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Once again the TL is knackered. Good job this is isn't my only bike!

The rear shock bottoms out just by sitting on it. The spring seems to be fine and everything looks shiny and new, but it's completely unrideable. Is this another epic job or is it something simple?
 

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The dampers have been known to spring leaks...Time for a rod through the swingarm pivot to lift the bike up. Either on jackstands or an Abba stand. get the weight off the suspension so you can do a real inspection...check all your bolts as well. Common probs are missing/loose/broken damper fasteners, cracked damper mounts on the frame (all of these start with a loose bolt). The other problem is a seized spring on a stick. And damper leaks as stated above.
 

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Is it the OEM rotary damper in there?
Have you checked the mounting points for cracks or broken bolts etc?
Any sign of leaks in the area?

The SOAS is OK?

Later edit: Exactly what abn said :stupid
 

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the spring holds the bike up not the shock
if it bottoms out its the spring .
if it pogos then its the shock.
 

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:stupid
 

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...ditch both the OEM shock and replace the stock SOAS with an 800# unit = this is a perfect opportunity to make some great mods:devious
 

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Check that the soas is straight - the have a tendency to make like a banana.
 

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the spring holds the bike up not the shock
if it bottoms out its the spring .
if it pogos then its the shock.
I know I :stupid But the spring is the shock absorber ;) The damper is a damper, a damper is not a shock aborber - contrary to what they're called in Auto shops etc. :laugh
 

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I know I :stupid But the spring is the shock absorber ;) The damper is a damper, a damper is not a shock aborber - contrary to what they're called in Auto shops etc. :laugh
I'd disagree with you here. The spring doesn't absorb anything. It just holds the bike up so that the shock absorber, i.e damper, can do it's job in both positive and negative directions. The spring does help applying an opposite force for "positive" shocks, but it will not absorb any of the force, but return it in the opposite direction, hence pogoing if the damper does not absorb the shock.

Absorbing a shock is by definition "damping".
 

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:doh I've not thought of it like that. I guess the spring is more for storage than abosrbing.
 

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but it will not absorb any of the force
How do we get into this shit:doh

essentially you are both right but the spring absorbs energy by manner of its operation. a little bit is lost on every cycle of compression and release. it is manifest in heat within the coils of the spring. If it didn't then the spring would oscillate indefinitely.

Rubber is an unususal material and is quite suitable as a self damping spring. It has both spring and damper properties. But that's just another can of worms:banghead :laugh
 

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How do we get into this shit:doh

essentially you are both right but the spring absorbs energy by manner of its operation. a little bit is lost on every cycle of compression and release. it is manifest in heat within the coils of the spring. If it didn't then the spring would oscillate indefinitely.

Rubber is an unususal material and is quite suitable as a self damping spring. It has both spring and damper properties. But that's just another can of worms:banghead :laugh
In theory I agree, but in practice, the amount of energy absorbed by a steel spring and converted to heat is negligible in these applications. You probably absorbe more energy in bearings in the suspension linkage. :dowhat
Put a lightweight spring with a weight in one end in a vacuum chamber. Give it a go and it will not go on forever, but pretty darn close. :laugh

However, the word "damper" is very a generic term. A rubber cushion does both act as a spring and does absorb more energy than a steel spring does. Air "springs" used pretty often in at least bicycle suspension probably absorbs a bit more energy than the corresponding steel spring would.

Shit or not. I think it's funny to discuss the physics behind various parts in our bikes. :)
 

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.....

Shit or not. I think it's funny to discuss the physics behind various parts in our bikes. :)
It's always fun to open the can.

I was thinking of the spring being the shock absorber because if you removed it the damper would do nothing and there'd be no shock absorbing at all (other than the air in the tyres) :laugh What you said makes more sense and is closer to the truth.
 

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The spring is the only shock absorber in the nowadays suspension setups of bikes in production.
The dampers, the oil, the valves inside the suspension, fast and slow rebounds etc are there just to control the actions of the spring and try to give it some useful way of functioning. Otherway, it would bounce and pongo-pongo out of control making the bike uncontrolable.
So, we load the suspension with valves and oil and we alter those valve passages so that the spring has to obey their commands, giving those dampening characteristics we call rebound and compression.
 

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The spring is the only shock absorber in the nowadays suspension setups of bikes in production.
The dampers, the oil, the valves inside the suspension, fast and slow rebounds etc are there just to control the actions of the spring and try to give it some useful way of functioning. Otherway, it would bounce and pongo-pongo out of control making the bike uncontrolable.
So, we load the suspension with valves and oil and we alter those valve passages so that the spring has to obey their commands, giving those dampening characteristics we call rebound and compression.
The spring doesn't absorb the energy, it only stores it and then releases it again... When you sit on your bike and load the suspension, you are effectively storing energy within the spring. If the spring did not store the energy, then the suspension would not extend again as there would be no energy left.

The damper doesn't actually absorb the shock/energy, it only converts it to heat. But that's another story :thumbup
 

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The damper doesn't actually absorb the shock/energy, it only converts it to heat. But that's another story :thumbup
True. It converts kinetic energy to heat.
Buy you could view that as absorbing kinetic energy, but not storing it. :O
 

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True. It converts kinetic energy to heat.
Buy you could view that as absorbing kinetic energy, but not storing it. :O
:confused Hmmm.... Yeah i guess you could.... It's a bit too much like a physics lesson going on here :laugh
 

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