HOW TO: Convert 1985+ NB50 to Disk Brakes
Posted: Wed Feb 12, 2020 11:40 pm
So, originally I said I wasnt going to do this. I really never planned to get further than a variator on an Aero. Then I got a cheap AF16, then I rebuilt it into a not so cheap AF16. Going 60+ just feels absolutely unsafe. Then the mentality sets in. I didn't cheap out on the rest of the motor, why cheap out on this part. I didnt cheap out on wheels or tires, so why cheap out on the brakes?
I have read of different ways to do things here, dio headset swaps are a little different. The threads and headset mount up differently, and Bonesv has a great writeup for that.
This should work on an elite, if you want to use the stock headset or naked bar. SA50 stems and NB50 stems are the same from the bottom race on up. I havent tried it, but Im sure you could swap them if you wanted to for some odd reason.
I picked up a used Honda Metropolitan stem for super cheap. My buddy and I split a part out on an SA50 and I basically got whatever I wanted but the plastics. At first it was just the motor and the wheels. Then i started using parts for this build. The bike Im doing the swap on has SA50 Wheels, larger front brakes, key-set, brake cables, speedometer cable, engine mount, engine, grab bar, tail light.... all can come over with a little bit of tweaking.
Now were going to take the SA50 stem and swap the tube over to the Metropolitan stem. The Met stem is shorter and the threads are in the wrong place. The race (which is pressed on) is also different.
I also got a set of Hella SuperTones for 10 bucks on Woot, so well see if they make the final install
I had a friend hack off the bottoms measuring the same distance up. Apparently it took a while and the steel tubes are pretty tough. Reassuring to hear. He sleeved the inside of the stem, beveled the edges, and welded the two stems together.
Finished product
Cant tell you how happy i was with the outcome!
Now I did not test out the Met stem at all, and I could not find anyone who has done this before. I just knew the SA50 stem would work. Most people doing these things end up cutting out the glove box.
The first test fit, and IT FITS AHHAHAHA IT FITS. No cutting
And with the panel on
I hope motormike doesnt kill me for trimming this NOS panel a little tiny bit
Since all the races seem the same as the SA50, I decided to order some bearings for them. Loads of older bikes use them i guess. The Aero had loose balls and I wont stand for that.
Ive been kinda struggling on what to get. I wanted to buy a kit, but then I didnt. I got some kymco calipers from a fellow on FB in taiwan. He sent me a ncy rotor as well but im not sure if it will work. Its 200 and i think the kymcos were 180mm. Caliper came with a brake line and newer pads, so one less thing to buy.
Wanted to do naked bar, but my wife thinks I should keep the oem headset, and that was enough for me to lean back over the edge. going to cut a hole for a brake reservoir.
Got a cheap master with good reviews on amazon.
Bought a pair of oem AF35 wheels on buyee as well as an axle, speedo, and spacers in a separate auction from an af34/35
I did some measuring, the Metro stem hangs down a bit, where the dio stems are recessed. Thats why most people cut glove boxes. From what I can tell forks come in Lowdown 300-318, Slammed 330, and stock is like 400 i think. 330 is about 13 inches. I went with that route, so that when you account for the droop on the met stem, it should be very close to stock height.
I grabbed some PG forks from VT Cycles, they are 330. Ive heard those forks can be rough but well see.
Hoping all my parts will be in by the weekend and I can mock it up at least.
I have read of different ways to do things here, dio headset swaps are a little different. The threads and headset mount up differently, and Bonesv has a great writeup for that.
This should work on an elite, if you want to use the stock headset or naked bar. SA50 stems and NB50 stems are the same from the bottom race on up. I havent tried it, but Im sure you could swap them if you wanted to for some odd reason.
I picked up a used Honda Metropolitan stem for super cheap. My buddy and I split a part out on an SA50 and I basically got whatever I wanted but the plastics. At first it was just the motor and the wheels. Then i started using parts for this build. The bike Im doing the swap on has SA50 Wheels, larger front brakes, key-set, brake cables, speedometer cable, engine mount, engine, grab bar, tail light.... all can come over with a little bit of tweaking.
Now were going to take the SA50 stem and swap the tube over to the Metropolitan stem. The Met stem is shorter and the threads are in the wrong place. The race (which is pressed on) is also different.
I also got a set of Hella SuperTones for 10 bucks on Woot, so well see if they make the final install
I had a friend hack off the bottoms measuring the same distance up. Apparently it took a while and the steel tubes are pretty tough. Reassuring to hear. He sleeved the inside of the stem, beveled the edges, and welded the two stems together.
Finished product
Cant tell you how happy i was with the outcome!
Now I did not test out the Met stem at all, and I could not find anyone who has done this before. I just knew the SA50 stem would work. Most people doing these things end up cutting out the glove box.
The first test fit, and IT FITS AHHAHAHA IT FITS. No cutting
And with the panel on
I hope motormike doesnt kill me for trimming this NOS panel a little tiny bit
Since all the races seem the same as the SA50, I decided to order some bearings for them. Loads of older bikes use them i guess. The Aero had loose balls and I wont stand for that.
Ive been kinda struggling on what to get. I wanted to buy a kit, but then I didnt. I got some kymco calipers from a fellow on FB in taiwan. He sent me a ncy rotor as well but im not sure if it will work. Its 200 and i think the kymcos were 180mm. Caliper came with a brake line and newer pads, so one less thing to buy.
Wanted to do naked bar, but my wife thinks I should keep the oem headset, and that was enough for me to lean back over the edge. going to cut a hole for a brake reservoir.
Got a cheap master with good reviews on amazon.
Bought a pair of oem AF35 wheels on buyee as well as an axle, speedo, and spacers in a separate auction from an af34/35
I did some measuring, the Metro stem hangs down a bit, where the dio stems are recessed. Thats why most people cut glove boxes. From what I can tell forks come in Lowdown 300-318, Slammed 330, and stock is like 400 i think. 330 is about 13 inches. I went with that route, so that when you account for the droop on the met stem, it should be very close to stock height.
I grabbed some PG forks from VT Cycles, they are 330. Ive heard those forks can be rough but well see.
Hoping all my parts will be in by the weekend and I can mock it up at least.