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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: BlueK11LT on August 24, 2019, 05:45:39 PM

Title: Rear suspension unit - anyone ever dismantled it?
Post by: BlueK11LT on August 24, 2019, 05:45:39 PM
from a friends K100 which iam helping him to give the bike a refresh,
I have a pair of motorcycle spring compression tools and the intention is to compress the spring,grip the top of the damper rod and loosen & remove  the top mount which I believe to be threaded to the damper rod.
Intention is to have the shock body rubbed down and resprayed and the spring powder coated and the crumbling 35 year old bump stop replaced.
I imagine the top mount will need heat to expand the aluminium enough to loosen the mount.
Anyone?
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: Laitch on August 24, 2019, 06:10:05 PM
Anyone?
How about this (http://www.k100-forum.com/t4326-rear-shock-advice#44229)?
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: Martin on August 24, 2019, 07:04:07 PM
As per Laitch. However we have a local suspension shop called RAD. He charges $200.00 for a standard rebuild on the OEM shock $250.00 if the shaft needs re-chroming. I'm on my second RAD in 21 years the first one lasted around 10 years the second one is still going after 7 years. They appear fine as far as performance goes, but if you race or really get stuck into it you might want to upgrade.
Regards Martin.
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: BlueK11LT on August 26, 2019, 04:18:25 PM
We managed to unscrew the top mounting from the damper rod eventually after gripping it with mole grips and applying quite a bit of heat,there was quite a bit of corrosion in the threads.
BTW it is not planned to actually  rebuild the shock,just remove the spring for renovation of it and the damper body and renew the bump stop.
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: K1300S on August 26, 2019, 05:01:34 PM
cleaning and repainting a 35yo shock is a waste of time.  it is dead.  just get a new one. 
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: BlueK11LT on August 27, 2019, 01:46:28 AM
cleaning and repainting a 35yo shock is a waste of time.  it is dead.  just get a new one.
why is it a waste of time? the shock still works well,no signs of leakage and the bike has low mileage the intention is to keep it as original as possible,early original naked K100s are much rarer than the RS or RT/LT and will have collector value in years to come.
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: johnny on August 27, 2019, 06:38:34 AM
greetings...

discerning collectors refere to them as dampers...

collectors prefer that 35 year old patina compared to rattle can spring and modern bump stop on vintage dampers...

putts a ram or yss on there and ride... putts the oe back on when you sell it to a collector...

make sure you do that in the next 10 years becsuse there will be no gasoline in 10 years... only electric vehicles... and if not we will all be dead in 12 years anyway...

j o
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: billday on August 27, 2019, 07:27:19 AM
We managed to unscrew the top mounting from the damper rod eventually after gripping it with mole grips and applying quite a bit of heat,there was quite a bit of corrosion in the threads.
BTW it is not planned to actually  rebuild the shock,just remove the spring for renovation of it and the damper body and renew the bump stop.

Got any pics of this project?
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: Laitch on August 27, 2019, 08:33:52 AM
. . . early original naked K100s are much rarer than the RS or RT/LT and will have collector value in years to come.
Will you be explaining to prospective collectors of this moto that it was once ablaze, or will that be a caveat emptor kind of thing?
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: K1300S on August 27, 2019, 10:49:05 AM
why is it a waste of time? the shock still works well,no signs of leakage and the bike has low mileage the intention is to keep it as original as possible,early original naked K100s are much rarer than the RS or RT/LT and will have collector value in years to come.

how do you know it works well?  have you had the damper on a dyno?  low mileage or not, age dries out the seals.  i have yet to see a damper more that 15-20 years old that is still effective.  if someone is going to actually ride this thing, they will be much happier with a new damper that has a spring sized for their weight.  not to mention new aftermarket dampers are better than the junk bmw put on these things when new.

LOL - i love K's, and love the optimism, but the concept of any early K bike, let alone a base model one, being worth money as a collector item in the future is really funny! 
Title: Re: Rear suspension unit - anyone ever dismantled it?
Post by: johnny on August 27, 2019, 11:32:50 AM
:smoke07