Correcting a cross-threaded bottom bracket?

[Sir Ridesalot]

I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?

Thanks and cheers

[AMuzi]

On 10/12/2015 4:06 AM, Sir Ridesalot wrote:
> I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?
>
> Thanks and cheers
>

A piloted tap set can remove occlusions and ensure both
threads are on the same axis.

Taps however are subtractive machining. You won't have any
more thread height than now, and likely less. Some
inspection, measurement, analysis and advice from someone
who does this work regularly would be a good start.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[avag...@gmail.com]

1 April, 1971

OCCLUSIONS !!! ***rrr44DSx00))&$))) !!

yeah el tapo ! you need expert hands for starting the tap...as AM sez

blue locktite on 2 prepared clean surfaces will hold that area together no prob.

and if the BB falls out...go with red.

I had spelts for dinner...

then we skinned the nabs weimeraner for winter gloves

https://www.google.com/#q=occlusions

[John B.]

Depending on how badly the threads are deformed it may be possible to
recut the threads sufficiently to install a new bottom bracket
bearing.

If that fails there are "threadless bottom brackets" that can be used
to repair it. Velo Orange, and probably others, sell them, see
http://store.velo-orange.com/index.php/components/bottom-brackets/grand-cru-threadless-bottom-brackets.html
--
cheers,

John B.

[Sir Ridesalot]

I'm taking the frame to a shop tomorrow(closed today due to it being Thanksgiving Monday here in Canada) and see what they charge to chase the threads. The threadless bottom braket might be the easiest way to go though. It's a very nice frame ideally suited for conversion to a drop bar touring bike for fire/logging/mining roads touring.

Cheers

[cl...@snyder.on.ca]

And an application of locktite to the repaired thread on assembly
would be a good second step. I had a Raliegh Twenty with a
cross-threaded bottom bracket (fixed cup) that I got the thread
cleaned up on resulting in about halth thread depth (or less) and it
would not stay tight. I took it apart, cleaned it with acetone,
sprayed it with loc-tite prime-bond, and applied a couple drops of
locktite stud mount. It never moved again. That was a good 10 years
ago.

[Frank Miles]

Ooohhh! Thanks! Never saw one of those before. We bought my son a used bike
(from a local used-gear store), only to discover recently that the right side's
threads were toast. He took it to a local bike shop - they charged him $100
for chasing the threads and replacing the good sealed bearing unit with a
crappy one that didn't even fit properly. In an act of desperation I drilled
and tapped a couple of setscrew holes and installed an old non-sealed hub that
kinda fit (threads still loose - just not enough metal left). This has worked
for a few months without any issues but eventually something like this threadless
version will probably be needed.

Again - thanks!

[Sir Ridesalot]

According to that manufacturer make sure your bottom bracket shell is no more than 68mm wide otherwise this threadless BB won't work.

Cheers

[John B.]

On Mon, 12 Oct 2015 13:39:35 -0700 (PDT), Sir Ridesalot

And the threaded bottom bracket standard seems to be 68mm for the
British, French, ISIS and Swiss bottom brackets. the Italian is 70mm.
In addition, the 'Bottom Bracket Tool' comes in two flavors. the
"Threading and Facing" Tool" or the "Facing Tool", so essentially any
shop that "does bottom brackets" has the ability of cutting the bottom
bracket a bit narrower, if necessary.
--
cheers,

John B.

[Sir Ridesalot]

On Monday, October 12, 2015 at 5:06:19 AM UTC-4, Sir Ridesalot wrote:
> I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?
>
> Thanks and cheers

I used an old pair of bottom bracket cups to make a tool to cleanup the threads. I cut some grooves into a fixed cup and made a spacer to fit inside the fixed cup and adjustable cup. I screwed the adjustable cup inmost of the way and then started the fixed cup supported by the internal spacer as I threaded the fixed cup in I backed out the adjustable cup which with the spacer kept the fixed cup square to the bottom bracket shell. Surprisingly, by working very slowly on it, it worked and I was able to cleanup the cross threading and then install a sealed cartridge bottom bracket. Everything tightened up okay. i guess my next step will be to strip the frame and repaint it. i also need to either get a riser quill stem, a quill to threadless stem adapter and stem, or an adjustable stem to get the bars uo to where I most prefer them. A shakedown ride today shows that all's well except I'd prefer a bit longer reach on my stem.

Cheers

[cycl...@yahoo.com]

You are absolutely correct but should add that steel bottom brackets in older bikes have MORE than enough thread length and depth to be strong enough unless the threads were almost completely stripped out by repeatedly cross threading..

[cycl...@yahoo.com]

I do not believe that they offer a system that would be compatible with yours. Unless you're willing to update to the newer style cranks with feed-through type connections. And since these are 10 speed the six or seven speed chains aren't compatible. etc. Andrew's suggestion of cleaning the threads was the best way. This will almost never give you any problems.

[cycl...@yahoo.com]

Old BB cups are not made with metal hard enough to clean threads properly. That's why taps are made of extremely hardened steel. To the point where they can be broken if mishandled.

[Sir Ridesalot]

Maybe not but that tol I made worked well. if there were no threads and i was cutting threads then i know i'd need a special tool. Bike shops with the proper tools and people who know how to use them are not that close to where i live. i have to either bicycle to tthe shop or take an inter-city bus.

As far as the cartridge bottom bracket goes, I have a number of NOS ones here suitable for triples and i have some for doubles and singles too. There's a shop 25km (15 miles) from me that has lots of NOS square taper bottom brackets including Italian threaded ones at very low prices i.e. $5.00 to $10.00 on average. that's only a 50 km round trip ride but I need to find out what days he's open.

One thing I really like about tthe old school cranks like the Deore and sugino that I've collected as replacementsa is that I can get a very low Q-factor with them.

Cheers

[xylon...@gmail.com]

segunda-feira, 12 de Outubro de 2015 às 10:06:19 UTC+1, Sir Ridesalot escreveu:
> I was finally able to get the bottom bracket off of a friend's steel frame English threads bottom bracket bike. Whew what a job! The fixed cup cup was cross-threaded. He wants to put in a standard square-taper spindle cartridge bottom bracket. The problem is since the fixed cup was cross-threaded I can't get the new cartridge to thread in properly. Does a decent bicycle shop have a way to correct the cross-threaded threads in the bottom bracket shell? If so what's a ballpark price for doing it?
>
> Thanks and cheers

Worth a try....desperate times - desperate measures. Cut 3 grooves in an old shell with a cutting disk as has been suggested and weld on a bar for leverage. Another "shit or bust" technique, not for the faint hearted...if you can get the cup in a few threads and can see it is skew by one thread (as often happens)give the part of the cup which protrudes more a SHARP TAP (a judicious blow)with a hammer! Then continue with the cup wrench and see if it goes in. THEN SELL THE KLUNKER POST HASTE! Or keep it (as in my case) ;-)

[AMuzi]

On 9/23/2017 1:09 PM, xylon...@gmail.com wrote:

A more circumspect technique would be to clean the BB shell
well, inspect for visible thread damage in good light with a
magnifier. If damage is found, correct that (tap to larger
size or fill and thread).

If not visibly damaged, run your go-nogo thread gauges on
the cleaned threads to evaluate before jamming something in
them.

Note that taps are subtractive only. Missing material cannot
be completely corrected by cutting, although smashed threads
may have sufficient height once cleared.

[cycl...@gmail.com]

It should also be stated that it is rare that ANYONE could install a bottom cross threaded enough that simply chasing the threads wouldn't restore full use. Though as someone that has apparently done it, it is possible.

[Sir Ridesalot]

On Saturday, September 23, 2017 at 6:02:16 PM UTC-4, cycl...@gmail.com wrote:
Snipped

> It should also be stated that it is rare that ANYONE could install a bottom cross threaded enough that simply chasing the threads wouldn't restore full use. Though as someone that has apparently done it, it is possible.

I know a guy who managed to screw a RIGHT-hand pedal onto a LEFT crankarm. I asked him did he not notice that it was REALLY HARD to screw that pedal on. He said he did notice that.

Cheers

[avag...@gmail.com]

SAAR ? or equivalent bike tool many ...

has a BB tap for you. I'm on immobile device n cannah see what but look at 'Bike tools ect'

Go to a machine shop.

Review Locktite products...beyond Red there is a loose plain bearing liquid.

If the new BB case is prob vinyl or plastIC I'm a sure there's a shock proof vi yl cement or epoxy to beef in the thread clearance to 0

That's a new area for me so ? I used red on butchered Stihl chain saw casing threadS 30 years ago worked ok. The case was prob vinyl kinda cardboard compared to today

[John B.]

Depending on how much money you want to spend there are "threadless
bottom brackets" that are intended for the repair of damaged bottom
brackets. One source states that "Grand Cru threadless bottom brackets
fit most frames, even those with Swiss threading. And they work on
frames with damaged BB shells, even if the existing threading is
totally stripped."

see
https://store.velo-orange.com/index.php/components/bottom-brackets/grand-cru-threadless-bottom-brackets.html
--
Cheers,

John B.

[Sir Ridesalot]

Perhaps there are special tools or adaptable threadlessbottom brackets; however I fixed that problem almost two yearsago. VBEG LOL.

Cheers

[cycl...@gmail.com]

I don't remember anything about my Time Edge but when I tried to remove the BB cups on the BB386 the right side will NOT come off. Sooner or later I will get around to cutting the cup most of the way through and then breaking it apart in the vice. At that point I will install one of those threadless bottom brackets.

I'm not sure but I seem to remember installing the cups and that they didn't appear to go in with any difficulty. They did have blue thread lock on them though. The right side unthreaded a turn or so and locked solid. No tool would move it. So I finally locked the cup in a vice and used the frame as a lever. All that accomplished was to break the BB liner loose from the carbon fiber bottom bracket.

So the only thing I can see is to cut through the cup and then smash it in on itself.

[Mark J.]

I could swear that I once threaded the (right-hand-thread) adjustable BB
cup into the (left-hand-threaded) right side of my Centurion Pro-Tour.
This was nearly 40 years ago; I was young and foolish.

When I figured out what I'd done, I pulled it out and could see no
damage (I know that should be impossible). Reassembled correctly and
rode the bike for many thousands of miles afterward, over 17 years.

If anyone told me the same story today, I would tell them they
misremembered, so maybe I am doing so, but the memory of the horror at
what I'd done - it was my first high-quality bike - is still quite fresh.

I've still got the frame. Maybe I should inspect those threads.

Mark J.

[avag...@gmail.com]

https://www.google.com/search?client=ms-android-verizon&q=var+bottom+bracket+taps+bicycle+tools&spell=1&sa=X&ved=0ahUKEwjW2_qZhsDWAhWmi1QKHd1QCTsQvwUIISgA&biw=360&bih=560

I assume Harris has one or 2

Schwin in Fort Myers has one or a set maybe common in a long standing shop

Stunning Goo's search results capacity

[ph in Aptos]

On Sunday, September 24, 2017 at 7:51:39 PM UTC-7, Mark J. wrote:
> On 9/23/2017 4:53 PM, Sir Ridesalot wrote:
> > On Saturday, September 23, 2017 at 6:02:16 PM UTC-4, cycl...@gmail.com wrote:

<snip>

>
> I could swear that I once threaded the (right-hand-thread) adjustable BB
> cup into the (left-hand-threaded) right side of my Centurion Pro-Tour.
> This was nearly 40 years ago; I was young and foolish.
>

<snip>
> Mark J.

Ah! Centurion. I remember my good old Centurion Super Lemans that I got back in college. I chose Centurion over Nishiki mainly because the rear brake action was so much crisper. (Nishiki used a full-length cased cable).

I was very leery of the SunTour finger-tip shifters but quickly realized that Suntour Finger-tip shifters are the best shifters in the known universe and are very likely the only shifters God intended.

(The same way He prefers 27" rims. Michelein used to make 1-3/8 tires to kind of reply to a different thread.)

I have some Rivendell shifters now, but still finger tip.

pH