russ4130
CB750 Member
Hi guys, has anyone ever had any success rebuilding those Showa rear dampers with the piggy back reservoirs please?
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RC42 Showa rear dampers
- Thread starter russ4130
- Start date
Try these guys.
https://www.teknikmotorsport.com/brands/showa-genuine-parts/
https://www.teknikmotorsport.com/brands/showa-genuine-parts/
russ4130
CB750 Member
According to this website, these dampers are non-rebuildable. I did think that might be the case. I can do a simple check to see if the reservoirs are still pressurised by removing the springs and compressing them by hand. If they rebound, there is still pressure. If they pass that test, they could be put on a dyno to check that they both respond with a similar curve. Failing that, I guess ill be logging on to the Hagon website for some new units. What other rear shocks have people used on their RC42s?
CBrat
CB750 Member
Also following this thread, looking at shocks as we speak. I have the Showa piggyback ones too, I wonder how they are holding up after 15 years sat doing nothing???
Biebs
CB750 Addict
Looks of Chinesism clones for the RC42 ie USA version Nighthawk 750.
I installed a set of YSS shocks on my 1992 Nighthawk from EBay not piggy back.
Always check on Ohlin’s
I installed a set of YSS shocks on my 1992 Nighthawk from EBay not piggy back.
Always check on Ohlin’s
Are YSS any good? Fail quickly, dependable?
Biebs
CB750 Addict
Yes YSS has a good product at reasonable prices. Made in Twain I believe.
This is the distributor I used based in Italy.
https://www.ebay.com/itm/3733270751...2yav5NCK4ZiSXlDUpKrARQeZ0=|tkp:Bk9SR8io4-apZA
This is the distributor I used based in Italy.
https://www.ebay.com/itm/3733270751...2yav5NCK4ZiSXlDUpKrARQeZ0=|tkp:Bk9SR8io4-apZA
Biebs
CB750 Addict
russ4130
CB750 Member
I really wanted to know how these units were put together and if it would be possible to service them.
I bought a pair from an eBay seller recently and did a fairly indiscriminate tear down, drilling the reservoir cover in the centre. Mistake, the valve is behind here, next time drill off centre 2.5mm and tap the steel cover three times at M3, 120degrees apart.
No problem, the cover pops off and reveals a schrader valve. For most RC42, Showa rear dampers, a re- pressurisation with Nitrogen at 15 - 20 bar should return them to good working order.
I’m not sure if the steel covers can be re-installed afterwards so I’ve found some metal valve caps to keep the crud out of there.
I was impressed with the quality of the dampers, especially since they are fitted to a road bike. I have worked on both Ohlins and Penske in the past so was pleased to find nice main shaft seals, a shim stack type piston assembly and a rubber bladder fitted reservoir canister with a schrader valve.
In summary, I think these rear dampers are worth preserving and most should give good service once re-pressurised.
I bought a pair from an eBay seller recently and did a fairly indiscriminate tear down, drilling the reservoir cover in the centre. Mistake, the valve is behind here, next time drill off centre 2.5mm and tap the steel cover three times at M3, 120degrees apart.
No problem, the cover pops off and reveals a schrader valve. For most RC42, Showa rear dampers, a re- pressurisation with Nitrogen at 15 - 20 bar should return them to good working order.
I’m not sure if the steel covers can be re-installed afterwards so I’ve found some metal valve caps to keep the crud out of there.
I was impressed with the quality of the dampers, especially since they are fitted to a road bike. I have worked on both Ohlins and Penske in the past so was pleased to find nice main shaft seals, a shim stack type piston assembly and a rubber bladder fitted reservoir canister with a schrader valve.
In summary, I think these rear dampers are worth preserving and most should give good service once re-pressurised.
