Seat post diameter

[Daddybus]

Is there a standard seat post size for 1960's 531 tubing? I have the old post from my Sun that I can measure, but with only having a standard ruler... not to the accuracy of .2 or .5 fractions of a mm.

 

[Gatters]

Aldi sell digital vernier calipers very cheap, a popular siuze was 27.2mm

 

[classic33]

Is it amongst this lot?
http://www.sheldonbrown.com/seatpost-sizes-m-z.html#s

 

[Daddybus]

@Gatters I'll take a look this w/e!
@classic33 wow thats a biiiiig list! Only sun listed tho is a solo from 1994 (25.4mm)

 

[classic33]

@Gatters I'll take a look this w/e!
@classic33 wow thats a biiiiig list! Only sun listed tho is a solo from 1994 (25.4mm)

Well bikes have been round a while!

 

[classic33]

"Most Raleighs use a seatpost diameter of 1" (25.4 mm) while other British 3-speed bikes usually use 1 1/16" (27.0 mm)"
http://www.sheldonbrown.com/english-3.html#sun

 

[biggs682]

Is there a standard seat post size for 1960's 531 tubing? I have the old post from my Sun that I can measure, but with only having a standard ruler... not to the accuracy of .2 or .5 fractions of a mm.

a couple of older ones that have either passed through Racing Bike Biggs682 hands have been 27.00 mm

 

[Daddybus]

...its got 'stop' with a line engraved on it wouldn't have taken much more to put the size on ..would it!

 

[mikeymustard]

Aldi sell digital vernier calipers very cheap, a popular siuze was 27.2mm

I bought a cheap one off the bay a while ago, dunno how I ever managed without it!

 

[Daddybus]

*Blush* .....it is written on.... 27mm

 

[biggs682]

should have gone spec save as they say @Daddybus

 

[Daddybus]

 

[Daddybus]

I bought a new 27.0 mm stem but it seems really loose!!..Could it be that the (non -original) one I took out was the wrong size?.. even though that seemed tight & needed heating up to remove. I've read that 531 DB tube should be 27.2mm but would .2 of a mm really make that much difference? The frame is a 60's 'sun badged' Carlton flyer btw

 

[mikeymustard]

.2mm diameter is a circumferencial difference of .63mm, still not much for a steel frame. If it's v.loose try a little bit of a shim and it'll be fine!

 

[sidevalve]

Just buy a calliper and measure it. They are cheap as chips [you're measuring in tenths not thousandths] and can be used for all sorts of other things including chain wear