Cracking frame mate...[Pace Content]

[Wold Ranger]

How do you plan to heat treat it after welding? If you dont you have just introduced a stress area that will probably break? Are pace frames 6000 or 7000 series aluminium I cant recall. Good luck, personally I would not trust it especially in that area.

Don't worry that is why they cracked in the first place, they were never heat treated post welding anyways, that was their big failing. favourite place was behind drive side BB/chain stay junction or the seat tube as you have found out! they needed a really long seat post to minimise that one!

On the other hand NEVER EVER use a shim in an Aluminium frame! too much flex ALWAYS a cracked tube. Why do folks do this, its basic engineering folly.

 

[Piers]

Good luck. When Pace made bikes they were happy to fix broken bits (at least that's what Adrian Carter told me) so fingers x'd for more years of fun for you.

My Pace 200 cracked at the bottom bracket end of the seat tube. Completely broken in a high stress/thin metal area so it's now an "art installation" in the conservatory.

re shims - some manufacturers fit them to their frames as standard; my Commencal Ti has one presed in (I would prefer no shim and a larger diameter seat post for extra strength since I have loads showing).

 

[explosif_fan]

I have had 6 RC1/2/300`s and always used 410mm posts of the correct diameter.

Pace shouldn't have provided an excuse to use a shimmed seatpost when they start supplying 29.4>27.2 shims

 

[Rich]

Thanks for the kind comments guys, 400 mm post being collected today as is the frame, will post up some pics of the re-weld when I get it today!

Rich

 

[reanimation]

re shims - some manufacturers fit them to their frames as standard; my Commencal Ti has one presed in (I would prefer no shim and a larger diameter seat post for extra strength since I have loads showing).

True,

GF complained her seatpost on her Giant CRS alloy bike kept moving down. turns out they use a 27.2 - 30.8 shim from factory. why would ya, surely better to either design it to fit 27.2 in design, or make sure they have posts to fit their frames. Got a 30.9 coming will see how that fares..

 

[missmyfat]

How do you plan to heat treat it after welding? If you dont you have just introduced a stress area that will probably break? Are pace frames 6000 or 7000 series aluminium I cant recall. Good luck, personally I would not trust it especially in that area.

Don't worry that is why they cracked in the first place, they were never heat treated post welding anyways, that was their big failing. favourite place was behind drive side BB/chain stay junction or the seat tube as you have found out! they needed a really long seat post to minimise that one!

On the other hand NEVER EVER use a shim in an Aluminium frame! too much flex ALWAYS a cracked tube. Why do folks do this, its basic engineering folly.

If true that really is very poor and an excellent reason for not buying a pace! Very bad engineering practice, and I always thought of them as a quality product that they seemed to take a great pride in the engineering aspect :roll: Barge pole comes to mind.......

 

[Piers]

That would be sensible...
Chas Roberts stuck a 27.2 tube in his custom frames built from tube-sets weird seat tubes.
I had a custom Columbus Genius from Hardisty Cycles in Newcastle that needed a 30.4 (or 30.6) seatpost - impossible to source in '93, so USE to the rescue with a long, snug fitting shim & post. It was a great bike 'till it melted in a car crash.
But evn with normal diameter tubes manufacturers can be totally slack - I've an M-Trax that came fitted with a 27.0 seatpost - the frame needed a 27.2!

 

[neilll]

Got a massively long post in my Pace (nearly as much in the bike as there is out), its also the correct size. Never had an issue and these days I'm way over the weight the frame was designed for......


Neill

 

[rc300]

I always use a quality 400mm+ post of correct size even BITD.
Better safe than sorry!

 

[Piers]

USE (if I remember right) did a 100mm shim which was accurately machined and fitted my steel frame perfectly - no play at all with the post in place. It's a shame most seat tubes are not so well finished. Like wise with X-Lite and Brand X shims.
Currently I use RooX 430mm, Tompson 410mm, USE 425mm and Ritchey 400mm. I cracked my old 420mm Syncros Pro - beautiful bit of kit

Pace changed their frames to have a replacable seat collar that bolted flush to the top tube. I'm guessing that got around the stress raisers assocciated with the junction of the square-section 'tube' sticking out above the toptube.