserted as it was being assembled. The whole crown was then heated with big flames until the brass melts and flows around, no human touch required. I don't know how automated it was at Nottingham but I've seen a video of it being done that way in an Asian factory, and I believe Raleigh was the leader in that kind of stuff. For a long time Nottingham was the biggest bicycle factory on earth.

Mark B

Andrew R Stewart 

Mark- I had known of the thimble crown construction in a general sense for a while but never saw a sectioned example. Pretty cool! So many riders today think the stuff done before Al or carbon were the rule is just for kids. Your description well explains why they are missing so much that came before them. Andy

Andrew R Stewart 

Prowler- Thank you much. Your numbers are pretty close to what I remember with the mid 1970s versions. IIRC the earlier ones had less trail and more rake. Andy

guy153

Thanks for the explanation! This explains a lot. I have been curious about this fork for some time and should have started my own thread about it.

Yes a brilliant design and I like the look. Modern Pashleys still use crowns that look like a bit like this.

I have been tempted to make a TIG fork in which it just would be a tube (probably a bit of steerer) but have never seen one like this. Superficially it looks like it might be a good design because everything seems to be in compression. But what if the fork becomes kind of sheared to the side while still being loaded? In that case the segmented design of TIG fork would be much stiffer. Resisting this kind of shear is probably one of the most important jobs a fork crown has to do.

It's a good thing I didn't make this fork based on a misunderstanding of an old and much superior Raleigh fork and then die as a result

verktyg 

Andrew, from experience, I measured a lot of frames doing research on ride and handling characteristics back in the mid 70's.

If you take 10 Raleigh Pros, same size, same year, you're going to get at least 3 different dimension sets with regard (staring from the front and working back) fork rake distance, fork bend, head tube angle, top tube length, seat tube angle, drop, and chain stay length. Beyond the front end, the differences may not be glaring but these were "hand crafted frames".

Raleigh was notorious for using whatever was on the shelf! Was it built Monday AM or Friday PM? Before or after a 3 pint lunch!

Now, if you take 10 different Internationals you're going to get 6 or 7 different spec sets! I'd always admired the look of the champagne International. At end of 2019 I came across a 1974 frame in nice condition.

When I measured it and checked the alignment... Oh the horror! Oh the horror! The head and seat tube were 75°, the forks had a 65mm rake. I took to a friend's shop and we corrected the frame alignment, It took him almost an hour to properly align the fork blades then remove 10mm of rake!

My suggestion is to find a bike that you REALY enjoy riding. Copy the geometry and dimensions. You'll be a happy man!

I'm having a frame built that way - in July, it will be 2 years!

I could built it myself but I've been promising him for years that I'd have him build me a frame (he needed the money too).

verktyg

Prowler 

I think I may have been lucky with my Worksop bike. That first winter I checked the frame alignments and spacings and all was well. Nothing needed. A couple of years ago I checked all my fork alignments, per Andrew’s postings, as two really needed work and I was doing periodic service on all the headsets anyway. My MK IV fork was spot on. Runs straight with no hands too.

The only issue with my MK IV is the danger of running into something cuz I was staring at that fine British chrome on the fork legs instead of watching ahead.

Andrew R Stewart , when you build your Pro-ish frame, be sure to include a stylised AS cut out on the BB shell so we can see the Campagnolo logo on the accordion sleeve over the BB spindle.

Andrew R Stewart 

"when you build your Pro-ish frame, be sure to include a stylised AS cut out on the BB shell so we can see the Campagnolo logo on the accordion sleeve over the BB spindle." Prowler

I got past my cut out BB shell phase way long ago. And I disliked the Campy two piece plastic shield/sleeve, Every Campy BBed bike I rode ended up with the far easier Sugino accordion sleeves.

Vertyg- Your experience mimics mine in that those era high end Raleighs seemed to shift geometry with each production series. I mostly want to make a Pro inspired frame/fork because of having some past with Pros and I learned to like the look. As I mentioned I remember my 1978 Pro (a far different Pro than those before) was the nicest riding Pro I have had. So I'm not married to any specific geometry. I'm noy looking to make a copy or replica, just a bike that looks like it might be a Raleigh Pro but won't be. Andy

verktyg 

Yes indeed! Some eBay sellers and online outlets offer the plastic accordion sleeves for CRAZY prices! They're just a cheap piece on molded plastic! When I find some at realistic prices - under $2.00 USD, I stock up on them. The older Campy 2 piece sleeves usually have a split or are mushed up and don't fit correctly!

By 1976-77 Raleigh cleaned up their act on the higher end models. We picked up the Raleigh line in 1977. The local Raleigh dealer was about 3 blocks from us and going south fast. We needed a sub $200 model - the Grand Prix sold for ~ $175.00 and filled the bill. The real reason that we wanted the Raleigh line was there were a number of loyal fans who wanted to buy Mk. V Pros and Team Pro frames. The Mk. V was well built but at $700+ we could put a customer on a top end all Campy equipped Italian or British frame for $100 - $150 less!

At the beginning of 1979 the Raleigh America sales team showed up at our shop unannounced and demanded that we drop all of our other brands and floorplan the complete Raleigh line! Most of the models were way overpriced plus we didn't have a market for them. Centurion and Nishiki were taking over a lot of the business in our area. They had much nicer cosmetics and features for a lot less $$$. We politely showed them which way the door opened! About the same time Trek stopped by with the same visions of sugar plums and they too went home empty handed. We didn't NEED either brand!

As far as looks go, back about 2006-2007 I started acquiring bikes that i liked but could never have afforded BITD. I found a 1975 Mk. IV Pro frame in nice condition. What I always liked about those bikes were the beautiful Davis sloping fork crowns. I was lucky, I got a frame that handled perfectly for my tastes.



What I really would have wanted was a 1972-3 with the "bird's mouth" lugs... Not sure what Mk. they were.



Factory specs for the 1975 Professional Mk. IV DL-180

I can appreciate your desire to build a frame with the Raleigh Pro inspired features. Last year, I picked up a bucket list Raleigh Pro frame, a silver and black 1974 Mk. IV from a BF member.



verktyg