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-   -   Crankarm Securing Bolt Stripped the Inner Spindle Threads (https://www.bikeforums.net/bicycle-mechanics/1015334-crankarm-securing-bolt-stripped-inner-spindle-threads.html)

kidcopernicus 06-23-15 10:31 AM

Crankarm Securing Bolt Stripped the Inner Spindle Threads
 
A little background: I ride an ON ONE Inbred with an internal Shimano 8, and it's kitted out for somewhat perilous urban riding - potholes, glass gravel, taxis, that kind of thing. It's also been doored twice in the past and lightly t-boned once, and it's an old warrior still fighting like Rambo on the .50 :bike2:


So, my crankset has been loose lately - started carrying an 8mm allen key, just to keep it on during a long ride. It wouldn't fall off, but it had way too much play after a couple miles.

Well, I should have looked into it. Yesterday the cranks actually fell off and I had to walk 5 miles across a very large city to get back home. :cry:

So, now I have a Race Face crankset with the alarmingly delicate inner threads of the spindle stripped (I will never understand why these delicate connections exist on a vehicle.) I take full responsibility for my situation - there is obviously a balance between spacers, BB, chain, my internal hub, 4-dimensional space, and Cthulu's Will that I just wasn't achieving.

Question: What are my options? Can I re-thread and pop in a slightly bigger bolt? Can I replace the spindle? Is there a patron saint of cyclists I can direct my supplications to?

Okay, I'm ready for the truth. How screwed am I? :twitchy:

FBinNY 06-23-15 10:38 AM

I suspect that you have a crankset where the spindle is integral to the right crank so you;re probably out a complete crankset. Stripped spindles are rare, so I don't agree that these threads are out of place on a bike crank. You might (barely possible) tap the spindle for a coil thread insert, but it's not a common size, and I don't know if there's enough meat to allow it to be done successfully.

So to answer your last questions, there is no god to appeal to, and you're royally screwed.

kidcopernicus 06-23-15 10:45 AM


Originally Posted by FBinNY (Post 17919166)
there is no god to appeal to, and you're royally screwed.


But the spindle IS a separate piece, no? What about warranty - would a company (RaceFace) be able to replace the spindle? The rest of the set is pristine. Can the crank arms be removed?

Coil insert - Helicoil? Hmm, again a bit delicate for that, but I will check their chart and see if I can order one. I've used them before on motorcycles.

Cheers

FBinNY 06-23-15 10:49 AM

The spindle is made as a separate part, but is pressed and bonded into the right arm (unless yours is bolted on -- the difference is obvious). On pressed in spindles, it is, in theory, posible to press one out and another back, but to my knowledge the spindles aren't sold, and nobody does the job that way.

Ronno6 06-23-15 10:53 AM

A photo might clear up any possible question................

kidcopernicus 06-23-15 11:02 AM

It's a RaceFace Atlas - it's pressed, there's no bolt holding the arm to the spindle.

INCORRECT IMAGE : Here's a shot from a site in the United Kingdom.

UPDATED VERSION: http://interbike.mtbr.com/wp-content...Face-Atlas.jpg

"Pressed and bonded". Got any more details on that process? What makes the bond - friction? Brazing? Just wondering..

"nobody does the job that way." Well, someone has that tech - the company that built it. Just sent an email to the warranty dept. We'll see if they can make all my dreams come true. I maintain a healthy skepticism, but it doens' hurt to ask - they are pretty new.

Incidentally, any pointers on why that may have happened to my crankset?

fietsbob 06-23-15 11:20 AM

If that is Your part there is a splined interface.. Race Face has been keeping up as best they could, to the latest trends .

and their External BB stuff is different from their earlier square Taper BB type arms .

If You stripped the threads eat the loss and go out and Buy a whole New crankset.

FBinNY 06-23-15 11:29 AM


Originally Posted by kidcopernicus (Post 17919254)
It's a RaceFace Atlas - it's pressed, there's no bolt holding the arm to the spindle. ...

A bit confusing. The photo you linked shows a more classic spindle bolted to both arms. On the more modern design the spindle is pressed through the right crank, and it's obvious that there was no bolt involved.

You're crank, if it's like your photo, should be replaceable as a separate part, along with new bolts for both ends.

A to why you're having this issue, loose crank bolts are like cancer. Once they loosen, the arm can shift on the splines. That movement causes wear and allows more movement in the future. The movement also walks the bolts back, and once the process starts and has a foothold, it can't be arrested and get progressively worse.

kidcopernicus 06-23-15 11:36 AM

Hold on, it's not the same. Thought that image showed the latest version. Mine is splined, but the bolt that connects the spindle is sunk into the spider and not removable. The other side of the spindle is NOT connected to the crank arm by any bolt.

http://interbike.mtbr.com/wp-content...Face-Atlas.jpg

FBinNY 06-23-15 11:38 AM


Originally Posted by kidcopernicus (Post 17919389)
Hold on, it's not the same. Thought that image showed the latest version. Mine is splined, but the bolt that connects the spindle is sunk into the spider and not removable. The other side of the spindle is NOT connected to the crank arm by any bolt.

http://interbike.mtbr.com/wp-content...Face-Atlas.jpg

In the linked photo, there appears to be a large black cap screw or bolt. Remove that and see what it's covering.

If you see the splined ends showing through the crank was pressed onto the spindle from the right. If you see what appears to be the rim of a flange, the spindle was pressed through the arm from the right the same as the one in the photo I linked.

kidcopernicus 06-23-15 11:54 AM


Originally Posted by FBinNY (Post 17919403)
In the linked photo, there appears to be a large black cap screw or bolt. Remove that and see what it's covering.

If you see the splined ends showing through the crank was pressed onto the spindle from the right. If you see what appears to be the rim of a flange, the spindle was pressed through the arm from the right the same as the one in the photo I linked.


It's non-removable as far as I can tell. - Wait, whoa.. Okay, just discovered how the bolt is attached, a small bit of 10mm over the 8mm hex slot. Clever. The bolt, not me.

So, brilliant, it looks like the failure happened mainly in the bolt itself. Which shouldn't be too hard to find. I'll have to report back on the state of the spindle threads, perhaps they aren't as stripped as they seem. Thought all that debris was spindle shavings - but the bolt is aluminium. I might have been wrong about the robustness of this gear.

Cheers for the help!


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