TZ250 B -91 Replica Build | Sourcing all the parts 09/19

[KennyBarroz]

Hi folks! Long time since i posted a project at this forum, but since winter is just around the corner here in Sweden, i figured that i might just start my new project here. (Sorry for the picture quality)

TZ250 B 1991 Replica build


So, what is this "replica" all about, well the TZ250 B has been my all time favorite TZ bike.
This one also shares the same characteristic design as Wayne Rainey's YZR500.

So i needed something that would be a great base for this project just like any other good gravy

The TZR250 3XV would be a great bike just to start with. but since these are extremely rare in Sweden, i decided to go with what is closest to the TZR250 bikes.

I bought what i could find...SZR660 - 96 model, fairly ok condition, made a good deal since the cooling system had mixed oil and alot of rust to it (might not be obvious on this sale-ad picture)
But since this was only a chassi donor, it would be the perfect donor.



So once home, i started to strip the bike for the parts that i did not need and that i could sell.




I also noticed other SZR660/125 4DL projects with a RD350, i gathered some useful information and inspiration for my project.

http://www.rzrd500.com/phpBB3/viewtopic.php?f=5&t=9695
http://www.rzrd500.com/phpBB3/viewtopic.php?f=5&t=9808
http://www.rzrd500.com/phpBB3/viewtopic.php?f=5&t=9850
http://www.rzrd500.com/phpBB3/viewtopic.php?f=5&t=4195

Couple mounts later i came to a small stop, this was mainly because i needed someone to help me weld the engine mounts that i had designed,
it took me around 6 mounts to ask a good friend of mine R-Oil on the forum for help,
Then he told me about a guy that works with bikes and could help me weld whatever i needed


So i started to take apart the bike and prepare it for engine install.








And the engine is mounted to the frame





So now you all now about the history, the present for the moment is that i have gotten the new swing that will be installed together with my wheel that iam waiting for.




I have not yet sourced all of the parts that i need, but iam gathering information and calculating what parts that would fit the best for this project.

So this is what i have and what i need... So far



Frame - SZR660 4SU Belgarda with custom subframe
Tank - TZR 125 4DL Belgarda
Front Fork - SZR660
Rear shock - Aprilia RS250
Brakes - Double Ducati 320mm front rotors with Brembo calipers, Rear 240mm rotor with brembo caliper.
Swing - TZR250 3XV - Small modifications to make it fit to the frame
Wheels - SZR660 Front, RF600/GSF600 93-99 Rear (17x4,5) (GS500 rear sprocket for the 520 pitch)
Fairings - New TZ250 B -91 Fairings
Radiator - YAMAHA TZR125 4DL or YAMAHA YFZ450
Engine - RD350 F2 -86, The one from my previous project.
Exhausts - Custom made from my previous RD350 project.


So, i guess that is all for now, next update will be whenever i get the swingarm installed together with the GSF/RF600 rim!


Any questions or thoughts about the project, please feel free to comment!

[hondaror]

Looks really good.

[RuZty]

Very nice work, I have a 3MA frame to get to one day. I am curious why the large cutout on the left side of the frame behind the intakes.

[Ricino]

Hello, Kenny

I'm very glad you started your project, which looks really sound. Cool that you included a link to my project and also makes me happy it served you as a source. You're a pioneer since there's almost no info on how to solve certain things.

Mine is awaiting to be continued, no real progress since you got in touch with me long time ago. I can see some really nice solutions for the engine mounts; very nice you included the torque bars underneath as they are very important to keep excessive vibrations that could lead to exhaust chamber cracks and failures. The engine silentblocks are quite soft, they work well but are not enough to contain the shaky cases and twisting under WOT that could also lead to chain misalignment.

Ruzty , that large cutout on the frame's left side was intended to give clearance to certain part of the original 660 four stroke single engine; from what I remember there used to be the bulky electric start.

Thank you Kenny for posting, I'll keep an eye to your very nice project.

[RuZty]

Ruzty , that large cutout on the frame's left side was intended to give clearance to certain part of the original 660 four stroke single engine; from what I remember there used to be the bulky electric start.

I see, I thought it was something Kenny had done. I am not familiar with the SZR frame, they were never sold in Canada. It looks as if Yamaha took existing 4DL frames and modified them. I will also be watching this with great interest.

[KennyBarroz]

Hello, Kenny

I'm very glad you started your project, which looks really sound. Cool that you included a link to my project and also makes me happy it served you as a source. You're a pioneer since there's almost no info on how to solve certain things.

Mine is awaiting to be continued, no real progress since you got in touch with me long time ago. I can see some really nice solutions for the engine mounts; very nice you included the torque bars underneath as they are very important to keep excessive vibrations that could lead to exhaust chamber cracks and failures. The engine silentblocks are quite soft, they work well but are not enough to contain the shaky cases and twisting under WOT that could also lead to chain misalignment.

Ruzty , that large cutout on the frame's left side was intended to give clearance to certain part of the original 660 four stroke single engine; from what I remember there used to be the bulky electric start.

Thank you Kenny for posting, I'll keep an eye to your very nice project.

Thank you Ricino!
I hope you get started sorting out your project to soon :)

Yes it came to my understanding that Yamaha put the torqe-bars there on the later RD models just because of the issue without them.

I hope to continue with the bike this week if i manage to get my rim

[adriangp84]

Great work so far, excellent choice of frame, looks to be a bit easier fit than if it was a 3xv frame or 3yl. As you can see from my thread. Good progress so far. You will probably be finished before I even start mine.

[KennyBarroz]

Great work so far, excellent choice of frame, looks to be a bit easier fit than if it was a 3xv frame or 3yl. As you can see from my thread. Good progress so far. You will probably be finished before I even start mine.

Nice project you got there!
Well it was fairly straight forward, i just have to get offset sprockets and figure out all the extra small parts like gearshifter and such later on.

Thank buddy!

[Ricino]

Hey Kenny, just a little question...
How did you determine the chain alignment and the triangle between the swingarm axis and both sprockets?

I have to say that I used the oem measurements as a starting point, and then tried to match those oem specs.

[KennyBarroz]

Hey Kenny, just a little question...
How did you determine the chain alignment and the triangle between the swingarm axis and both sprockets?

I have to say that I used the oem measurements as a starting point, and then tried to match those oem specs.

Hi Ricino!

you mean like this?


Well i had the bike on the working bench, fixed in its neutral position, then calculated where center would be between front sprocket and rear sprocket. Draw the line and fixed my engine mounts that way.

Dont know if its the correct way or the wrong way, but i been thought that any way that works is a good way

Btw just got my rear wheel, its a perfect match! The RF600 wheel fits PERFECT in the 3XV swingarm. The rear brake disc is 240 compared to the SZR660 220. so i need to remake the rear brembo caliper bracket.

Easy fix! Then i will move over to the rear suspension

[RuZty]

When the swingarm pivot is below the centreline of the sprockets the application of power will squat the rear end, so with you sitting on it you would want it still above the centreline.