How much heat build-up is normal on the rear axle?

[Sledge Hammer]

In a recent thread, I mentioned that I had come back from a 30 mile ride and rear wheel was hot to the touch. I also had found that the head of the axle (outside the swing arm on the left side) was hot to the touch but the axle nut (outside of the swing arm on the right side of the bike) was barely warm. I did wind up pulling the wheel and found the right wheel bearing was bad for sure, and the dealership replaced both sets of bearings on the wheel and the set on the driven flange, but after I reinstalled the wheel (torquing the axle nut to where it felt snug at 50 lbs-ft and adjusting the chain for 1.1" of upward deflection on the bottom run of chain) and went for a eight-mile test ride this morning, I noticed the same trend:the front tire was barely warm but the rear (at about 42 psi) much warmer than the front; the axle is much warmer where it passes through the swing arm on the left side of the wheel than it its where is pass through the swing arm on the right side of the wheel; I do not hear any groaning from the rear wheel, just chain noise.

Does this sound like I goofed something up and pinched the races on the bearings? Something else that I overlooked? Normal? I would welcome input from anybody more mechanically savvy than I am.

[tmds3]

Just wondering if the chain is getting as hot? If getting really hot maybe transferring heat from the engine? Don't know if that is something you looked at or if it is possible to transfer as much heat as you are getting.

[TLRam1]

Anyway you can check the temps Mike? If so maybe Lawrence, Robert or someone with a temp gauge can check theirs after a ride for comparison.

I have never thought or inclined to check the axle as yourself. When you say hot, is it burning hot to the touch, warm.... does your back tire spin freely if off the ground, may let the dealer who replaced the bearing jack it up and see if he deems something wrong.

Is your tube between the bearings bent, warped or the ends flattened where it would not give good support? This tube keeps the torque off the bearings. I take it the rear wheel alignment is good.   

Did you replace all 3 bearings?

[Greg Cothern]

http://www.troybuiltmodels.com/items/PXTPE1.html is a pretty neat small temp gun that I have used for my RC stuff.

If you do not have the rear adjusted to run straight it can cause this, in other words, if when adjusting the chain etc you got the rear tire turning left or right then heat will build up.. 

I bought a neat (expensive though) laser chain alignment tool that makes this adjustment easy to get perfect.  http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=282571&store=&catId=&productId=p282571&leafCatId=&mmyId=  have used it a few times and as long as you remember to turn it off and not run down the 2 watch batteries it works great!!!

[Sledge Hammer]

Just wondering if the chain is getting as hot? If getting really hot maybe transferring heat from the engine? Don't know if that is something you looked at or if it is possible to transfer as much heat as you are getting.

The chain and sprocket do not seem to be getting quite as hot as the end of the axle, David, but that is based purely on what my fingertip is able to sense.

[Sledge Hammer]

Anyway you can check the temps Mike? If so maybe Lawrence, Robert or someone with a temp gauge can check theirs after a ride for comparison.

I have never thought or inclined to check the axle as yourself. When you say hot, is it burning hot to the touch, warm.... does your back tire spin freely if off the ground, may let the dealer who replaced the bearing jack it up and see if he deems something wrong.

Is your tube between the bearings bent, warped or the ends flattened where it would not give good support? This tube keeps the torque off the bearings. I take it the rear wheel alignment is good.   

Did you replace all 3 bearings?

It isn't what I would call hot to the touch, Terry, and even with the chain in place, I can get the back tire to spin through three or four revs in each direction after a good pull on the tire.

By "tube between the bearing", Terry, do you mean the tube that sits between the left and right wheel bearings inside the hub? If so, I have no way of knowing because I did not see it when it was out, but it seemed to roll freely prior to installation and there was probably 1/32 of freeplay between it and the bearings. Rear wheel alignment is as good as I can get it: ~ 19 threads showing on either chain adjuster and showing the same hash marks in the windows on the swing arm.

I did replace all three bearing sets.

[Sledge Hammer]

http://www.troybuiltmodels.com/items/PXTPE1.html is a pretty neat small temp gun that I have used for my RC stuff.

If you do not have the rear adjusted to run straight it can cause this, in other words, if when adjusting the chain etc you got the rear tire turning left or right then heat will build up.. 

I bought a neat (expensive though) laser chain alignment tool that makes this adjustment easy to get perfect.  http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=282571&store=&catId=&productId=p282571&leafCatId=&mmyId=  have used it a few times and as long as you remember to turn it off and not run down the 2 watch batteries it works great!!!

So that's what you've been using, Greg! I tried using a laser level, and that was a bit of comic futility. I may take a ride up to the dealership tomorrow to let them check it out. It seems to me I am hearing more noise than I would expect from the front sprocket area, and I would hate to find out my front sprocket bearing is about to go. Of course, I can't checj that because the bolts are stuck. It's one thing after another...

[lragan]

Of course, I can't check that because the bolts are stuck. It's one thing after another...

I have this handy-dandy impact screwdriver, to which I can fit sockets, that you hit with a hammer.  It pushes in and twists at the same time.  Gets most stuck nuts/bolts/screws loose in a heartbeat.

If it fails, I also have a set of "easy-outs" to remove the bolt after I break the head off!!

Unless the swing arm is bent, the tire and chain should run straight if the chain wear markers in the windows of the swing arm, just aft of the rear axle bolt, are set at the same indicator mark.  Not as precise as a spinning laser, perhaps, but according to the manuals, should be good enough.

I don't see how it can have anything to do with the problem, but I discovered that the torque on the swing arm bolt, which is buried under the round chrome covers where the swing arm attaches to the frame, were torqued way above spec on my bike.  I suspect it came from the factory that way.

Hang in there, Mike, if it was easy, then anyone could do it. 

[Capt. Howard]

Of course, I can't check that because the bolts are stuck. It's one thing after another...

I have this handy-dandy impact screwdriver, to which I can fit sockets, that you hit with a hammer.  It pushes in and twists at the same time.  Gets most stuck nuts/bolts/screws loose in a heartbeat.

They have at Harbor Freight that handy driver...Called an Impact Driver 3/8 drive. Not expensive as my snap-on and does the same job.I have both. Also bought a laser light with magnet on it reasonable..Real handy..Also when you talk about the heat or temp. how does it compare to the ignition key temp. It gets pretty "HOT". Just another thought. I will check mine tomorrow morning when I get back from breakfast. My chain is lose and needs lubed. Should get warm or maybe "HOT"..I think some heat is expected..but I'm curious....

[Sledge Hammer]

The impact driver  -- as recommended by Lawrence, Capt. Howard, and a friend of mine at work -- did a wonderful job getting two of the three sprocket cover bolts loose. It would have been nice if the top bolt head hadn't stripped out, but two out of three ain't bad, especially since the two that I did get loose were the least accessible. Working on a strategy now for the top bolt to try to avoid using an extractor, but I have those, too.

I splurged and bought an IR thermometer hwile I was at Sears that was a bit pricier than the one Greg recommended, but with a 8:1 distance to target ratio should allow me to follow the trail of heat build-up a little more precisely. Once I get the bolts replaced and get the bike out on the road again, I will be better able to to tell you how hot is "hot."

[Magnum Magna]

When I first got the Magna I went 3 or 4 weeks before oiling the chain.  I road it to work (20 minutes / June) The chain was so hot that the spray oil boiled as it hit the chain.  I now oil it every other tank about every two weeks.  I have never had the oil boil hitting the chain again.  I will get my temporary gauge and some time this week I will record the temperature of the chain, axle bolt, brake hub,  and rim touching the tire. 

[Chad in Michigan]

I rode mine today after new tires and chain for about 50 miles. tire was warm, right side of axle was not warm at all, the rim was pretty warm, and the left side of the axle was about as warm/hot as the rim. Maybe your rear brake is dragging and/or not releasing properly? spin it both front and backwards and listen for squealing slightly and feel or notice any drag. I noticed when i reassembled mine to where I like the brake pedal, it was dragging. I loosened it up to where it didnt drag at all, and gently worked the brake pedal more than usual and drug it ligtly for a hundred feet or so at every light. came home, readjusted a few turns tighter to where I like it, and no more drag or noise from the rear wheel.

[Sledge Hammer]

I rode mine today after new tires and chain for about 50 miles. tire was warm, right side of axle was not warm at all, the rim was pretty warm, and the left side of the axle was about as warm/hot as the rim. Maybe your rear brake is dragging and/or not releasing properly? spin it both front and backwards and listen for squealing slightly and feel or notice any drag. I noticed when i reassembled mine to where I like the brake pedal, it was dragging. I loosened it up to where it didnt drag at all, and gently worked the brake pedal more than usual and drug it ligtly for a hundred feet or so at every light. came home, readjusted a few turns tighter to where I like it, and no more drag or noise from the rear wheel.

Thanks for the feedback, Chad. Sounds like the heating I noticed is fairly normal. I bought an infrared thermometer, so I will soon be posting measured temperatures.

[Sledge Hammer]

Of course, I can't check that because the bolts are stuck. It's one thing after another...

I have this handy-dandy impact screwdriver, to which I can fit sockets, that you hit with a hammer.  It pushes in and twists at the same time.  Gets most stuck nuts/bolts/screws loose in a heartbeat.

If it fails, I also have a set of "easy-outs" to remove the bolt after I break the head off!!

Unless the swing arm is bent, the tire and chain should run straight if the chain wear markers in the windows of the swing arm, just aft of the rear axle bolt, are set at the same indicator mark.  Not as precise as a spinning laser, perhaps, but according to the manuals, should be good enough.

I don't see how it can have anything to do with the problem, but I discovered that the torque on the swing arm bolt, which is buried under the round chrome covers where the swing arm attaches to the frame, were torqued way above spec on my bike.  I suspect it came from the factory that way.

Hang in there, Mike, if it was easy, then anyone could do it. 

[lragan]

Way to go, Mike.

Did the extractor mess up the bolt head?  Small price for a new bolt, given that you did not have to drill it out, just curious.  My tool is not exactly like the one in the picture, which looks to be more effective.  Where did you get it?