Reynolds 731 OS?

[Oldaircool]

Hi,

Anyone got any info on 731 OS? Can't seem to find much about it. I think it's hot worked 531 and some of the tubes have 'internal flats' for rigidity...........all info gratefully received...........

 

[mattr]

Wasn't it 708 that had the internal flats? 8 of them funnily enough! 731 does ring a bell tho......
Can remember being shown some special/New tubes in the sbdu when i picked up one of my raleighs.

 

[KermitGKona88]

Re:

Here you go all you need to know

https://www.google.co.uk/url?sa=t&rct=j ... BHqdj8PZRw

 

[mattr]

There is some stuff on Wikipedia actually.....

 

[Mike Muz]

Re:

I thought 708 had internal splines :?

 

[oonaff]

Re:

nah they got me !! 708 not butted but 8 internal flats running the length of the tube.
is this a grooved effect or octagonal internal section ?

731 lateral splines to butted sections ? does this mean that they are parallel to the tubing
a kind of internal cog effect ?

 

[Mike Muz]

Re: Re:

nah they got me !! 708 not butted but 8 internal flats running the length of the tube.
is this a grooved effect or octagonal internal section ?

731 lateral splines to butted sections ? does this mean that they are parallel to the tubing
or a series of internal spiral washers. nah i would like to see some diagrams..i must be thick

I'm saying nothing :roll:

Mike

 

[Chat Noir]

Introduced in 1992, around for few years only, 8 internal ribs on main tubes at each end. I'm new to this site and don't know how to attach photos so can't attach the Reynolds catalogue from 1992, but it says: 'this brand new tube set introduced in 1992 features double butted oversized main frame tubes, with laterally aligned stiffening ribs on the butt sections to maximise stiffness and tortional rigidity, as with the 708 Classic set. 731OS race is approximately 10% lighter than comparable competitive tube sets and is suitable for road, track and timetrial frames at professional level'.
I have a Bob Jackson 731OS from early 1990s and one of my favourite bikes for long distance cycling. Just acquired a Gazelle 731OS frame from 1996 which I'm busy setting up with DA 7403.
If you follow this link: http://www.velocipedesalon.com/forum/f2 ... 19682.html shows the Reynolds catalogue and references a Bicycle Guide review of 731 from 1993.
Good luck.

 

[xxnick1975]

Dave Yates made diablos out of it

 

[oonaff]

chat noir. thank you for the link to the drawings !
perhaps 731 could be viewed as 708 only at the ends and because of this butting its lighter!+more compliant[yes the internal shape in the drawings match]
" 708 a comparable concept to columbus slx,tsx etc minus the spiral,rifling of the grooves,but i guess
the columbus ones were butted also.


cheer's kevin the gerbil