Rear shock repacement Fox Alps 5r on a Kona U'Hu

markwhalebone

Hi there,

As the title says my Kona U'Hu (1998 I think) has a Fox Alps 5r rear shock and I would like to replace it.

What are my options? New, refurb or eBay ? What measurements do I need to match on the new shock in order that it fits the frame and works?

(I have tried to service the shock but the body is seized and I cannot undo the lock ring so I think its game over)

Bike info - http://www.bikepedia.com/quickbike/Bike ... gtIL5K1F8E

Thanks, Mark

nicklouse

it needs to be the same i2i and same stroke. and you will need a suitable fitting kit for the new shock.

thought about sending it away for a service?

markwhalebone

It seems nobody services the shock any more as its so old. No replacement parts are available...

So if I match the i2i and stroke can I assume I will be able to find the right bushes to fit it to the bike?

Thanks for the reply

nicklouse

the bushes are in the shock. you will just need the fitting kit.

have you asked Mojo?

and more info http://www.klassickona.com/oldgold/98bi ... einfo.html

markwhalebone

Ok so I measured the i2i and stroke.

i2i = 160mm
stroke (total length of piston) = 50mm
stroke (total travel of piston) = 35-40mm.

Here is a picture of the shock - the rubber o-ring is sitting a bit to the left of the maximum travel of the shock to explain what I mean that the stroke is much less than the total piston length (the conventional way of measuring stroke).



So can I replace it with something like a Rock Shox Monarch R 165 x 38mm? Will the extra 5mm i2i make a big difference.

In order to mount it I suppose I need to buy the correct mounting kit to give me the right width to fit the frame right?

nicklouse

markwhalebone wrote:

Here is a picture of the shock - the rubber o-ring is sitting a bit to the left of the maximum travel of the shock to explain what I mean that the stroke is much less than the total piston length (the conventional way of measuring stroke).

NO.

stroke is what it says it is. the distance of the piston stroke.


viewtopic.php?f=40073&t=12678279

so is the stroke 35 or 40mm?

what was the travel stated and can you find out the leverage ratio?

too much stroke and you could have part hitting other parts.

markwhalebone

That picture will help me explain.

My shock when fully compressed does not go all the way in as the one in the diagram. I know the shock was bottoming out when I was riding and the rubber o ring allowed me to see where piston stroke ended. The actual stroke was between 35 and 40mm. However if you measure the stroke in the conventional way as shown here it comes out as 50mm



So I would say the stroke is comparable with the Monarch. The issue is the slightly longer i2i measurement.

markwhalebone

This explains what I mean;