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Old 03-08-10, 11:19 AM   #1
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Help! - I Need advice on a cross-threaded crank

I have a 30 year old road bike with a Sakae "Custom" alloy 3-piece crank, and the original (Japanese) steel spindled Right Side pedal badly cross-threaded in the crank arm.

I removed the left side with no issue, but this right side pedal was driven home cockeyed, possibly at the factory, since the prior owner was not disposed to work on his bike.

I was able to back it out about 1 turn by pounding on my 15mm pedal wrench, but now it only seems to be getting TIGHTER. (I can see that that it was driven in not-square-to-the-crank)

I don't know what to do -
- Should I continue to pound on it?
- Is there a better way to remove it?
- If I do get the pedal out, WHAT can I expect to find ?
- Will this crank be TOAST? - - Or can I chase the threads?
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Old 03-08-10, 11:41 AM   #2
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It does sound like those threads are toast. Is this crank definitely worth saving? If so, you can repair that damage by drilling out the hole (once you get the pedal out) and using a Helicoil insert. That will make the crank usable, though never entirely as strong as it once was because some material must be removed to put in the Helicoil. Should be okay for standard use, though. here's an old thread about it.
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Old 03-08-10, 11:49 AM   #3
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You are aware that the non-drive side pedal is left-hand threaded and removed by turning it clockwise when facing the bike from that side?

If you removed what you referred to as the "left" pedal and it was the drive side, the threads are normal right-hand threads so it would have removed normally. So, are we referring to left (non-drive side) and right (drive side) the same way?
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Old 03-08-10, 11:54 AM   #4
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Factories never installed pedals.
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Old 03-08-10, 12:27 PM   #5
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You are aware that the non-drive side pedal is left-hand threaded and removed by turning it clockwise when facing the bike from that side?

If you removed what you referred to as the "left" pedal and it was the drive side, the threads are normal right-hand threads so it would have removed normally. So, are we referring to left (non-drive side) and right (drive side) the same way?
^^ Thanks Hill rider, but we are not making that error here !
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Old 03-08-10, 12:30 PM   #6
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Assuming you're talking about the drive side pedal then it is the right hand threaded side assuming the pedals were correctly installed by whoever did this. Since I can't see a bike shop installing them wrong or cross threaded it would appear that some previous owner did indeed take up the challenge at some point so any combination of mistakes is possible. If it's a cheap pedal then the spindle may well be bent so it'll LOOK like it's cross threaded but really it isn't. If it truly is cross threaded and driven home and you're turning it the correct way then my own feeling is that you'll find that the crank arm is toast. Once a pedal is driven home completely cross threaded then the only cure is either a heli-coil or other such thread repair or to toss it and buy a new part.

Chasing threads does not restore the original metal, it just cuts away more metal. Chasing is only good for threads where they were just started crooked but where most of the thread is OK and you're just trying to clean up the first few turns. A fully driven home cross threaded pedal will have ruined the threads.

Try heating the arm with a propane torch to exand it. Direct the heat mostly at the aluminium and let it travel along the arm to the pedal end by conduction. That should allow you to turn the pedal out and see what the situation really is.
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Old 03-08-10, 12:30 PM   #7
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Factories never installed pedals.
Can't argue with that - I suppose I could blame the bike store then, but they are long gone.
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Old 03-08-10, 12:39 PM   #8
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It does sound like those threads are toast. Is this crank definitely worth saving? If so, you can repair that damage by drilling out the hole (once you get the pedal out) and using a Helicoil insert. That will make the crank usable, though never entirely as strong as it once was because some material must be removed to put in the Helicoil. Should be okay for standard use, though. here's an old thread about it.
Thank you simplify - Though I was hoping to hear that it was not Toast.
They are the old style Sakae's - not a rarity exactly, but it's the old wide BCD so it's harder to find in good condition for low cost.

I am familiar with Helicoils (though I've never actually done one) - However- if it is not as secure as a new crank, I would think I may be better off scouring eBay for a new one.
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Old 03-08-10, 01:54 PM   #9
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...
Try heating the arm with a propane torch to exand it. Direct the heat mostly at the aluminium and let it travel along the arm to the pedal end by conduction. That should allow you to turn the pedal out and see what the situation really is.
BCRider - I'm going to take this bit of advice before doing anything more -( From just a quick look on ebay , it looks like all the 144 BCD cranks are both scarce and expensive!).
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Old 03-08-10, 02:04 PM   #10
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I am familiar with Helicoils (though I've never actually done one) - However- if it is not as secure as a new crank, I would think I may be better off scouring eBay for a new one.
The threads formed by the Helicoil will actually be stronger than the original aluminum threads. you will be removing a small amount of material thickness from the aluminum arm around the hole so it is theoretically slightly weaker in that area. I doubt you'll have an issue with it though as this is a common repair. If you wanted to do it yourself, the tools and supplies to do so would end up costing you more than a new crank arm however you'll have enough inserts to repair several crank arms. If this does not interest you, take the arm to your LBS and let them do the inserting. You'll want to use at least a drill press and vice for this process (crank arm removed from bike). Drilling by hand, especially with the arm on the bike, is not likely to yield a pretty result.
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Old 03-08-10, 02:20 PM   #11
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The threads formed by the Helicoil will actually be stronger than the original aluminum threads. you will be removing a small amount of material thickness from the aluminum arm around the hole so it is theoretically slightly weaker in that area. I doubt you'll have an issue with it though as this is a common repair. If you wanted to do it yourself, the tools and supplies to do so would end up costing you more than a new crank arm however you'll have enough inserts to repair several crank arms. If this does not interest you, take the arm to your LBS and let them do the inserting. You'll want to use at least a drill press and vice for this process (crank arm removed from bike). Drilling by hand, especially with the arm on the bike, is not likely to yield a pretty result.
In that case, it is worth a second look. I will probably resort to having the LBS do it for me - ( I don't expect to be doing this to many cranks -( In fact I never encountered one of these before!) but in any case I will remove the pedal with the torch, so at least I don't have to pay for that too... thank you joejack951 - and thank you all for sharing your insights.
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Old 03-08-10, 02:54 PM   #12
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In that case, it is worth a second look. I will probably resort to having the LBS do it for me - ( I don't expect to be doing this to many cranks -( In fact I never encountered one of these before!) but in any case I will remove the pedal with the torch, so at least I don't have to pay for that too... thank you joejack951 - and thank you all for sharing your insights.
The threads in the crank arm are toast, so in my opinion, skip the torch and just force the pedals threads out. You'll save the finish on the crank arm at least. Some penetrating oil should help the process.
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Old 03-08-10, 03:25 PM   #13
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I talked to my LBS about doing the helicoil repair for a friend's bike. He quoted $10 for the whole procedure which probably included pulling the crank. Prices may be higher in your area but if transporting the bike is easier than crank removal you might let the shop do that to.
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Old 03-08-10, 04:03 PM   #14
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I've never seen a helicoiled crankarm hold up for very long. Play inevitably develops and the helicoil ends up ripping out of the aluminum.
If the pedal wasn't crossthreaded all the way into the arm, you could try removing the pedal and threading it in through the opposite side (inside) to push the threads back into some sort of useable position. Then use a tap from the inside as well to clear the mangled threads on the very outside edge. Carefully try installing the pedal the proper way while making sure it goes in completely square and it might hold up OK.
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Old 03-08-10, 04:14 PM   #15
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Thank you simplify - Though I was hoping to hear that it was not Toast.
They are the old style Sakae's - not a rarity exactly, but it's the old wide BCD so it's harder to find in good condition for low cost.

I am familiar with Helicoils (though I've never actually done one) - However- if it is not as secure as a new crank, I would think I may be better off scouring eBay for a new one.
If going to replace the crank then you don't need to use one with the same BCD.
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Old 03-08-10, 05:22 PM   #16
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Roughly 1/2 the lower priced bikes I buy to rehab or as parts donors come with at least one crank arm partially stripped. The big tip off is HOW HARD it is to get the freakin' pedal off. How the installer managed to not notice how hard it was to install-no idea!!

I've had good luck running a tap thru-usually just the first 1-3 threads are shot.

You might get lucky, and get it out with some of those "modified threads" in good enough shape to hold a pedal.
Luck
Charlie

Last edited by phoebeisis; 03-09-10 at 07:32 AM.
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Old 03-08-10, 05:24 PM   #17
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If going to replace the crank then you don't need to use one with the same BCD.
I was considering re-using the same chain rings which are in excellent shape.
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Old 03-08-10, 05:48 PM   #18
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UPDATE -
I spent an inordinate amount of time trying to remove the pedal, but it had no effect - even in spite of the propane torch.

- But it did deform the jaws on my open ended 15mm wrench from my highly polished Blackhawk long handled set

It makes me wonder how anyone could have driven it in that way to start with... I had the crank clamped in a big vise, and even with my big hoofy braced against the bench for leverage, I could not pull hard enough to move it, nor would repeated blows from my ball peened hammer. So there it sits- backed off from the arm by one full revolution, but going no further.

Exhausted, I knew the LBS could do no more than I did - so I decided to get a new crank on eBay - or crank set, as the case may be. (I'll have to cut the old crank to get the pedal. )

Earlier I did explore the Helicoil costs - the LBS quoted $30-35 for a straight forward coil insert.
They were not adverse to doing it, and did not try to sell me a new crank.
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Old 03-08-10, 05:55 PM   #19
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Roughly 1/2 the lower priced bike I buy to rehab or as parts donors come with at least one crank arm partially stripped. The big tip off is HOW HARD it is to get the freakin' pedal off. How the installer managed to not notice how hard it was to install-no idea!!

I've had good luck running a tap thru-usually just the first 1-3 threads are shot.

You might get lucky, and get it out with some of those "modified threads" in good enough shape to hold a pedal.
Luck
Charlie
Thanks Charlie - I hear you - but this was doubly frustrating because it is not a low end bike. You would think they would have exercised some care - or not allowed some shlemiel to assemble it.
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Old 03-09-10, 07:15 AM   #20
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Now you know WHY the previous owner was "not disposed" to do his own work -- likely did this, realized the major screw-up, and left any/all other work to more qualified folks.
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Old 03-09-10, 07:50 AM   #21
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WOW-managed to chew up a good wrench?? Guess those chrome moly spindles are tougher than the wrench jaws.

This is a lost cause, but sometimes, you can get these things loose by working them back in forth over that one turn it will turn.Maybe the aluminum chips/spirals that are jamming the threads will eventually loosen if you work it back and forth- 1.1 turn in- 1.11 turn out-1.11 turn in 1.2 turns out- 1.2 turns in -1.3 turns out- repeat /repeat etc.

There is close to zero chance that the crank will be useful, but maybe the pedal will- AND NOW IT HAS BECOME A POINT OF HONOR-MAN AGAINST PART!!
If you have already tried the in-out-in -out-in out- sorry to bring it up again-and maybe with maybe a hand impact driver( it might have a allen(allan??) on the inside, not that I expect an allen-5-6 mm of steel- to not snap off- but....

It is a Lost Cause-you have more sense than I do. I would chase this lost cause until a broke a couple more tools-then I would cut the pedal out

Frame this crank as some sort of cautionary lesson.
Luck
Charlie
PS You could also POUND,POUND with a thick flat punch(or allen with hand impact impact) on the inside end of the pedal -hope to crack up/deform/distort these " hand forged" new threads-go both ways-
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