Welcome to the Roketa Café

[Weldangrind]

I need to work on my TW and Lifan, but there are two bikes in pieces that need to move forward. One is an XR200 for a young man who is staying with us for awhile, and the other is a Roketa-based café that will likely go to my Brother in law.

This follows my recent discovery that the Roketa and 1981 XR200 frames are nearly identical. To further cement the point in my mind, I installed the upper and lower XR200 triples in the Roketa frame today. Perfect fit. While at it, I trimmed the steering lock off, because I intend to weld it onto the Lifan.

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00323_zps1cdd9fe4.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00323_zps1cdd9fe4.jpg.html)

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00324_zps29d991c5.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00324_zps29d991c5.jpg.html)

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00327_zpscc06be54.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00327_zpscc06be54.jpg.html)

The swingarm mounts are also identical, so I mounted the XR200 swingarm into the frame. The following pics also illustrate the differences between the XR200 swingarm and the Roketa swingarm.

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00328_zps4893c9b6.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00328_zps4893c9b6.jpg.html)

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00329_zps9127a1d3.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00329_zps9127a1d3.jpg.html)

The original shock mounts are used for the carrying rack on the Roketa, so they're not machined quite right for the shocks. I'll weld some XR200 mounts there soon. For now, the frame is mocked up with the shocks on the rack mounts. The proportions are ok, but they'll be even better once I bend the subframe to suit a café seat and install 18" wheels front and rear.

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00330_zps306c2f86.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00330_zps306c2f86.jpg.html)

While at it, I mounted the Roketa triples, a set of Gio forks and the Roketa swingarm to the XR200 frame. The steering stop doesn't line up quite right, but that's an easy fix.

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00334_zps7fb41583.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00334_zps7fb41583.jpg.html)

This shot shows the rear suspension link that I need to pirate from the Roketa frame and transplant onto the XR200. I'll also move the upper monoshock mount to the XR200. The frame member that supports the link (and the footpegs) is really poor on the Roketa, so I'll eventually weld a spare XR200 piece on there.

http://i158.photobucket.com/albums/t109/Weldangrind/Roketa/IMG-20130608-00335_zps4d6ca71a.jpg (http://s158.photobucket.com/user/Weldangrind/media/Roketa/IMG-20130608-00335_zps4d6ca71a.jpg.html)

That'll be it for awhile. I need to work on the other bikes for now. My Bro in law will visit next weekend, at which point we'll make more progress.

[zingshoen]

that s two racers you got in your roketa cafe! what s the coffee like? ;)

but seriously, it is very interesting to compare those frames from the bare bones up up. :tup:

[katoranger]

I am waiting on the next update of the roketa based machine.

Going to send you a PM. I think I have some things you may be able to use.

[nyvdub89]

This is awesome!

[JPG1911]

just reminds me how much I miss my garage... I'm happy with my station in life, and the huge amount of money I'm saving by living at work, but MAN do I need a garage/man cave/shop again

but I can't wait to see how these bikes turn out! looking great so far

[Weldangrind]

Thanks for the comments, guys. I haven't been able to stop thinking about the café project since I started the thread last night. Since I'm literally swapping parts between two bikes, I need to be careful about measuring before I start chopping brackets, etc.

For example, the XR200 frame originally had drum brakes, but it will have the Roketa discs front and rear, but with some cool red Gio calipers and braided hoses. In order to make that work, the passenger peg mounts need to be removed from the Roketa and welded onto the XR200. I'll need to be sure of placement before I weld them in place. The same goes for the tank mounts, seat mount and other bits. I should probably start a thread on the Chinafication of the XR200 as well. It's a lot to wrap my mind around.

I'm grateful that I have an identical XR200 frame that has been tweaked; I can chop tabs and mounts from it with little regard for accuracy, and then prepare them carefully for transplant onto the Roketa.

I measured the XR200 forks that are now on the Roketa, and they are 31mm. As such, these are the clip-ons that I'm looking at: http://www.ebay.ca/itm/31mm-Fork-Clip-On-Handle-Bars-1-pair-Black-/251283506484?hash=item3a81aa0534&vxp=mtr

To anybody wondering why I would bother with all of this, it's largely because I need supervision. Aside from that, the Roketa has a title and the XR is dirt-only. The only way to create a dirt bike and a café is to swap everything between the two frames.

[katoranger]

And is provides us entertainment.:tup:

[edtardo]

Hey Weld, I have to ask. What ever happened to the Roketa body plastics?

[Weldangrind]

Hey Weld, I have to ask. What ever happened to the Roketa body plastics?

Still have the cracked originals and the Lifan-style replacements I bought and trimmed. I might be using the new panels on the XR200, if the XR200 panels are too much of a hassle.

[SpudRider]

Wow! What a great thread! :clap:

I have been considering upgrading the forks on my Zongshen 200GY-2. :) If I'm correct, I believe you have a Roketa DB-07A. I also believe your Roketa forks and front wheel are identical to the same parts on my Zong. Am I correct? If so, I surmise I could install either an XR200 triple tree and its conventional forks, or the Gio USD forks in my Zong's triple tree. Is that a good assumption?

What is the travel for the XR200 forks? Also, what is the travel for the Gio USD forks? My Zong forks have about 6.5-inches of travel, and I would love to get another 2 or 3 inches of fork travel. :)

[Weldangrind]

Wow! What a great thread! :clap:

I have been considering upgrading the forks on my Zongshen 200GY-2. :) If I'm correct, I believe you have a Roketa DB-07A. I also believe your Roketa forks and front wheel are identical to the same parts on my Zong. Am I correct? If so, I surmise I could install either an XR200 triple tree and its conventional forks, or the Gio USD forks in my Zong's triple tree. Is that a good assumption?

What is the travel for the XR200 forks? Also, what is the travel for the Gio USD forks? My Zong forks have about 6.5-inches of travel, and I would love to get another 2 or 3 inches of fork travel. :)

Thanks, Spud. :D

With whatever swap you choose, there will be challenges. I'm pretty sure that all XR200's had drum brakes front and rear, so that's a less desirable option. As well, the XR200 triples would lack the mounting bosses for your ignition and gauge cluster.

The Gio forks are longer, and I believe they have more travel, although I'm not sure by how much; I can measure the free length if you wish. The Gio forks lack the speedometer stud on the right fork leg, and the lowers are narrower than the Roketa / Zong. That is workable, because you could fabricate a speedo stud and spacer, but I'm not sure it's worth it.

Both the Lifan GY5 and Roketa DB-07A in my shop have forks like the Zong, but the Lifan forks lack the lower cover mounting boss. I'd use the Roketa forks, but the chrome sliders are rusted quite badly.

If you wanted to try conventional forks, you could likely install the triples, forks, disc brake and speedo from an '84 / '85 XL250. I installed a set on Son of Weldangrind's '83 XR200R, and it was a perfect fit. The headset tube on the XR200R and the XR250 / XL250 is larger than the early XR200 / Roketa, so some bearing swapping would be necessary. I'm not sure what the answer is there.

The only upgrade that comes to mind as simple and effective is something like your CRF. Have you measured the CRF forks for comparsion? I'm sure we'd all enjoy hearing about the viability of CRF forks on a Zong. The CRF front end (as you are well aware) comes equipped with a disc brake and speedometer.

[SpudRider]

As always, thank you for your thoughtful reply. :)

Looking at the Thumpertalk forum, I discovered one has many options to upgrade the XR200R forks. For example, I believe you can substitute XR250R forks, which have a front disc brake. :) However, I have decided not to mess with the ignition lock and dashboard problems, et cetera, associated with swapping the triple trees. ;)

Based upon your information, I will also decline to swap the Gio Performance Forks. ;) The Zong forks are actually pretty good, so I will stick with them, unless a simple upgrade presents itself in the future. :)

[FastDoc]

This is a great thread.

You are a hard and a skilled worker, Weld. Thanks for taking the time to take pictures and start this thread to let us all be involved.

[Weldangrind]

This is a great thread.

You are a hard and a skilled worker, Weld. Thanks for taking the time to take pictures and start this thread to let us all be involved.

Thanks, Doc. I hope this thread will help others down the road. Check out my Lifan thread for somewhat relevant info.

[Weldangrind]

I haven't updated in awhile, and I'll post some pics soon that show how Bro in Law and I have unceremoniously chopped the Roketa frame.

Before we get to that, we pulled the motor apart last night and determined a very strange setup. The bore is a whopping 68.5mm, but the stroke is only 52.5mm; this motor is obviously designed to rev, but that's not our plan. I'm going to try to stuff a 66.2mm crank in out of a 223, which will produce a theoretical 244cc. I'm geeking out just thinking about it. :D

[FastDoc]

Excellent plan, sounds technically challenging but that's right up your alley!

Looking forward to the pics. Is this bike going to Bonneville?

[SpudRider]

We eagerly await further updates! :tup:

[Weldangrind]

Excellent plan, sounds technically challenging but that's right up your alley!

Looking forward to the pics. Is this bike going to Bonneville?

It just might! :D

[Weldangrind]

Since this bike will no longer be suitable for off-road, I've moved it to the Street category.

[katoranger]

:zzz:Where are the pics?

[Weldangrind]

Don't have much to show yet. Bro in Law lives in Calgary, so we're lucky to get time once a month on this bike. He doesn't want me to proceed on my own, since he appreciates the learning curve. It's his first bike and first fabrication project.

We're still in the process of de-tabbing the frame and figuring out what changes to make. I find this shot to be particularly interesting, since it compares the Roketa frame with an '81 XR200 (not the R version). You can see how we've removed the seat base metal and cut the gussets. We then heated the steel and bent the seat hoop down until it was in line with the area that is forward of the seat.

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This shot shows how I've yet to fabricate the mounts for the rear shocks, which were donated by the XR200, as was the swingarm.

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There is much to be done, and we're now focused on the motor, since it's easy work to do inside the shop during cooler and wetter weather. Stay tuned.

[SpudRider]

All right! Brother Tom is working the angle grinder! :tup:

[SpudRider]

I can hear the neighbors. :) "What are they doing over there now?! :wtf:





:hehe:

[Weldangrind]

I can hear the neighbors. :) "What are they doing over there now?! :wtf:





:hehe:

They're very used to me. They also appreciate that I'm always ready to lend a hand.

[SpudRider]

They're very used to me. They also appreciate that I'm always ready to lend a hand.

I was kidding, of course. ;) I'm sure your neighbors were not disturbed, and they appreciate your willingness to help. :tup:

[Weldangrind]

Further to the displacement discussion, I remember being quite puzzled by the markings on the Roketa motor when I first brought it home (page 3 http://www.chinariders.net/showthread.php?t=12200&highlight=roketa&page=3 ). I couldn't wrap my mind around how 125cc was indicated, yet it was badged as a 200. I'm still not sure why the markings are as they are, but I have the answer about actual displacement.

With this 200cc OHC motor, the bore is a whopping 68.5mm, and the stroke is a tiny 52.5mm.

The standard-issue 223cc OHC motors use a 65.5mm bore and a 66.2mm stroke.

My 200 would rev nicely, but make very little power down low. The 223 would have more low-end grunt, but would max out at a lower rpm. I'm very hopeful that I can combine the 68.5mm bore with the 66.2mm stroke for an unprecedented big bore and stroke China motor. I'm about to pull the trigger on some parts from Taobao to do the deed.

For the sake of interest, I compared the OHC Roketa parts with Honda XR200 parts, and found very little that would swap over. The stud spacing is considerably larger on the Roketa, so you can't put a China cylinder and head on a Honda bottom end. Even the valvetrain is different. What remains to be seen is if I can stuff a monster crank in an XR200 motor to create an awesome stroker; that, mixed with the 10:1 Wiseco piston I have would be lots of fun. I know that the China crank has a different flywheel taper, but I could likely overcome that by using a China flywheel and electrics.

I can't answer that at this time, because the flywheel requires a 28mm female puller that I've never seen. That'll come from Taobao as well.

[edtardo]

this thread brings me so much joy

[katoranger]

They're very used to me. They also appreciate that I'm always ready to lend a hand.

You probably fix all their broken stuff too.

[Weldangrind]

this thread brings me so much joy

I presume that you're not giving me a hard time. :D

I totally geek out over engine building, especially when I can manipulate the rod / stroke ratio and stuff like that.

[Weldangrind]

You probably fix all their broken stuff too.

I've been known to. Doesn't hurt to stay on the neighbour's good side, especially when your son and his friends fire up the dirt bikes when you're not home.

[SpudRider]

I've been known to. Doesn't hurt to stay on the neighbour's good side, especially when your son and his friends fire up the dirt bikes when you're not home.

:)

[Weldangrind]

Resurrecting this old thread. Some plan changes; the bike is no longer going to Bro-in-law, but to a buddy of mine instead. Bro-in-law is buying a sweet CJ360T.
The Roketa will now be more of a scrambler. I bought a repop CG125 seat and tank on eBay. I'm quite happy with the shape and quality so far.

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[Weldangrind]

I'm lacing an old DID aluminum rim to the rear wheel to ditch the rusty chrome crap. I'm using an identical rim for the front, so it will have 4.00-18 trials tires front and rear. To make that happen, I bought a CJ360T front hub, which has a very cool dual leading shoe drum brake. I also bought fresh spokes for the front.


One rims had a crack where the rims were originally spliced together at the factory. My buddy TIG welded the crack for me, then I ground the welds down and brushed the aluminum. Here's the result:

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[Weldangrind]

Once the hubs are cleaned up and ready, I'll lace them up and take pics.

[culcune]

Do you have a photo of the bike these will be installed on?

[franque]

Hey, did the motor end up being a TW/XT copy? It seems like a bizarre mix of things otherwise. Honda never produced a 52.5 mm stroke crank for the CB/CG series.

[JerryHawk250]

Looks like somebody finally got some me time. lol The project is coming along real nice. I like the seat and tank.

There is some good that come out of all this corona virus mess. I've gotten some things done around the house myself. More families are staying home doing things together like a family should.;)

[Weldangrind]

Do you have a photo of the bike these will be installed on?

It's a bare frame ATM. It's the sandblasted frame in this thread: http://www.chinariders.net/showthread.php?t=12476

[Weldangrind]

Hey, did the motor end up being a TW/XT copy? It seems like a bizarre mix of things otherwise. Honda never produced a 52.5 mm stroke crank for the CB/CG series.

It's a typical CB250 from China, kinda like a CRF230. Definitely not Yamaha-cloned. I won't be using that motor for this build, at least not yet. For now, it'll be a CG223.

[Weldangrind]

Looks like somebody finally got some me time. lol The project is coming along real nice. I like the seat and tank.

It's more about space than time. I lost all interest there for awhile, but I'm back at it. Glad to hear you like the seat and tank. Also glad to hear that Monroe is 4.5 hours away from you. :tup:

[JerryHawk250]

Also glad to hear that Monroe is 4.5 hours away from you. :tup:
Yeah, they got hit pretty hard with the tornadoes. We lucked out and all the bad weather just missed us but did have a whole lot of wind here.

[Weldangrind]

New adjustable LED flasher, speedo with indicator lights and tank mounts arrived. I did some research on the speedo, and I think it is the correct ratio for an 18" front rim. Still awaiting the rear hoop, so I can build the subframe to suit the seat.

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[Weldangrind]

I also received this cool tail light and new turn signals. It is an LED light and it seems to be decent quality; it has a license plate light underneath. The turn signals have an amber light in the middle and a red halo. If the halo isn't too bright, I'll use it as a running light in the rear. If it's really bright, I'll tie them into the brake circuit only.

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[Rangerscott]

Make sure to seal those threaded ends on the tail lights. Water will get in and destroy them.

[Weldangrind]

Thanks for the tip! That hadn't occurred to me.

[Weldangrind]

Not sure where Spud went. Doc still randomly checks in, and he and I exchange texts occasionally.

[Merlin]

Spud doesn't post here anymore but he looks in every so often. Last time was about three months ago.

[2LZ]

I'd imagine one could find Spud on a Kawasaki forum somewhere....probably doing a bang-up job of documentation too. Didn't he buy a 300?

[Rangerscott]

I found out the hard way.

[Weldangrind]

I found out the hard way.

Thanks again for sharing your experience; I'll be sure to seal up the water entry points.