Seat Post Diameter

[Kestevan]

I've got an old Falcon 501 frame - guess it's early 90's without a seat post.
Anyone know what size post it's likely to take (it's smaller than 27.2) - I've tried to measure it, and it looks to be slightly less than 26mm - but without verniers it's difficult to be accurate.

 

[raleighnut]

25.4 or 1" possibly

 

[the snail]

26.6 would have been my guess, but I think 501 came in various sizes, so measuring is the only way. Your LBS probably have a guage to measure it?

 

[RebornBumbler]

Get something thin and flexible that won't stretch (a cable tie is OK)
Wrap it around a clean area of the post, and cut it where it overlaps (so it's exactly the circumference of the tube)
Measure the length and divide by pi (3.14159265359)
Should be pretty accurate

 

[raleighnut]

Get something thin and flexible that won't stretch (a cable tie is OK)
Wrap it around a clean area of the post, and cut it where it overlaps (so it's exactly the circumference of the tube)
Measure the length and divide by pi (3.14159265359)
Should be pretty accurate

That might work............If he had a seatpost

 

[RebornBumbler]

Doh!

(Probably still do-able, but a lot more tricky)

 

[Vapin' Joe]

Use an adjustable wrench to gauge the ID of the tube then measure that with a rule.

 

[Profpointy]

all this ruler or bits of cable tie thing really isn't good enough - even a vernier is tricky to get it dead on and a micrometer is better, but not everyone's got a 25-50 mic. You need to be within 0.1mm as the different sizes are very very close

 

[evo456]

Could just roll a piece of paper and put it in the seat tube, let it unravel itself, mark where the edge overlaps, Take out, unroll and measure distance between edge and marking.

 

[raleighnut]

Take the frame to a cycle shop and ask for "a seatpost to fit this please"

 

[Kestevan]

Take the frame to a cycle shop and ask for "a seatpost to fit this please"

Yeah - pretty much resigned myself to that... although I might try the paper idea first
Cheers