Let’s make a rolling chassis
(Nov 2 2009) Ok. The list of all the things needed to complete the motor that I laid out in the previous chapter is a bit overwhelming, so we’ll just ignore that part of the project for the time being. Besides… The mechanic up the road has promised to discuss how much money it will take to finish the 650 by the end of this week. There is the (unlikely) possibility I will actually have the first Triumph I bought back in May as a running motorcycle, so maybe I should hold off spending a lot of money on the rusty Triumph from Kentucky for a bit.
As it stands right now, I have almost everything I need to make a complete bike, everything except the engine – what we would call a ‘rolling chassis’. I can have tons of fun building what I have on hand and keep rein on my wallet, so let’s proceed.
Step one: Let’s mate the exquisite Ceriani forks to the rusty frame – not permanently, just a mock up – see if we can make them fit.
The Ceriani forks were the ‘big deal’ for dirt bikes in the late sixties. Made in Italy, they didn’t come standard on any bike, but were an after market add-on and everybody wanted them. They were light, durable and had excellent characteristics. Flat track racers, desert racers, factory sponsored enduro machines, European motocrossers even Daytona 200 road racers – everybody wanted them. They still make them – selling for over $2,000
Here’s a picture of a pair of Ceriani (cherry-awnie) forks:
The Triumph I bought back in May was fitted with them, which is one of the main reasons I bought it. After I bought rusty Triumph from Kentucky, I found a set on eBay that had probably been used on some 70′s motocross bike for less than $200.
Problem is they weren’t custom-fitted to rusty Triumph from Kentucky, so I knew there might be some modifying needed in order to use them. I was right.
As you can see in the picture below, the stem is a little short.
The stem coming through the center needs to be almost as tall as the nut which is sitting to the right. I talked to some knowledgeable folks an there was an estimate of maybe another $200 to make a new stem at a machine shop and that just didn’t sound like much fun to me. (Oh. you noticed in the photo… yes rusty Triumph from Kentucky is in fact… rusty – don’t worry, we’ll fix that later : -)
Here’s my dilemma – the stem needs to be longer and I am wanting to figure how to do it on the cheap. I went through this last year with a bicycle – exact same problem. The fork stem was too short for the frame I wanted to use it on. My boss welded two stems together and the length was perfect but the weld was too thick to allow the bearing to slide past, so I ground the weld smooth and about a week later the weld failed; I face-planted going about 5 miles an hour. I was bleeding. This must be avoided on a bike capable of going almost 100 miles an hour.
Length with strength is what I’m looking for.
The inside diameter of the stem is just about exactly 3/4 of an inch. The local hardware store has a fantastic collection of fasteners – grade 8 bolts, crazy odd stuff – including a bolt as large as 3/4 of an inch! I brought it home and it fit inside the stem like a glove. Or not a glove, but a pretty darn tight-need a hammer to knock it in-tight, fit.
I drilled holes through the stem with bolt inside and have bolted it fast. After it’s welded it is going to be stronger than strong and now… It’s long enough – cost? $7.18
(Good thing I haven’t welded it yet – I forgot to put the bottom bearing in place – Hope I remember to do that before I weld it : -)
Next – We’ll modify the seat rails for a narrower bum-stop.