Kona frame ID and post/headtube sizing

[IbocProSX]

Hi,

I've just come from the land of the retro search on Kona sizes. There's a lot of info in the older threads, notably pointing out the pitfalls. Below is a picture of the actual frame with the 93 paint scheme, butI don't have acces to it, it is on it's way to me:

In 92-93-94 the Kona sizes change year on year it seems. So please can you confirm/correct me in the list below:

19" frame, stated by seller, confirmed by the steeper angle of seatstays compared to the downtube.

130mm head tube length (ref Anthony): some say it's 150 for the 19", but with the help of a ruler I can see 130 in the picture. It is important if a 170mm steerer fork will be long enough for fitting with a threaded headset?

?? seatpost size. I read 26.8 - 27.0 and also 27.2 really cannot get a landing on this. Sheldon B doesn't list the 93's and confirms all sizes are used in Kona's at some point. FWIW I'm Interested in the corresponding front mech size as well (28.6?).

Thanks in advance and happy trails

 

[Anthony]

In 92-93-94 the Kona sizes change year on year it seems. So please can you confirm/correct me in the list below:

19" frame, stated by seller, confirmed by the steeper angle of seatstays compared to the downtube.

130mm head tube length (ref Anthony): some say it's 150 for the 19", but with the help of a ruler I can see 130 in the picture. It is important if a 170mm steerer fork will be long enough for fitting with a threaded headset?

?? seatpost size. I read 26.8 - 27.0 and also 27.2 really cannot get a landing on this. Sheldon B doesn't list the 93's and confirms all sizes are used in Kona's at some point. FWIW I'm Interested in the corresponding front mech size as well (28.6?).

Thanks in advance and happy trails

It does look like a size 19. I believe the headtube length for size 19 was 15cm up to 1992, then reduced to 13cm from 1993 onwards as part of allowing for 'suspension-correction' (although confusingly I believe that 1993 frames were not suspension-corrected, and certainly were all sold with 39cm P2s as standard)

It is a 93 frame and I take it that it's an Explosif, in which case I think it ought to take a 27.2, but I'm not absolutely sure - the frame is a Tange Ultimate mix, but I think the seat tube is a Concept. If so, it's the same as on my 94 Kilauea and that accepts a 27.2.

Yes the fm is a 28.6, has to be conventional-swing (as if you'd fit anything else anyway!) and bottom-pull.

 

[Kona Paul]

Just to add a note for Anthony related to another thread: my 92 Explosif does accept a 27.2, so t's starting to look like that became the standard for Explosifs already in the early 90's. Probably a very good chance his frame will be a 27.2 as well.

 

[mousemat]

I have a 1993 Explosif still with the original seatpost and it is a 27.0.

 

[IbocProSX]

Thanks for your help, much appreciated.

I was already pretty certain about the 130 head tube, but the 27.2 seat post would be a bit of a bonus, I have some nice options in 27.2 against just the one in 27.0.

The bit about the suspension corrected geometry is significant. If Kona indeed shortened the head tube but did not spec the P2 fork "higher" this begs the question what they did with the head angle. It would be logical to be correct for the 390 P2 but that would make the suspended bikes slacker in the HA? Rule of thumb says 20mm is about 1 degree HA, noticeable but not imposible.

I have my eyes on a 410mm P2 with a long enough steerer, but now wonder if I should hold out for a 390mm? Upside of the 410mm is I probably have a better riding position with it. My other option is my Pace RC36.

Enjoy!!

 

[Tallpaul]

My 1992 19" has a 130mm headtube.

 

[Anthony]

I have a 1993 Explosif still with the original seatpost and it is a 27.0.

Yes, my 97 Kilauea came with a 27.0, but that and a 96 and a 98 Explosif all take a 27.2 just about. I find a 27.0 on the loose side and for strength purposes I like a seat post to be tight. I think it's just that if you have a 28.6 tube with a 0.6 wall thickness, that leaves 27.4. So 27.0 fits easily, 27.2 is a bit of a squeeze and 27.4 is impossible.

It may just be a coincidence, but I have seen two Konas for sale with cut-down seat tubes and it did make me wonder whether over-clamping to compensate for a loose post can lead to a crack from the slot. No idea what post they had used of course, I doubt whether a 27.0 could cause that, but maybe a smaller one could.

 

[Anthony]

Thanks for your help, much appreciated.

I was already pretty certain about the 130 head tube, but the 27.2 seat post would be a bit of a bonus, I have some nice options in 27.2 against just the one in 27.0.

The bit about the suspension corrected geometry is significant. If Kona indeed shortened the head tube but did not spec the P2 fork "higher" this begs the question what they did with the head angle. It would be logical to be correct for the 390 P2 but that would make the suspended bikes slacker in the HA? Rule of thumb says 20mm is about 1 degree HA, noticeable but not imposible.

I have my eyes on a 410mm P2 with a long enough steerer, but now wonder if I should hold out for a 390mm? Upside of the 410mm is I probably have a better riding position with it. My other option is my Pace RC36.

Enjoy!!

Based on my experience, I would wait and try the 27.2. I'd guess it'll either be just right or slightly too tight, depending on how much reaming that particular tube needed.

You do see 93 P2s on eBay, they're not that rare - and of course as well as the geometry advantage, they're silver to go with the silver front ends of the European 93 range. But yes a RC36 on 70mm setting would be nice also.

 

[IbocProSX]

The frame has arrived! my second steel steed 16 years after....

I have goods shipped to my work address where I have 24/7 goods receipt. The headtube is 130mm confirmed, no tools to check the seat tube, that'll have to wait until this evening. What strikes me is how light it is, and how thin the head tube is. Also it does look rather small but I guess that is the thin tubes effect. About those tubes, now I understand the fluted downtube/ bulged seat tube comments, it is an Explosif.

At first inspection it looks in fine fettle, with good details. I must have a closer look inside the seat tube, but it looks OK. I think I'll build it with what I have to go riding and then work out a plan for a respray and dedicated build this winter.

Enjoy!!

 

[IbocProSX]

Final update, the 27.2 post does go in, it's fairly tight but it moves. Luckily this is the frame with the most seatpost extending.

I'm now peeling off the stickers with the missus hair dryer and then it's in for a thorough cleaning.

Enjoy!!