Touratech front sprocket guard and chain guard

During maintenance, I realized that my stock sprocket cover was busted. First I thought about fixing it, but then the desire to farkle won.

How do you spell trouble? 

The front sprocket cover is a simple, two piece design.

At first, it did not want to fit properly as the front kept interfering with an engine case bolt, but with a little bending it worked out. I opted for the original design vs the Rally style, as the original maintains some protection between the chain and the engine, whereas the Rally appears wide open on all sides. I know I've picked some stuff on my chain in the past I would not want hitting the engine case.

  Since I was doing the sprocket cover, I also got the lighter, cleaner-looking chain guard.
Again, a simple, two piece construction with an extra ABS guard that goes on the opposite side.

The long vertical piece bolts to the chainguard, and then attaches to the bottom of the swingarm via a plastic hex spacer. Really? Not only those little bolts (3mm dia, IIRC) that attach the spacer are the weak link, but the lack of any through bolt leaves me wondering about the longevity of this piece. On the plus side, the hex spacer was far too long to fit: 

So I modified it with a nylon spacer, and a 6mm stainless through bolt.

I also read some stories about the TT chainguard breaking from vibration, so I used some O-rings between the chainguard and the mounting points on the swingarm. Loctite is a must :)

Overall, not a bad looking piece.

I also reused the stock BMW bolts since they are Torx and I already carry Torx bits on my bike (for all the other BMW stuff). The stainless Allen bolts just strip too easily.

Here is the ABS guard, again, attached with stock BMW bolts and backed by O-rings.

 So, my first impression of Touratech? Decent product at a not-so-decent price. The material could be much thicker and the instructions could be in English (German only). Shipping was fast and reasonable, packaging was exceptional, and their stuff is just...cool. The quality, however, could be better. Finish is rather nice, and there are no sharp burrs, but the parts lack "meat" for lack of a better word. 

My homemade light bar and rear master cylinder cover are three times as thick.

It's been a long maintenance week for the GS and me.

What started as a simple tire change - going for the TKC 80 here - turned out to be sightly more complicated.

When the wheels came off, I looked at the sprockets. No doubt, they needed changing. My chain started stretching at a higher rate in the last 500 or so miles, so I knew I would have to change them soon, but I was hoping to finish the season on the old set. At 11k, the stock sprockets looked like this (new sprockets right next to them):

The front, especially, was pretty bad.

Every time I take my wheels off, I like to check the bearings as well. The front was fine, but the rear would not even turn when trying to spin them by hand (on the bike, however, I never noticed this). So out came the bearings and then it was time to shop for new ones (which I found at a local industrial supply shop at a low cost - same part numbers as the stock ones, SKF brand).
To remove the bearings, first I had to pry the seal out (with a dull blade screwdriver), remove a circlip, then knock on the bearings a couple of times to free the inner spacer. Once I got the spacer moving enough to tilt it slightly, I could get a long screwdriver in to hit against the bearings' inner races. A little heat from a hairdryer on the hub helped things along the way. I've seen some people use propane torches to heat the hub, but the gentle heat of the hairdryer did a fine job without melting any paint.
The sprocket carrier bearings are a little different. The inner bearing has to come out first, followed by a spacer, a circlip, and finally the outer bearing. Again, a little heat and they came out without any problems. You just have to move the spacer out of the way to be able to hit the inner race.

Before installing the new bearings, I cleaned everything really well (on the inside).

On the outside of the sprocket carrier there is a spacer that rides halfway in a seal. The trail-made lapping compound of mud and sand did a fine job in making two smooth groves in it. This would either allow more dirt behind the seals, or damage the seals over time, so I had a stainless steel spacer made at a local machine shop. There were also some rock nicks on the spacer.

A little cleanup around the front sprocket shaft, the rear carrier, and swingarm, and it was time for my new chain. I decided to go with RK XSO chain. I'll see how long it lasts under the harsh, Dualsport use. If I can't get any decent mileage from this one either, I'll be switching to cheap, non-O-ring chains and swapping them more frequently. 

I cut the change to stock length, 112 links, then used a clip master link instead of the rivet type. Some people like the clip links, some don't. I have never had one fail, so I used one on this chain as well. I think the key is to install the clip properly. First I put the O-rings where they belong, then squeezed the plates together with a pair of 6mm nuts over the pins. This pushed the O-rings in place and, after removing the vise, install the clip without any issues. I then cleaned the outside of the clip and baseplate with brake cleaner, and applied a little RTV to secure the clip in place should it fail for some reason.

While the wheel was off, I noticed my rear brake pads were on the thin side, so I replaced those as well.

And then I found that my from sprocket cover has a crack at the bottom and two of the brass inserts (through which the bolts pass through) pulled out of the plastic. Fix it or Farkle? Farkle won, but that is a story for a separate post.

The TKCs do look nice on the bike though. :)

Converting from single to a dual seat

 Time has come to sell my CB750F. After crafting the bike's single seat design a year ago, I had to change a thing or two. Well, the buyer really wanted to have the option to ride the bike 2up, while still retaining the possibility to keep it as a single seat machine for his leisure rides alone.  He was looking for an easy way to change from one seat to the other, and that meant that the stock solution was out of the question.

To do this, I had to relocate the taillight and the rear turn signals, as they were attached to the rear cowl. This way, lights and license plate would stay attached at the same place regardless of the seat choice.
 
First, since there was no rear fender (the cowl acted as a fender), I had to make one. Fiberglass being the material of choice (no matter how much I hate working with it, it is pretty damn versatile as far as materials go), I laid down two layers of cloth with two layers of mat sandwiched between them.

 

 

 And after trimming all the excess off:

 

 Here is the fender mounted on the bike:

 Next it was time to come up with a seat design. I did not want the seat to look out of place on the bike, so I decided to copy the frame contours with fender and all. This is the first protective layer of duct tape (to make sure no resin would get where it does not belong), which was followed by a cardboard cutout of the desired seat shape, taped over and held in place by wire. 

 Here are the first few layers of mat.

 After trimming excess and shaping the sides of the seat pan to follow the frame:

 Followed by a quick sanding with 60 grit to provide for some "bite" and two more layers of mat. This one has five layers of mat and two layers of cloth. Plenty strong for two people.

 Final seat shaping (the front drops down more to accommodate for the gap between frame and side covers).

 I got the foam from two old seats I had in the garage (one was not long enough). Front section is nice plush, with rear being made of a firmer base (there is not as much material due to the rear frame crossbracket). The two pieces of foam were glued together, then belt-sanded smooth and contoured. The final shape was then covered in a 1/2" foam tro provide uniform appearance and hide any foam repairs I had to do here and there)

 And, a quick mockup with some white vinyl I had around. The buyer will be taking the seat to a pro upholstery shop for a white seat with green stitching.

The small rear fender now holds the taillight, while turn signals drop down from the frame on small brackets. To change from a dual to single seat, all that has to be done is to pop the side covers, remove two bolts (holding seat to the frame), replace seat, and attach rear cowl with two bolts. Total of 6 bolts and maybe fifteen minutes. Voila.