So for reasons I don't think anyone knows the SP Shock isn't particularly serviceable. I bought an SP shock to be the final piece of the puzzle in converting my R model to an SP model. But the nitrogen seems to be a little low (shock reservoir cap can be pushed in about 1mm). Nonetheless, I would like to add a schrader to check the pressure from time to time. I was thinking of doing two things:

Adding a schrader valve however not sure what the best approach is: threading a valve into the cap and/or welding a nut to reinforce the area around the valve

OR

Use the shock reservoir off another bike, probably an 80s CR125 or CR250. From my understanding, the SP Shock is different to other shocks in the design of the reservoir however I'm guessing the threads would be the same in the reservoirs for the oil line. I guess this would also change the settings on the shock too.

Anyone have any advice on which to do? Ideally I would just get an Ohlins shock however with the US dollar recovering, an Ohlins shock is nearly as much as what I paid for my NSR and the OEM SP Showa Shock was 10% of the price. I think the seals are good as well.

Also, the spring collars seem to be quite stuck but I'll tackle those another time.

I have a 96 MC28 SP and it has what appears to be a factory shock with a schrader valve on the end of the reservoir cap, just what you are think of doing with yours. I don't know if my shock is a kit shock or if someone has modified the stock shock but at ant rate it can be done.

It depends on where in Aus you are, but there is a guy in Melbourne called Bruce Linsdell who runs BLS suspension and is awsome at rebuilding shocks that arnt meant to be rebuilt and custom modification work like what you are reffering too. He has done some custom work for me in the past and has worked for both Ohlins and Honda Aus racing team so his suspension knowledge is awsome. The only problem is that he is always flat out so you may have to wait a while to get anything done.

We rebuild rear shocks.









"R" model and MC16/18 shocks too...




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Andy.
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Thanks for the replies guys. I was considering getting you guys to do it (Andy, that is) but I think the shock is just a little low on gas and doesn't need a rebuild yet (when I eventually start taking it to track days I'll be keen to get the suspension properly done). Although the refurbishment works to as-new condition is quite enticing! I'm mostly just wondering the best way to get the cap off and best way to add a valve. I just don't want the end of it to get blown apart when under pressure. I was thinking to just getting the valve welded on (My friend is a pretty good MIG/TIG welder) but just wondering what might be the best plan of attack.

There are two types of bladder in the MC21/28 shocks; a large one, which makes charging with gas extremely difficult, and a small one, that makes charging with gas... extremely difficult! LOL

We make our own custom end-caps (sometimes with a larger capacity that stock), rather than modifying the OEM steel cap, but that should work equally well.



I would personally use a bolt-on type valve over a threaded one, as there's not much metal to play with. I wouldn't weld one in either, as I would expect it would probably distort.
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Andy.
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I would be asking myself why has the nitrogen pressure dropped. My guess would be a seal has gone, does it have any oil in it? Something is leaking somewhere either oil or gas.

Either way I personally wouldnt use it without a proper strip and rebuild, just regassing it isnt the way to go in my opinion.

That end cap is neat Andy, looks like the one on my f3 shock. Those rebuilt shocks look superb, I think Im gonna have to do a full refurb on my 28SP shock now Ive seen those

Hmmm, I must have a different type as the cap on mine domes outwards (unless that is your custom cap). Nonetheless, as Paul G mentioned, it might be a better idea to just get it rebuilt by GT. Andy - Would you be able to PM me a quote for a rebuild with a schrader valve end cap (Rider weight 70kg)?

I have no idea why Honda made these shocks so hard to service! They're supposed to be performance motorcycles!

KICKER wrote:
I have no idea why Honda made these shocks so hard to service! They're supposed to be performance motorcycles!

So you'd buy the fully rebuildable HRC shock!

I'll PM you.
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Andy.
NSR-WORLD.COM

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