Thank you jtrops, John and Roger.
Well I successfully replaced the tube (first time I’ve done that) and re-assembled the giraffe. Jtrops, I am mechanically inclined but I have no experience with bicycle/unicycle mechanical work. With that said, I had to look up what a spindle and bottom bracket is to understand your answer. Upon researching that, I read the obvious fact that bikes with derailers inherently have offset. That made me a little more at ease. Upon re-assembling I noticed the fork opening had enough extra room to allow me to insert 2 washers as spacers. I inserted them in such a fashion as to reduce the offset. The factory offset appears to be aproximately 1/2 inch. (The top sprocket is aprox. 2" from the center of the frame and the lower sprocket is aprox. 1 1/2" from the center of the wheel.) I tensioned the chain as recommended and then looked for any change in tension as the wheel is turned. I did not find any change in tension. Great! Nor did it come close to losing the chain as John warned. Time for my first Giraffe ride!
I’ve gotta say I was very nervous. Even though it’s just a 5 footer, that’s a big jump in hight! For comparison, I’m a skydiver with 380 jumps. The fear of skydiving is long gone. But there I was, with my feet just a few feet of the ground, and I was scared. You see, when I skydive I know I will land tiptoe soft. How will I “land” off of this? So this was like my first skydive all over again. What you say, there’s nothing in common between the two? I disagree. With both activities you are worried about plowing into the ground! I laughed nervously as I pondered this.
So I used a 6 foot stepladder at a school playground/parking lot to mount the beast underneath a basketball goal. I’d donned all my protective gear - helmet, shin guards, wrist guards and elbow guards. I got myself ready but was hesitant to go for it. Yep, I was sweating bullets. I ended up psyching myself up and then went for it! There I went, then down I went! I made it about 2 feet and fell off. But the fall wasn’t bad! OK, try it again. Same thing. At least now the fear was receding because my falls hadn’t been bad. I quickly remounted and yes, the third time was the charm! I realized you have to lean out a bit, then start pedaling to keep it under you. Ta Da! I was riding my Giraffe! As I’d hoped, it wasn’t too bad once I got going. I laughed to myself for a good ways as I rode around the parking lot. What a feeling! I was doing great. Then I came upon a small piece of broken glass. I did an evasive maneuver to miss it and again laughed to myself. Then I crashed and burned. Hmmm, I need to get knee protection!
While riding I felt the giraffe was doing just fine. The offset does not appear to be an issue at all, as Roger indicated. In fact, my first impression is that it is a very fine product.
With daylight ending soon, I rode all I could - about 30 minutes. I upd’d every time but the last and fortunately came out with no injuries. The planned dismount was good and I was able to catch the uni as well. Once again though, I was hesitant. I found myself riding around mustering up the courage to do a planned dismount! All in all, I had a blast. Viva Nimbus!
Now back to the original post…
As for the valve, it appears to be the original. The seller stated he could ride well forward, but couldn’t idle or ride backwards. The mint condition of the giraffe and the flat tire with Dunlop valve made me doubtful he ever rode it at all. Therefore I don’t believe he would have changed anything on the uni. Plus I have heard of at least one other Nimbus being shipped to the US with a non-Schrader valve type. Not a big deal though. I now have experience changing a tube and I’m the kind of guy that likes to learn that kind of thing.
John, when the LBS applied the locktite to your Giraffe, how long was it allowed to set up?
jtrops, I will probably leave the uni as is now that it has passed a riding test. I do have a question about your solution though, in case I decide to perfect the uni. The spindle is what I take to be the axle, which is with the wheel. After looking at the glossary of Sheldon Brown’s website, I can see how this could be replaced or modified to alter the location of the sprocket. What confuses me though is your mention of the bottom bracket. I understand the bottom bracket to be the “guts” of the crank assembly (not the bottom of the fork as I would have guessed). Which are you suggesting that I change - the crank assembly or the axle of the wheel in order to eliminate offset?
Last question (for now):
I noticed that the wheel itself doesn’t spin as freely as I would hope when disengaged from the chain. What is the proper way to grease the axle internally? Please forgive my ignorance. I don’t even know if this is something that can be greased or if it is a sealed assembly that you simply replace.