Forum home› Road cycling forum› Workshop

Bottom Bracket threads on new frame

battaglinbattaglin Posts: 36
edited December 2017 in Workshop
I bought a brand new Planet X RT-58 V2 alloy road frame, ready to build up for a Winter/commuter bike:
https://www.planetx.co.uk/i/q/FRPXRT58A ... d-frameset

The Bottom Bracket is stated as BSA 68.

I'm fitting it with 11 speed Campag centaur. Accordingly I bought brand new Campag Record Ultra Torque Bottom Bracket Cups - English threaded:
http://www.highonbikes.com/campagnolo-r ... -cups.html

On trying to fit, only the non drive side will screw in at all, and even then only a little way by hand after backing off and going again to make sure of no cross threading. The drive side just won't fit at all! The torque wrench hasn't been near either.

The threads on the frame are obviously clean, with it being a brand new frame, and don't appear to have any obvious imperfections. I have however noticed that other threads on the frame so far haven't felt smooth right from the off. The rear derailleur and the bottle cage threads all required a little bit of fiddling before the screws sat nicely for example.

So my question is...is it normal to have to get a new frames bottom bracket re-threaded before fitting the cups?, or have I got a poor frame? The cups are new and undamaged.

What advice can anyone give please? Should I give up on the frame and try and get my money back? Or have someone re-thread the bottom bracket for me?

Posts

  • gazza1286gazza1286 Posts: 45
    Had the same problem with a new (old stock) Scott Roadster alloy frame which I sourced to replace the original frame which had failed. The threads on both sides needed re-chasing. My LBS sorted it in minutes. Neither BB would go in beyond 3-4 turns.
  • battaglinbattaglin Posts: 36
    gazza1286 wrote:
    Had the same problem with a new (old stock) Scott Roadster alloy frame which I sourced to replace the original frame which had failed. The threads on both sides needed re-chasing. My LBS sorted it in minutes. Neither BB would go in beyond 3-4 turns.

    Thanks. So looks like a re-chasing (apologies for calling it re-threading earlier) at my LBS will hopefully get me sorted then.

    I'm disappointed that a new frame, even one as cheap as this Planet X, comes with such poor threads. I've already had to take the forks to my LBS because the bottom race on the FSA headset (only one that's compatible) wouldn't go on without the right tools as there was no split in the race making it impossible to push on by hand. This is my first complete build - I'd not factored in one trip to the LBS, let alone two! :(
  • redveeredvee Posts: 11,920
    I found 90% of the threads on my PX frames needed a tap running through them before building them up but these were bottle and guard bosses, the BB thread was OK.
    I've added a signature to prove it is still possible.
  • lesfirthlesfirth Posts: 1,130
    You have all got further in building up a PlanetX frame than I did. The very first thing I wanted to do was check the tyre clearance to decide what tyres was going to use. I could not fit the back wheel. The drop out was too small for the axle.
    I did not fancy using a file on a new frame so it went back.
  • battaglinbattaglin Posts: 36
    lesfirth wrote:
    You have all got further in building up a PlanetX frame than I did. The very first thing I wanted to do was check the tyre clearance to decide what tyres was going to use. I could not fit the back wheel. The drop out was too small for the axle.
    I did not fancy using a file on a new frame so it went back.
  • Nick PayneNick Payne Posts: 288
    The BB shell gets distorted during the welding of the frame, and few manufacturers bother to chase and face it post-welding to ensure the threads and faces are back in alignment. Here's a couple of shots of the left and right faces of a BB shell that I took part way through prepping a very expensive Ti custom frame from a well-known builder (I'd already chased the threads). You can see that he obviously hadn't bothered to check that things were still in alignment after welding the frame - on both sides of the BB the front of the shell was wider than the back, and I had to use the cutters for several minutes each side to get the faces back to parallel and square to the threads.

    The same goes for head tubes - if the seats for the top and bottom cups/bearings aren't reamed and faced post-welding, they won't be in alignment.

    BB_LEFT.JPG

    BB_RIGHT.JPG
  • battaglinbattaglin Posts: 36
    Funnily enough, this frame is very similar. The back wheel is really really tight to go in.

    I wish I had started to build this frame up the minute I bought it because I'd probably have sent it back too. I'm starting to discover that the finish really isn't very good. There's obviously a reason it was so cheap to buy. Now it's well over the 28 days and I'm not sure where I stand.

    Starting to wish I'd gone for the Dolan Prefissio instead.
  • battaglinbattaglin Posts: 36
    Nick Payne wrote:
    The BB shell gets distorted during the welding of the frame, and few manufacturers bother to chase and face it post-welding to ensure the threads and faces are back in alignment. Here's a couple of shots of the left and right faces of a BB shell that I took part way through prepping a very expensive Ti custom frame from a well-known builder (I'd already chased the threads). You can see that he obviously hadn't bothered to check that things were still in alignment after welding the frame - on both sides of the BB the front of the shell was wider than the back, and I had to use the cutters for several minutes each side to get the faces back to parallel and square to the threads.

    The same goes for head tubes - if the seats for the top and bottom cups/bearings aren't reamed and faced post-welding, they won't be in alignment.

    BB_LEFT.JPG

    BB_RIGHT.JPG

    Alarming to hear you're getting that even on an expensive frame.

    Seems like some manufacturers are taking the public for a bit of a ride then (no pun intended). Surely it's not too much to ask for a new frame to be build ready straight out of the box.
  • crankycrankcrankycrank Posts: 1,830
    Never could understand why any frame builder would deliver a frame that needs all kinds of thread chasing and facing of the BB shell and headtube, etc. They could certainly do it at the factory at a lower cost and charge accordingly than having the customer pay extra at a shop to do it. The bad publicity from unhappy customers getting on forums complaining about the poor condition of their new frames would seem to warrant a change but I guess not. We're in the 21st century now, it's time to end this practice. I say send a note to Planet X and every builder you purchase a frame from that you're not a satisfied customer.
  • battaglinbattaglin Posts: 36
    crankycrank wrote:
    Never could understand why any frame builder would deliver a frame that needs all kinds of thread chasing and facing of the BB shell and headtube, etc. They could certainly do it at the factory at a lower cost and charge accordingly than having the customer pay extra at a shop to do it. The bad publicity from unhappy customers getting on forums complaining about the poor condition of their new frames would seem to warrant a change but I guess not. We're in the 21st century now, it's time to end this practice. I say send a note to Planet X and every builder you purchase a frame from that you're not a satisfied customer.

    Well said!

    I'm taking it to my LBS to see if they can chase the threads and I suppose face it up while they're at it. All rather defeats the object of a DIY build project, so I'm not a happy customer.

    I shall be leaving a full and honest review of the frame, if and when I've managed to build it up and start riding it.
  • jgsijgsi Posts: 5,027
    My older style RT58 frameset was had for a bargain.. reason being it came with basically nothing and threads incl BB area knackered. Sometimes I think if PX could charge for the forks for a frameset they would.
    I bought a Lifeline bottom bracket tap set and facer because I could be bothered taking it to a shop and them laughing.
    Doing a job myself that should have been done by professionals was satisfying.
  • redveeredvee Posts: 11,920
    lesfirth wrote:
    The drop out was too small for the axle.
    I did not fancy using a file on a new frame so it went back.

    Mine needed some wet n dry to remove some of the paint, being an alloy frame corrosion wasn't a concern.
    I've added a signature to prove it is still possible.
  • gazza1286gazza1286 Posts: 45
    The requirement to re-chase the bottom bracket threads is no big deal. I cannot see that it has anything whatsoever to do with distortion due to welding. It's more likely as a result of paint over-spray on the treads.
  • timothywtimothyw Posts: 2,482
    It is a handy reminder that it wasn't all sunshine and rainbows back in the days where every bike had a screw fit bottom bracket, with all the press fit bottom brackets that we have to contend with nowadays.

    I built up one of the unfinished Merckx frames that Merlin had at the start of the year, that had a very dirty italian threaded bottom bracket - not easy to find a bike shop with the tools to clean italian threads I can tell you!

    Anyhow. Hardly surprising that these bargain basement frames need a little more preparation - it is at least easy money for your local bike shops (as how many home mechanics want to spend the money for a threading tool they might use three times in their lives?)
  • Nick PayneNick Payne Posts: 288
    gazza1286 wrote:
    The requirement to re-chase the bottom bracket threads is no big deal. I cannot see that it has anything whatsoever to do with distortion due to welding. It's more likely as a result of paint over-spray on the treads.
    Really? Then explain why it's needed on frames that aren't painted.
  • lesfirthlesfirth Posts: 1,130
    Nick Payne wrote:
    gazza1286 wrote:
    The requirement to re-chase the bottom bracket threads is no big deal. I cannot see that it has anything whatsoever to do with distortion due to welding. It's more likely as a result of paint over-spray on the treads.
    Really? Then explain why it's needed on frames that aren't painted.

    Dont bother Nick. Gazza says," I cannot see ...". Probably not all he cant see.
Sign In or Register to comment.