1994 Lava Dome seat post. 27.0 or 27.2?

[hbn]

Found somewhat contradicting info regarding the seatpost diameter of 94 Konas. Is it 27.0 or 27.2mm?

The 27.0 post sinks as soon as I loosen the bolt and release the post.
The 27.2 post goes down far enough with some pressure. But I have a nagging fear, am I doing harm to the frame..?

What do the experts say?

 

[jinjrich]

Re:

27.0

Check the seatpost you are using with decent verniers. I've found over the years certain brands are out by just enough to make a fit slightly loose or tight.

 

[hbn]

Re:

Thanks. You’re probably right. What confuses me is the document with ‘Kona basic frame specs 1988 to 1999’ here on retrobike that states the 94 lava to be 27.2

 

[Kona-Ian]

My 1994 Hahanna is 27.2.

 

[jimo746]

Re:

The one I had was 27.0

Best bet is buy some cheap-ish digital vernier calipers, I've used mine quite frequently to check (bike) parts.

 

[CassidyAce]

Re:

As above: digital verniers help and some seatposts are slightly out by several hundreds of a millimetre. Your 27.0 might actually be 26.95 or thereabouts. The seat tube might be out too. (I never really bother measuring that.) Some carbon gripper paste can sometimes help stop the slipping in these cases.

 

[Kona-Ian]

Had cheap Aldi digital verniers and they don't last.
You get an error reading after a while.
Halfords one was alright but Magnusson one from B&Q has 5 year Guarantee.
Kept receipt.

https://www.diy.com/departments/magnuss ... 897_BQ.prd

 

[Byrned1978]

I'm currently working on a 1994 Lava Dome.

The original seat post was 27.2. I've replaced it with a better quality 27.2 post and this seems to fit perfectly.

 

[hbn]

I'm currently working on a 1994 Lava Dome.

The original seat post was 27.2. I've replaced it with a better quality 27.2 post and this seems to fit perfectly.

That’s interesting to hear. How tight is the fit? I don’t force the post, but I have to put some weight on it to make it sink.

 

[hbn]

Re:

Got the digital verniers out today:

94' Dome
seat tube diameter at top (insertion): 27,02mm inside / 29,92mm outside
=tubing material + paint thickness: 1,45mm
mid seat tube diameter: 29,03mm

95' Dome
seat tube diameter at top (insertion): 26,94mm inside / 29,74mm outside
=tubing material + paint thickness: 1,40mm
mid seat tube diameter: 28,71mm

Difference:
seat tube diameter at top (insertion): 94' is +0,08mm inside / 94' is +0,18mm outside
mid seat tube diameter: 94' is +0,32mm

94’ with a 27.0 post feels loose, but a 27.2 (measured at 27.19) feels a bit tight.
95' takes a 27,0mm post which feels just right.