GPR Camp: Replica Racers

Very nice work Remi. Also thanks for that tip on the pistons.

Small progress on the engine. Replacement of the original clutch bell pinion against that of a Derbi euro3 with bearings (same as MRD kit).

I also used the Derbi Euro3 gearbox forks, because they have a specific treatment that avoids wear. The Euro2 forks are strongly subject to premature wear.



The new generation of forks is in right on the image (gray)

Today I received a Metrakit MRD balancer. It weighs 10g more than the original one. Does anyone know the benefits? I suppose it helps to reduce the vibrations on a « big bore » cylinder 70 ProRace, and maybe adds a little elongation to the engine?

Does anyone have information about this product?

RemS wrote: ↑

Thu Feb 07, 2019 1:48 pm

Reception today of a Balancing Balancer Metrakit MRD.
it weighs 10g more than the original one.

does anyone know he benefits? I suppose it helps to reduce the vibrations on a « big bore » cylinder 70 pro race  , and maybe adds a little elongation to the engine? information about this product?

Yes that’s exactly the reason for it. If you were to weigh the stock configuration of the 50 reciprocal weight, and compare it with the Metrakit setup you'd find some disparity. I expect it would be more than 10g though because the balancer is rotating with a much smaller radius. I don’t know the math involved here so I can’t get more specific.

It’s awesome that you found one of these. I’ve often suspected that this part existed—because well it just had to exist! I’d really like to know that math to calculate the differences, and it would be great to have multiple weighted ones available. This would allow us to tune the vibrations right out of our bikes.

okay

if I see one happening one day, I'll think about you toratora

a little progress on the engine ...
I closed the crankcases with a new crankshaft malossi RHQ (the reference).
then put "clean" metrakit cylinder. machine-cut cylinder head, and corrected lateral diagrams.
something very soft, I have not retouched the exhaust that is already high (195 •).
I would like to remind you that I want a motorcycle that is simple and not too prepared, with an "easy" engine, with a pleasant range of use, for the road ...

here is the engine block and its peripherals, ready to be mounted in the chassis of the bike. (The exhaust will be modified with a long leakage tube, like the one designed for GPR ..) also remains to adapt the carburetor and air filter in the best possible way.



my son wanted to be on the picture

Hey rems.. nice work btw!! Oh and I did notice the table in the background.. I have the same lol

Berkeley wrote: ↑

Thu Feb 14, 2019 12:47 pm

Hey rems.. nice work btw!! Oh and I did notice the table in the background.. I have the same lol

Swedes are everywhere !!