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

[Chad in Michigan]

LOL   I am now deflated, woosh!

[roboto65]

 

[Magnum Magna]

I apologize for taking so long but had issues at work.
Chain, rim by tire, and brake drum were all around 30 C = 86 F out side temperature was around 95 F.
The temperatures where dropping fast, actual temperatures I would suspect was closer to 95F.  It took me two or three minutes to get my meter to check the temperature.

A little different then Sledge Hammer measurements but not by much

[Sledge Hammer]

I apologize for taking so long but had issues at work.
Chain, rim by tire, and brake drum were all around 30 C = 86 F out side temperature was around 95 F.
The temperatures where dropping fast, actual temperatures I would suspect was closer to 95F.  It took me two or three minutes to get my meter to check the temperature.

A little different then Sledge Hammer measurements but not by much

I apologize for taking so long but had issues at work.
Chain, rim by tire, and brake drum were all around 30 C = 86 F out side temperature was around 95 F.
The temperatures where dropping fast, actual temperatures I would suspect was closer to 95F.  It took me two or three minutes to get my meter to check the temperature.

A little different then Sledge Hammer measurements but not by much

Interesting data points, Robert. Was your bike garaged before your ride (since the temps were lower than the outside air temp)?

I checked mine again after riding in to work at about 70 mph in about 65°F air: 115° on the tread, 101° on the sidewalls on the rear tire; 101°F on the tread; 92°F on the sidewalls on the front tire; around 116°F on the axle head and 95° on the axle nut. In other words, reasonably comparable heat rise despite much longer time at high speeds (I think I can rule out bearing issues on the back now).

This issue came up in an ST1300 riders' forum last year. Looks like it is a non-isssue.

http://www.st-owners.com/forums/showthread.php?p=433138

[Magnum Magna]

It was under a bike cover.  I will try to check the temperature again tomorrow.  That surprised me also that it was cooler then the air temperature. 

[Magnum Magna]

Update

rim by tire, and brake drum were all around 46 C = 115 F
Chain 44 C = 111 F
out side temperature was around 95 F.

[Sledge Hammer]

Update

rim by tire, and brake drum were all around 46 C = 115 F
Chain 44 C = 111 F
out side temperature was around 95 F.

Seems like a comparable rise, Robert. Mind if I ask how far you rode before recording the temperatures?

BTW, I am not too happy with my Crapsman thermometer from Sears. The sighting laser has already gone out. Considering what that feature added to the cost, I expect it to last longer than two uses.

[Magnum Magna]

About 15 to 20 minutes average speed of 35 - 40 miles an hour.

[lragan]

My recollection of use of the remote reading thermometers is not good.  Very old data, as they may have somehow improved in the interim, but here goes:

What they measure is the infrared intensity.  They must then correlate this to temperature.  The emissitivity of the surface being measured is critical to this translation.  A bright white surface will not emit as much infrared as a black one, even if they are the same temperature, for example.  Bright chrome will not emit as much as a black surface either.

I tried one of these to understand the temperature of various components in an early solid state transmitter design without much success.  Wound up painting little black spots on the surfaces I needed to measure.  Made as much as 20 degrees (Celsius) difference.  Finally switched to a thermocouple, held against the surfaces in question with a plastic rod.  Got much more consistent results. 

With the thermocouple, conducted heat is measured (instead of radiated heat).  This is not without its detractors, by the way.   If the thermal mass of the measured object is on the same order as the thermocouple, then it doesn't work well.  But for the bike parts in question, it should give good results.  More tedious to use, perhaps, but less expensive, too.

[TLRam1]

Robert,

What are you using to measure yours with? I still would like to measure my regulator temps with the added aluminum plate added to the backside.

[Magnum Magna]

I have an attachment that I plug into a DC millivoltmeter.  I touch the probe tip on what you want to measure.
We can check your regulate temperature.

[lragan]

I have an attachment that I plug into a DC millivoltmeter.  I touch the probe tip on what you want to measure.
We can check your regulate temperature.

It is highly likely that your attachment is a type K thermocouple.  They are quite accurate.  You can confirm this by placing the tip in ice water (both water and ice present in a container for a few minutes) and in boiling water.  Mine are correct to 0.1 degree C, and I bet yours are too.

[TLRam1]

I have an attachment that I plug into a DC millivoltmeter.  I touch the probe tip on what you want to measure.
We can check your regulate temperature.

Wonder if I have a place on my Volt-Ohm meter for one and where I could get a probe.

[lragan]

Wonder if I have a place on my Volt-Ohm meter for one and where I could get a probe.

I tried to send you one, including the meter, but the PO lost it.  I would recommend buying the meter with the correct connection on the face.  Because thermocouples are necessarily made of two different metals, it is really easy to create another thermocouple at the meter, and you wind up measuring the difference between the temperature of the probe (the intentional thermocouple) and the one you inadvertently created at the meter when you connected the wires. 

Here is the link to the unit that was lost:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95670

It is the only one I found on their web site with the temperature function.  Maybe you could use the tach, too, I don't know.  The one I use was maybe $25.  I don't see it in the current offerings.

[Magnum Magna]

Fluke 80T-150



https://www.techrecovery.com/ccp1565-fluke-80t-150-temperature-probe-80t-150-54.htm