Rob’s Guide to Shock Absorbers

With many choices of brand and size available from Cool Air we thought we would sum up our range in this handy guide to help you make the right choice for your desired ride.

Oil Filled vs. Gas Filled.

Oil filled shocks are softer than gas filled shocks, which offer a firmer ride.

The easiest way to tell the difference is to compress the shock. An oil filled shock should stay in the position when you let go, a gas shock will return automatically to its fully extended position.

When fitted to the vehicle the gas shock will help to raise the suspension up to its natural ride height. 

Gas shocks are often used when lowering the height of your vehicle to stiffen up the suspension a bit.  This can help especially when you have little clearance between tyre and wing for instance.

Getting the right shock height for your ride.

There are a number of ways to lower your VW which we will discuss at a later date, but basically when you lower your car you are probably going to need a shorter shock.  When it comes to shock length you need to make sure that the shock is not going to run out of travel when the suspension goes up and down over the bumps in the road, this is the damping and rebound measurement.

A shock that is too long would create a very compressed shock and going over a bump may cause the shock to ‘bottom out’.  This is when the shock runs out of compressed travel.  It is normally followed by a loud bang as the shock stops moving.  A shock bottoming out will cause the suspension to become solid and will put stress on the shock mounts.  In severe circumstances shock mounts and bolts can even break.

A shock that is too short however would create a situation where the shock can ‘top out’.  This is when the shock runs out of extended travel.  Whilst not as severe as a shock that is too long, it can cause an uncomfortable and unstable ride.  Especially when you go over a pot hole and the wheel does not drop as it is held off the road by the shock that is too short.

So getting the right shock length is essential to a safe and comfortable ride.

When customers speak to us about shocks, it is a very common statement from you guys to say ‘I have lowered my bug 2” from stock, what length shock do I need?’  And the answer we give is ‘We haven’t got a clue’.  It’s not that we don’t want to help, of course we do, but there is a problem.  We don’t know what height your car was sitting at as ‘standard’.  Remember, we are dealing with cars that were made as early as the 1940’s.  Now if you were born in the 1940’s you are probably going to be a bit saggy in places, not so flexible in others.  Well guess what, it’s the same for your beloved VDub.  Your torsion leaves in your front beam and your torsion bars in your rear axle will probably have lost some tension over the years.  You might have a cracked leave spring or two.  This will all cause the suspension to drop a little.  So when lowering your car 2” it could be 3” or 4” lower than when it came out of the factory.

So the only way we can get it right is to get out your trusty tape measure and find out where we are at.

So first things first.  Lower your car to the desired height without any shocks on the car.  Make sure you have all of your interior back in the car, all the heavy glass and fuel tank back in.  Then with the wheels back on the car (remember no shocks fitted at this point) roll the car back and forth a bit so that the suspension drops to its natural resting position.  Now look at the car.  Are you happy?  Is it sitting how you want?  When it comes to the rear of the car, make sure that the car is not sitting on the bump stops.  If it is, take them off or raise the car up a bit.  OK so now you are happy with the ride you need to crawl under the car on each of the 4 corners and measure.

On the rear of all models you need to measure between the top and bottom bolt holes (centre to centre) where the shock mounts.

This is the same on the front of all models except Ball Joint Beetles and Karmann Ghia’s from August 1965 onwards.  These models use a different type of shock on the front which have a pin on the top of it instead of the usual eyelet which you will find on all other models.  For these ball joint Bugs you need to measure from the centre of the bottom hole to the underside of the front beam where the pin goes through the top mount of the shock tower.

OK so now you have your 4 measurements you can now select the right length shock.  Depending on the length you require, this may reduce your options in brands.  Ideally what you are aiming for is a shock that will travel 50mm in each direction from your starting point.  So for example if you’re measured length was 300mm then ideally you would want a shock that would extend to a minimum of 350mm and compress to a minimum of 250mm, but this is not always 100% achievable, getting as close to this rule will be your best option.  If you do have to sacrifice some of the measurement, then having a shock with a shorter extended length is preferable to a shorter compressed length.

Preparing your shock

Whether you have Oil or Gas shock absorbers before you install them you will need to prime them before installing on your car.  Oil shocks are quite easy to prime as there is very little resistance.  Just compress them and then extend them a few times.  Gas shocks are a little harder to prime as they naturally want to extend.  Priming them can be easily done by putting the shock against the floor while holding it upright in its correct position.  Once in position then lean on the shock to compress it fully.  Then release the shock until it is fully extended.  Repeat this process 4 or 5 times until the shock becomes quite hard to compress.  This process helps to remove bubbles that may have formed in the fluid whilst in storage and will improve the effectiveness.

Standard Shocks

Standard shocks are available in Oil filled or Gas filled as an option.  Obviously if you have not changed your suspension height then these will fit your model without requiring any measuring.

Ball Joint Beetles and Karmann Ghias (August 1965 onwards except Super Beetles)

Beetles and Karmann Ghias with ball joint front suspension (Pin top and eye bottom) have a range from 300mm fully compressed to 450mm fully extended.  Oil Filled shocks are available HERE and Gas filled shocks are available HERE.  Both of these shocks are supplied without the fitting kits which include the bump stop which goes on the top of the shock. The fitting kits are available HERE.

The rear of Ball joint Beetles and Karmann Ghias have an eye top and bottom and the standard range of travel is from 250mm to 385mm.  Oil Filled shocks are available HERE and Gas filled Shocks are available HERE.


King and Link Pin Beetles and Karmann Ghias (January 1953 to  July 1965)

These Beetles feature the same shock both on the front and rear and has an eye top and bottom.  The standard range of travel is from 250mm to 385mm

Oil Filled shocks are available HERE and Gas filled Shocks are available HERE.


Splitscreen Buses

All Splitscreen Buses feature the same shock both on the front and rear and have an eye top and bottom. The standard range of travel is from 250mm to 385mm

Oil Filled shocks are available HERE and Gas filled Shocks are available HERE.


Baywindow Buses

Early Bays and Late Bays featured slightly different shocks.  The changeover was in July 1970.  Standard shocks for the Baywindow are only available as an oil filled option.  For Gas versions you would need to purchase one of the aftermarket shocks at the correct height.

Early Bay

Early Bay Shocks feature a front shock that has a standard range of travel from 250mm to 385mm and are available HERE.  The rear shock on these models were unique in length and had a travel range from 340mm to 560mm.  They are available HERE.

Late Bay

Late Bay Shocks feature a front shock that has a standard range of travel from 265mm to 415mm and are available HERE.  The rear shock on these models was unique in length and had a travel range from 350mm to 590mm.  They are available HERE.

KYB GR2 Shocks

The GR2 range of shocks from KYB are one of the most popular aftermarket shocks that we sell.  They are Gas shocks and come available in a few different heights to suit most requirement and being a Gas shock they are firm and very popular on lowered Bugs and Buses.

Pin Top and Eye Bottom

220mm to 330mm are available HERE
335mm to 420mm are available HERE

Eye Top and Eye Bottom

245mm to 385mm are available HERE
265mm to 420mm are available HERE


KYB Gas Adjust Shocks

The Gas Adjust range of shocks from KYB is an uprated version of the GR2, these Gas shocks will give an even stiffer ride over the GR2.  These are very popular with Bus owners as a special extra long version is available in this range which can be fitted to the rear of Baywindow Buses.  This shock allows you to use your original shock mounts without the need to modify anything.

Pin Top and Eye Bottom

335mm to 455mm are available HERE

Eye Top and Eye Bottom

270mm to 410mm are available HERE
345mm to 565mm (Ideal for the rear of Baywindow Buses) are available HERE


EMPI Shocks

EMPI shocks are available as an oil shock or gas filled shock so they have you covered whatever you requirements are.

Pin Top and Eye Bottom

265mm to 385mm Oil Filled are available HERE
370mm to 455mm Oil Filled are available HERE
280mm to 385mm Gas Filled are available HERE
390mm to 455mm Gas Filled are available HERE

Eye Top and Eye Bottom

250mm to 370mm Oil Filled are available HERE
270mm to 410mm Oil Filled are available HERE
285mm to 370mm Gas Filled are available HERE
300mm to 410mm Gas Filled are available HERE


GAZ Shocks

Manufactured in the UK these adjustable dampers allow you to adjust the firmness of the shock to your exact requirements.  Adjustment can be done whilst fitted to your car with an easy to adjust knurled knob on the bottom of the shock.  This knob can be turned up to 36 points.  The more you turn it the harder the shock will become.

Pin Top and Eye Bottom

250mm to 345mm are available HERE
320mm to 435mm are available HERE

Eye Top and Eye Bottom

235mm to 295mm are available HERE
265mm to 380mm are available HERE
275mm to 400mm are available HERE
365mm to 590mm (Ideal for the Rear of Baywindow Buses) are available HERE


SPAX Shocks

Our top of the range shocks are from Spax.  Spax is a UK based company that have been manufacturing upgraded suspension to manufacturers, race teams, restorers and enthusiasts since the 1960’s.  Each shock is Krypton Gas Pressurised offering the user the ability to tune their suspension for the optimum driving style.  This special gas ensures minimum damper fade and an increased lower speed response. 

Just like our range of GAZ shocks each shock is installed with a tuning knob on the bottom of the shock allowing for on car adjustment of the stiffness of the shock.

Cool Air stock the basic range of SPAX shocks known as the CKX as well as our own range of shocks specifically designed by Cool Air for the VDub market.  We have branded this custom range only available from Cool Air as KSX.  If you have a lowered or standard VDub then we will have a SPAX Shock to suit your ride height!

All shocks are fitted with an integrated bump stop on the shaft.  This bump stop measures 27mm in height.  NOTE: In order to obtain the full compressed value quoted below then the bump stop must be removed (Cut off with saw)

Pin Top and Eye Bottom

205mm to 280mm are available HERE
220mm to 310mm are available HERE
230mm to 330mm are available HERE
245mm to 360mm are available HERE
256mm to 380mm are available HERE
258mm to 370mm are available HERE
270mm to 410mm are available HERE
280mm to 430mm are available HERE
295mm to 460mm are available HERE
347mm to 435mm are available HERE

Eye Top and Eye Bottom

205mm to 280mm are available HERE
220mm to 310mm are available HERE
230mm to 330mm are available HERE
245mm to 310mm are available HERE
245mm to 360mm are available HERE
256mm to 380mm are available HERE
258mm to 382mm are available HERE
270mm to 410mm are available HERE
280mm to 430mm are available HERE
295mm to 460mm are available HERE
310mm to 490mm are available HERE
320mm to 510mm are available HERE
335mm to 540mm are available HERE
358mm to 568mm are available HERE
360mm to 590mm are available HERE

BETA

My VW