Donna planned to meet up with her good friend Julia in Fountain Hills yesterday. Julia was was house-sitting and taking care of two older dogs. We rode the Spyder to Fountain Hills and met Julia at the market near the gated community where she’s staying. Donna spent the night there so they could catch up and go out for a hike in the morning. I came home and had an uneventful bachelor night.

This morning I did some work on the Spyder. After changing the rear tire, I noticed the toothed drive belt was running too close to the inner shoulder of the rear pulley. It should have a minimum of 1mm clearance from the inner shoulder but shouldn’t run so far to the left as to overhang the outer edge of the pulley. Adjusting the rear wheel alignment to get the belt right is an iterative process. You loosen the rear axle, then move the axle adjusters and tighten everything up again. Then, after a test drive, you see if you hit it right.

Before I worked on the alignment, I checked the belt tension with a Gates Kriket II belt tension gauge. I ordered it from Amazon and received it a few days ago. It showed the belt tension was too high. This can cause vibration. So, the first thing was to get the belt tension right, then work on the belt alignment.

Krikit II belt tension gauge

My first attempt at aligning the belt didn’t provide enough clearance from the inner shoulder – I was too conservative with the adjustment. So I tried again. This time I overshot it and the belt rode too far to the outside of the pulley.

Too far to the outside of the pulley

It was a bit of a pain to go through the steps of properly torquing the rear axle, then loosen it and start over again, but that’s what it takes. It reminded me of the time I was building an engine for my friend’s race bike. Pat wanted to learn how, so one of the things I told him was, “You have to be willing to put things together, take measurements and then take it all apart and start over.” We were putting new main and rod bearings in the bottom end when I told him this. We assembled the crankcase with plastigage to measure the clearance. To do this, you have to completely assemble the crankcase – which also houses the gearbox on a motorcycle – then take it all apart to read the plastigage. When you confirm the correct clearance, you put it all back together again.

After a few more misses with the belt alignment, I had it. There’s about 3mm of clearance from the shoulder on the inner side of the belt and it doesn’t ride too close to the edge on the outer side.

Looking good

When I reassembled the axle, I used a torque wrench to tighten the nut to the specified 96 ft-lbs. I actually tightened it in two stages. First to about 60 ft-lbs, then to 96 ft-lbs. I often mention torquing lug nuts on our cargo trailer. Torque wrenches are handy tools to ensure fasteners are properly tightened.

My friend Pat – the one I taught how to build a motorcycle engine in the story above – worked on the production line at Boeing. The workers there all had to take mandatory training on the proper use and storage of torque wrenches. When they build airplanes at Boeing, proper torque on all fasteners is paramount.

The most common type of torque wrench is probably the “clicker” type. I have a few of these – mine are marketed by Craftsman. I have more than one, so I have the proper range of torque for the fastener I’m tightening. I have a small wrench calibrated in inch-pounds and two larger ones including a 1/2″ drive that goes up to 150 ft-lbs. There are fancier torque wrenches with digital readouts and audible beeps when the proper torque is reached, but the clicker type works fine for me. I’m guessing Boeing mostly uses electronic torque wrenches equipped with strain gauges nowadays.

Back to Pat and Boeing training. At Boeing, they told him to always exercise the torque wrench before applying the final torque. You do this by setting it to a lower value first and tightening the fastener until it clicks. This helps distribute the lube inside the wrench and makes for a more accurate final reading. Then you can set the value to the final torque setting and tighten until it clicks. It should only click one time. I see guys that click the wrench several times in succession – this isn’t proper.

Another important thing they taught him that many people don’t know is how to store the torque wrench. You don’t want the torque wrench to be dropped on the floor or bounce around loose in a toolbox. The most important step though is to set the torque setting on the wrench to about 20 percent of its highest value for storage. My 150 ft-lbs torque wrench is stored with the setting at 30 ft-lbs – 20% of 150 ft-lbs. At Boeing, they also calibrate their torque wrenches on a regular basis – I can’t remember for sure but I think he told me it was every six months. I check mine occasionally by putting two wrenches together with a socket on one and a hex driver on the other and see if they click at the same time.

That’s probably more than you wanted to know about torque wrenches, but I didn’t have anything else exciting going on this weekend. I managed to get a few games of pickleball in around midday. Tomorrow should be a good day for pickleball with cooler weather – the high is expected to be in the lower 70s.

*Just so you know, if you follow one of my links to Amazon and decide to make a purchase, you pay the same price as usual and  I’ll earn a few pennies for the referral. It’ll go into the beer fund. Thanks!