delicious

Hi folks,

I'm normally over in C&V, but I could use your particular expertise on this. I received a purchase via Fedex today, and on disassembly encountered two problems I haven't run into before. This is on a mid-1980s Pinarello Montello, in my size. Something I've been looking for for a long time.

First: The threaded insert for one of the bottle bosses is gone. Note the larger diameter of the hole on the left. Is this fixable without paint damage or otherwise looking like a repair? Maybe rivnuts?


Second: Much more seriously, there is a bulge on the seat tube, extending around the rear half of the tube. Hard to photograph, but easy to see and easy to feel from inside the seat tube. It's directly to the right of the vent hole in the attached picture. I know this absolutely kills resale, but is it even rideable? This would be used for long and fast road rides.



Needless to say, this is a major bummer for a bike that cost $775. I feel a headache coming on!

Thanks a lot for any info/advice.

Andrew R Stewart 

1- The cage boss could be repaired with a RivNut. not knowing the hole's current size I can't say if it would need enlargening. But that's easy to find out once the RiveNut is on hand. There is a possibility of some slight paint damage as the RivNut will grab the edges of the hole and might cause a small bit of paint chipping. The other issue is that a RivNut really likes a thicker wall then steel frames usually have. So adding an epoxy "ring" to help bond the RivNut might be considered (and what I would likely do).

2- That bulge could have been from a few causes. The seat post too high up and then heavily stressed causing some rock within the seat tube. The seat lug area was over heated during brazing and the tube swelled. There was a ring of rust/corrosion around the bottom of the post pressing out of the seat tube. Of the three causes #2 is the one I'd worry about as it also means that the tube is compromised strength/grain wise. But you'll likely never know why and won't be able to do much about it anyway. So just ride the bike with enough post past the bulge. should it ever crack there will be a lot of warning and little safety concerns.

I never liked the fashion of filing down the brazed on cage boss "head" flush with the tube surface. seen it before and always felt that it was inviting trouble. Andy.

hueyhoolihan

if i could find a long seatpost (not too difficult these days, but it wouldn't be vintage) i would feel safe using it as is, assuming it would fit properly and a thorough visual inspection didn't turn up anything other than the bulge.

don't know about the water bottle boss. i would probably put a screw in the good one and lightly epoxy a screw in the other one, and be done with it.

i'm working under the assumption that you very much want to use this frame and don't want to put 500 or more into a rebrazed water bottle boss, a seattube replacement and a new paint job.

easyupbug 

Campy made long seat posts, I have a vintage Chorus that is 270mm. As you say your frame fits it would work and you can find them NOS from time to time. I hate to see that damage but you can work this out per Andy's post.

easyupbug 

I just remembered I cut down a vintage Dura Ace post that hit the bottle boss on one of my daughters frames so Shimano made very long ones as well.

fietsbob

Riv Nuts wont require a repaint like brazed in Bosses will .

delicious

Thanks everyone. I've been gone all weekend, but I really appreciate your expertise on this. I do have just a few more questions. I'm going to get a bike shop to look at this as well, but a range of opinions is always helpful. I'm also going to try and work out with the seller some sort of partial refund that's fair to both parties.

It's good to hear the seat tube is probably rideable with a long post. But how far past the bulge, approximately, should the post extend? I'm ~155 pounds, and this is Columbus SLX tubing, butted .6/.9mm. [strike]The bulge is in a .9mm section.[/strike]

Rivnuts seem like the only option for the failed water bottle braze-on. I've gotten wildly divergent estimates for this repair from shops - $50 to "several hundred" as upper-limit ballparks. Any thoughts on what this should cost?

Also, unfortunately, as Andrew R Stewart mentioned, Pinarello filed the braze-ons flush with the tubing, so a standard rivnut repair is going stick out even after touch-up paint. I'm currently looking into low- or no-profile rivnut options, but it may not be possible to replicate the "flush" look. Would it be foolish/possible to carefully file down the head of the rivnut after installation?

Thanks again in advance.

fietsbob

Yes, foolish.. put a water bottle cage on and who's to Know..

The 0.9mm section is down by the BB shell not Up Top , thats the .7 or .6 [ (28.6 - 27.2= 1.4mm) halve that = tube wall thickness of 0.7mm]

delicious

Ah, that's right. So it's actually in a thinner section than I thought.

fietsbob

26.8 mm seat posts are used in straight gage 0.9mm wall 28.6mm seat tubes .