Cupped front tire

[MArkRD]

Gentlemen,

After spending an afternoon with the GS i found that the front tire is cupped.
Strange thing is that it's a Bridgestone BT45F tire with just 7000 km on it and its about 7 months old. I check tire pressure every week..
After searching through previous topics here i noticed that an average tire should/could last about 10.000-12.000 miles.

It's obvious that i need to replace it, but i'm a little concerned with the short lifespan of the bt45.



Whats happening here?

[ls 64086]

crappy front shock and or driving habits from what i have read here. i just ordered my progressive shock - $65 with shipping. peep this link, tons of info and more links

http://gstwins.com/gsboard/index.php?topic=41733.0 

as far as driving habits go, apparently this can cup too. I'll let someone with more then a month and a half of riding elaborate on that 

[ben2go]

Yep.I lost my tire in 3000 miles.Progressive springs and 15w fork oil cured it.I also had to add a Katana shock to the rear.When I would hit a bump the front would hold but the rear would dip.Giving the sensation of loosing control.Also out of balance wheel/tire can cause cupping.

Here's a link to fork spring info.I got mine from the same place.Price has went up a little.
http://cgi.stanford.edu/~sanjayd/gs500/Upgrades/FrontSprings

Here are some links to rear shock option just in case.
http://cgi.stanford.edu/~sanjayd/gs500/Upgrades/RearShock
http://pantablo500.tripod.com/id12.html
http://pantablo500.tripod.com/id39.html

[bluelespaul]

pardon the ignorance but whats a cupping tire? the pic looks fine to me 

[ben2go]

It's when the tire cups between the tread grooves.If it becomes bad enough it can cause front end wobble and bounce.If it gets bad like mine was it's hard to hold the bars.Some people say that the tread has a saw tooth look to it.

[MArkRD]

To make the topic even more exciting:

I already have progressive springs and 15w oil. This must have been the best thing i did so far.

So that leaves a bad driving habit then?

I really thought about it. How i drive, the use of brakes, cornering, etc.
The only thing that popped up is that i use the front brake alot. But is that a bad habit?

[ls 64086]

i only use front brakes - i have to stand on my rears just to get them to be useful. i've been in several close calls and never needed the rears. but.... my front tire is cupped also

[MArkRD]

hm. interesting.

How many miles did you get on the front tire when you discovered the cupping?

It seems we have moreless the same braking "habit"

[ls 64086]

i only have put ~700 miles on. the bike has ~4000. maybe it is , maybe it isn't the original tire. i just recently noticed it after seeing someone post something about cupping on here, thats when i checked and found out mine is slightly cupped. i then ordered the new shock. i always noticed alot of travel on the front forks, but never paid much thought until i saw that many thought it was to extreme. did your progressive and 15w fix this? i have about 5 inches of travel, btw

[ben2go]

i only use front brakes - i have to stand on my rears just to get them to be useful. i've been in several close calls and never needed the rears. but.... my front tire is cupped also

You back brake needs to be blead and the master cylinder push rod adjusted.

hm. interesting.

How many miles did you get on the front tire when you discovered the cupping?

It seems we have moreless the same braking "habit"

My experience has been that bias ply tires cup easier and more often than radials.Cupping is the reason I upgraded to wider rear wheel and tires.

[The Buddha]

Progressives, yea bandaid on cancer. Now 15wt is good, except it kills compression and rebound.
I have a set of progressives and still can get it to wallow and bottom at will. A bad front end, is a bad Front end, progressives are only going to postpone your date with the rear end of the car in front of you.
Just being harsh ... but honest.
Cool.
Buddha.

[mojonixon]

So I guess what you are saying is that everyone should buy a Katana front end and that will cure the problems the right way? Then we will need to buy a machined kat stem to fit to the GS's right? Who's the guy selling those again?

[The Buddha]

Oh yea ... OK ... However Dgyver and other people also do conversion kit etc, Also any machinist can do it.
Just like jetting ... its knowledge out in the open, I just give people an option ...
Essentially I am doing a conversion later this week for a local guy, who bought most of it on ebay, I did the top triple for him, he borrowed my 89 top triple to run while I am slicing his top triple ... I dont care. Its knowledge out there, I am experimenting with GS seals etc too ... GS forks dont seal up too well after a few 1000 miles, and you essentially dont have hydraulics after that.
BTW I also sold Katana shocks a plenty while promoting kat rear shocks, jets while saying run 40/125, Flanges while promoting wiley co's and my handlebars while saying stock handlebars suck ... any further questions ...
Cool.
Buddha.

[ohgood]

no one posted a detailed summary of a particular riding style, and my google foo is poor today.

anyone care to elaborate (minus the changing forks/oil/etc bit) about late braking, or whatever that is the cause of cupping please ?

mine looks like hell but i have around 10,000 miles on it, and i'm STILL waiting on June 5th for my front battlax to come in.

k tanx

[gsJack]

MArkRD's front tire looks pretty good to me with a lot of life left in it yet.  I got 13-14k miles each from the two BT45 fronts I ran.  I've had 13 different front tires on my GS's over 9 years and 140k GS500 miles.

All my GS front tires have cupped and/or beveled badly except the Metzeler ME33 and Lasertec tires which remain my favorite GS front tires for use with either bias or radial rear tires, keep a good shape right down to the wear markers.

I'm trying one of the new Roadrider fronts now.

http://img.photobucket.com/albums/v443/jcp8832/GS500tirelog.jpg

[ls 64086]

ok, just to clearify to me

Buddha, you suggest kat front fork? no other options for making stock work?

gs jack, i can't make heads or tails from your jpg - can you dumbie it up for me? whats your recommendation on a front and a rear tire for the gs?

thanks gentlemen 

[gsJack]

Left click on the tire log to enlarge it so you can read.

[ls 64086]

oh i see the jpg just fine, it just doesn't make sense to me. is there some place on there that says "i liked this one"?

[dgyver]

All tires will cup to some extent. How much depends on a lot of factors... tread design, spring rate, fork tube diameter (smaller flex more), road surface, braking & riding style are just a few. From my experience, proper spring rate is the biggest factor with riding & braking style playing an important role on your setup. I have had less cupping with the same tires after installing the proper springs for my weight.

[The Buddha]

ok, just to clearify to me

Buddha, you suggest kat front fork? no other options for making stock work?

gs jack, i can't make heads or tails from your jpg - can you dumbie it up for me? whats your recommendation on a front and a rear tire for the gs?

thanks gentlemen 

I am still doing the last few things to the stock ... but a combo of 1 huge disc, poorly made overall, lousy springs and a fork seal that will not seal up for very long = recipie for useless junk.
I have a set of kat forks that has the seal and dust cover literally swelling and blistering from rust and crap, and I pump it a few times and its not leaking ... I am still working on some stuff on GS and kat though ... I'll post here soon.
Cool.
Buddha.