strange tire ware

[stillhere]

my bike is an 08 fxstc with 14000 miles on it.
below are pics of how the tire ware,s. this is the thrid front tire on it.
seems i cant get near 5000 out of a front. the tires ware funny ( cuppin )
before this tire was put on the rim was trued at a dealer.
when i got the bike new the neck bearing kept haveing to be ajested
because it was not sitting right. seems that proplum was solved.
but every tire cup.s. as it starts to go i get a shimmy rideing on the slab,s
today it damn near shook me off the thing. looked at the tire and this one allso is wareing funny. ( saw it comeing by watching the tire last few hundred miles )
any ideas what would make this happen to every front tire so far ?? 
i know first thout is air presure but trust me after the first tire
and people saying air presure i check it 2 or 3 times a week and add when needed.
tire size is mh90-21 other numbers i see are m/c 54h D407F
nothing has been done to the front end other than a fork brace.
as you can see in the pics theres plenty of thread left on them and should last a lot longer.
heres the pics and thank you for any help coments or ideas.









one of the front end / fork brace


thanks again
                     stillhere

[digger384]

Not too long ago there was a thread about a Dunlap tire that was wearing like that and the dealer was replacing them, don't recall of it was a 407 though, but worth looking into.

Digger

[Coff 06]

I don't about your problem,but on front tires,I have ran both the H-D Dunlop  D407F and the D402F in a 90-21 on the front of my 06 FXSTSI with 33k, and the milage is about double on the 402 over the 407.Other people I know that run the 407s on the front also get around 5K and that's it.Depending on how you ride,a 402 could go 10k,but I change mine at around 8k and there is always still some tread left.I like to ride hard sometimes so I tend to change my tires early.JMO  Coff 06

[deucegray]

My last front tire started cupping . I was told to change fork oil and make sure the oil level was exactly the same in both legs . My Deuce called for 11.6 ounces , 6000 miles so far and cupping has not started. Running Avons. I was low in oil on one side .

[PoorUB]

tire size is mh90-21 other numbers i see are m/c 54h D407F

There is the problem. The 407 front was a crap tire and has been discontinued and replaced with the 408 front.
Simple as that! Make sure you buy anything other than a 407 for your next front tire.

[Princess Butt]

I had a rear wear out like that on a Road King. Turns out I was missing a bolt which held the lower link on the front motor mount.

I know this doesn't apply to your particular situation, but it may help someone having a similar problem.

I would check the fork oil first.

[Gary S]

How can I keep my tires from cupping?



You may not be able to entirely avoid cupping. Tire cupping or irregular wear is a somewhat common occurrence on all vehicles. On a four-wheel vehicle, you are advised to rotate your tires periodically to even out wear. Unfortunately, you do not have this luxury with a motorcycle because front and rear tires, unlike those on a four-wheel vehicle, are not interchangeable.

However, there are steps that can be taken to minimize cupping and uneven wear on a motorcycle:
Maintain your motorcycle and particularly your front forks and suspension.


Avoid hard braking whenever possible. Braking causes the tire to grab and wear in one direction. When braking is applied to the front tire, the load transfer over-flexes the tire and increases the tendency for cupping and uneven wear.


Maintain your tire pressures. Underinflation or overinflation in motorcycle tires are significant causes of cupping and uneven wear, particularly in association with hard braking and/or trailer use.

Some of today's tires feature tread patterns and constructions that are less prone to cupping than the ribbed tires of old. The Dunlop 491, D401 and D402 touring and sport touring tires are good examples.

Tire companies can, and are, helping to minimize cupping and uneven wear but you, the rider, must do your part. Follow the aforementioned guidelines. How Much Run-in Should I Give a New Tire? When new tires are fitted, they should not be subjected to maximum power or hard cornering until a reasonable run-in distance of approximately 100 miles has been achieved.

This is necessary for a number of reasons. Replacements for worn tires with different patterns and construction will not react the same. Also, a new tire is stiffer than an old tire. The new tire has a rounder tread profile, different contact patch and "lean-over edge" than the worn profile of an old tire. The new tire will also not react the same in combination with its remaining tire.

Carrying out the required run-in will allow you to become accustomed to the "feel" of the new tires and tire combinations, so you are better able to achieve optimum road grip for use in high speed, high acceleration and handling situations.

[Gary S]

I have had cupping on my bike and I have been able to get rid of it by keeping the tire inflated toward the higher end of the recommended range. If the manual says 32 psi for solo rider and 36 for two up the two up pressure is what I've run with success.
Gary

[02rk59]

Isn't the main difference between the 407 and the replacement 408 the direction of the installation.  In other words, didn't the installation orientation of the 408 reverse from the 407?

[autoworker]

Harley Service Bulletin 1258B.
Could this possibly apply to your situation?

[seattledyna]

yep, they swapped tread direction for the 408, my 09 RG original 407 cupped pretty good, they changed it for a 408 with the warranty deal, no issues at all with the new one so far

However I noticed some tire howl in corners lately and checked the back tire "the fat 180 dual compound one" and it was cupping badly, and I always check tire pressure btw. could be the lack of straight roads and all the twisties I ride    anyway, they put a new rear tire on last week no questions asked and were surprised to see that tire cupped like that.

[stillhere]

thanks for the input.
dealer is calling harley to see what they say. ( think its the rim or fork bearings )
i will have them check the fork oil.
i run the upgraded fork oil. way i understand it is there are three fork oils
normal / better than normal / and raceing oil. mine is the better than normal.
i want to go with e-3s radials but i want to kill the rear tire first.
mite just have to put a new front again then the rear should be ready.
if they put a "Potty mouth" tire on my bike im going to try and get them to replace it.

[stillhere]

quick update

harley is replaceing my 407 tire with a 408 at no cost to me.
going in tomarow to have it put on.
felt so guilty i orderd 1000 bucks in chrome when i was there 


thanks for all the help and info

[autoworker]

Apparently SB1258B applied in your situation.Good to hear that you will be taken care of.