My Cafe Racer Build (and Re-Build)

They are from a pre 2005 aprilia RS-125. You won't find any for sale here in the US (you can sometimes find complete bikes, but you won't find any being parted). I got mine from the UK, but you can check any European eBay and they are plentiful. I think I paid around $250 shipped. They are a nice swap since you don't need to mess with the stem, just requires new upper/lower stem bearings, and left and right wheel bearings. You will also need to cut new bearing spacers, one for the inside then 2 for the outer.

You can get any set of forks to work, but these are probably the easiest and cheapest, while still offering decent performance.

 

A few more odd and ends.

Ordered some carbon fiber rod to replace my bars with. Same ID and OD. Weight on the aluminum bars is 125g, weight on the carbon fiber is 58g, and I still need to cut 2 inches off. Although that may not seem like a big deal, it is when you are trying to run a bike in a landspeed race. I need to start shedding weight anywhere possible without compromising rigidity/strength. This is the first step, and was cheap and easy.






More displacement. I had originally given up on this idea, but I'm all in now that its winter and have the time. I'm going with bigger pistons from a bike that shall remain nameless. If used with XJR rods, the dome height will be the same as stock. The piston in the pics is a stock one that I grabbed for testing. The ones I'm ordering are custom from MTC. They are boring the wrist pin hole to 18mm for me. I will have to cut the proper valve pockets on my own. Chambers on the head will have to be CNC cut to be able to use the pistons, or I can modify the piston dome. Modifying the head will be the best option. Will be going with 72mm bore on the stock sleeves. Target CR will be 11:1. MTC says they can supply me any size I want with bigger liners if I decided to go that route. Should be good for another few ponies.

 

Another project complete. Wanted a gear position indicator, so I made one. Just modified the shift drum and the neutral indicator.

 

Yep took about 10 min. All you need is a drill press, hole saw, 3 and 4 mm drill bits, and a bit of ingenuity!

There was a guy that used to modify the sensors a little differently but charged quite a bit. These can be used on any 6 speed Yamaha that share the part number 1L9-82540-00-00

 

Write up wouldn't be a good idea, as there is some measuring involved that changes placement depending on where you drill and such. It's pretty much one of those things where if you need to be shown, you shouldn't attempt

I can point you to the parts though. You can get them off aliexpress as linked above. I recommend finding a seller with good communication, as all the junk on the site may be pictured the same, but you'll get different parts than shown. So you'd need to measure, then find a seller that can actually verify size.

 

I would only do the transmission parts. Some people do cranks, rockers, cams, etc, but the process WILL change the clearances (they say it won't but trust me, it does). So you would have to get the parts done, then have them reworked with proper bearings and all. Would be a waste IMO for the very very small benefit.

 

Yep got it on Ali. The seller was 'sunny sky'. Should be able to do a seller search and find them.

The blue display is a little more expensive than the red unfortunately. I wouldn't be able to stand having red lights blaring at me at night.

 

Red means slow. No thanks.

 

Done! Well not really, but pretty close



Still waiting on my Pamco, then I can finish the wiring. Need to shim the rear sprocket to match the front, then I can cut the chain. Need a shorter front brake line for the new setup. Working on the shifter and brake linkage as we speak. And that's all that's left to be rideable. Hooked up the GPS speedo to the battery to check its function. It works, but I'm not happy with the satellite sync time. Fastest was 15 sec, but most times took about 30-40. Not a huge deal, just have to wait a bit before taking off.

Carbs all done, mods in place. In these pics you can see the front controlled power jets. This allows me to adjust for atmosphere/elevation on the fly. You jet the main a few sizes lean and then make up for it with the power jets. Gives a good range of adjustment. These only affect jetting under load, mostly at WOT. I have the adjuster mounted on the fairing brace near the headlight. And in the last pic you can see the fittings added for carb sync.







Had to add 2 different killswitches to comply with a race rule book. They require one manual on/off switch accessible with your hands on the bars, and another attached by a lanyard that will cut the engine if tossed from the bike.