Topic: Building of a CB500 classic racer

[bwaller]

Rene, you must be using aftermarket exhaust primary tubes welded to the 600 collector? The stock double tubing would be heavy. Any idea how much your new exhaust system weighs yet?
 
I'm still thinking about your hoping to get the bike down to +-125kg. Man that is impressive, good luck.

Looking good.

[kpier883]

hallo kirk
the gsxr rods are in two types the 40F and the 41G
the 40 F pp hole wil be about 18mm after removing the stock insert
the 41G pp hole wil be about  17mm after removing the stock insert
for the bronze insert i use  cual10ni
outside dimension about 0,05 to 0,07 bigger
easy to machine  but expensive
inside clearance  0,01

Is it difficult to machine the bronze sleeve? 

Do you mind sharing the clearance information of both the inside and outside of the bronze inserts?  That is, what clearance for the insert to the rod hole and what clearance for the wristpin to the bronze insert hole?

I assume the bronze insert should not turn (spin) inside the rod, correct?

As you can tell I don't know anything about machine work.  But I would like to know how you did that!

Kirk

 

Very NICE!  Thanks for the information, and excellent looking work!

Kirk

[Howell]

Rene, you must be using aftermarket exhaust primary tubes welded to the 600 collector? The stock double tubing would be heavy. Any idea how much your new exhaust system weighs yet?
 
I'm still thinking about your hoping to get the bike down to +-125kg. Man that is impressive, good luck.

Looking good.

The primary tubes are from an old 4 in1 , I don't know the weight yet , but when the parts are weld together I will put it on the scale.

[Bluegreen]

Looking forward to seeing progress on the MkII.

[Howell]

Some nice pictures of the Davies 500 four:

[Leino]

Impressive looking bike but I don't think the throttle response is nothing to mention 

 Juha

[CB750faces.com (Lecram)]

Impressive looking bike but I don't think the throttle response is nothing to mention 

 Juha

I think there is a Bluetooth connection between throttle and carbs 

[Howell]

Today a friend welded with TIG some bobbins and brackets at the frame and welded also the exhaust.

[voxonda]

Nice going, René.

[Retro Rocket]

Sorry if its already been mentioned here , but what type of metal is the frame made from.? Crome moly.?

[Howell]

Sorry if its already been mentioned here , but what type of metal is the frame made from.? Crome moly.?

Reynolds 631: http://www.alumacraft.co.uk/motorcycle/motorcycle.shtml
                        http://reynoldstechnology.biz/assets/pdf/rtl_2010_moto_tech.pdf

[Retro Rocket]

Sorry if its already been mentioned here , but what type of metal is the frame made from.? Crome moly.?

Reynolds 631: http://www.alumacraft.co.uk/motorcycle/motorcycle.shtml
                        http://reynoldstechnology.biz/assets/pdf/rtl_2010_moto_tech.pdf

Thank you...

[Howell]

After yesterday's welding I made some progress building up the bike.

[Howell]

Exhaust is complete finished now.

 

[bwaller]

Your exhaust looks very good. I don't recall you saying there were any planned engine changes so it would be interesting to see if this exhaust shows a change on the dyno. 

[turboguzzi]

looks good indeed,

have to add that from all i read there's quite bit to be gained by playing with the lengths of the primaries vs, the secondary vs tail lengths of the 4-2-1 pipes.

had the chance to see an exhbition of all the Yamaha M1 motors at their headquarters in Italy and they played quite a bit with these parameters throuogh the years.

some of the systems had cyls 1-4 & 2-3 paired while others had the more classic 1-2 & 3-4 joined like in yours.

TG

[Howell]

Rene, you must be using aftermarket exhaust primary tubes welded to the 600 collector? The stock double tubing would be heavy. Any idea how much your new exhaust system weighs yet?
 
I'm still thinking about your hoping to get the bike down to +-125kg. Man that is impressive, good luck.

Looking good.

The weigt of the complete exhaust system is 6 kg.

[Howell]

To save weight from the wheels I told before that we gonna use smaller and lighter tyres with no innertubes and a smaller rearrim.
We have now a smaller 2.15 rearrim instead of the 2.50  , a Avon Am22 110/80 -18 reartyre and a Dunlop KR825 2.75-18 fronttyre.
For riding without innertubes you have  to take care that no air escapes trough the nipples on the innerside of the rim and you must use valves for tubeless rims.
How to do this I learned from a racerfriend.
I have sealed the innerside of the rims with an sealant gasket and let it dry for 24 hours.
After that I put duct/duck tape around the sealant.
Today we fit the tyres on the rims and put 6 bar in it to test it and lucky there was no leak.
After a few days I will check the tyre pressure again to see if the pressure is the same.
If the pressure is lower after a few days, I think we swap back to innertubes.

[Howell]

We make slowly progress at the moment, the bike is technical nearly finished.
I'm waiting for a new steering stem made by forum member Voxonda, old one is 1 cm to long , I mounted it provisional with two spacers.
At the rearwheel we saved 1,5 kg and at the front a 300 gr. , the weight saving at the front  is little because the Dunlop has nearly the same weight at the Avon we used before.
So I could only save weight to take away the innertube and to make the axle hollow , but had to put a lot of of sealant on the spokenipples to avoid escaping air.
The tyrepressure remains steady.
The plu from XPS foam for the tank and seat are ready , a lot of shaping , filling ,sanding and dust.
Now we are gonna try to make a mold from the XPS foam plug with fibreglass.

[Howell]

Yesterday I received two alu parts made by Voxonda , a shorter steering stem and a rear brake panel stopper.
I  've replaced the stem and mounted the stopper , now the bike is technical finished.

[Howell]

It has been a long time quiet about rebuilding the bike with the Davies frame.
We tried to built a carbon tank and seat but didn't succeed in it because it's difficult to make a good model for it.
Evenso in februari it was to cold in the garage and I had problems with my back so I had to lay in bed for a week and after I was recovered we made a wintersport holliday.
But last two weeks I picked up things again.
The bike was already technical finished.
Instead of making a carbon tank and seat we decided to make only a new seat from fibreglass.
Making a model for it was not so difficult as a fueltank.
See the result:

[Howell]

Now the seat was finished I made a heatshield behind the cylinderblock to keep away hot air from the carbs and two air intakes leading fresh air to the carbs.
This year w're also gonna use a GPS laptimer/trackmaster , (I know it's classic racing but this is allowed) to improve the laptimes.
http://trackmaster.trackaroo.com/welcome



Last week I've weighted the complete bike , with the old frame it was 155 kg and now 135 kg ! with oil and no fuel.

Next weekend we go to French to the circuit of Val de Vienne , a three days test before the first race on april 9th.
Here some pictures:

[bwaller]

20 kilos= congrats, very well done.

[turboguzzi]

20 kilos= congrats, very well done.

+1, yep, 135 kg for a faired 500 is good work indeed, and quite more realistic than 125 kg

After so much effort i guess Yrjo is doing his part and doesn't drink any beer or eat any chips or burgers right?

BTW, i use data logging too, both trackmaster on a samsung and racechrono on a nokia, found them both ok for lap timing
here we are not allowed to have them as a display like you, but i can carry it in my pocket and have all my laps immediately after a session

but if you do also want to get into detailed  speed, brakepoints, lateral G,  etc analysis, both system really need an external 5hz BT GPS, the internal 1 hz of the phones just isnt accurate enough.

So Rene, when is your first race? Here in Italy we are already up and running.

Big change in the field this year, hardly any 500 sohc4's racing anymore here. Sad, but everybody is moving to the post classic, up to 83' TT1 and TT2 classes.....

Back in 2007-2008 there where something like 10-15 guys running 500/4's, only two 500/4's left now!

good luck

TG

[Yrjo#54]

20 kilos= congrats, very well done.

+1, yep, 135 kg for a faired 500 is good work indeed, and quite more realistic than 125 kg

After so much effort i guess Yrjo is doing his part and doesn't drink any beer or eat any chips or burgers right?

BTW, i use data logging too, both trackmaster on a samsung and racechrono on a nokia, found them both ok for lap timing
here we are not allowed to have them as a display like you, but i can carry it in my pocket and have all my laps immediately after a session

but if you do also want to get into detailed  speed, brakepoints, lateral G,  etc analysis, both system really need an external 5hz BT GPS, the internal 1 hz of the phones just isnt accurate enough.

So Rene, when is your first race? Here in Italy we are already up and running.

Big change in the field this year, hardly any 500 sohc4's racing anymore here. Sad, but everybody is moving to the post classic, up to 83' TT1 and TT2 classes.....

Back in 2007-2008 there where something like 10-15 guys running 500/4's, only two 500/4's left now!

good luck

TG

I lost this winter also some kg's; 4,5

We use an external 5-10 hz GPS; Qstarz bt-q818xt 10hz

Our First race is 9th of April at TT Circuit Assen