Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

I started to put the rear end together to check chain line, tire clearance etc, and unfortunately the 3.50 SR241 has too much tread width at 4 inches to clear the swingarm, because the wheel does not sit in the center, it actually sits quite a bit to the right side. I returned the 3.5 and am waiting for a 3.00 to show up.

In addition, I realized I had the wrong output shaft seal installed! This engine came with a new seal kit, pretty sure it's the one from Dos. That kit only comes with a 15x30x7 output shaft seal meant for PP/PR engines with the circlip style sprocket/shaft. I have the threaded style shaft, which has a spacer that rides inside the seal, so I need a 20x30x7. Womp womp. Popped out easy with a seal puller!

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Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

I tried some Meguiars liquid polish to try and revive some of the faded single stage paint. Works quite well, and while not perfect, its 10x better than it was before. I'm leaving this bike with some charachter and patina.

Right side before polish, left side is after. And this is just rubbing it a little with a paper towel.

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Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

I was missing this little M bracket for the front engine mount. This piece is actually very important, as it keeps the engine from being able to lift up out of its mounts if the nuts were to loosen. Luckily my recently acquired Laguna project has an identical piece, so I borrowed it to make a template. You can see how the plate is mounted to the frame on the Laguna, and it hooks over the engine studs, making it impossible to lift up.

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Re: Derbi RD-50 adventures

this is awesome man!

Re: Derbi RD-50 adventures

this is cool, nicely documenting the work done

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

The front fender had cracks by the mounting holes, I used a hot air "plastic welder" to melt the plastic and smoosh the cracks back together with a smooth flathead screwdriver. Forgot to get a before picture. Time will tell how strong is...¯\_(ツ)_/¯

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Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

Forks got some NOS dust covers from DOS...

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And we have a roller!

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Getting the engine in and out is a real chore. Poor design makes it impossible to remove the bolts holding the engine into the swingarm subframe without unbolting the swingarm itself, and finagling the engine this way and that...chipping the paint in the process. :/

It's in, hopefully for good.

Re: Derbi RD-50 adventures

Dang, that looks good.

Re: Derbi RD-50 adventures

Damn dude that looks great. Polished real nice almost looks like you painted the frame.

Re: Derbi RD-50 adventures

Great work!

Re: Derbi RD-50 adventures

Looks killer. Does it say gross or cross on your forks and what is the meaning?

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

> Steve Dolan Wrote:

> -------------------------------------------------------

> Looks killer. Does it say gross or cross on your forks and what is the

> meaning?

Says Cross, but taking some white paint and making it Gross would be a funny prank haha

Re: Derbi RD-50 adventures

Wasn't sure if gross was slang for sick or dope or rad or etc.....

Re: Derbi RD-50 adventures

What the meaning?

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

> Steve Dolan Wrote:

> -------------------------------------------------------

> What the meaning?

Gross has a few definitions depending on the context.

A "Gross" is a unit of measurement, usually denoting a quantity of something, or a total. Like, "Gross vehicle weight rating" (GVWR) is the total maximum weight a vehicle can be and still function within specification. Say your car moped weighs 100lbs, and has a carrying capacity of 300lbs, your GVWR 400lbs

"Gross" is also an adjective, used to describe something as disgusting, revolting, unpleasant, etc.

Re: Derbi RD-50 adventures

But , what is the CROSS on your forks suppose to mean ?

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

> P D Wrote:

> -------------------------------------------------------

> But , what is the CROSS on your forks suppose to mean ?

I put my money on "Motocross"

Re: Derbi RD-50 adventures

I thought of that , too .

I just wondered if maybe there was some 'secret' behind the display . ;)

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

> Alex hernandez Wrote:

> -------------------------------------------------------

> Damn dude that looks great. Polished real nice almost looks like you

> painted the frame.

thanks! I did some touch up and sprayed a few areas with some duplicolor engine enamel. It matched really well, although it is slightly darker. The swingarm and bottom of the triple tree are completely repainted. if i were to start over i would just have everything powder coated, because i hate paint prep. Main reason i hate it is that i don't have the space to do it properly! Learning how to paint properly and consistently without orange peel is a goal of mine, be it with rattle cans or spray gun

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

Cut some carbon .30 reeds. Wet sanded the edges to shape! Read it in a thread somewhere.

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Making a custom VM18 intake

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(edited)

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

Tacked in place, then welded in sections all around. It warped, but some strategic hammering and some sanding got it nice and flat.

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Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

The bolt that holds the rear of the seat to the frame snapped when i initially took it off the bike. It was a captive bolt that was welded to the seat pan. At first, I wanted to avoid cutting the mount, so I mounted a hacksaw blade upside down and cut the welds holding it in place. But in the end, the only real solution was to copy the original design. So i cut the bracket and welded a new m8x1.25 bolt in there.

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Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /
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Re: Derbi RD-50 adventures

Reeds and intake came out nice. Your weld are super slick I can't believe you don't use shielding gas. I have to grind the shit outta my welds to have them look half as nice as yours.

Re: Derbi RD-50 adventures

It’s all in the prep work and having good quality flux core wire. Oh yeah, also skill.

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

> Alex hernandez Wrote:

> -------------------------------------------------------

> Reeds and intake came out nice. Your weld are super slick I can't

> believe you don't use shielding gas. I have to grind the shit outta my

> welds to have them look half as nice as yours.

Thanks! The welds on the intake were tough. Welding in a straight line is hard enough, let alone a small circle with thin wall tubing. They're strong, but not that pretty haha.

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

Got this sick pipe from DOS that they recommended, originally a GPR 50 pipe. Cut up the stinger to make mounting the chamber easier...I hope I can get it right. Exciting, but also anxiety inducing! But that's moped isn't it?

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Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

So, I actually decided to mount this pipe on the right side. Seems to fit better, and I can utilize the pipe's bracket for mounting.

I cut the chamber at one of the welds with the bandsaw to rotate the header portion. I just need a few curved sections of 25mm header to complete it, I have plenty from the exhausts I've cut up over the years. I'm losing a little ground clearance, it sits higher up than in the picture. Plus, lengthening the pipe with this extra header should make it more usable for my setup, power wise? I hope! Got the welder dialed in, surprised it welds this nicely with thin stuff with flux core! (Just a few short beads for now, until the rest is figured out)

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Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

just for kicks i wanted to see how this pipe mounts to a GPR50 which it's made for. Its actually an undermounted pipe! found this video here that shows it.

Re: Derbi RD-50 adventures

Brandon Weiss (Detective brandon to you) /

Tough crowd lol

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