loctite for crank splines?
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loctite for crank splines?
I still haven't done anything about my mr whirly left crank falling off, I keep putting off buying a new crank because I'd rather find a Surly dealer somewhere with a replacement crank in stock, but that takes research.
My buddy suggested why not just loctite red that mutha on there? And I thought, hey why not? The crankset is apparently a writeoff already, so if the crank has to be removed destructively, no loss. And if it works, I've got my bike back for maybe another month or year or whatever.
Thoughts? How well do I need to clean all the grease off? Should I go for red or green?
My buddy suggested why not just loctite red that mutha on there? And I thought, hey why not? The crankset is apparently a writeoff already, so if the crank has to be removed destructively, no loss. And if it works, I've got my bike back for maybe another month or year or whatever.
Thoughts? How well do I need to clean all the grease off? Should I go for red or green?
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Pinch bolt issue on the NDS arm? Heilcoil repair possible?
I don't see locktite helping bad threads or splines. If considering potential destructive removal of temp repairs, I would consider an epoxy, like JB Weld, Permatex Steel Weld, etc.
I don't see locktite helping bad threads or splines. If considering potential destructive removal of temp repairs, I would consider an epoxy, like JB Weld, Permatex Steel Weld, etc.
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Pinch bolt threads buggered, may be fixable with next larger bolt size and an undersized drill out of old threads and retapping.
Helicoil needs a much larger hole to be made for the insert.
As to the splines, this crank appears to have fine splines and a keyed area for crank location. If some of this is buggered then
using a space filling compound (loktite/epoxy) might work for awhile. For thin layers not much difference between the two,
both are relatively soft compared with metal, epoxy probably a little harder. Both can be damaged by heat so removal might
need a heat source that can heat the junction to 300-400F+ . Under normal cycling torque I think space fillers would only
work with a very small gap before coming loose. So a marginal repair. I assume the spindle is ok?
Space fillers require assiduous removal of grease, more than just a wipe-off for best results.
Helicoil needs a much larger hole to be made for the insert.
As to the splines, this crank appears to have fine splines and a keyed area for crank location. If some of this is buggered then
using a space filling compound (loktite/epoxy) might work for awhile. For thin layers not much difference between the two,
both are relatively soft compared with metal, epoxy probably a little harder. Both can be damaged by heat so removal might
need a heat source that can heat the junction to 300-400F+ . Under normal cycling torque I think space fillers would only
work with a very small gap before coming loose. So a marginal repair. I assume the spindle is ok?
Space fillers require assiduous removal of grease, more than just a wipe-off for best results.
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Hmm, nobody on the previous thread suggested that the pinch bolts might be stripped and failing to pinch. I hadn't thought of that. I'll pull those bolts out and try to have a look, but if there are not spiral aluminum threads actually falling out, is it easy to tell if that kind of thing might be the problem? When I retightened the pinch bolts on the trail, I did not perceive that either pinch bolt felt stripped.
One thing for sure, the end-cap for preloading the crank arm before tightening the pinch bolts, has some stripping. The threads can only engage when the crank is already pushed all the way on, you can't really use it to snug it up. I'm sure the first time the crank worked its way off (which may have been during my ownership or a previous owner) it took some of those threads with it.
"Pinch bolt threads buggered, may be fixable with next larger bolt size and an undersized drill out of old threads and retapping."
What about the possibility of just forcing the next larger bolt size right in? Would steel bolt threads just cut themselves new threads in the softer aluminum crank? I've never tapped before.
"I assume the spindle is ok?"
My understanding is the spindle is steel and the arms are aluminum, so it should be more likely that the problem would be in the arm. Certainly the spindle looks ok visually, but I know a problem like this would not be easy to see with the eye.
One thing for sure, the end-cap for preloading the crank arm before tightening the pinch bolts, has some stripping. The threads can only engage when the crank is already pushed all the way on, you can't really use it to snug it up. I'm sure the first time the crank worked its way off (which may have been during my ownership or a previous owner) it took some of those threads with it.
"Pinch bolt threads buggered, may be fixable with next larger bolt size and an undersized drill out of old threads and retapping."
What about the possibility of just forcing the next larger bolt size right in? Would steel bolt threads just cut themselves new threads in the softer aluminum crank? I've never tapped before.
"I assume the spindle is ok?"
My understanding is the spindle is steel and the arms are aluminum, so it should be more likely that the problem would be in the arm. Certainly the spindle looks ok visually, but I know a problem like this would not be easy to see with the eye.
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Not sure about thread pitch, but I believe the pinch bolts have 5mm heads, probably whatever the most standard metric size is.
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"Pinch bolt threads buggered, may be fixable with next larger bolt size and an undersized drill out of old threads and retapping."
What about the possibility of just forcing the next larger bolt size right in? Would steel bolt threads just cut themselves new threads in the softer aluminum crank? I've never tapped before.
What about the possibility of just forcing the next larger bolt size right in? Would steel bolt threads just cut themselves new threads in the softer aluminum crank? I've never tapped before.
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Red = permanent, Blue = medium, reversible, Green = medium to high strength, wicking (you can apply it after tightening the bolt, or for a sleeve).
Check out: https://henkeladhesivesna.com/blog/t...threadlockers/
The classic repair would use thread repair inserts, like Helicoils. To install those, you'd want a good drill press to drill and a vise to hold the arm. Drill. Then thread. Then put the coil or thread insert in using a tool. Not sure you have enough meat in your crank arm for this, though.
You might be able to do a temp job: I'd find longer bolts of the same size as your crank arm clamp bolts. Then find nuts to go on the ends. Then you should be able to get the current arm to work, but this would be reversible. You'd also have the nuts pretty visible and ugly, but its cheap and if you muck up the crank arm, you can remove it easily.
Using a steel bolt to form new threads would be called form tapping. Normally, you do this only in appropriate alloys that you know the heat-treat history of, using a hardened steel form tap. Can work fine if you had an untapped hole of the correct size in a the proper alloy. For a hole that's already drilled and tapped and has been rounded out, not a very good approach. Probably not a good approach for the Al crank arm alloy.
By the time you mess around finding the right threadlocker or adhesive, or Helicoil, you may be time and dollars ahead just buying a new crankarm.
Last edited by WizardOfBoz; 07-08-19 at 01:04 PM.
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Consider what will happen if you break the bolt off in the hole. You will have a steel screw stuck in a softer alloy hole; good luck drilling it out.
"I've never tapped before". That is pretty clear. Except for a deliberately designed press fit, "force it in" has no place in machine work.
"I've never tapped before". That is pretty clear. Except for a deliberately designed press fit, "force it in" has no place in machine work.
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Consider what will happen if you break the bolt off in the hole. You will have a steel screw stuck in a softer alloy hole; good luck drilling it out.
"I've never tapped before". That is pretty clear. Except for a deliberately designed press fit, "force it in" has no place in machine work.
"I've never tapped before". That is pretty clear. Except for a deliberately designed press fit, "force it in" has no place in machine work.
But if something goes wrong I dremel through the eye of the crank to get it off. A lost crank still lost.
Last edited by RubeRad; 07-08-19 at 02:03 PM.
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You might be able to do a temp job: I'd find longer bolts of the same size as your crank arm clamp bolts. Then find nuts to go on the ends. Then you should be able to get the current arm to work, but this would be reversible. You'd also have the nuts pretty visible and ugly, but its cheap and if you muck up the crank arm, you can remove it easily.
This would determine, anyways, whether the problem is in the pinch bolts, or as I originally thought, the aluminum receiving splines are worn or rounded or something and can't stop from rocking and eventually moving off.
Note also, I am a fattie and I use 20mm pedal extenders, so that exerts a probably unusual amount/direction of leverage on the crank. Surly always says, though, "fatties fit fine"
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The Mr. Whirly spindle is chrome-moly, the arms are 7075 aluminum, so any wear should be in the arms. But its hard finding parts (and a set of arms seems to be around 120 bucks) - is this still an item that Surly offers and supports? You may have better luck just finding a different make/model of crank.
The pics I saw look like the clinch nuts use a through-hole and not a blind one. Put the bolt in,tighten it a little. Then put the nut on the bolt where it extends and tighten it pretty good. Then torque the bolt, using a wrench on the backing nut. My goal with this advice is to preserve as much of the existing thread as you can.
If you are a big guy, and using extensions, this makes it extremely important to torque the clinch nuts down. Which I think reinforces what dsbrantjr says above.
The pics I saw look like the clinch nuts use a through-hole and not a blind one. Put the bolt in,tighten it a little. Then put the nut on the bolt where it extends and tighten it pretty good. Then torque the bolt, using a wrench on the backing nut. My goal with this advice is to preserve as much of the existing thread as you can.
If you are a big guy, and using extensions, this makes it extremely important to torque the clinch nuts down. Which I think reinforces what dsbrantjr says above.
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I called my LBS, they said they could not order me a replacement arm from QBP, so I don't think Surly is making/selling them anymore. Online listings also say out of stock
Instructions say that the pinch bolts should be torqued to 10Nm=7ft-lb, which seems laughably loose (drive side is 50Nm, like a normal drive side crank bolt). What would be the effect of over-tightening?
Instructions say that the pinch bolts should be torqued to 10Nm=7ft-lb, which seems laughably loose (drive side is 50Nm, like a normal drive side crank bolt). What would be the effect of over-tightening?
Last edited by RubeRad; 07-08-19 at 04:38 PM.
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Instructions say that the pinch bolts should be torqued to 10Nm=7ft-lb, which seems laughably loose (drive side is 50Nm, like a normal drive side crank bolt). What would be the effect of over-tightening?
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The instructions https://surlybikes.com/uploads/downl...structions.pdf illustrate what dsbrantjr has said. The DS bolt is like 14mm or so in diameter, and the cinch bolts are like 6. 10Nm for an M6 bolt is not laughably low.
There's a reason they make instructions! Follow 'em!
But unless you find a used crank or someone with some old stock of Mr. Whirly parts, I think you're gonna have to consider a different crank. Too bad, though, cuz "Surly Mr. Whirly" is like the best model name ever. But I think that there's better performing cranks out there.
There's a reason they make instructions! Follow 'em!
But unless you find a used crank or someone with some old stock of Mr. Whirly parts, I think you're gonna have to consider a different crank. Too bad, though, cuz "Surly Mr. Whirly" is like the best model name ever. But I think that there's better performing cranks out there.
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I don't need performing. All I need is not breaking. The biggest reason I would like to hang onto this crank if I can is the tiny bcd for the Surly 28-tooth narrow-wide chainring I bought which is still basically brand new. Nobody else makes a 1x smaller than 32 (that I can find)
Last edited by RubeRad; 07-09-19 at 09:09 AM.
#18
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Keep your eye out on eBay... the Local shop here has done several Motor Conversion, Mid Drives ,
Replacing the whole Crankset .. Just not on Surlys (so no Mr Whirlys getting listed) ..
But that is a source of no longer imported parts..
...
Replacing the whole Crankset .. Just not on Surlys (so no Mr Whirlys getting listed) ..
But that is a source of no longer imported parts..
...
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I googled Mr Wurly crank. (I hate these names..... made for a 6th grader) and a lot comes back saying that crankset falls apart.
Buy something new and different.
Buy something new and different.
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think big picture what is the bike worth? is it work it to replace the whole crankset? or cranset and bb if moving to another brand?
Also what happens if you kludge a repair and it goes south, fast and hard when you are riding? How good is your health insurance.
This is some thing to do right and not kludge
Also what happens if you kludge a repair and it goes south, fast and hard when you are riding? How good is your health insurance.
This is some thing to do right and not kludge
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(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)
#22
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bike is worth ~$1k, I'm just probably too stuck on the fact that I just bought the chainring, and I don't think anybody but surly ever made a 58bcd crankset, and it doesn't look like surly even sells cranksets anymore.
I guess now is the time to jump off the sinking (sunken?) ship of surly's proprietary bcd standard
I guess now is the time to jump off the sinking (sunken?) ship of surly's proprietary bcd standard
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bike is worth ~$1k, I'm just probably too stuck on the fact that I just bought the chainring, and I don't think anybody but surly ever made a 58bcd crankset, and it doesn't look like surly even sells cranksets anymore.
I guess now is the time to jump off the sinking (sunken?) ship of surly's proprietary bcd standard
I guess now is the time to jump off the sinking (sunken?) ship of surly's proprietary bcd standard
On the plus side, my neighbors are all jealous. We're the only ones with a gas stove around here.
Point is, you can get too wrapped up with one thing to see the big picture. Step back and check it out.
But if you can find a Mr. Whirly crank, used, it may be cheaper to do that. But they don't seem to be very durable judging by the reviews.
Good luck.
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