1973 T500 Cafe Project

[Gene]

Hi,
New member here and looking for support and resources for my T500 project. Didn't see a welcome thread so saying hello here.

First a little about me, been riding bikes since 1969 when I acquired a Hodaka powered Sachs at age 14. Over the years I've been in and out of the hobby because of marriage, back surgery and all that. Current machines include 2 Banshees for sand, 2 Hayabusa powered sand cars, a pristine 1989 Honda Transalp and now the T500.

Plans for the bike will take several years to execute since I have a job to report to in Angola. You know how it is, when you see one of these at a price that is agreeable - buy it. I bought the bike from a guy who said it had been built professionally a few years ago. He and two other guys owned it, all school age. They wanted out so now it's mine. Overall it looks good other than the booger welding for the rearset tabs. Got a good deal I think at 1500 bucks.

In the meantime I have a very experienced tuner who will mod the engine while I'm away. I'm told it has 125 - 128 psi in each cylinder, the oil injection system banjo bolt is missing and it needs tuning. No reason to start the thing until going through it properly.

Current thinking on this project is to modify the cylinder and weld on reed housings from a Banshee cylinder, port the cylinder, change the squish area in the head, get some expansion chambers from Jemco, Titan or Swarbrick (are there others?), add disc brakes front and back along with new forks and possibly a monoshock. I'll cut and grind off any brackets I don't like, add a brace and use another oil can like Titan has done on one of their builds.

I have a decent shop in my back yard with TIG, MIG, metal brake, hydraulic tubing bender, etc., so I can do all the fabrication work necessary once the engine is built and tuned in the bike as it sits today. I have the ability and skills to build a frame from scratch and did that once using an OSSA Stilletto to build a jig. Put a DT360 in that back in '73. Hauled the mail for sure.

I too plan to ride to vintage bike nite as well as other bike events populated by look alike hogs. So if anyone has ideas that I should consider please speak up.

Gene

3n53kf3p55V15Z25U5ac1a7cb00c24ae31da0.jpg

[Suzukidave]

Hi Gene and welcome to the group with your cool 500 cafe project , this site has a good bit of info for the 500s http://www.ozebook.com/compendium/t500index.htm" onclick="window.open(this.href);return false; and there is a nice collection of 500s here on Sundial viewtopic.php?f=21&t=1874" onclick="window.open(this.href);return false;

[tz375]

Hi Gene,

Welcome.

That's a sharp looking T500 you have there. Sounds like it's a sound basis for your proposed changes. That's quite a shopping list with reeds, squish heads, spannies and porting. Do you have a specific HP or torque target in mind? The reason I ask is that with those changes you could end up in a couple of different places. Is it safe to assume that you want a bike that's faster than stock but not so powerful that it becomes unreliable, and presumably you want it to be rideable but much more sporty?

Squish heads are a good idea and Eric (Zookie) that created this forum is quite the expert on those.
Banshee reeds are a little small on a Banshee, but can handle the air demands of a 70HP motor, so they should be adequate if that's the sort of target you are aiming for.

Swarbrick are really a race pipe, Higgspeed make nice looking pipes with an odd corn popping sound thhat you either like or hate. JEMCo pipes come in Swarbrick copy and JEMCO original flavors and have a great reputation for a street pipe with mild to moderate porting. If you want more power, there are a couple of people here that could work out dimensions and make pipes.

Cranks are really heavy on those motors and I'm sure the racers here can tell you what they did and how effective it was. Typically the crank wheels are turned down, but the cases are not stuffed any more.

Carbs. What are you thinking there? Flat slides flow slightly more air than the equivalent round slide, but more importantly, they seem to have much better pickup.

Angola. There's quite a large ex-pat community down there that is very supportive. We have run a few Cross cultural programs for people headed down that way. It's a very different culture, but you are probably used to that.

All the best on your assignment and on the trip.

teazer

[Jughead]

I was working on a set of Banshee Reed Cylinders but had to Shelve them.I'm gonna work on a set of Moo Reeds soon.(I Promise Moo. ) Just got to get everything Situated.Welcome to the Board.Sounds like you have everything in the Bag.Is that a 69 Tank?

[Gene]

Thanks for the welcome and information too.

Ordered a set of Jemco racing pipes today as it seems cost effective and compatible with what I have in mind. Off with the center stand, relocate the side stand.

The tank badge sure makes it look like a 69 - 70 but the fuel cap matches the '73. I like the badge on it more than what I see beginning with the '71 model. The tank seems perfectly straight.

My neighbor runs a company in Vancouver, WA called Streamline and builds high performance Banshees and other bikes and quads. He and I were talking about the project and I mentioned to him that I'd like to reed this engine. He has donor banshee cylinders waiting to carve but I will see what else might lurk in his shop that will flow a bit more. Since he builds monster motors too we will talk about options.

Horsepower wise 70's seems reasonable. When it's complete I will dyno the bike for a rear wheel number. It has to be reliable and for street a nice torque curve rather than massive hit is the goal. I don't know how much it weighs as-is and hope to get it below 350 lb. if possible. That should give it a 5 lb to 1 HP ratio. Sound realistic to you?

Regarding stuffing the crank that was one thing I planned to do based on an old article I read. I'm interested in more information about that so I make the right choice mechanically and financially. Why do it if it doesn't produce results or the results take me away from desired torque curve?

On carbs I have to believe that we will go to 34's and will run K&N or some other free flowing filter.

So now I need to start gathering bits beginning with updates for brakes and wheels. Any recommnedations?

Thanks!

[ja-moo]

Thanks for the welcome and information too.

Ordered a set of Jemco racing pipes today as it seems cost effective and compatible with what I have in mind. Off with the center stand, relocate the side stand.

The tank badge sure makes it look like a 69 - 70 but the fuel cap matches the '73. I like the badge on it more than what I see beginning with the '71 model. The tank seems perfectly straight.

My neighbor runs a company in Vancouver, WA called Streamline and builds high performance Banshees and other bikes and quads. He and I were talking about the project and I mentioned to him that I'd like to reed this engine. He has donor banshee cylinders waiting to carve but I will see what else might lurk in his shop that will flow a bit more. Since he builds monster motors too we will talk about options.

Horsepower wise 70's seems reasonable. When it's complete I will dyno the bike for a rear wheel number. It has to be reliable and for street a nice torque curve rather than massive hit is the goal. I don't know how much it weighs as-is and hope to get it below 350 lb. if possible. That should give it a 5 lb to 1 HP ratio. Sound realistic to you?

Regarding stuffing the crank that was one thing I planned to do based on an old article I read. I'm interested in more information about that so I make the right choice mechanically and financially. Why do it if it doesn't produce results or the results take me away from desired torque curve?

On carbs I have to believe that we will go to 34's and will run K&N or some other free flowing filter.

So now I need to start gathering bits beginning with updates for brakes and wheels. Any recommnedations?

Thanks!

Crank stuffing was old tech with lousy pipes, the higher crankcase compression the sharper the rpm range, not a good plan. Better pipes need more clrank case volume to make the suction wave from the pipe work easier.

As Juggs said, I have a nice kit, that Juggs WILL be testing soon..... Welding on cylinders twists stiff and is a major amount of work, and that big of reed is not needed for 70 rwhp........ my 2 cents......

[Gene]

Thanks for describing why crankcase stuffing is unneccessary. I'll be interested to learn results about the head kit. so will stay tuned from wherever I happen to be.

Just returned from my local MC junkyard and it has a 79 GS front end complete for $250. Seems from what I've observed on Ebay that I won't do any better piecing one together and paying shipping. Comes with front mag wheel, rotors, calipers, cables and brake fluid reservoir. Is it blasphemy to use mags on this bike provided I do the same in back. Would the rear GS wheel fit my swingarm or is it a fab job?

Also I read on an international forum in an older post about 2 into 1 pipes saying it reduced surging. It also said Jemco made 2 into 1 pipes but Jon at Jemco did not mention them. Does anyone run 2 into 1 pipes?

Related to the 2 into 1 question is that a few years ago I saw a single carb kit for Banshees and am curious to know if it's been done before, good, bad or nuts.

While at the wrecker I saw an old Sachs roller with springer front end, just like the Hodaka powered machine I had over 40 years ago. It was cool!

Thanks

[Jughead]

I had a 2 into 1 Strader on the Lil Orange monster for a Little While but about all they are fit for is Noise.Power Drops off too early.You can't go wrong with Jemco's.Like Moo said the Banshee reeds would be a little bit Over Kill on the T500 Motor.Of course I was going to go all out.Lack of Money don't get you far though.

[Gene]

I'm getting educated slowly about converting the front to disc brakes. The mag wheel on the 79 GS 850 is as ugly as it gets. All those wheels should stay at the scrapper.

Seems the same era GT 750 front wheel is the way to go if going dual disc. From what I'm reading it wasn't a very good brake and later attempts to vent the rotor did not help much as better brake pads from EBC apparently did. I've read that the SS rotors are "greasy".

So if I'm reading all this material correctly a GT750 front end is a good choice. If the GS fork tubes and triple tree are compatible with the GT front wheel and caliper I will get the GS forks here since they are in good condition.

Will the GS forks work with the GT wheel?

[oldjapanesebikes]

Will the GS forks work with the GT wheel?

Maybe, although it looks like you'd have to change out the whole triple tree etc. as the tubes are different diameters. This won't tell you everything you need to know, but it might help with the decision process

http://www.oldjapanesebikes.com/Additio ... eSizes.pdf

Enjoy !

[Jughead]

You'll pretty much have to find out what works on the forks.Here is my T500 as I rolled it out of the Darkness for the First time.It has 75-77 GT750 Forks,Triple tree and Wheel with GSX1100 Discs and Calipers.With the GT550 and GT750 Forks you will pretty much have to raise the tubes as far as possible in the Triple tree since the Tubes are Longer.If you go with the 76-77 GT500 front end it'll will be the same Height as the T500.Uses the same wheel as the GT550/750 BUT will only have 1 Spot for a Caliper on one Leg.Just my Opinion but Dual Discs are kind of an Over Kill.Looks good but with the set up I have you just barely have to touch the lever to lock up the front wheel.

[titan performance]

Got to say Gene, the bike looks superb as is. Does the camera lie, or is it really that pretty?

We are experimenting with front brakes on one of our builds at the moment....it looks like we are going with a dual piston Nissin caliper, which is used on many models....and an exup disc.
The disc will need an adaptor plate to fit, but it's nice and light. We have swapped the standard Gt500 legs around, so the caliper sits behind, and will only need, a relatively simple to fab adaptor bracket.
Sadly, opposed piston calipers foul the spokes.

[tz375]

There are no shortage of disks and calipers that can be made to work.

I prefer the SV650/EX500 style for ease of fabricating adapters.

CBR600F 3(?) disks have the same bolt pattern.

GT disks are almost 6 pounds each and modern disks are about 3.

[Gene]

Thanks Titan. It is a privelige to have this bike as it is. Here are more taken today. I've done nothing to it yet, not even wipe it down.

A single caliper would suit me fine and works well on my Transalp. The two are about equal weight and some reduction in unsprung weight would be nice.

The references supplied are very useful. Spokes and Akront with a single rotor. I'm taking notes for sure.

Thanks

SlantsRear.jpg

73GasCap.jpg

BoogerWeld.jpg

[Gene]

a few more

FrontBrake.jpg

Headlight.jpg

RightFront.jpg

It's pretty nice. I'm not going to Frankenstein the bike, just reasoned updates based on what I learn.