Sugino 75 stripped...
 

I raced an alley cat in a downpour on Sunday.

Went in to service my BB and the puller yanked all of the extraction threads on the drive side. I'm super bummed, as I bought these cranks 4 weeks ago. I'm almost wondering if I may be able to figure out some kind of warranty deal with these, but it's unlikely.

So I'm needing a new drive side crankarm, 165mm, silver. If anyone has a lonely drive side, PM me.

Wow. How the heck did that happen? I'm an ersatz mechanic but I've never done that. Do tell. I promise to laugh WITH you.

Using park ccp-2, the threads literally pulled out with the puller.

So, I had the puller threaded in, and when I was backing it out to pull the crankarm, the puller walked out with the extraction threads. I've never done this to a crank arm before and it makes me question the quality of this set.

you get what you pay for.

get a sealed BB, no service needed.

ride it around without the crankarm bolt in it.
it will eventually loosen.
also, park makes a tool specifically for this (stripped crankarm threads.)
the tool looks like a hex nut with threads and threads into the crankarm while recutting the threads.
i know a certain shop in the dallas suburbs that has this exact tool.

it's in a part of town east of downtown dallas that's known for the rock wall.

That had to be cross-threaded, or not threaded in all the way or something right?

i bet you forgot to take out the bolt washer.....i almost did this last week

You still need to be able to pull the arms to replace the unit when it does die.

I wasn't being serious about it.

On my old crank set I partially stripped the threads because I didn't get the crank puller snuggly in there before I tried to extract it. Maybe you did the same?

Probably SOL on warranty replacement -- extractor thread problems are almost exclusively a result of "user error" and unless you can definitively prove otherwise that's what they're going to call it.

Some possible options for you:

If the threads aren't *totally* gone, you may be able to chase them out and get the extractor to work:

http://www.biketoolsetc.com/index.cg...item_id=BR-TC8

http://www.biketoolsetc.com/Product_Images/BR-TC8.jpg

Otherwise, there are tools to cut new threads at a slightly larger diameter, but they're expensive for a one-off job. Perhaps an LBS already has them:

http://www.biketoolsetc.com/index.cg..._id=VR-PE11000

http://www.biketoolsetc.com/Product_...VR-PE11000.jpg

http://www.biketoolsetc.com/index.cg...item_id=SN-CES

http://www.biketoolsetc.com/Product_Images/SN-CES.jpg

Hey mr. robot,

what is said name of the elusive shop near the rock wall, is it rockwall cycling?

And no, the threads weren't crossed. The tool threaded in smoothly; it was the action of the puller pushing against the spindle that caused the crank arm to barf it's extraction threads. Basically, the puller walked out and the threads sprung off it in a bunch of coiled metal.

This isn't my first time using a crank arm puller on a ST crankset, I pulled the washer before I put in the puller.

John, thanks for the tool advice; I'll see if my LBS carries any of that.

Yeah sorry not trying to imply you're incompetent or anything, this is just completely unexpected. I've stripped threads on a crankarm before, but only when I didn't thread the puller in far enough or crossthreaded.

Crazy.

You could probably flush/clean it from the non-drive side, will be a PITA, but doable.

Ugh I know dude.

I'm so sick by this.

$200 set of cranks down the damn drain.

ianjk, I thought ab just removing the non drive arm and the adjustable cup, and using my 36mm headset wrench on the drive side cup and pulling it all out as a unit. It could work, but aside from that, I'm just wishing the equipment would hold up for simple maintenance like this in the first place.

Just make sure you have your new crank ready to install as this will ruin your crank arm.

Although I have never had this experience of thread failure with a crank arm, it has happened with other aluminum threaded parts such as the cases on my old Harley-Davidson. It is the result of bad metallurgy/machining in which the material becomes brittle and cracked when the threads are initially made, and is in no way the result of your actions. It is disturbing to see this sort of thing happen with a high end part, and I would expect better from Sugino. I still have and use 2 Sugino Mighty Comp cranksets from the 1970s, which have been pulled many times to service the bottom bracket without incident. I have yet to pull the Sugino 75 cranks on my 3 year old Bianchi Pista Concept, and hopefully I will not have the same problem you've experienced.

I did this once. It was my mistake because I didn't thread the puller in all the way. Did you thread the puller in all the way? You can tell if this is the case because if you did, then all of the threads will be destroyed.

This was already asked and answered man. Looks like he just got boned on some bad cranks.

Beware riding around waiting for it to loosen, you run the risk of rounding the taper.

fixed.

Did you grease up the threads? You gotta grease those threads and then thread the crank puller in deep before you start to torque it. I have stripped those threads before, luckily it wasn't on a $300 crank.

Anyways, crank pullers suck. I hate using them.

I have a complete set of silver Sugino 75 cranks if you have a nice, black crankset for trade??

Also, I agree it can be very dangerous to ride around waiting for it to loosen. I rounded out the inside of my crankarm taper doing that. I don't think there's really another way to get it off, though. The good news is that you will round out the inside of the crank arm LONG BEFORE you round out your BB spindle. So, if that crank arm is already toast, then it might not be that bad. Just make sure you're running a brake.

this makes more sense if the bb spindle wasn't greased before installation, and if the crank arm was drastically overtightened... but still... stripping out all of the threads from a new crankarm from a reputable company seems a bit unlikely without some other factors involved. crank pullers are some of the easiest tools to use. not ragging on you man, but this is just an unlikely thing to happen if you're doing things right.

there are obviously defective parts here and there as well. sorry to hear about this.

I'd definitely check into the repair system JohnDThompson mentioned. Even if you can't find a shop nearby with the tool, it may well be cost-effective to send the arm to a shop that does. If I'm understanding correctly, the plug installed after re-tapping would accommodate a regular extractor, so this one-time fix would put the arm back in service without having to replace the whole thing.

Right, but right now I'm thinking about how to pull the crankarm off without destroying it if I need to ship it off somewhere. I'm thinking about using a ball joint fork or perhaps an adjustable 3 arm harmonic balancer puller.

I use a light layer of phil grease on the taper before installation; I also lightly greased the puller. It yanked the threads out from the very bottom, so if you feel the inside of the arm where the extraction threads are, it's totally smooth.

Completely understandable that there's some skeptics out there, but I've removed and installed dozens of SqT cranks in my days. Again, I was surprised by how easily the things let loose. It was like pulling a cork out of a wine bottle.

Pedalling, let me know if you want to sell your set. Unfortunately I don't have any other spare square tapers lying around to fit an ISO, let alone any in black.