Had a busy couple days in the garage, and the Cub is now functional, though not yet finished. I took the boy for some test rides/stress testing today with a make-shift seat (16mm MDF and foam fixed in place with good old duct tape) and he loves it
We found a few issues, most fixable, one not. The non-fixable problem was an oversight on my part. While I made sure the BB boom was the correct length (and is in fact somewhat adjustable), I forgot about the "Flintstones" reverse method, and while seated on it, his legs don't
quite reach the ground. As such, he has to pretty much dismount to reverse. I should have foreseen this, and used 17" wheels on the front. Much too late to do anything about it now.
Another issue we found on the first test ride was to do with the rear wheel. I was given a Shimano Nexus 8 speed hub which I fitted instead of a 5 speed cassette equipped rear wheel, and planned to use a RD to allow the chain length to adjust to the BB boom, as well as routing the return side away from the chain stay. Unfortunately, this simply didn't work, as every time he back-pedaled the drive side went
very slack, and dropped off the idler (there seems to be more resistance in the internally geared hub than a cassette fitted hub) causing it to rub on the underside of the seat frame when he resumed pedaling. As the RD was only there to facilitate adjusting to BB boom and routing the return side of the chain, I just removed it and added another idler that both routes the chain off the chain stay and doubles as a guide for the drive side idler. This means when we get around to lengthening the BB boom, we'll have to add some links to the chain too, but as this will be an infrequent bit of maintenance I don't see it as a major bother. Oh, the hub is also missing the gear-changie-dealie piece (technical term), so it's currently a single speed, presumably in it's low gear. The gear-changie-dealie piece should be arriving at my LBS in a week or so.
I also need to fit new brake pads to the front brakes, as the existing ones came from scrapped 17" K-mart bikes, and are old, ill fitting, and less effective than I'd like. However, this is a 5 min job, assuming my LBS has some on hand. At least I don't have to worry about him tipping it forward and going over the front. Yet.
The last issue that showed up on the second test ride (after ditching the RD and re-routing the chain) was his left hand head stem. Seems no matter how tight the head stem bolt is (where it fits into the kingpin inner, the bolt that pulls up the triangle piece inside the fork tube... not sure what it's called) there is still some slippage during hard cornering. This is particularly annoying, as I searched long and hard to find near matching head stems, and the two I've used were the closest to matching I could find, given that I didn't realize until after I'd attached the kingpins to the frame that they were slightly different sizes (internal diameters of 21mm and 22mm if memory serves). The smaller of the two I have only one head stem for. I've yet to take a closer look, so I'm hopeful its the larger of the two that's slipping, and I can simply swap out the either just the triangle piece, or if need be, the whole head stem.
Also, while the boy was impressed with the amount of chain grease on his leg, Mrs Dent was not. Seems the Cub will get a chain sheath too, most likely sooner rather than later.
Pics to come once the sun is up again (and probably after I make and fit the seat cover. The MDF/foam/duct tape is ugly as hell. The "lawn-chair" look is
sooo much classier).
Dent.