Hi all! The CR has had some good topics recently.Here's my take on some: All the commentaries as to our bike boom were on the money and when taken as spokes in the wheel the finished product is quite true. Thanks to all who posted.
On the Rally derailleurs. I agree that the Japanese shifters made for wide range were better shifting, but they all had a much shorter life span. But for average use recreational riding as most Americans practiced it, it didn't make much difference as they weren't used enough. Those heavier mileage riders just replaced them a little sooner and were happy. For Campy friendly types the slightly less response was an easy trade for the durability and when set up well the Rally performed just fine on most bikes. I found that people who had good touch in shifting fared much better with the Rallys. Don't ask me why but some bikes, chain, cluster and chainwheel combos didn't work right. When we played and moved parts around, bingo. I'm sure many of you who massage(d) the 1/2 step triple grannies know exactly what I mean.
Time to get shellaced. The posts on shellac brought an almost lost art to light. I don't think any one uses shellac anymore, glues like 3m and others have taken over the job. All the track riders I ever knew had at least 1 extra set of wheels to race with, or two complete track bikes and an extra wheel set at the races. At the six days or derbies we had two complete bikes and at least 2 sets of extra wheels, ALL shellaced. Usually when we had a flat on a shellaced tire we were able to pull the tire off at the puncture spot about 6/8 inches and open the tire, patch it and reshellac the tire without having to take the tire completly off the rim and redoing the whole wheel. This follows previous description on proper prep to build up the bed so it stayed on the rim. The sprinters and pursuiters who wanted to save weight took the base tape off and saved another 20 gms.+ or - and glued the tire (and stitching) right to the shellac. This made the tire hard to patch, and it usually got enuf use so that the tire was pitched after defect. It could take several weeks to properly prepare a wheel, but never heard of boiler room tactics. There was enough hot air and steam in the locker/mechanic rooms after races that the boilers were hardly necessary. Having a real thick, firm but not brittle bed was the key. When the tire and rim with their thin coats were stuck together and inflated to 80/90%, it took the stretch out of the tire without squishing the wet shellac out and it bonded so that the tire couldn't roll off unless the base tape and shellac didn't get along. It did not happen often, as the manufacturers tried to have everything compatible. The shellac tended to bond the base tape to the casing.
Perhaps this is a good time to mention the difference between track and road protectors. Track tires have a consistent thickness of rubber strip (protector), compared to road tires which have a tapered strip, thicker on the top and middle, getting thinner at the edges. Track tires handle more critically exact when the strip is of uniform thickness for control at high speed on steep banking. We even off-centered the tire a little toward the right to even out the wear and control because of the different angle at different speeds on the track, especially in team races. It took some of the pressure off the edge of the strip so it wouldn't loosen with slower riding and more acute angle at lower speeds.
Motor pace tire prep is even more critical because of the extreme speed
and pressure against the track at different angles.
The bed build up is the same. Motor pace tires are delivered WITHOUT the
base tape. No chance is left for a base tape to loosen. The tire is
shellaced and seated solidly into the shellac bed. If done correctly,
when a tire is removed the sewing will leave a tread like a fossil in
the shellac.
As to the linen bandage, it was done as a secondary safety factor. The
linen was glued to the casing just at the edge of the protector, nice
and evenly with the tire at 90% inflation, after the shellac had set.
The bandage was contoured to the tire and over the rim, the glue was
TIGHT and FLEXIBLE so it would not chaff the casing and puncture! The
first layer was cut in with a scissors at the nipples and laid over and
glued at the far edge of the rim. Then the other side was done with the
same procedure and overlapped the first layer to secure the taping. I
was taught by the old timers at the tracks in Europe, and did all my own
work, not wanting to trust my hi-speed wheels, even tho the guys were
cracker-jack mechanics, some thing one likes to do for ones' self.
Besides it kept me from chasing the gals. Idle hands are the devil's
plaything and all that jazz. Never had a tire come off, either.
Maybe Aldo can find that picture of the guys at the track burning the
shellac to soften it he had up some month's ago. It gave a little flex
and with a quick coat of shellac made it stick like hell. It was called
'burning the shellac' on. That's the vintage word/term of the week. I'll
try to post one oldie each week.
Too late to rubberneck the latex tonight. I'll try to catch you all
tomorrow.
Ted Ernst
Palos Verdes Estates, CA