Girvin Fastrax - replacing with a rigid fork

[goobyson]

I can get a decent 26" MTB from plain gauge Tange tubing almost for free. It has a Girvin Fastrax fork, but the elastomers have definitely bitten the dust a long time ago. For the price of the replacement elastomer set I can easily get a new rigid fork.

Obviously, I don't want to alter the geometry of the bike too much, so I'm looking for one with similar axle-to-crown dimension. The current suspension corrected rigid forks I can get have 440 mm A-C, which is meant to replace at least fork with 100mm of travel, I guess?

Does anyone have any ideas about the A-C measurement of Girvin Fastrax, or its travel? I assume it was around 80mm? I found a picture of the original packaging in another thread, but the travel is not mentioned there.

 

[joglo]

Hi,
First of all, just out of curiosity, are they labeled also Girvin?
It looks like that Girvin/Proflex may have used Fastrax forks for some specific models, just I haven't seen one labeled with Girvin.
Girvin had late ProForx and focused soon on their Vector design while Fastrax had been sold by others like Stevens.
Yours look similar like this one:
https://www.retrobike.co.uk/threads/help-me-find-a-frame-for-this-fastrax-suspension-fork.447434/
But to answer your question. I think those have rather just 40mm of travel. The later Fastrax LT (LongTravel) from 1996 had 60mm. Also the crown looks flat.
With that i would recommend a 410 or 420mm rigid fork.
(BTW most forks with 100mm travel are 480mm)

Why not just measuring the axle to crown height on your bike while lifting the suspension manually a bit almost to maximum (Elastomer forks in new condition usually do have not a lot of SAG) if Elastomere are crumbled meanwhile?

 

[goobyson]

Thanks a lot for your insight! (I completely forgot to reply back then, oops!)