Saturday, August 14, 2021

'64 BSA Lightning Rocket - Building Wheels

The wheels on the Lightning Rocket were in vastly different condition front to rear. The front was close to as new condition as you hope to find while the rear wheel was quite crusty. One thing I have learned is to spin the rims to an indicator to see how true they run before breaking them down. It is much easier to check them at this point than when they are laying in parts on a bench.

Overall pretty good shape although a few rust spots through the chrome sealed its fate. 

Pretty crusty....no question what to do here...off for new chrome....

The spokes looked good but were rusted in the nipples. Many broke off upon disassembly. They were discarded for new stainless items from Buchanan's Spoke and Rim. The rims were re-plated as they were not pitted into the base metal to badly and were straight. I prefer to reuse the original rims when possible but I always question this while I am paying for plating and trying to indicate in old rims....

My "custom" wheel prints to guide my assembly. The factory workshop manual also has offset specs.  

The rear rim ready for assembly.

Although the front brake drum was slightly grooved it probably could have been used as is. One thing I have found with 50 year old castings is that they tend to relax over the years which is probably brought on by all of the heating and cooling. Truing them removes the pulse you can experience with these old units. Very little material was removed on this drum which translates into brake shoes that will be fit with minimal sanding.

Skimming the front drum to improve brake performance. 

Building the wheels was pretty straightforward having done the task several times previously. It is one of the parts of the build I find very satisfying. Having taken notes on the wheel offsets, spoke alignment, having photos and another BSA for a pattern made the job a snap.

Lacing the front wheel with Buchannan stainless spokes and nipples.

The rear wheel was laced to .03 TIR which matched what it had prior to disassembly and I could not improve upon it. Spokes were torqued to 30 inch/lbs. I found specs from 22-80 and settled with 30 which was close to my original bikes and seemed quite tight. I think 80 would have been too much while there is a lot of support for 35-55 on the net......The front rim was a different animal. I used "feel" to get the spokes to where they rung and the hub was at the proper offset.  A check with the torque wrench showed them at 24-26 which seemed plenty tight.  

One puzzling thing on the rear wheel was the fact that it possessed threads for a speedo drive. The '64 BSA had an engine driven speedometer while the '65 had a rear hub drive gear. My bike had the transmission gear and the hub drive threads. Odd. The bike was built at the very end of the model year and I believe the combination of parts came from this bike being caught up in the changeover. 

Hidden under the hub dust cover are threads to mount a rear wheel speedo drive. A sign that '65 model year parts were starting to work their way into the assembly line or did someone put on a later wheel? 

BSA used 19 inch rims front and rear in 1964. My newer BSA's used 18 inch rear tires and I was tempted to update the 64. After pondering the situation I decided to stick with the stock rims as the 19 inch rims front in rear on my Norton work well. I also stewed over which size tires to fit. The '64 had a 3.25 front with a 3.50 on the rear. I like the steadier feel of the 3.5 on the front of my Hornet but eventually decided to go with what the BSA folks sent from the factory. A lot of thinking for something so simple. I can't wait to take it for a spin and see how all that pondering worked out.

The brake shoes were fit by taping sand paper into the drum and lightly working out the shoes. I have done this on the bench in the past but find I get better results with the wheel mounted to bike. 

The "marker" cross hatch has been mostly sanded through. 
The brakes are fit and ready for a road test...

Tire dilemma behind me, brakes fit and hub assemblies sorted. 
Time to line up fenders and tighten things down...

The completion of the wheels closes out the majority of the chassis build. Now it's on to the rebuilding of the power egg which is a job I rather like. The LR should be on the road by spring of 2022.....