BGM rear shock ~ rebuildable ?

[Warkton Tornado No.1]

Post by Storkfoot » Sat Aug 20, 2016 12:46 pm

Warkton Tornado No.1 wrote:
....but the special section seals will work better because they are designed to distort so that the piston retracts a little once the pressure is off.

Dave Webster may have been a pedantic character, but he knew what he was on about by advocating the use of the correct seals in his brake conversions..


I am interested in this. I have recently suffered a binding inboard hydraulic. I have just replaced the seal ( they are a Kawasaki part number) but I can't test it until I get the hub back from paint (DOT 4 does make a mess).

When I took the old seal out I was hoping there would be some visible signs of degradation but there were none. The new one did "feel" more springy rubber though.

Anyway, sorry for the thread drift but that's useful to know WT

It would be useful if you knew the manufacturer of the conversion. I suppose that a Kawasaki derived brake is likely to incorporate the correct section seal but it may be that it can be fitted the wrong way around...

MSC brakes were apparently derived from some obscure car.

Getting way off subject now (Sorry!) but if you look @ the BSSO 'Production(!?!) Class', Big Bob West retains his inboard hydraulic & I would bet he remains competitive....

[Storkfoot]

I do know the manufacturer. He gave me the Kawasaki part number. I never thought to ask if there was a right and a wrong way.

Funny you should mention Bob West. My GP ( well large parts of it including the frame) was one of his race scoots in the '80s and '90s.

[dickie]

I do know the manufacturer. He gave me the Kawasaki part number. I never thought to ask if there was a right and a wrong way.

As an erstwhile zxr400 racer who for one reason and another felt the need to continually modify and maintain brakes of my own and several fellow racers; i can say with 100% confidence that there is no right or wrong way.

The tokico used by kawasaki and nissin used by Honda are also the same either way round.

Keep them away from thin oil and diesel though or they expand (a surprising amount) and won't work properly in terms of retracting the piston after operation.

[Warkton Tornado No.1]

Post by dickie » Sat Aug 20, 2016 2:46 pm

Storkfoot wrote:
I do know the manufacturer. He gave me the Kawasaki part number. I never thought to ask if there was a right and a wrong way.


As an erstwhile zxr400 racer who for one reason and another felt the need to continually modify and maintain brakes of my own and several fellow racers; i can say with 100% confidence that there is no right or wrong way.

The tokico used by kawasaki and nissin used by Honda are also the same either way round.

Keep them away from thin oil and diesel though or they expand (a surprising amount) and won't work properly in terms of retracting the piston after operation.

Good that you clarified that as far as Tokico. Thank you.

It may be universal to a great extent nowadays, but that was not always the case, I believe.

[dickie]

Yes, intuitively I'd expect them to be trapezoidal which is why I know they weren't as I measured them to check.

Of course that info is only valid for the calipers I've worked on (Japanese sports bikes from about 85 to 2005ish). It would be a rather bold/stupid statement to say that it applies to all calipers!

[Storkfoot]

Thanks, D