Looking to do a Bobber-esque Build, Nothing Permanent

Hi all,

Got an '81 XJ650 Maxim. I want to do a light build with no permanent mods, and had a few questions for those of you who now the bikes inside and out.

Lowering by one inch in the rear is fine, correct? ( I know it changes handling, done it on other bikes just worried about the shaft drive)

The rear grab bar/hoop, I'm guessing that adds rigidity to the frame to prevent the suspension from twisting? Or is it safe to remove? Not gonna chop. (maybe until I pay someone to do it for me and weld in some extra frame bracing) Maybe I fabricate a smaller but thicker bar that bolts into the same place?

Anybody have builds of bobbers/cafe/scramblers that didn't permanently alter the bike?

And yes, I've done a lot of forum searching, not about to try to make pods work haha.

Any other ideas and suggestions are more than welcome, thank you.

 

1 inch lower at the rear is absolutely fine. The rear grab bar is just that. It's for passenger comfort. The frame won't be compromised at all by removing it. If you really want a reversible bobber, buy a set of fenders to hack up. A proper bobber focuses on reducing weight while improving everything else without spending a penny (if possible).

 

Awesome, thanks! Still a ways out in terms of work needed on the bike but it's good to get this info ahead of time.

 

Sometimes what I'll do is buy a second part from ebay and cut or modify it for my custom look and save the original part to put it back to stock if I so choose.
If my modification sucks or I screw up the part I'm not out much. Also helps with resale of the bike to have all original parts.
BTW, vis a vis losing weight, the easiest way to go faster is to remove weight (as you mentioned). My XJ 750 Maxim weighs 410# down from the factory weight of 524# weigh on race car scales.
Cheers, 50gary

 

Oh man, over a hundred pounds? Now I am curious.... What all did you do?

 

Dropping my personal weight helped too.

 

Not to be glib but.. everything. The biggest reductions are the exhaust, the entire front end of the XJ is very heavy, wheel/tire, rotors/calipers, fender, instrument panel, mine are all digital, plastic fender R1 forks/wheel/tire everything same with the rear. Just an example that you might not realize until you weigh them but my flat slide carbs are 1/2# lighter not to mention no air box etc. Further the light weight wheel/tire/rotors are all spinning weight, at speed they act a s flywheels limiting agility and acceleration and braking. Lightweight rotating mass is a triple win with no penalty. The weight has mostly come off the ends of the bike this will also concentrate the center of gravity and allow the bike to rotate around the C of G more quickly (lower polar moment of inertia) How to make your bike much faster without stressing the motor at all. Oh, and fuel economy as well. Do the arithmetic of power to weight ratio 524#/82 bhhp = 6.39
vs. 410#/82 = 5# per hp. 5/6.39 = 78%. It's a very cool bike, fun to ride, (dirt cheap if you can build it yourself, I bought mine for $250 non-running without carbs and only 2500 miles on the clock. It needed the carbs that's another reason I went to flat-slides and a voltage reg/rect.) reasonable quick, bomb proof Yamaha XJ reliability. I would like one more gear though.
Cheers, 50gary