29 Tips For Trials.

[litew8cub]

These are some tips collected and tried during many decades of fooling with bikes, particularly Cubs. I wish to write them down while I still can, and pass them on to newbies, so they don't have to reinvent the wheel multiple times without end, and perhaps to recall some of them for us oldies.

Litew8cub's 29 Tips.

1) To properly get a good solid purchase and avoid slipping and damaging very thin nuts as found on top of fork tubes, steering stems, clutch hubs, gearbox output sprockets, etc, I have found it very helpful to grind away the ends of my sockets, removing nearly all of the radius leading to the nut cavity, so more of the socket and nut flats are in good contact.

2) BSA and Triumph factory brochures always show the kickstart cotter key nut installed towards the front of the bike. A careful analysis reveals that the heaviest kickstart load is thereby borne by the narrowest part of the cotter key flat! BAD! If the cotter is inserted from the front of the bike, with the nut at the rear of the kickstart lever, the heavy load will be applied to the wide end of the flat, thereby vastly reducing the loading, the stresses, and potential problems with loose levers. The available kickstart lever range of motion will be slightly reduced because the pedal is now rotated slightly farther back, and you must carefully check that the relocated nut does not gouge the engine side cover.

More musings---I may remember from years ago that bicycle crank cotter pins were soft and useless for us--Proper motorcycle ones were harder, and could be identified by a circumferential groove just below the non-threaded end.

Also, it is easy to make a much more durable replacement by hand- merely use a better grade 3/8 dia bolt (allen bolts are ideal-good steel, tough, properly heat treated, and may have a slight case hardening), file or grind an angled flat with the wide part of the flat right into the bolt threads- even with a portion of the thread diameter filed away, this is still a LOT stronger than the puny 1/4-26 threads of the "proper" item- now just trim the bolt to length at both ends,and you are probably done. If the nut gouges the side cover surface, just take a smaller 5/16 nut, drill & tap it to 3/8.

Always try to support the kickstart lever boss when installing or removing the cotter, and use a drift to transfer the blows to the end of the cotter and keep the hammer away from the cases. I find things tighten up really nice if you keep tightening the nut while gently tapping. You only need 3 hands and a knee on the k/start lever.

Some of my old Cub k/start assemblies are worn so that the full diameter of a 3/8 bolt just goes right through- it takes surprisingly little wear!- a shim made from a piece of hacksaw blade to fit between the flats of the cotter and the k/start spindle has served me for decades.

3) Since the previous owner did not keep the pinch bolts for your bike's finely splined gearshift, brake, or Bantam kickstart levers tight, they are now permanently floppy, even when you hack the slot wider on the non-threaded side, and use a high-tensile bolt to replace the one that broke in a desperate mending attempt. The problem is that the splines on each side of the pinch slot resist the bolt tightening forces. The cure is to file away 3 or 4 of the splines on each side of the slot, allowing proper tightening. Unfortunately the thin kickstart sleeves for the Bantam and Can-Am are crushed by now, and shift the engine into gear when you kick it!

4) I have found there are 2 types of tyre valve stem cores- long and short--I have only recently come across my first long one which was bad, but I have garbaged dozens of leaky short ones, usually very slow leaks!

5) A hypodermic needle filled with heavy engine or gearbox oil is perfect for oiling control cables (the thin needle will go right in between the inner cable and outer sheath) and it is very easy to place a minute spot of lube right where it is needed, even in very tight inaccessible places, such as control lever pivots and pull cable barrel ends. I also use them to supply a bit of fuel into the sparkplug hole or carb to start a reluctant engine-much safer than dribbling fuel from a large container! I have found that the ones using an "O" ring seal on the end of the plunger tend not to dribble or be affected by oil or fuel, whereas the ones with a rubber cap on the plunger end are problematic.

6) Years ago, even the cheapest Japanese bicycles brake levers had a little pin-hinged stirrup into which the brake cable end fitted, avoiding all bending and eventual breakage of the cable end. I use them on some of our bikes. When I repaired my own cables, I used to heat the end strands red-hot to try and burn off the oily gunge and make the strand ends easy to spread out and solder. Bad idea! The ends then break off easily because the inner strand have been burned. The best idea I have come across is to insert a small shoe tack into the cable end after the strands have been frayed out inside the end fitting counterbore, apply lots of zinc chloride paste flux (corrosive!) to the heated cable end, then solder.

7) A quick PERMANENT emergency repair insert for a stripped 5/16 or 8 mm threaded hole can be made from the threaded end of a 10 mm spark plug. Use a 9 mm or "T" drill to clean out the ruined threads in the hole, tap the hole 10