Rocky Seatpost Size: what are the chances?

[ted andkilde]

Going over my 95 blizzard to undo all the things I've "gooned" on it over the years.

I bought a 27.2 Syncros post to replace the no-name 27.0 that's currently fitted to it.

I've carefully worked the top with a chunk of dowel and spent a good hour spinning a brake cylinder hone in it and I simply can't get the 27.2 in more than a centimeter or two. Even a spare 27.0 hangs up at the toptube/seatstay join. I've put the old 27.0 back in and it seems to fit nicely.

Should I just source a 27.0 Syncros? Or is the catalog (which states 27.2) gospel?

All advice welcome, even if you're just having a laugh

TIA, Ted

 

[syncrosfan]

Get the proper 27.0 seat-post for it. If it were an aluminum frame with a thicker walled seat-tube you could ream it up to 27.2 using the proper tools (adjustable blade reamer, none of the spinning sandpaper stick nonsense). For the steel frame with a much thinner wall I wouldn't do it even though it might be possible. If a 27.0 fits nicely I think the catalog's wrong at least in your case. 27.0 Syncros seatposts are still available (albeit not as plentiful as 27.2).

 

[ted andkilde]

Get the proper 27.0 seat-post for it. If it were an aluminum frame with a thicker walled seat-tube you could ream it up to 27.2 using the proper tools (adjustable blade reamer, none of the spinning sandpaper stick nonsense). For the steel frame with a much thinner wall I wouldn't do it even though it might be possible. If a 27.0 fits nicely I think the catalog's wrong at least in your case. 27.0 Syncros seatposts are still available (albeit not as plentiful as 27.2).

Thanks syncrosfan, I may just buff the logos off this post with some scotchbrite for now and wait for a proper post to find me over time.

Cheers, Ted

 

[dirttorpedo]

Re:

My 2000 Hammer Race takes a 26.8 post. You sure that old 27.0 is the right size?

 

[syncrosfan]

"My 2000 Hammer Race takes a 26.8 post. You sure that old 27.0 is the right size?"
That's a good question too. You mentioned that another new 27.0 seatpost you have doesn't go all the way down but hangs up at the seat-tube junction. Makes me wonder if the original seat-tube reaming was done improperly? Shine a flashlight into the seat-tube and see if there are any welds sticking out (or feel it with your finger). I purchased an unfinished (raw aluminum) frame not too long ago and I had to go in with a reamer to clean up the welds that penetrated on the inside of the seat-tube (wasn't a lot but enough to interfere with proper seat-tube insertion). Generally speaking frames sold to the public have this step done at the factory so it shouldn't be the case for you but I would double check. If there's anything sticking out in the weld junction area then it could be that you need to ream out the seat-tube (then maybe the catalog's right and it is a 27.2 seat-post but you can't use one due to weld interference). Most likely I'm over-thinking this though...

 

[captaincosmic]

Re:

My '95 is definitely a 27.2

 

[ted andkilde]

Re:

Yeah, the catalog definitely shows the 95 to be a 27.2.

Don't have a clue where I'd find a long 27.2mm reamer, maybe there's a framebuilder I can lookup nearby.

As I mentioned, it isn't hanging up at the top, as it would if I'd over-squeezed the top of the seat tube. But, TBH, i'd rather find someone who know's what they're doing and pay them than screw it up trying myself

I'll shine a light down to take a look, I didn't feel any lumps when I was running the brake cylinder hone up and down.

Cheers, Ted

 

[schwartzy16]

My 95 Blizzard takes a 27.0 as do my 94 and 96 Blizzards

 

[ted andkilde]

Re:

Eek, Jim's got a 27.0 listed on eBay, but judging by the BIN, the alloy in his was refined of bauxite extracted from the blood of 1000 virgins

Cheers, Ted

 

[captaincosmic]

Re:

They are a bit pricey in that size !
When manufacturers sell frames by year they sometimes have previous year stock that gets painted up and sold on if there is no significant difference so it may be a '94 ?
My '92 is a 27.0 so it would be telling if the '94 was too.