Retrobike Forum Index

It is currently Sat Dec 03, 2016 1:48 am

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 28 posts ]  Go to page 1, 2, 3  Next
Author Message
PostPosted: Sat Aug 14, 2010 9:31 am 
Retro Guru
User avatar

Joined: Wed Dec 19, 2007 10:05 am
Posts: 961
Location: Brussels
Hi folks,
I'm finally (but still slowly!) getting round to building a TI Team replica with the 753 fastback frame I bought last year. I'm having trouble with the seatpost though! I was told that the seat tube was 27.0mm and when it arrived I measured it with a caliper and it read 27.0. All good, so I bought a nice DuraAce post - it's stamped 27.0 on the shaft, and measures 27.0 with the same caliper - but I can't inset it more than ~3cm into the frame! It doesn't clear the minimum insertion level, and just about gets past the bottom of the slot in the seat tube.

What's going on here? Is it possible that the frame is 26.8mm but has been slightly flared out at the top. What size post do I need?? The frame is an SB stamped one from the early 80s, so what would the norm have been back then?

Cheers, Gareth.


Top
 Profile  
 
PostPosted: Sat Aug 14, 2010 10:42 am 
Old School Hero

Joined: Wed Aug 11, 2010 4:54 pm
Posts: 165
garethrl wrote:
Hi folks,
I'm finally (but still slowly!) getting round to building a TI Team replica with the 753 fastback frame I bought last year. I'm having trouble with the seatpost though! I was told that the seat tube was 27.0mm and when it arrived I measured it with a caliper and it read 27.0. All good, so I bought a nice DuraAce post - it's stamped 27.0 on the shaft, and measures 27.0 with the same caliper - but I can't inset it more than ~3cm into the frame! It doesn't clear the minimum insertion level, and just about gets past the bottom of the slot in the seat tube.

What's going on here? Is it possible that the frame is 26.8mm but has been slightly flared out at the top. What size post do I need?? The frame is an SB stamped one from the early 80s, so what would the norm have been back then?

Cheers, Gareth.

It should be 27mm but its possible the seat tube was put in the wrong way around or maybe you just need to ream it out.Sometimes the soldering heat can make the butts at the joint bulge slightly
PS measure the tube I/D properly and do not be tempted to ream it O/S ,buy a new seat post to fit


Top
 Profile  
 
PostPosted: Sat Aug 14, 2010 3:10 pm 
Retro Guru
User avatar

Joined: Sun Jul 25, 2010 12:22 pm
Posts: 1994
Location: North Ayrshire
we used to sell these frames in the 80s and i had one built at the Ilkestone Special Products place myself - the lightest 753 i ever had and for good reason! (now, all gather around the fire and i'll tell you a short story...lol)

TI Raleigh and Reynolds were close working partners and part of the same TI group of companies. these two were forever changing their tube specs and so as a cycle shop boffin i was fascinated by all this jiggerypokery! the truth is that 753 came in various different seat tube diameters, if i remember rightly ranging from 26.8 up to 27.4!!! indeed the one i have just now is 27.2 which is just my luck 'cos a 27.2 campagnolo c record seatpost is just about the dearest diameter version you can buy these days, if indeed there are still any cropping up that have not been mangled by many winters' use by being relegated to someone's winter bike many moons ago!

anyway, i hope this helps - for the record i owned SB8650 (i think!) and was in the panasonic team colours - beautifully light and master crafted - a joy to ride and what did i do? got it resprayed and chromed against all advice - the result? it broke!! well, a trendy 20-something in the mid 80s couldn't have been told what to do!

any chance of some photos of this frame of yours? :D

rusty


Top
 Profile  
 
PostPosted: Mon Aug 16, 2010 12:39 am 
Old School Grand Master
User avatar

Joined: Wed Feb 20, 2008 12:21 pm
Posts: 5782
Location: Lost in Translation
garethrl wrote:
What's going on here?

26.8mm was a common seatpost size for earlier 753 frames. 753 was originally made in continental (metric) diameters only, so a narrower post was required. Measure the external diameter of your seat tube: I wouldn't be surprised if it's 28.0mm (allowing a little for paint) instead of the more common 28.6mm.

It sounds as though the upper end of the seat tube may have been distorted by a previous owner trying to force in an oversized seatpost.


Top
 Profile  
 
 Post subject:
PostPosted: Mon Aug 16, 2010 12:57 am 
Old School Grand Master
User avatar

Joined: Wed Feb 20, 2008 12:21 pm
Posts: 5782
Location: Lost in Translation
Here's a 1984 753 Raleigh with a 26.8mm post:

http://www.wooljersey.com/gallery/v/Pet ... Pro+Super/

and a 1980:

http://www.wooljersey.com/gallery/v/Pet ... n/album94/

The second one is the one I was looking for. It's interesting because the 753 frame was a warranty replacement for a 531 model, and the purchase of a 26.8mm post to fit the new frame is documented.


Top
 Profile  
 
 Post subject:
PostPosted: Tue Aug 17, 2010 12:10 am 
Retro Guru

Joined: Wed Sep 19, 2007 10:43 pm
Posts: 270
Hi there, I also have a Raleigh 753 frame and I've found out the following - which may be of interest to you . . . . . . .

As written by Mike Mullett - :

1) 753 is Metric-diameter tubing (28.0 mm O.D. for the seat and down tubes, 26.0 mm O.D. for the top tube), and was introduced in about 1975. Seat posts for 753 frames are either 27.0 (for small frames) or 26.8 mm (for large frames).

2) 753R and 753T are Imperial (English/Inch) diameter tubing (28.6 mm O.D. for the seat and down tubes, 25.4 mm O.D. for the top tube), and began production in 1983. Seat posts for 753R and 753T are either 27.2 or 27.4 mm.

Of particular interest is the thinner Imperial tubing which takes the 27.4mm seat pin (pillar). Not a lot of people are aware of this. All these tube sets have a part number starting 80*, but Reynolds seem to have lost these specs.

A seat pin should be an easy fit and it should not be necessary to fit the saddle to act as a tommy bar to gain extra purchase.

For those who are searching for a time scale for their frames, the following is as near as dammit a time line from Mid 1974 until close down. Hope this helps.

[b]Year Number [/b]
1974 0
1975 200
1976 700
1977 1400
1978 2100
1979 2800
1980 3500
1981 4200
1982 4900
1983 5600
1984 6300
1985 7000
1986 7700


Mike Mullett former Works Manager for Raleigh
------------------------------------------------------------------------------

I have a 753 frame; I certainly would not ream it out - it is very thin-walled tubing. I would search out a seatpost which is an easy fit. Interestingly, on mine I've tried two 27.2 seatposts; one fits, the other doesn't.


Top
 Profile  
 
 Post subject:
PostPosted: Tue Aug 17, 2010 1:16 am 
Retro Guru

Joined: Sun Aug 03, 2008 12:31 am
Posts: 585
Location: London
Quote:
I was told that the seat tube was 27.0mm and when it arrived I measured it with a caliper and it read 27.0. All good, so I bought a nice DuraAce post - it's stamped 27.0 on the shaft, and measures 27.0 with the same caliper - but I can't inset it more than ~3cm into the frame!


If both the internal diameter of the seat tube and the external diameter seatpin are the same then it's not going to fit; one has to be slightly smaller than the other.

Seatpins are not always accurately sized. A lot of the times one seatpin will be a good fit in a particular frame, but another one with the same marked diameter will be too tight.

I've got a mid 80s 753 frame and it takes a 27.2 seatpin.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Aug 19, 2010 8:27 pm 
Retro Guru
User avatar

Joined: Wed Dec 19, 2007 10:05 am
Posts: 961
Location: Brussels
Thanks for all the detailed info guys - now I'm going to further confuse the situation with some more info of my own!

The frame number is SB5817, which makes it a 1983 build. The frame decal says 753R while the forks just say 753 - though the frame decal says "Guaranteed built with Reynolds 753R Fork Blades, Stays and Butted Tubes". Frame weight is 1690g while the forks are about 660g! So I think it's clearly all 753! Not at all shabby for a 56x57cm frame.

The frame tube ODs don't tally with the above info though. The top tube is 26.2mm, down tube is 28.2mm and the seat tube is 28.6mm all the way down. The ID of the seat tube comes out at 27.0mm no matter how many times I measure it, though my caliper only goes about 1cm down into the seat tube and I can insert my 27.0mm post about 4cm in. I'll pick up a 26.8mm post to experiment, and as a placeholder.

So here's a few pics to show the general condition and some detail. I left the frame at my car mechanic's place for about a week so that he could mix some paint up, and it looks like he's made a really good match. The next step is to get the fixed cup out and clean as much rust off the bare metal as I can. Then prime it with a light shade of Hammerite, and put a few layers of customised Nissan Red on it. Once I've touched up the paint I'll build it with a mixture of Record and Super Record, with Cinelli up front, and a Rolls to top it off. I need to replace the Super Champion Arc en Ciel on the F wheel after I trashed it last week, but I have a pair of Record du Monde on the way from Denmark. The plan is to ride it in the retro Ronde van Vlaanderen next year.

Don't hold your breath for progress on this one, but I'll get there ...

Cheers,
Gareth.


Attachments:
19082010076.jpg
19082010076.jpg [ 199.62 KiB | Viewed 6199 times ]
19082010078.jpg
19082010078.jpg [ 148.79 KiB | Viewed 6199 times ]
19082010081.jpg
19082010081.jpg [ 176.19 KiB | Viewed 6199 times ]
19082010083.jpg
19082010083.jpg [ 151.18 KiB | Viewed 6199 times ]
Top
 Profile  
 
 Post subject:
PostPosted: Thu Aug 19, 2010 9:54 pm 
Retro Guru

Joined: Sun Aug 03, 2008 12:31 am
Posts: 585
Location: London
Maybe your frame has a mix of metric and imperial tubes. If the imperial tubes were introduced in 1983, maybe there were some metric tubes left over they wanted to use up.

26.2mm for the top and down tubes would match the metric spec if 0.2mm is allowed for paint.

This is from 1987 or after:
http://www.equusbicycle.com/bike/reynolds/Reynolds-tubing-sizes.jpg

753 seat tube is single butted 28.6 OD with 0.7/0.5 walls.

Perhaps very early 753 imperial seat tube was 0.8/0.5.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Aug 19, 2010 11:45 pm 
Retro Guru
User avatar

Joined: Sun Jul 25, 2010 12:22 pm
Posts: 1994
Location: North Ayrshire
DON'T DO IT!!!!!
PLEASE get this lovely old frame PROPERLY renovated!!! honestly, it would be a waste, sacrelege even to get anything less than a professional job done on this rare and wonderful frame!!! try master frame builders like mercian, bob jackson or dave yates - i can recommend all three equally.

check out cyclomondo on ebay for your transfers:

http://cgi.ebay.co.uk/Raleigh-TI-531-75 ... ccessories


now, 753.... i think we are going too deep with this!!

simply *pinggg* any of the maintubes and if they sound like
they are incredibly thin and fragile then you've got a 753! if they go
*THUDDD* like a lead pipe then it something not so exquisite!! could you film
it and put it on youtube perhaps - i could diagnose a 753 much easier that way! lol going by the brazed components and the battered 753 badge it all ties in with the features found on a genuine early 80s special products frame!

the reason your forks have the unusual TI badge was raleigh's
decision alone - no one else to my knowledge had those badges
on the forks and indeed they didn't come with the tubesets available
to the ordinary framebuilders outwith raleigh. personally i never
liked them and indeed on the SB8650 frame that i had in panasonic
colours there were no 753 badges of any description, instead a red
and yellow motif with the raleigh "heron" on.

you have got a cinelli cast bottom bracket and internal fork crown (was it called the CCA? hmm...) and by the look of it prugnat lugs but the original owner must have requested the "shot in" stays as i'm sure that raleigh ilkeston built with the standard side-brazed stays - they certainly did on the larger frames as it was deemed stronger. also you have the under-offset brake cable stops on the top tube - another classic raleigh special products feature. i can't tell from the photos but are they campag dropouts? i know they used simplex for a while but think that was in the raleigh weinmann days of the panasonic colours, from '86 onwards and i'm thinking they might have been drilled for lightness too...now i'm guessing! yours looks like a 21 1/2" or 22" frame, perhaps?

god, where has all this stuff come flooding back from!?! i haven't thought about this for over twenty years!!!!!

luvvit!

where did you find this frame? please tell us all more about it!!

rusty


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 28 posts ]  Go to page 1, 2, 3  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Google Adsense [Bot], riddim-track, Webskipper and 30 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group