Rear Tire/Wheel Heat Build-up

Sledge Hammer · July 22, 2009, 12:21:04 AM

This past weekend, I took my Magan out for a ride of about 90 minutes. I was averaging about 35 through the towns I drove and then 70 on the highway about ten minutes. When I got back to house and got ready to tweak the rear wheel alignment (yet another story), I was stunned to find the rear tire was hot to the touch. The front tire was lukewarm at best, as I would expect given a ride in 80° weather. My first inclination was to think I had misadjusted the rear brake and that it was dragging, but two commutes later, the tire is still getting much warmer than the front and I was careful today to stay off the rear brake to avoid building up heat in the rear wheel that way.

What I observed today was that the area around the drum brake was cooler than the outer perimeter of the wheel. The heat was discernibly greater on the left side of the hub than the right, and the axle bolt head on the left arm of the swingarm was much hotter than the axle nut on the right arm. Chain tension is about 0.9" of deflection when on the sidestand.

I am suspicious of a bad left bearing but I would welcome input from anybody else with insight as to what is probably going on.

hootmon · July 22, 2009, 08:03:42 AM

Mike - I'm a little confused by your description... in the beginning you say your tire was hot, but you were concerned about the brake dragging, which would make the wheel hot. I also assume that when you say "left" side you mean "chain" side...
With that said... IF it were a brake thing.. I would expect the Chain side (left) to get hotter than the brake adjustment side (right side). The right side holds the shoes, the left side contains the wheel, and the drum portion of the brake system..
I'd get the rear wheel in the air (I use a jack on the right axel bolt to achieve this) and spine the wheel to see if the brake is dragging.. -
Now on my bike.. I've always had a little momentary brake drag when I spin the tire in the reverse direction, it does not matter how tight/loose the brake adjustment.. But no brake drag sound in the drive direction.. This test is harder now for me since I use Dyna beads in the rear tire..

I've never felt my wheel after a run... I don't know how much heat builds up from the chain friction either.. You seem like a guy that would keep his chain adequately lubed, so I'm assuming this is not the issue...

With all that said, and knowing that you have higher mileage on your bike.. I would agree with you that I would suspect a left bearing issue..

Magniac · July 22, 2009, 10:41:06 AM

Also confirm proper air pressure. Low pressure by even a couple of psi will cause heat buildup in a tire.

Sledge Hammer · July 23, 2009, 11:31:15 PM

Quote from: hootmon on July 22, 2009, 08:03:42 AM
Mike - I'm a little confused by your description... in the beginning you say your tire was hot, but you were concerned about the brake dragging, which would make the wheel hot. I also assume that when you say "left" side you mean "chain" side...
With that said... IF it were a brake thing.. I would expect the Chain side (left) to get hotter than the brake adjustment side (right side). The right side holds the shoes, the left side contains the wheel, and the drum portion of the brake system..
I'd get the rear wheel in the air (I use a jack on the right axel bolt to achieve this) and spine the wheel to see if the brake is dragging.. -
Now on my bike.. I've always had a little momentary brake drag when I spin the tire in the reverse direction, it does not matter how tight/loose the brake adjustment.. But no brake drag sound in the drive direction.. This test is harder now for me since I use Dyna beads in the rear tire..

I've never felt my wheel after a run... I don't know how much heat builds up from the chain friction either.. You seem like a guy that would keep his chain adequately lubed, so I'm assuming this is not the issue...

With all that said, and knowing that you have higher mileage on your bike.. I would agree with you that I would suspect a left bearing issue..

Hoot, the tire itself was hot and the wheel was hot, too. Presumably, the wheel heated up first and transferred the heat to the tire, though Dobie's point regarding inflation is well taken.

Now that I have reviewed everything I have done in the last couple of months, I think I may have been overtightening the axle nut. I have seen no less than three torque values in Honda's manuals for the rear axle nut. The shop manual calls for 63 lbs-ft, the '95 owner's manual calls for 69 lbs-ft on page 61, and the owner's manual also calls out 35 lbs-ft on page 90. I suspect the first two values are meant for dry torque and the last value for wet torque (now that I know to check for stuff like that, which I didn't when I started this exercise). The rub is that when I first got the bright idea back in April that it was time for this year's chain adjustment, I had had one heck of a time breaking the axle nut loose. Not wanting to go through that again since there were hints of rust on the axle threads, I had applied a think film of chian wax and then in my ignorance torqued the axle nut down to 63 lbs-ft. Now I realize that was "wet" torque and was probably compressing the spacers and bearings, which would explain the heat build-up. I may have trashed the bearings, though I did not hear any roaring noises when coasting it down my driveway into the garage with the engine off, but I will have perfect opportunity to replace them since I need to replace the left side's chain adjuster. I just hope I haven't put too much stress on the primary drive linkage.

I just got back inside from trying (unsuccessfully) to clean all the wax off the threads of the axel nut. I torqued it to 38 lbs-ft and will just have to ride carefully for a while to see if a) the heat build-up issue is gone, b) the bearings aren't complaining, and c) the chain slack doesn't increase.

Sledge Hammer · July 23, 2009, 11:37:50 PM

Quote from: Magniac on July 22, 2009, 10:41:06 AM
Also confirm proper air pressure. Low pressure by even a couple of psi will cause heat buildup in a tire.

True, and I keep a pretty close eye on tire pressure. I tend to run both tires at the rated upper limit of pressure.

The front tire is still wearing out quickly, but I think the fork tubes may be twisted a little, because I have to apply a slight amount of pressure on the left side of the bar to keep the bike tracking straight and have had to do so ever since I got it and started riding it. I am hoping that I can loosen the triple clamp bolts very slighty -- as was suggested on another thread -- and correct the issue that way. That's been the only thing about my Magna that has just made me crazy and I think I have been in error thinking I had a rear wheel alignment issue.

Sledge Hammer · July 25, 2009, 12:31:19 AM

Yep, definitely trashed at least one of the bearings on the rear.

The wheel catches and grinds as it turns. Since Hondaparts-Direct.Com seems to have folded, it looks like I'll be placing an order with Ron Ayers Motorsports to the tune of about $!75 for parts, some of which like the chain tensioning collar was on the list of replacement items needed anyway. At the risk of wasting money, I am going to order a replacement axle while I am at, just it case this one has been compromised. Probably unnecessary, but I'd hate to find out I economized and shouldn't: that could be A Bad Thing.

All of this has given me an idea for a way to make millions of dollars by producing my own gameshow. Coming this fall to some desperate network: Are You Dumber Than A Torque Wrench?

hootmon · July 25, 2009, 06:38:03 AM

Hey Mike.. I still don't understand the difference between wet and dry torque..
Can you elaborate a little??
Thanx

(So I guess the answer to your game show is YES)

roboto65 · July 25, 2009, 06:51:01 AM

I think I can answer that one!!! Wet torque is when you add a lube to the bolt or nut and dry is well Nothing added!!!!

Pretty sure thats it.

And as far as the torque thing goes not sure that did it! I mean I do not torque my rear axle bolts just get them TIGHT. I was under the understanding that the spacers contact the inside of the bearing not all of it would it not take a whole lot of muscle to distort the inner race that way?

Sledge Hammer · July 25, 2009, 04:28:40 PM

Quote from: hootmon on July 25, 2009, 06:38:03 AM
Hey Mike.. I still don't understand the difference between wet and dry torque..
Can you elaborate a little??
Thanx

(So I guess the answer to your game show is YES)

I didn't understand it, either! That's why I had to order new bearings, seals, etc. today. (At least the dealership's price was about the same as Ron Ayers Motorsports for everything, and I should get it faster through the dealership.)

Señor Rugg's answer is correct. Wish I had known that before I acted on the wrong answer. I'll bet my torque wrench knew better. This is the second time I have bungled something because of a false sense of security in using a torque wrench, and that's why...

"My name is Mike, and I am dumber than a torque wrench."

Sledge Hammer · July 25, 2009, 04:33:47 PM

Quote from: roboto65 on July 25, 2009, 06:51:01 AM
I think I can answer that one!!! Wet torque is when you add a lube to the bolt or nut and dry is well Nothing added!!!! Pretty sure thats it.

And as far as the torque thing goes not sure that did it! I mean I do not torque my rear axle bolts just get them TIGHT. I was under the understanding that the spacers contact the inside of the bearing not all of it would it not take a whole lot of muscle to distort the inner race that way?

One of my buddies at work (a professional mechanic in his previous career) said the same thing about tightening axle nuts and bolts by feel. He said there are only a very few things for which he uses a torque wrench, and axle nuts do not qualify.

Incidentally, the chief mechanic at dealership said the figure of 35 ft-lbs was way too light and (assuming a torque wrench is used), recommended a torque value of 65 ft-lbs.

Sledge Hammer · July 26, 2009, 12:37:08 AM

Quote from: Magniac on July 22, 2009, 10:41:06 AM
Also confirm proper air pressure. Low pressure by even a couple of psi will cause heat buildup in a tire.

By the way, Dobie, I should say that the centerstand is now paying for itself in spades. The bike is up on the stand now while I wait for the dealership to get in the parts to replace the bearings.

Charles S Otwell · July 26, 2009, 10:09:22 AM

Mike before you beat your self up over the torque wrench thing, consider that bearings do just fail without any fault of the mechanic. I don't personally believe you can crush or distort the bearing race or even the spacer, at least not with the axle bolt and nut. The bearing race is hardened steel, the spacers are just mild steel and you will strip the threads out of the axle nut long before you could put enough torque on it to do any damage.