Update on vintage Yamaha racer [Archive]

Yamahammer490

05-04-2004, 11:13 PM

Things are finally moving forward! After trying unsuccessfully to find a front end I decided to make my own from dirt bike parts like they did in the old days. Today I received the triple clamps from my buddy's machine shop. I designed them on my CAD program and he cut them with his laser cutter.

I've got a wide front tire and wheel from a Yamaha 225, so it will have the wide front end with a drum brake. Very old school.

Here's the triple clamp parts now. I've got to spend some quality time on the drill press next so they will actually clamp. I'm probably going to paint them a light gold/titanium color, or maybe I'll have them plated.

More pictures of the assembly will be posted soon, but here's a few of the triple clamp parts as they are now. (Assuming I've done the attachment thingy properly...)

Jeb

05-05-2004, 09:49 AM

Great to see some info on this! Can't wait to see more progress.

200xalltheway

05-05-2004, 07:14 PM

coool!!!!!

Yamahammer490

05-06-2004, 03:14 PM

Here's a CAD rendering of what it should look like in the next week or two. I've gotten a bunch of blue parts from the various doner vehicles so I'm going with the Yamaha sky blue theme. It will have silver wheels, blue plastics and yellow trim, just like the IT series of bikes.

My next big project is to fabricate the swingarm. I'm working on the design right now, so I've attached a rendering of what it will hopefully look like. I ripped off the design from several aftermarket quad swingers, but I will add a few of my own touches. I want it to look really trick like a factory works trike.

cliff2302

05-06-2004, 03:17 PM

those plans look sweet! Are those cad drawings?

Yamahammer490

05-06-2004, 03:46 PM

those plans look sweet! Are those cad drawings?

Yes, they are CAD models. I use Autodesk Inventor. My company sells CAD software and training, so I get the "friends and family" discount. :D

Jeb

05-07-2004, 09:18 AM

Awesome! I've got some models of a front hub, triple clamps, and swingarm I modeled up in SolidWorks because some day I will build a 80cc or 60cc trike. I'd like to base it on a 1984 YZ80 for a Tri-Z 80. They are preliminary, i'd have to get the actual bike and measure it and adjust the models accordingly. I've also thought alot about making screen number plates. I've modeled up a frame and may end up making a simple mold for them.

I figured I was the only person in the USA CAD Modeling trike parts! :)

I also had started modeling up a futuristic looking race trike. I wanted to use it for a 3D spinning GIF file. It's time consuming and I haven't finished it. I enjoy 3D modeling but sometimes it's tough to design on CAD all day for a living and then go home and work on extra stuff.

Anyway, Awesome Models! Especially the fender. Contoured models can be a pain.

Yamahammer490

05-07-2004, 11:38 AM

Here's my finished swingarm design. I've added a top and bottom flange for strength, added the welds, and dropped on a 3WW sticker. (It's Friday, the weather is nice and I really don't feel like working on work stuff... ;) )

I've got a business trip next week but will start cutting and welding the week after.

Jeb

05-07-2004, 02:04 PM

Yamahammer490

05-07-2004, 02:45 PM

That's great! You should have put on one of those old Yamaha "MONO-X" stickers from back then. I think Dennis Kirk still has some of those in their stickers they offer in their catalog. You could probably scan them in.

Yeah, Jeb, that's what I will probably do. I've researched this in old Dirt Bike magazines and on the web. In 1983 the sticker was black and said "MONO-X" while the 1984 version read "MONO CROSS" and was black on the YZs and yellow on the ITs. An example of each is attached.

I'm leaning toward the yellow 1984 version just because it will look cooler with the blue and yellow color scheme.

Jeb

05-07-2004, 03:15 PM

Man, seeing those old Mono-X rear ends sure brings back memories of my younger years!

If you look closely, you'll notice the 1984 YZ's did say mono-cross, but the mono-cross is in red like the 85/86. That's the way it is in an old Dirt Rider magazine I have from 84 with a test of the 84 YZ 250. if you need any info or pics, let me know.

I'd definitely go with the yellow version. it would look best of all.

Jeb

05-07-2004, 03:36 PM

You might want to add some Fillet Radii or Chamfers to prevent sharp-corner stress concentrations on the Hub Brackets. A cross-brace back towards the Hub Brackets will stop any flexing back there also.

See Pic (sorry for the poor mark-up!)

I know, everyone's a critic. For what it's worth, the west-coast arm on my Tri-Z has similar construction. It's even got some round tubing bracing spanning between the Hub Brackets themselves.

Yamahammer490

07-01-2004, 04:39 PM

I haven't had much time to spend on the beast because I've been so busy at work, but at least that means I have a job, right? :D

Here's a couple of updates:

1. This weekend I hope to have the triple clamps finished. Hopefully even have some of the front end put together if I get a few quality hours to work in a row. (Maybe what I need to do is drill a hole through my cell phone. ;) )

2. One of my buddies found the picture of the motorcycle below and thought it might be cool to do a similar color scheme. The bike is a Yamaha TZ roadracer. It is similar in color to the blue IT and Tri-Moto lines from the mid-80s. I mocked some graphics up and added them to my CAD models that are attached for your viewing pleasure. Any comments?

short4stuff

07-01-2004, 04:45 PM

so what exactly is it your making anyways? ... is everything custom? .. are you using an it490 engine ?? ... maybe i missed something somewheres ...

BigGreenMachine

07-01-2004, 04:47 PM

That is sweet. So its gonna be a MX'er? Do you have a set of YTM blue plastics? Gonna be such a unique bike when its done.

Yamahammer490

07-01-2004, 05:45 PM

so what exactly is it your making anyways? ... is everything custom? .. are you using an it490 engine ?? ... maybe i missed something somewheres ...

What I have is a project that started as one thing and spiraled into something completely different along the way. The short version goes...

I wanted to make a Yamaha racer like the old 3B trikes. Basically a race version of a Tri-Moto 175 with full suspension and the works. Since it was common to take IT 175 parts and use them on the Tri-Motos I started looking for a Blaster donor to get an engine and rear end from. I wanted a blaster so I can get spare parts easily.

Along the way I met a guy in my town that used to race trikes in the day. In fact he had a "home made" Tri-Moto 175 made from a converted dirt bike. (An IT 175) He used to race it in the 200 class and has lots of pictures with him on a podium. We had a few (too many) beers and decided that a bike conversion might be kind of cool. He had done a bunch of them and still has some old parts in his shop.

I then found an IT 490 in good enough shape to use as a donor bike, so that's where the engine, frame and suspension are coming from. I'm almost finished with some old school looking triple clamps. I've got a Blaster rear end and we're making a lot of other parts.

A lot of the parts will be custom just because we want to build one the really old fashioned way.

I couldn't find a nice set of blue plastics so I am painting them. Again, I'm not after factory restoring/authenticity but something really cool like a privateer race shop would have made in the early 80s.

BigGreenMachine

07-01-2004, 07:17 PM

This thing is gonna be sick, its fun to watch a project develop.

trikerider2oo7

07-01-2004, 08:03 PM

looks cool...you must be good at computers. those models are awesome!!

CHAINSAW

07-01-2004, 09:19 PM

Those front fender graphics looks like the Fear Factory logo.

BigGreenMachine

08-18-2004, 07:51 PM

Any progress Yamahammer490?

I have to get my Tecate together in September and over the winter I plan to build a custom 2 inch extended aluminum swingarm from rectangle tubing with the stock carrier and heim joints and misalignment bushings to replace the swingarm bearings...can't wait to get started on it.

Yamahammer490

12-17-2004, 11:57 AM

I finally have somewhat of an update to post: Last night I finally got a few hours to work on the trike. I was drilling and tapping the triple clamps so they actually clamp. I was tapping the last hole, hurrying to get done before dinner, when I broke off the friggin tap. :(

I thought about using an easy-out but the broken tap is as hard as my drill bits so I couldn't get a deep enough hole started for the easy-out to work. I didn't know what the heck to do so I grabbed my small Dremel tool and a chainsaw sharpening bit and started to slowly grind out the broken stub of the tap. It actually worked pretty well.

I got the tap out but obviously boogered up the threads in that hole. I think I will re-drill and tap all of them to the next larger size so they're the same. And, yes, I will be careful not to force it too much. :D

I'll post some pictures of the clamps when they're finished.

I'm going to take some time off between Christmas and New Years specifically to work on the trike and will post updates as I go.

Yamahammer490

06-25-2005, 12:01 AM

It's been a long time since my last update and not much has changed yet. We had a new baby in November and I under estimated how much work a new baby is. (But I love her to death :) )

A bunch of my buddies also got new quads so I got "quad envy" and sort of lost interest in fixing up old trikes for a while, so the project went on life support. I tried to sell the parts a couple of times but the deals kept falling through, which must have been a sign.

Then out of the blue my father calls me after no contact for 15 years, telling me he wants to set things right after some problems we had earlier in life. He's retired now and tells me that he's really getting into metalworking. He's also, get this, been making 3 wheeled bicycles for his geezer buddies to ride around on. Weird coincidence, heh?

I've kept on the board here watching all of the CR500 conversions going and have come to the conclusion that there needs to be some Yamaha representation too, so the project is back on! :Bounce

I don't have any new pics to show the progress yet, but I did finish the triple clamps and will be painting them this weekend. They turned out pretty cool.

I'm excited about getting back on this project and looking forward to working with my dad again after all these years, so there will hopefully be some regular updates on the project as we move forward.

MTS

06-25-2005, 07:07 PM

Thats cool your back on track.......but dont expect the yz490 motor to blow by any cr500s...lol will be freakin cool anyways!

Yamahammer490

06-27-2005, 02:54 PM

No, I don't expect to blow away the CR500s. I just want to make something cool and, perhaps, give a little competition to the sea of red out there.

That been said, this is a 500cc two stroke and it boogies no matter how you look at it. With the wide-ratio tranny it has a great top speed too. It should be fun :D

Yamahammer490

06-28-2005, 10:50 AM

My wife worked this weekend so I was only able to peck around on the smaller stuff, but I made a little progress.

I painted the triple clamps charcoal metal flake, and they look much better in person than the pic shows. The bottom one will probably have to be bored slightly for the steering stem to fit but I just used the same pattern for the top and bottom. The holes in the top one are obviously where the handlebar mounts go and the corresponding holes in the bottom will be sleeved down and used to mount the fender. I also used chrome bolts which look nice with the charcoal color. Hopefully next weekend I'll be able to get the trike front end on the frame, though I still need an axle and a brake mounting plate.

I had a little extra time so I started messing around with the headlight/numberplate that was on the bike. (I also chose to start with this because it is the most easily replaced part that I had and if it got screwed up could just be swapped with some other style or a number plate.)

It is held on the bike with rubber loops that go around the fork legs so I added plastic "wings" to the side so that the whole assembly would be wider. Then I drilled the holes and put some screen behind just for cosmetics. I purchased new yellow number plate material that was cut to fit. I've got to put the rubber loops on yet, but this shows the colors that I'm working with and I think it turned out pretty cool.

BigGreenMachine

11-10-2005, 12:42 PM

Hey Yamahammer490, how is the bike? Rolling yet?

thedeatons

11-10-2005, 02:32 PM

So, FYI, if you break a tap, McMaster-Carr has broken tap extractors. For a four fluted tap (Tap for steel) it has four hardened steel feelers that go in beside the broken piece, then you slowly turn it out. We didn't think they would work, because it looks pretty delicate, but it did... I assume they have them for two and three fluted taps also. Make sure you are using the right kind of tap, if it is not a thru hole there is a special spiral tap that pushes the metal back out the entrance hole, instead of pushing it towards the bottom of the hole, where it packs up. That is a common reason for breaking a tap... James

slow200s

11-10-2005, 09:04 PM

anything yet? sounds like an awesome time and money pit right now, those are sometimes the best?!? well good luck, would like to see pictures when compleated

Yamahammer490

11-11-2005, 05:32 PM

Not many updates, guys. My dad decided that the first thing I needed was a better workshop so he built me some cabinets and countertops. At least now I have a place for most of my tools.:beer

Besides that my own business has been going just crazy! (We sell engineering software and training to manufacturers.) I've gotten to spend some time modeling parts with Autodesk Inventor, and one of my customers even paid me to draw the exhaust pipe I've attached. They make the CNC bending machines and wanted to see how our software could help them with the tooling.

I'm living in hopes that I can spend some time on this and would love to make the trip to TF06 with a running trike.

Yamahammer490

12-28-2005, 12:43 AM

Merry Christmas everybody,

I managed to spend a little time on the project today and wanted to provide some updates. First, I finally test fitted the forks into my triple clamps. I've attached a picture of this and I think it gives me that first-generation "wide" front end I am looking for. (Obviously the wooden dowel will be replaced with a real axle.)

Last month I worked on the bike itself and got the motor running well. It has been ported and polished, has a DG pipe and Answer silencer, just like the Wrench Report from 1983 recommends. I cleaned up the jetting after repacking the silencer and it really goes like a raped ape. It may not be quite as fast as a CR500 or KX500, but it IS a 500cc two stroke and really rips no matter how you look at it.

My challenge right now it which front brake to use. I want to stick with a drum but have two options, the regular front binder that came with the front wheel from the donor trike or the double leading shoe unit that's on the bike. Right now, as you can see in the picture, I will have to fabricate a brake stay to make the donor trike's brake fit. I'm guessing that 1/4" plate would be plenty strong and I could bolt it to the fork leg and through the slot in the brake housing.

To use the double leading shoe brake I will have to fabricate a new hub, as it is about 1" larger in diameter than the one shown in the pics. This would be really cool because the double leading shoe brake is very trick looking and very powerful. It may also be an excuse to buy a larger lathe.:D

The front fender is from a YTM 175 and has a similar rounded side profile like the bike's fender, so it should look pretty factory. I'm sticking with a leading axle setup because it will let the brake be on the correct left side and looks good. (And when I turn the forks around for a trailing axle arrangement the wheel comes very close to the exhaust pipe.)

Lastly, I've decided that I want the trike to look like something Yamaha might have made, so the graphics and color scheme will be similar to the 1983 IT and YTM graphics though I might make some minor changes.

Hopefully I'll have more time to work on this project in the coming months, and will post when progress is available.

Yamahammer490

12-28-2005, 12:50 AM

Ooops... I had a brain fart and didn't actually click the "Upload" button to attached the pictures I said were attached. They are now!

BigGreenMachine

12-28-2005, 01:10 AM

The plastics look sweet, as well as the tripples and everything else. Very cool project.

Billy Golightly

12-28-2005, 01:17 AM

This is a cool project, gonna be watching it. If I remember right, your using the dirtbike forks right? Just make sure you keep your ride height and stuff in check ;-)

westcoast TRI-Z

12-28-2005, 01:24 AM

Very cool! I like projects like thse, they interest me alot. So in a way, you are building like a vintage replica-racer of the past?

vartiak15

12-28-2005, 01:44 AM

i think the axle is a little weak. lol jk. looks good man.

N5HNY

12-28-2005, 02:33 AM

Whoa ! That is awesome !

I really like looking at CAD designs.

Yamahammer490

12-28-2005, 02:36 PM

This is a cool project, gonna be watching it. If I remember right, your using the dirtbike forks right? Just make sure you keep your ride height and stuff in check ;-)

Yes, I will be using the dirtbike suspension and will have the same ride height issues as the other dirtbike conversions. (I watched your CR500 post closely too.)

I will have to run with the forks a couple inches up in the triples. Like all conversions, the geometry just isn't the same as a native trike, so I will have a little monkeying around with the height.

Here's a computer layout I did a while back to try and figure out what it will look like. This is all done with raster images so it isn't "completely" to scale but it is pretty close.

MTS

12-28-2005, 03:30 PM

This is a Sweeet project, That bike will go like Snot off the line when it is done, How's the DG pipe on that thing? i was thinkin of one for my IT465 cause mine is rotted n baged up pretty good..

Yamahammer490

12-30-2005, 12:12 AM

This is a Sweeet project, That bike will go like Snot off the line when it is done, How's the DG pipe on that thing? i was thinkin of one for my IT465 cause mine is rotted n baged up pretty good..

The DG pipe and Answer silencer combo seem to work well, but I've not had a chance to ride this bike with the stocker. When I bought the bike it had been ported and fitted with the DG pipe.

I will say that this is an awesome motor, though. It has super torque off the low end and a monsterous midrange. And, since it has a 5 speed tranny, it really boggies when opened up on a dirt road.

MTS

12-30-2005, 02:53 AM

The DG pipe and Answer silencer combo seem to work well, but I've not had a chance to ride this bike with the stocker. When I bought the bike it had been ported and fitted with the DG pipe.

I will say that this is an awesome motor, though. It has super torque off the low end and a monsterous midrange. And, since it has a 5 speed tranny, it really boggies when opened up on a dirt road.
Amen to that! im havin mine ported and done out in the near future, i havent come up to anything that can Out Climb this thing yet, Buddy;s ported Cr500 dosent even put out as much bottem end as this thing..its unfreakin real.

Darius1502

12-30-2005, 02:19 PM

Wow...this project is very exciting!

It will be awesome!! Keep it up!! Long live the vintage racer 490!!

Yamahammer490

12-31-2005, 12:10 AM

Amen to that! im havin mine ported and done out in the near future, i havent come up to anything that can Out Climb this thing yet, Buddy;s ported Cr500 dosent even put out as much bottem end as this thing..its unfreakin real.

I know this is a little off topic, but the IT engine was quite different from the YZ. The YZ 490 had a bad reputation and, having had one when I was a kid, I can say it had its faults. You can't ever get the jetting right it seems. The IT is a completely different animal.

It's important to remember that back in the 80's, Yamaha made the IT and YZ line as two distinctly different motorcycles. The ITs were not YZs with different colored plastics but, in fact, different designs. Dirt Bike Magazine hated the YZ but raved about the IT 490.

I do think it will make a great trike because I can lug it down to an idle in 3rd gear, twist open the throttle and have it almost rip your arms out as the scenery starts rushing by. It has a very smooth power delivery.

I'll be working on a few things yet this weekend and will post more soon. Probably going to work on the brake stay tomorrow see if I can figure that out.

Happy New Year, All!:beer

3leggeddog

12-31-2005, 12:28 AM

dude this is a sweet little project.i am very impressed by the planning,and the work shown so far.very uniuqe,and classy.keep it up.

are you gonna remove some of the rake,the front wheel appears way out in front.

BigGreenMachine

12-31-2005, 12:34 AM

Sounds great, my 250 needs some slippage to get back into the meat of the powercurve most times. Sounds like you have that itch again that doesnt go away until you have it well taken care of. Great to see some headway on this trike again.

MTS

12-31-2005, 01:31 AM

I know this is a little off topic, but the IT engine was quite different from the YZ. The YZ 490 had a bad reputation and, having had one when I was a kid, I can say it had its faults. You can't ever get the jetting right it seems. The IT is a completely different animal.

It's important to remember that back in the 80's, Yamaha made the IT and YZ line as two distinctly different motorcycles. The ITs were not YZs with different colored plastics but, in fact, different designs. Dirt Bike Magazine hated the YZ but raved about the IT 490.

I do think it will make a great trike because I can lug it down to an idle in 3rd gear, twist open the throttle and have it almost rip your arms out as the scenery starts rushing by. It has a very smooth power delivery.

I'll be working on a few things yet this weekend and will post more soon. Probably going to work on the brake stay tomorrow see if I can figure that out.

Happy New Year, All!:beer
Yea so i hear, my bike you feel the power comin on but the scenary dosnt move that fast on dirt, *Edited**Edited**Edited**Edited**Edited**Edited* thing throws a 60ft roost in 5th gear just spinnin,,, on asphalt its a whole nother animal, theres NO keeping the front end down in anygear.......no freakin way...dont matter how much gas your giver her she comes up like NOTHIN...

3leggeddog

12-31-2005, 11:17 AM

Yamahammer490

01-01-2006, 01:34 AM

i have rode a few 500's,i was amazed the first time i opened one up.the amount of tourqe is unreal.i got my uncles on the road,second gear i layed into it,the thing just spun the tire.a knobbie,on dry pavement.i was amazed.

Yup, 500s are a thing to behold. I'd encourage eveyone who hasn't ridden one to do so before they're extinct. The new 450 four strokes are very quick, and may even be faster on a motocross course, but they're not the same.

:beer

3leggeddog

01-01-2006, 01:43 AM

no not nearly the same animal.the new 450's are very user friendly,they can make any one feell like a pro.the power is so easy to use.and they are tourqy.not near as fast in a straight line though,just better balanced,and more mx oriented.

Yamahammer490

01-01-2006, 11:28 PM

I had a few minutes today to work on the project so I figured out exactly how I'm going to mount the front fender to the triple clamps. (Yeah, I know this isn't a monumental decision, but today IS a holiday.:D )

Since the YT 175 fender was intended for a trailing axle mount, it will be mounted a good 3" further back than original. Since this is a lot of unsupported plastic I decided to go with a fender brace.

I drew one up with Inventor and then cut it out in cardboard to see how it will actually look. Once on the fender with the headlight in place, I think it needed to move further forward so I extended the "ears" on the back. This latest version is shown in the screen prints.