new member, fork question.

wondering if anyone has tried installing longer fork tubes on one of these bikes. i noticed they sell lots of them for the xs650's and was wondering if it would be possible to make something like that work? thx

 

I'm sure it would. "Overlength" tubes were and still are a cheap "chopper mod" but I would be concerned about one or two details:

Installing longer tubes raises the center of gravity of the bike, especially toward the front, where the XJ's motor is at it widest. An extended-fork inline four is a bit "tippy" compared to a twin (which is why it's so popular with the XS's.)

You also tilt the motor backwards by more than a few degrees. This may affect oil distribution to the valve train, especially on the hotter exhaust side. Again, not so much a concern for a low-revving twin; might prove to be a death blow to a 10K motor like the XJ.

 

I'm sure it would ride better for touring but I think that it would push the front wheel in the twisties, like comming downhill at high speed.

 

The fork diameter may be a problem too, The xj's are relatively heavy or should I say that they have skinny forks for their weight, mine are only 36mm with a 535lb bike and a 230 lb rider (me) and 110 90x19 front tire I'm affraid mine would flex if they were much longer. With Seca wheels 18" it would probably handle better than maxim 16" I wouldn't go much longer than 2"over with the stock rake though.

 

I think you should probably change the rake/angle of the neck if you extend the tubes. But thats my opinion. You should probably ask someone a little more experienced in this. Personally i have not done it but all the ones ive seen have had a modified neck tune to adjust for the longer forks.

 

I know my 750 forks went up about 2" and looked reall cool with 7-8 lbs of air in them but it felt very light over 60 mph, and with 2 up (over 500 lbs) the front wheel felt like it was skipping over rough parts in the road. Slow poking around parking lots and old narrow streets (downtown Vegas) It felt tippy. More rake (5-7 degrees) with 2-2 1/2 inch longer forks would bring the frame height back down to stock and I'm sure it would handle better (and ride better due to longer wheelbase). (vsx650 customs are 32 degrees rake) There are some tripple trees out there that are offset, I know AME makes one that is 310 mm width, (fork centerline) but it's over $800 alone. They have a wide glide kit but it's over $2000 complete. It would probably be more economical to have an HD neck welded in to replace the yamaha neck, at whatever angle you want, then there's 100's of setups to choose from but good luck matching xjwheels (there are no ready made rear wheels available other than stock 16s' or 18s')

 

I don't think that any modifications you do will make it handle as good as stock.