What's the widest rear tire....

[Mother]

I can run on a stock fender 2002 flht. I do have chain conversion, thanks guys!

[q1svt]

What size rim are you running or planning to...

sidewall flex is more on a smaller rim and higher profile tire (i.e. 16" rim / 90 series profile)

Custom (Without Motorcycle Modification) 18x4.25 150/70-18, not sure if you can get more with a chain...

[lilchief]

I put a 140 on my 02' FLHT with stock wheels but I used the Pingel pulley spacer. I still run a belt though.

Lil' Chief

[Durwood]

I have installed a couple MU90 Elite 3's on 2002 baggers,I think they are equivalent to a 140 Avon.With a chain a 150 should go without a problem.

[TweekmyTwin]

Even with a chain drive, 150cm  is the max due to your fender.
Jim

[JohnCA58]

Even with a chain drive, 150cm  is the max due to your fender.
Jim

And even if your running a chain (130) the chain is 1. 1/16 in. wide,  so same size tire for chain or belt.

[Bakon]

Ran 140 on 2001. Only removed the belt guard.

[DresserDan]

Put a Elite3 MU 90 [140x16] on a 03 Ultra No problem Didnt even trim the belt deflector

[nicadocius22]

got a 150 70 18 on my 07. with proper wheel alignment i needed to make to adjustments

[koko3052]

What size rim are you running or planning to...

sidewall flex is more on a smaller rim and higher profile tire (i.e. 16" rim / 90 series profile)

Custom (Without Motorcycle Modification) 18x4.25 150/70-18, not sure if you can get more with a chain...

I 'm thinkin the sidewall only flexes where the rubber hits the road.

[q1svt]

That's one type of flexing...   

Rim size helps in maintaining overall tire shape.  a 150x90x16 3" rim vises a 150x60x18 4.5" rim, the 90x16"x3" will allow for a greater inward flex and the tire will grow in circumference...  just something to consider when measuring tire clearances between tread and fender.  Think of what happens to a top fuel drag race slick as an example (no your motorcycle tire is not going to grow to that extent).   

[easyricer]

I recently put a 160/60R18 Avon on the back of a 2000 model Ultra Classic using a 2002 Swingarm and Axle. It took a little bit of modification to the wheel, Iso drive pulley and to the rear fender but I have 3/8in clearance from the tire to the fender. (I removed the lip on the inside of the fender. It's running a 1inch belt.
EASY

[TorQuePimp]

  What diameter wheel are you wanting to run or do you have ?

Makes a huge difference

I know the pirelli scorp and metzler me880 150/16's fit and a friend from pa has a 160/17 Avon on his 02 and it is damn close to the fender but does not rub

[koko3052]

That's one type of flexing...   

Rim size helps in maintaining overall tire shape.  a 150x90x16 3" rim vises a 150x60x18 4.5" rim, the 90x16"x3" will allow for a greater inward flex and the tire will grow in circumference...  just something to consider when measuring tire clearances between tread and fender.  Think of what happens to a top fuel drag race slick as an example (no your motorcycle tire is not going to grow to that extent).