Re: Hilfe beim Versand von Stossdämpfern in die USA
Verfasst: 18. Sep 2023, 08:53
Hi Michael,
naja natürlich gibt es Leute die alles selber machen können / wollen, aber ganz viele haben eben keine Möglichkeit sich neue Lager zu drehen. Ich denke eher, dass das fast alle hier sind. Auch wenn ich es theoretisch könnte, habe ich natürlich keine Drehbank daheim.
Anbei mal ein Schreiben von Peter was er alles macht. Dazu bietet er noch einstellbare Dämpfer an. Arbeit kostet Geld und gute Arbeit eben ein wenig mehr und für den Aufwand den er betreibt ist das absolut ok. Das ist nicht überteuert. Schau Dir mal die Preise für den Umbau auf Frontline VA an.
First. What fails in a lever shock? Almost all of the (non-traumatic) failures result from lack of oil in the shock. The manuals always recommend checking or topping-up your shox in various intervals 3000 miles or so. Why? Because they leak!.. what a surprise! They don't leak just because they are British, they leak by design (now there's a bumper sticker). Speaking here of the rear shox... the shaft that protrudes from the body of the shock is rotating in the body without a bearing. To ensure sufficient lubrication there is often a channel or groove in the shaft bore. At the outside there is a rubber packing retained by a thin metal washer. A packing needs some lubrication to work at all and the weeping of oil acts as a deterrent to dirt getting in.
Dirt getting in will score the shaft at the seal area hastening the demise of the packing and wearing the bearing surface in the body.
The solution that all of us rebuilders use is to machine the body and install a bearing. We use Delrin, others use bronze. Bronze requires oil, Delrin doesn't. We also machine the body for a rotary oil seal (others don't) (in fact we use a double lip seal with dust excluder). One guy does, now out of business did use a rotary single lip seal and the others use several rubber washers held in place with a steel washer or two. To solve the pitted and scored shaft problem, others sand or grind the shaft down.(you don't need to be precise with rubber washers) We have manufactured for us, to our specs, stainless steel sleeves that allows us to have a 3 micron finish and consistent diameter and concentricity of the shaft. After many years, we have found this to be very reliable. Our shox don't leak.
The process... step by step. Receive grimy old shock, tumble clean in a deburring/tumble cleaner. Glass bead blast entire shock. Disassemble. Tumble and hot wash in ultrasonic tank internals. Bead blast the rest of the arm. Machine for the bearing and for the seal. Wash again. Press in bearing and seal. Press on sleeve. Inspect and repair/replace as necessary the pistons and the valving. Reassemble components using all new hardware of proper thread and style. Fill with oil and bleed. Compare valving with NOS shock, adjust if necessary. Wash AGAIN. Paint 2 coats primer and 3 coats high heat black enamel. Date code and ship.
There you have it. I can provide details of the valving and design changes over the years, etc. But my carpel tunnel is acting up.
Peter Caldwell
naja natürlich gibt es Leute die alles selber machen können / wollen, aber ganz viele haben eben keine Möglichkeit sich neue Lager zu drehen. Ich denke eher, dass das fast alle hier sind. Auch wenn ich es theoretisch könnte, habe ich natürlich keine Drehbank daheim.
Anbei mal ein Schreiben von Peter was er alles macht. Dazu bietet er noch einstellbare Dämpfer an. Arbeit kostet Geld und gute Arbeit eben ein wenig mehr und für den Aufwand den er betreibt ist das absolut ok. Das ist nicht überteuert. Schau Dir mal die Preise für den Umbau auf Frontline VA an.
First. What fails in a lever shock? Almost all of the (non-traumatic) failures result from lack of oil in the shock. The manuals always recommend checking or topping-up your shox in various intervals 3000 miles or so. Why? Because they leak!.. what a surprise! They don't leak just because they are British, they leak by design (now there's a bumper sticker). Speaking here of the rear shox... the shaft that protrudes from the body of the shock is rotating in the body without a bearing. To ensure sufficient lubrication there is often a channel or groove in the shaft bore. At the outside there is a rubber packing retained by a thin metal washer. A packing needs some lubrication to work at all and the weeping of oil acts as a deterrent to dirt getting in.
Dirt getting in will score the shaft at the seal area hastening the demise of the packing and wearing the bearing surface in the body.
The solution that all of us rebuilders use is to machine the body and install a bearing. We use Delrin, others use bronze. Bronze requires oil, Delrin doesn't. We also machine the body for a rotary oil seal (others don't) (in fact we use a double lip seal with dust excluder). One guy does, now out of business did use a rotary single lip seal and the others use several rubber washers held in place with a steel washer or two. To solve the pitted and scored shaft problem, others sand or grind the shaft down.(you don't need to be precise with rubber washers) We have manufactured for us, to our specs, stainless steel sleeves that allows us to have a 3 micron finish and consistent diameter and concentricity of the shaft. After many years, we have found this to be very reliable. Our shox don't leak.
The process... step by step. Receive grimy old shock, tumble clean in a deburring/tumble cleaner. Glass bead blast entire shock. Disassemble. Tumble and hot wash in ultrasonic tank internals. Bead blast the rest of the arm. Machine for the bearing and for the seal. Wash again. Press in bearing and seal. Press on sleeve. Inspect and repair/replace as necessary the pistons and the valving. Reassemble components using all new hardware of proper thread and style. Fill with oil and bleed. Compare valving with NOS shock, adjust if necessary. Wash AGAIN. Paint 2 coats primer and 3 coats high heat black enamel. Date code and ship.
There you have it. I can provide details of the valving and design changes over the years, etc. But my carpel tunnel is acting up.
Peter Caldwell
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