Wave washers?

[aldo5468]

On the bolts that secure the brake disc to the front hub and the sprocket to the rear hub, is anyone using wave washers instead of the stock folding tab locks? I'm thinking about possibly going to button-head socket screws next time a wheel needs to come off for a cleaner "look", but absolutely will not compromise safety. What is the bolt size?

 

[DogBunny]

Those bolts are M10-1.25.
I kept the stock bolts but put lock washers on mine (I think I got the idea from 5twins). Then I painted little alignment marks on each bolt head with a corresponding mark on the hub, so I could see if they ever start backing out. So far, so good.
Give your idea a try, and make alignment marks like I did.

 

[jd750ace]

I'm thinking safety wire if there's room.

 

[TwoManyXS1Bs]

Ditto on the safety wire. But you'll have to drill .040-.062" holes into hardened heads, acquire the safety wire and pliers, and learn the procedure. It's the route I would take.

 

[5twins]

I switched to stainless fasteners on both my wheels. On one, I went with button head Allens and wave washers, the other has normal hex heads so I re-used the lock tabs. I've had no problems to date but an alignment mark on those Allens does sound like a good idea. I figure a small dot with a Sharpie on the inside pointing at the axle should do.

The hex heads were a tight fit. The originals must be J.I.S. bolts because the head size is smaller compared to a standard metric M8 (12mm vs. 13mm wrench size). They do look sharp with the heads polished though.

 

[retiredgentleman]

While the lock tabs work fine, you can certainly use regular split-type lock washers. I now have the split-type lock washers on both brake discs and on my rear sprocket. With some anti-sieze and torqued to the proper torque number, they never back off. I've had my brake discs on and off several times, and have never found any bolts loose.

Using safety wire locking..................used on aircraft, and also used in Nuclear power plants.....................would seem to be overkill for a bike, but good for the guys that can't sleep at night worrying about loose bolts.

 

[jd750ace]

Using safety wire locking..................used on aircraft, and also used in Nuclear power plants.....................would seem to be overkill for a bike, but good for the guys that can't sleep at night worrying about loose bolts.

Not usually a term I would use (as you can probably tell from my posts!) but I like "THE LOOK"

My SV650 and Road Star's brake discs were originally installed with bolts that have the anti-vibration polyurethane dollop of crap on the threads, and they are a beast to remove the first time. I pull the discs every time I change tires to get them out of my way. I have never changed the bolts or used any kind of thread locker on them, just torqued to spec, and with nearly 120K miles between the two, neither has ever had a loose disc bolt. Every bike is different though.

 

[xjwmx]

My sprocket bolts constantly loosen and try to back out. They would back out even with the locking tabs; I think because the hole in the tab is large enough to let the tab bend move out of the way. I discovered that with three sides of the lock tabs bent up they wouldn't back out. They still loosen though, and I've just been living with that. Before I discovered the three sides trick one backed out and tore off my chain guard.

 

[jd750ace]

Wow! That makes safety wire sound like an even better idea!

 

[retiredgentleman]

My sprocket bolts constantly loosen and try to back out. They would back out even with the locking tabs; I think because the hole in the tab is large enough to let the tab bend move out of the way. I discovered that with three sides of the lock tabs bent up they wouldn't back out. They still loosen though, and I've just been living with that. Before I discovered the three sides trick one backed out and tore off my chain guard.

You should try using split-type lock washers, and torque to 27 ft-lbs. I little anti-sieze on the threads also.

 

[xjwmx]

^I know they won't back out with the tabs. You don't know they won't back out with the split washers.

 

[retiredgentleman]

^I know they won't back out with the tabs. You don't know they won't back out with the split washers.

I've been using the split washers for about 4 years now, and the bolts don't loosen at all.

 

[TwoManyXS1Bs]

Jd750ace: "but I LIKE the look!"

Everytime I would safety wire one of my props, I would stand back, admire the work, then cover it up with a spinner.

I wonder how many bikes here are using safety wired bolts...

 

[arcticXS]

Normally, a little Loctite 243 on clean degreased bolts, and torquing to the correct spec with a good, calibrated torque wrench should be more then enough. If a bolt loosens, I can not see that lockwire or locktabs will hold for very long. The benefit of wire or tabs is that a loose fastener is easier to spot.
If a particular problem fastener keeps coming loose, I would try "Nord Lock Washers". These are used as a pair, and requires VERY high torque to loosen the fastener after it has been tightened. I work offshore, and we use these in problem applications.

Also, longer bolts have more stretch than shorter bolts, so should be less prone to coming loose. So a good solution is to use a longer bolt, and machine a steel spacer sleeve to compensate.

 

[jd750ace]

If a bolt loosens, I can not see that lockwire or locktabs will hold for very long. The benefit of wire or tabs is that a loose fastener is easier to spot.

I disagree. The tensile strength of the preferred wire size for each fastener in motorcycle appropriate sizes is (generally, don't quote me!) as much as 50% of the torque value on the fastener, depending on diameter of course. A correct safety wire job will allow less than 5% of fastener rotation before arresting the rotation, and something would have to be failing in a major way to break the wire, or fall apart at that.
Have installed and inspected many miles of it in the last 26 years, and never seen a proper wire job break. I have, however, removed many, many safety jobs and found loss of clamp-up torque on the assembly. Good enough for flying in the sky, well good enough for flying on the ground. A couple of manufacturers (Dassault is well known for it) use lock tabs extensively as well, and forbid anerobic adhesives on the threads unless specific to the installation.

 

[aldo5468]

Thanks to all for the quick replies and suggestions. Like almost everything else with these great old bikes, there's different ways to do things and seldom just one "perfect solution". At this point, I'm leaning toward the stainless button-head Allen bolts w/ split-ring lock washers, marked after proper torquing. On a previous 650, I did have a couple of sprocket bolts loosen after having a new rear tire mounted in a local shop, so I'm a bit sensitive to the possibility and motivated to check the alignment marks regularly.

 

[jd750ace]

Haven't looked lately, but lockhart Phillips used to sell pre-drilled hardware in popular sizes for disc and sprocket installations. They also sell aluminum bodied nuts with stainless steel thread inserts for durability when frequently changing sprockets. Seems loosening is much more prevalent on the sprocket hardware than brake disc hardware.

 

[5twins]

I've encountered several rear mags with seized sprocket bolts, even some broken off. I was unable to remove the broken parts. No amount of heat, penetrating oil, EZ-Outs, etc. worked. Basically, the wheel was junk now. I highly recommend putting anti-seize on those sprocket bolts.

 

[xjwmx]

Yous guys who are using various bolts for the rear sprocket. Are you using bolts threaded all the way up to the head? Just curious.

 

[XSLeo]

articXS, longer bolts with spacers won't work well. On my 75 I put a thin flat washer and a split lock washer and used Allen head bolts, they almost hit the forks.
5twins, On the mags with broken bolts, Can you use a hole saw the size of the bolts, go deep enough to get the bolts out, Thread the hole for an insert or if too big then build your own inserts.
Leo