Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Classic & Vintage (https://www.bikeforums.net/forumdisplay.php?f=181)
-   -   Are all square taper fixed cups left hand threads? (https://www.bikeforums.net/showthread.php?t=1288830)

RH Clark 02-22-24 09:49 AM

Are all square taper fixed cups left hand threads?
 
Watching vids on overhauling a square taper BB. The fixed cup on the drive side is left hand threaded and loosens by turning clockwise. These seem fairly difficult to loosen and I have 3 bikes, 86 Trek 560, 80's Trek 400, and 83 Miyata 610, that I would like to service. I would hate to be trying to turn the fixed cup backwards on any of them. Will the fixed cup on all those bikes loosen clockwise?

PhilFo 02-22-24 09:59 AM

Yes. Get some good fitting tools to pull your particular cups, some penetrating oil, maybe even a heat gun, then take your time. Sometimes a bit of a whack with a hammer on the tool itself will help to break the friction if there is any corrosion in there.

Kabuki12 02-22-24 10:06 AM

On your bikes , they would be left hand. Italian BB are different.

sd5782 02-22-24 10:13 AM

Many folks leave them alone while servicing rather than fighting with them and possibly damaging something. It isn’t terribly difficult to reach and evaluate the bearing cups from the opposite side. Lubing is also doable.

RH Clark 02-22-24 10:18 AM


Originally Posted by sd5782 (Post 23164183)
Many folks leave them alone while servicing rather than fighting with them and possibly damaging something. It isn’t terribly difficult to reach and evaluate the bearing cups from the opposite side. Lubing is also doable.

I thought about that when watching the video.

I was about to order the tools and may leave off the fixed cup tool as it costs as much as the bb lock ring tool and pin spanner combined.

John E 02-22-24 02:21 PM


Originally Posted by RH Clark (Post 23164191)
I thought about that when watching the video.

I was about to order the tools and may leave off the fixed cup tool as it costs as much as the bb lock ring tool and pin spanner combined.

Just use the Sheldon Brown nut, washers, bolt removal system. It is also OK to treat it as the fixed cup it is. :)

Polaris OBark 02-22-24 02:27 PM

Don't fix it if it ain't broke.

If you had an Italian frame, then a RH Italian fixed cup would work, but if you have left-handed helical threads, you are stuck.

Unless this is a museum piece, it might be worth it to upgrade to a modern external BB and 24mm or 30mm spindle crankset.

RH Clark 02-22-24 02:36 PM


Originally Posted by Polaris OBark (Post 23164439)
Don't fix it if it ain't broke.

If you had an Italian frame, then a RH Italian fixed cup would work, but if you have left-handed helical threads, you are stuck.

Unless this is a museum piece, it might be worth it to upgrade to a modern external BB and 24mm or 30mm spindle crankset.

No, I'm far from a museum piece collector. I actually started riding during the worst financial time of my life. I have bought all my bikes cheap off marketplace and have slowly acquired tools and knowledge to repair them. This is a quite nice 86 Trek 560 with Shimano 600 group. I picked it up for $100. It fits me great and will be a very nice ride for me pretty cheap. I'll post up a thread about it when I get finished.

madpogue 02-22-24 02:53 PM

Fixed doesn't mean you don't remove it. Fixed simply means you don't adjust it, like you do with (duh) the adjustable cup. Removing it assures you that you'll be able to remove it when you might really need to, for example, if the frame needs to be stripped bare for repairs or paint. Or if your BB completely wears out and you want to replace it with a cartridge. The longer you leave it without removing it, the harder it will be to remove the day you REALLY NEED to

Absent the spanner that fits snugly all the way around the cup (and even with such a spanner), I found the best method to be to use one of the trigger squeeze clamps used in furniture making, or for jobs like gluing cutting boards together. I've even used this method to hold a bigeffin' adjustable wrench on the cup flats. With a long enough cheater bar, I haven't encountered one yet that has not yielded.

gearbasher 02-22-24 03:01 PM

I agree with madpogue. If you plan on keeping the bike and using it regularly, remove the cup now. You will thank yourself later.

merziac 02-22-24 03:52 PM

The "fixed" cup ALWAYS comes out for proper service of the cup and BB shell threads, inspect, clean and torque, period.

Any other version is neither complete or correct.

trainman999 02-22-24 04:34 PM

A few tips for removing BB 1 loosen the fixed cup first. 2 Clamp the removal tool to the cup. 3 set the bike on the ground with air in the tires, 4 stand in front of bike holding handelbars, press down on tool with foot, use cheater bar if needed. 5 loosen the adjestable cup. .6 put bike in stand and dissamble.

Whit51 02-22-24 05:21 PM

I’ve always left the fixed cup in place if possible, but when I’ve needed to remove one a heat gun was a big help.

Piff 02-22-24 05:32 PM

If the fixed cup is a pain to remove because it's been in there for so long or it was super-duper torqued down, then this is exactly the right moment to remove the fixed cup. I agree with the others. If you're servicing the bottom bracket, then do all of it.

SurferRosa 02-22-24 05:41 PM

I usually treat the bb fixed cup like the two head tube press fit parts: make sure it's in there snug and leave it alone.

I usually only remove it if it needs removing. The homemade Sheldon tool has worked for me.

If you started a poll on the subject of fixed cup removal for bb overhaul, I will guess it would be a 50/50 result.

bikingshearer 02-22-24 05:49 PM


Originally Posted by Kabuki12 (Post 23164173)
On your bikes , they would be left hand. Italian BB are different.

Ditto for French bottom brackets; right hand threads on the fixed cup (which, as many of us have found out the hard, is far more likely to loosen spontaneously after 10 or so miles; left hand threaded British fixed cups don't do that).

Yes, all of your bikes should have the British threading, i.e. left hand threading on the fixed cup. American and Japanese builders used the British standard for bottom brackets (probably with one or two outliers that do not matter with your three fine steeds).

As for the remove/don't remove the fixed cup debate, I am neutral. Like Switzerland. Which has it's own bottom bracket threading standard (same as the French, except left-handed thread for the fixed cup).

Bottom line: British, Italian, French and Swiss fixed cups are not compatible with each other. Swiss and French adjustable cups are the same - swap to your heart's content, but French/Swiss. British and Italian adjustable cups are not interchangeable. This silly state of affairs dates back to the days when the Alps and the English Channel posed much greater barriers to international trade than they do now.

79pmooney 02-22-24 06:07 PM


Originally Posted by SurferRosa (Post 23164590)
I usually treat the bb fixed cup like the two head tube press fit parts: make sure it's in there snug and leave it alone.

I usually only remove it if it needs removing. The homemade Sheldon tool has worked for me.

If you started a poll on the subject of fixed cup removal for bb overhaul, I will guess it would be a 50/50 result.

I bet more leave the cup in for service but don't talk about it (or vote). Shamed by the "gotta take it out" folk. 50/50 for those willing to say sounds right.

gearbasher 02-22-24 06:09 PM


Originally Posted by SurferRosa (Post 23164590)

If you started a poll on the subject of fixed cup removal for bb overhaul, I will guess it would be a 50/50 result.

A poll was actually taken by me: https://www.bikeforums.net/classic-v...t-removal.html

Kabuki12 02-22-24 06:53 PM

I’m lucky , I have a friend that has a very nice tool that securely removes the fixed cup . Sometimes it takes both of us but it hasn’t failed us yet. If he is not around , I lay the bike on a rug and use my big Sugino wrench . I have one bike with a Phil BB and , to me , my favorite…..NO MAINTENENCE!

albrt 02-22-24 07:11 PM

Most fixed cups can be removed with a big crescent wrench, but it definitely helps to have a clamp or a version of the Sheldon Brown tool because the exposed flats of the fixed cup are so thin. The Sheldon tool gives you an extension clamped into the cup itself to give you a better purchase with the wrench. You can also use a longer bolt with bigger washers to keep the wrench snug against the bottom bracket cup, like with the clamp. I would say it makes more sense to spend a few bucks on some version of a clamping device than on the specialized wrench to fit the cup.

dedhed 02-22-24 07:57 PM

Until I got the tool I used a big adjustable held in with a big washer and bolt. Even with the tool I bolt it in if it doesn't come out easy.

RH Clark 02-23-24 06:37 AM

Thanks for the help, guys. I will attempt removal with a large wrench and an all-threaded bolt with washers and nuts to keep it in place. I suppose the danger is slipping and rounding the flats of the nut. If it looks like I might damage the nut I may leave it. I would rather get it out if possible, without damaging anything. Hopefully this one won't require a cartridge now, but I would like to have the option later.

BTinNYC 02-23-24 06:59 AM


Originally Posted by merziac (Post 23164514)
Any other version is neither complete or correct Peugeot.

:)

Reynolds 02-23-24 07:15 AM


Originally Posted by merziac (Post 23164514)
The "fixed" cup ALWAYS comes out for proper service of the cup and BB shell threads, inspect, clean and torque, period.

Any other version is neither complete or correct.

I suppose the final word is the manufacturer's recommendations/instructions. Is your affirmation based on any of them? Just curious.

merziac 02-23-24 11:33 AM


Originally Posted by RH Clark (Post 23164910)
Thanks for the help, guys. I will attempt removal with a large wrench and an all-threaded bolt with washers and nuts to keep it in place. I suppose the danger is slipping and rounding the flats of the nut. If it looks like I might damage the nut I may leave it. I would rather get it out if possible, without damaging anything. Hopefully this one won't require a cartridge now, but I would like to have the option later.

I would strongly encourage you to get a proper fixed cup tool and use some method to hold it firmly in place, all thread, clamps, etc.

A fixed cup wrench encircles the cup for far better purchase when every last bit counts.

I have a Sugino that I have had for over 50 years that is the only one I really use, Campy is next with Park last, I have them all, the Sugino has never failed me.

Then have a good cheater set up, I have a 4 foot thinwall pipe that is flatened at one end and slips over the wrench when needed.

The big crescent wrench can work ok but most have tapered jaws that can be hard to hold flat, square on the cup and often try to "cam" out/off and round off the flats, once this happens, you lose the best footing and success is much less likely without extreme measures.

It can be imperative to get it very right from the jump. ;)


All times are GMT -6. The time now is 09:38 PM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.