Sachs rear shock

[howard]

Just bought a used Sachs rear shock for my old LC but I’ve never heard of these before so I’m not sure if they are cheapo or OK, I was very surprised when I checked the air pressure though as it was holding 55psi which seems a lot , what do you think ?

[dusty350]

Do you know what model bike it came off ?

[howard]

Not sure , it came with a LC rear swinging arm etc so hopefully it’s come off a LC .

[midlifecrisisrd]

Not sure how the piggy back reservoir will fit 🤔

Steve

[howard]

I’m not either but the bike isn’t standard at the mo .

[fletche36]

Ok, as im aware sachs are a fairly high level shock and fitted to some top end bikes like bmw and ducati. i have had a couple of beta enduro bikes which come with sachs shocks ( now called sachs zf) and they have all performed well but issues do arise due to anodizing wearing off the shock body which contaminates the oil. but not all are affected. As regards the air pressure ( nitrogen if its been re gassed correctly) on my enduro bikes its around 140 psi. Obviously this may not be applicable to a road bike shock but im just sharing my limited knowledge with you.

[dusty350]

The reservoir is the reason I asked what bike it came from, plus the fact it has a fork at one end instead of an eye. Knowing which model it came from will also help know that particular bikes weight, and whether its close to the weight of an Lc. The res will cause an issue if using an Lc inner guard I would think. And length ? 315mm is standard for an Lc shock

🙂

[JonW]

Apr 1, 2024 20:20:00 GMT 1 fletche36 said:

Ok, as im aware sachs are a fairly high level shock and fitted to some top end bikes like bmw and ducati. i have had a couple of beta enduro bikes which come with sachs shocks ( now called sachs zf) and they have all performed well but issues do arise due to anodizing wearing off the shock body which contaminates the oil. but not all are affected. As regards the air pressure ( nitrogen if its been re gassed correctly) on my enduro bikes its around 140 psi. Obviously this may not be applicable to a road bike shock but im just sharing my limited knowledge with you.

Totally agree with what has been said here. The gas pressure seems low to me at 55psi, Id expect around 100 etc. Also agree thats Sachs was/is a decent brand, not quite Ohlins perhaps, but better than Hagon. Maybe equiv of YSS but of the older league table before YSS came along. Today a modern YSS would be better. Yours looks to have come off something else Id think, something 'production' perhaps.

There was a Sachs that used to make bikes back in the day... dunno if same company tho.

[dusty350]

You might get away with the physical fitting of that shock on a Pv, but not sure it's gonna work with the Lc. I fitted an R6 shock to a Pv once upon a time, and it works fairly well, fit wise. Shame the R6 was a fair bit heavier than a Pv though !!
Done this a few times now over the years, and have come to the conclusion that a shock designed for the Lc is always my best bet (I wont mention the Rgv remote res shock that was like a pogo stick, or the z1300 Marzocchis on my old 400 !!)

[crogthomas]

As a complete aside to the thread title, I recently had the chance to test some springs and found that the R6 shock/spring (5EB) that people use on the YPVS is about the same rate as the standard one. The R6 must use a different linkage ratio, or be very softly sprung.

R6 5EB = 9.86 kg/mm
31K = 10.75 kg/mm
F2 = 9.71 kg/mm

Some slight differences, but considering production tolerances and many years of corrosion on the springs, they are all within a small percentage of each other.