Inverting Forks.

I have a friend at a local bike shop that says he can invert my front tubes on my 85 700n for about $150 am. He says this would also get me new seals install as part of the operation.
Can anyone explain to me what this is, the purpose, the advantages or disadvantages other that the cost difference for the seal repair.I have been quoted $250 just for the seal replacement alone....Something smells fishy.

 

i say sounds cool!

i need new seals too

 

Whats the purpose of inverting the forks, if he's truly a friend he'd still be making some money on the deal at $150, he's just not charging you as much labor as your other quote for just the seals, truthfully the $250 quote sounds steep to me. What benefit did he tell you you'd get from inverting your forks?

 

Unless he means replacing them with inverted forks from another bike, I can't possibly see how this would work, considering the tubes have no provision for mounting the wheel or any hardware, the sliders will not fit the yokes, and all of the damping mechanism inside the forks will be at the top, out of the fork oil, and therefore inoperative. If there is enough oil in the forks to reach the dampers, they are overfilled and will hydraulic lock on the slightest bump. I think your frind is full of it.

The whole idea of inverted forks is to put the thickest part of the fork at the top, where the most bending torque occurs under braking. There may also be an improvement in suspension action, since the tubes are lighter than the sliders and hence may respond quicker to inputs than the heavy sliders do.

 

MacMcMacmac - also less unsprung weight...

There is no way you could do it with the xj forks though - as MacMcMacmac says all the mounting hardware is the wrong end AND the diameter of the fork is way bigger on the 'bottom' so how do you propose fitting them through the triple clamps.

Aside
I've got a complete ninjja 600 frontend I've eyed up a number of times - To mount it on my xj I'd be replacing everything from the triples down... and the reason I haven't even tried to do it - geometry change on the bike probably would be too radical and the head of the frame likely wouldn't accept the ninja tripples.

Tell your friend no thanks... this isn't a small afternoon project your might think it is. If you understand to do it that it'll probably takes weeks of fabrication and won't really help your bikes performance then go for it, but it is in no way going to be cheap.