Red Loctite question...

[punga]

If one wanted to apply red loctite to a first gen. Octalink XT crank so that the drive side arm would refrain from loosening each ride, where would you put it? The threads of the crank bolt? The splines of the bottom bracket? The inside of my mouth so that I'll stop complaining? :p

p!

[mark w]

Do you have slop in the spline/arm interfaces? One of my biggest criticisms of the original octalink was the ability to wallow out the splines if you aren't really careful reinstalling your cranks. If that is where the problem lies (as it does on some of my older M-95x XTR cranks) dab some in the spline pockets on the spindle and tighten the arms on. The loctite will set up like plastic and eliminate the slipping back and forth which can loosen crank bolts. I usually make sure the bolts are lightly greased so that they don't get glued in place. If it's just the bolts backing out, I'd stick with blue. Something I got into a little while back is loc-tite stick. It's like a glue stick and lets you put the stuff exactly where you want it. Works a charm for building Mavic tubeless rims with the inserts. I do prefer the liquid for "alternate" applications like crankarm repair.

[Dirt]

Remember that when using loctite, all parts must be perfectly clean. Additionally, the release temp for red loctite is something like 550 degrees F. You won't get a second chance to do this.

Mark was right on the money.

Pete

[bkjoe]

fwiw, I cleaned the threads on my crank arm bolt and bb threads & applied red loctite on the bolt threads, figuring any more life I got out of the cranks was a bonus. That held last season fine and actually came off w/ a lot of leverage (cheater bar) when I went to work on it recently. So I put it back together the same way.

bk

[punga]

Do you have slop in the spline/arm interfaces? One of my biggest criticisms of the original octalink was the ability to wallow out the splines if you aren't really careful reinstalling your cranks. If that is where the problem lies (as it does on some of my older M-95x XTR cranks) dab some in the spline pockets on the spindle and tighten the arms on. The loctite will set up like plastic and eliminate the slipping back and forth which can loosen crank bolts. I usually make sure the bolts are lightly greased so that they don't get glued in place. If it's just the bolts backing out, I'd stick with blue. Something I got into a little while back is loc-tite stick. It's like a glue stick and lets you put the stuff exactly where you want it. Works a charm for building Mavic tubeless rims with the inserts. I do prefer the liquid for "alternate" applications like crankarm repair.

Mark, I'm not 100% where the slop is coming from, they need to be retightened fairly often and I think you heard them creaking the last time we rode at Wakefield. They're 2001 XTs and have a ton of miles on them, so I can't complain at this point about the wear and tear. They're going on my Soul Cycle as I've put a set of Firex on the Stumpy.



Remember that when using loctite, all parts must be perfectly clean. Additionally, the release temp for red loctite is something like 550 degrees F. You won't get a second chance to do this.

Mark was right on the money.

Pete

Pete, The cranks are self extracting; will I be able to get off if put the loctite on the splines using just standard tools? Or will I need a torch to remove them? It looks like Joe may have answered my question as I was typing ;)

p!

[Dirt]

Pete, The cranks are self extracting; will I be able to get off if put the loctite on the splines using just standard tools? Or will I need a torch to remove them? It looks like Joe may have answered my question as I was typing ;)

p!
Hey Punga.

The reason that came loose was probably because there was some dirt in there to help it release. If the metal is properly prepared, red loctite will not release. So maybe you need to clean the areas where you're using it pretty well, but not too well.

If your cranks last another year or two, then it was worth the risk. If in the end, you need to use a torch to heat up the cranks, that is a small price to pay. An inexpensive propane torch should do the job pretty well. If you're careful it won't even mess up the frame.

Pete

[mark w]

I always just left things "a little dirty" since I was using it more as a filler material than an adhesive. Make sure the threads on the spindle and the crankarm (self extractor socket) are still greased as you don't want loctite getting down in there. You also want to make sure you leave it time to set up before riding. As for breaking them loose, if you don't get any on the threads you shouldn't have an issue as the extractor pulls them straight off the spindle.

One way to check is to stand up on the pedals with the cranks level and then rotate them 180 degrees and stand on them again. If the splines are wallowed, they will shift just a little bit. This is what was causing my bolts to come loose as each time you turn the cranks, they rock back and forth a little bit.

[snapper]

My older XTs(2002?) were creaking and making me crazy. So I cleaned the splines meticulously with acetone and alcohol, applied blue removable strength loctite
and now my cranks are quiet. I seem to recall that loctite had a product(green) designed to fill small gaps in mating power transfer components such as pump shaft-coupling interface. That might work well too as it was advertised to be easily removal. I hope I can get my cranks off when the time comes without damage.

[Dirt]

I always just left things "a little dirty" since I was using it more as a filler material than an adhesive.
Yeah.... I come from an automotive background where cleanliness is the only way to build a really good motor.

[bkjoe]

I don't know why I was able to get the red-loctite bolts out w/o heat, just that I did. And I cleaned them w/ Perf. degreaser & a toothbrush before application - nothing's gonna hold as long as they're still greased up. maybe my loctite was old or something. it did take a good bit of force to loosen - I was half-expecting the bolt to shear. nothing beats luck, I guess.

bk

[CountZero]

FYI, in my garage I keep a little propane torch as a means to release loctite-ed parts. It's a good investment.

[BikerMiker]

TOMMY O IS ALIVE!

mike

[sevenforty]

I don't know why I was able to get the red-loctite bolts out w/o heat, just that I did.

Thread locker manufacturers don't always stick to the color scheme of actual Loctite...or sometimes there will be different strengths of "red" thread locker depending on the manufacturer. So you may have had some medium strength "red" thread locker. Red, heavy duty, loctite is overkill IMO for cycling applications...blue will be just fine.

[bkjoe]

nope - real Loctite. tried the blue first and it broke free after a while, that's why I tried the red. I was going to have to 86 the crank if it didn't work, so I had nothing to lose. It held and the bonus was I was able to break it free later. that was my experience. whatever. your results may vary.

[sevenforty]

Mmm, yeah, I've never heard of permament red thread locker coming off without all the hassle of applying heat. So that's why I was thinking that you may have some medium strength threadlocker that happened to be red. Color isn't a great guide to the strength of thread lockers.

[mark w]

To be specific...I used Loctite 262 (red) on my M-95x XTR cranks to help eliminate slop in the spline interface. The threadlocker hardened like plastic in the gaps but was able to be broken free with the normal self extractors. Any other combo and your mileage may vary. ;-)

[punga]

To be specific...I used Loctite 262 (red) on my M-95x XTR cranks to help eliminate slop in the spline interface. The threadlocker hardened like plastic in the gaps but was able to be broken free with the normal self extractors. Any other combo and your mileage may vary. ;-)

I think this is the route I'm going to go. I just need to be careful not to get any on the crankbolt or extractor threads. And clean out any old grease before applying. Thanks for the tips.

p!

[smdubovsky]

I've had red locktite come off easily w/o heat. Other than porsche 911 cylinder studs, I can't say I've EVER needed heat to get a bolt w/ thread sealant (that wasn't rusted) out. IMO, Red locktite isn't permanent on any decent sized bolt. That said, its still got to be overkill in aluminum. Be aware, that you probably f-up any aluminum part you apply heat too (500+ deg is well into the artifical aging temp of most Al alloys.)

FWIW, If you've wallowed out the octalink splines, you need the bearing retainer/gap filler stuff. I think its orange but its been a long time since I've used it (though I do have a bottle somewhere). Its designed to do EXACTLY that type of job. Red/Blue aren't designed for the task.

I did a quick search on the loctite board. Red 262 is rated to a whopping 16lbft of breakaway torque on a bare steel M10 bolt. Heat def not needed. Also, most bolts are zinc plated which looks to reduce the initial strength to 60%.

[sevenforty]

I guess I should have rephrased it...medium duty (red/blue) thread locker is all you need for most purposes. I know Honda makes some different thread locker/goo intended for their motorcycles. They might have some stuff that is applicable to what you are trying to do if you are looking for a really secure bond.

[macdaid]

Ok, this is a general question, so it's almost on topic:

If there is this issue of slop & wallow in the splined set ups, and locktite has to be used to correct it,

then why are splines better than square taper?
One would think, with all of those mating surfaces, it would be a rock solid connection.

Comments?

[Dirt]

Ok, this is a general question, so it's almost on topic:

If there is this issue of slop & wallow in the splined set ups, and locktite has to be used to correct it,

then why are splines better than square taper?
One would think, with all of those mating surfaces, it would be a rock solid connection.

Comments?
This was a problem for some implementations of some splined cranks... not a general indictment of all splined cranks.

There have been many square taper cranks that have had similar issues. Some were easily damaged if you overtightened the bolts. Others had general durability problems due to bad design or manufacturing defects.

I remember the headaches that the first generation 600ex road cranks gave. The shop I was working in at the time (1987?) sold a lot of bikes equipped with them and a very high number came back until Shimano got them right.

Pete

[mark w]

The damage to the splines is the result of self extracting designs allowing the crank bolt to engage before the splines do. This can result in a slight mismatch when cranking the soft Al arm onto a steel spindle and subsequent damage to the splines in the arm. Splined cranks in all their iterations are still better than square taper IMO but I am not usually worried about the common detractors to spline systems (shorter BB life due to smaller bearings and wider Q-factor). i also don't miss having to readjust my f.der every time I take my cranks off.

[smdubovsky]

common detractors to spline systems (shorter BB life due to smaller bearings and wider Q-factor)

I think you have one of those backwards. An external bearing splined BB has larger bearings. MUCH larger. It does have wider Q, but thats sortof due to the current designs of the cranks, not an inherent limitation of the external bearing BB system.

AFAIK, the current shimano octalinkII system wont wallow out unless you goofed up the install. Its a pretty straight forward pinch bolt system. It doesn't use a bolt to pull the system together like square taper & ISIS cranks.

[jfoley]

i think he meant the original splined internal BBs, which did have smaller bearings to make room for the larger hollow axle. i've never had any problems with the octalink (XT-75x & 76x) internal BBs i've had (and still use), but a lot of the ISIS BBs were notorious for wearing out very quickly.

these problems are WHY we now have external BB designs and BB30 (it's coming, embrace it) with room for a bigger axle AND bigger bearings...

I think you have one of those backwards. An external bearing splined BB has larger bearings. MUCH larger. It does have wider Q, but thats sortof due to the current designs of the cranks, not an inherent limitation of the external bearing BB system.

AFAIK, the current shimano octalinkII system wont wallow out unless you goofed up the install. Its a pretty straight forward pinch bolt system. It doesn't use a bolt to pull the system together like square taper & ISIS cranks.

[mark w]

I was indeed referring to the original splined stuff (Octalink and ISIS) Current external BB offerings seem to be very durable and 2 piece cranks are almost foolproof (Race Face and newest XTR excluded).