My fender is 7" wide as well, at the lip anyway. The wheel is the front wheel off of a '10 FLHX, 18"x 3.5". I believe a 160 might fit under the fender with the wheel centered; I am also replacing the OEM wide belt/pulley with the later narrow belt/pulley. I am concerned though that with the taller wheel, there could be some tire/fender contact in the "curve" of the fender. The change is all about improving handling and not about fitting the widest tire I could on the rear. I will avoid PITA and "un-fun" jobs if at all possible.

Thanks for the reply; good to know.

 

I think you have a plan that will work fine.

These are not like sport bikes that a rider is more apt to "throw" into a tight left hander and immediately after "throw" into a right hand turn. In this case the rider is expecting the same reaction turning either way on exact opposite turns. In-line alignment is more critical in the sport bike world but we are less likely to notice any difference with a slight offset. If you started comparing bikes, there would be slight variations found which is considered the norm.
Thats not to say you can't make it better, for handling as well as appearance. If handling is the ultimate goal, you can set it up quite nicely using a flat level build platform that is measured in a square grid pattern. I used everything from plumb bobs to laser lines to zero in on my "at home" optimal handling attempt. Of course I had the additional task of rebuilding the swingarm so it allowed the wheel/tire to travel vertically exact as well.
I installed the Progressive stabilizing link as a failsafe after insuring the bushings/bearings were up to par.
New Progressive 944s are a slight improvement over the stock air shocks (you get what you pay for).
Don't overlook the importance of the motor mounts as well. Keeping the reciprocating forces as vertical and as inline as possible is paramount. Lastly, do a fall away test and make sure the head bearings are working well.
Great handling on a budget.

 

I have installed the same '10 FLHX wheel up front with R/T springs and modified Ricor Intiminators; the front works well. Did a fall away a while back and all was good. Front motor mount is the Buell mount with less than 5K miles. Rear shocks are stock but will be changed soon to something better than the Progressives and Bagger Brace might also be part of the plan, if needed. The bike has never exhibited behavior indicating alignment is an issue. No head shake, ever, and she has seen 110-120mph on several occasions. She will run straight as an arrow with no hands on the bars. She does wag her tail a bit I a long sweeper at 75-80mph under power but nothing scary.

I am now thinking I will center the wheel and check alignment after; however, I am confused about machining the rear caliper. It appears that the material should be removed from the outside of the caliper but the caliper "registers" on the swing arm tab. I was concerned that removing material from the outside of the caliper might cause the caliper to "****" inward when the axle is torqued. Removing material from the inside of the caliper moves the wheel but then rotor and caliper don't align and the only way to align moves the wheel back where it was.

I appreciate the help.

 

The easiest way in my view is to first center the wheel within the swingarm & struts. I use a long 1/2" extention for this purpose but you can use the actual axle. It just makes it easier to slide the wheel from side to side. Now you can measure and cut your left side spacer making sure you have sufficient swingarm and belt clearance. Keep in mind that clearance needs to be addressed through the entire range of swingarm travel. You may need to trim/grind a bit off the left side frame bracketry if there is any interference. Once the left side spacer is mocked up in place you can determine how much needs to be milled from the inner side of the caliper in order to center it on the rotor. It may be necessary to trim some from the caliper pad on the swingarm as well. Once the caliper is centered on the rotor all that is left is, measure and cut a right side spacer. Hope that helps somewhat but keep in mind that your build is a lot different than mine and I'm trying to visualize what you will encounter. I'm sure it will become obvious to you what needs to be done to accomplish this job. Good luck!

 

I understand, makes sense. I have some room to move the wheel toward the center by trimming the inner spacer and pushing the right side bearing to full depth. My first mockup followed the SM bearing install procedure; right side bearing full depth, '10 inner spacer ('02 inner spacer too short) and push left side bearing to contact the inner spacer. The inner spacer was too long that way and the left side bearing could not be installed without protruding past the wheel hub; lost 20% of the bearing contact surface which IMHO is unacceptable. Reverse the bearing install procedure for the second mockup and it fits; however, the right side bearing is not pushed in to full depth. So, I can trim the inner spacer and push the bearing all the way in which will also allow the left side bearing, which is inside the boss about .125" to be pushed out to finish flush with the wheel hub and move the wheel toward center. I think I should mock up that way, hang the wheel and adjust outer spacers as required. Thoughts?

 

Sounds logical. If the math works out and you can draw it on paper, fitting the entire assembly within the given parameters, it will fit fine.

From your picture it is hard to tell how much of your rear wheel offset is attributed to an actual offset or if the fender or strut assemblies are off to one side making the offset look worse than it really is. That stuff is just hung from the frame and any centering measurements need to be taken from the frame itself. I would remove the fender and strut uprights before centering the wheel.

That is another thing to consider. I am sure an alternate method of mounting the rear fender, such as I did, will allow the rear fender to be forcefully widened without being noticable if you needed to. An 18" wheel/tire is a bit more of a challenge to mount than a 16" from what I hear.

 

I have considered the fender being off to one side but close examination of how the fender is hard fastened to the frame rails tells me that the fender is not the issue. I appreciate your insights and as you suggested, mounted the wheel with no spacers to try and center the wheel between the frame rails. The wheel will only move so far to the right. That exercise showed me that the only way the wheel moves to the center will require trimming the caliper anti-rotation tab on the swing arm or removing material from the swing arm side of the caliper axle boss or machine the face of the hub where the rotor mounts; there ain't another way. No matter what bearings, how they are installed, what inner or outer spacers are used or machined. The caliper registers on the swing arm; a fixed dimension. The outer right side spacer must be whatever dimension is required to align the rotor in the caliper; also a fixed dimension. Those two dimensions control everything else and fix the wheel position in the swing arm. The only other variable in the equation is the face of the hub where the rotor mounts which, if machined allows the rotor to move to the left which allows the wheel to move to the right.

I am checking alignment before taking the next step. Have worked out a way to string line check with the bike on the lift. If there is not an alignment issue, I will have to exercise one of the three options listed above to move the wheel enough toward the center to provide comfortable tire to fender clearance; most likely will trim the caliper axle boss; I figure I can take about .200" off before the caliper hits the anti-rotation bracket. If there is an alignment issue; correcting it should move the wheel toward the center.

I wouldn't be having the problem if the stock wheel had been centered in the swing arm but it wasn't; the luck of the Milwaukee draw. Thanks again for your insight.

 

I thought that but they don't! I have an '08 rear fender in my 1990 bike and it is the same width as the stock one. I now have an '07 swingarm and ran an '07 rear wheel which was plumb centre in the rear fender, as is my current Deuce wheel with 160/70 tyre. Clearance is minimal and the fender needs to be 'adjusted' to take it.