R80 ST Rear Shock

[dr nosh]

Does anybody know how to get the spring off a standard BMW rear shock?

I need to do this for 2 reasons;
Powdercoat the spring (its a bit rusty0
The spring preload adjuster appears rusted so I cannot turn to adjust.

I am assuming that if I compress the spring, the alloy cap/eye will unscrew from the shaft.

Any hints, tips.

(Currently overhauling a 1984 R80 ST into a G/Sesque machine for riding around the lanes of North Norfolk).

Thanks

 

[VAL. H.]

Does anybody know how to get the spring off a standard BMW rear shock?

I need to do this for 2 reasons;
Powdercoat the spring (its a bit rusty0
The spring preload adjuster appears rusted so I cannot turn to adjust.

I am assuming that if I compress the spring, the alloy cap/eye will unscrew from the shaft.

Any hints, tips.

(Currently overhauling a 1984 R80 ST into a G/Sesque machine for riding around the lanes of North Norfolk).

Thanks

Not too sure about the shock. It might be a completely sealed unit like the Para shock. But there will be someone along in a minute with the correct info.

Now: Please do the ST a realy big favour. Keep and store ceafully all the parts you change for g/s bits.

The ST 'as well as being considered the best handeling bike BMW made at that time' is fast becomming a very rare beast these days, what with them being converted into would-be g/s's.

Give it ten years, maybe less. The ST will quite possibly become a very sort after classic. Especially ones that haven't been molested in any way.

If you look around you can see evidence of this with the R100R Mystic. Newer yes, but rare as hens teeth and comanding prices as high as the top end R100GSPD's.


Val.

 

[fayeslane]

I am assuming that if I compress the spring, the alloy cap/eye will unscrew from the shaft.

I'll have a look at mine in the morning.
Be bloody careful compressing the spring, potentially quite dangerous.

 

[dr nosh]

Val H.

Thanks for your concern.

I am certainly not going to throw anything away. Bike will be pretty standard just have a G/S look about it.

I've just spent the morning making new lugs for the 2 side panels in aluminium. Luckily there was enough of the original lug left to be able to use
M3's to fix to.

LH side panel fixed by some previous owner to the exhaust heat guard by self tappers...!!!
Also found that the threaded inserts in the heat guard had been drilled out (?) so no threads. Fitted M4 sheet metal threaded inserts now.
Panels now fit perfectly. Holes to fill but will do this later at the painting stage.

 

[bumpmuncher]

looks like it will come appart to me just need some lightweight spring compressors. not as easy as the parra with its split collar but it will still come appart

 

[dr nosh]

Success.

How To Strip Standard BMW Monoshock (1984 R80 ST)

1. Press out the eye bush from the alloy end cap.
2. You can then see into the eye and confirm evidence of threads in the central hole holding the shaft
3. Compress spring about 25mm, or enough to get your mole grips in place to grip the shaft. (Push the rebound rubber out of the way first)
4. Home made spring compressor Cost £0, (materials already in "stock") and about 1 hours work. Nothing measured, all done by eye and a black marker pen.
5. Grip the rod with grips. Use blow torch to heat up alloy end cap. The threads are threadlocked, so heat up to break down the adhesive. Insert metal rod into eye and rotate. Conventional R/H thread.


Now to paint up the spring and body.