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.
(http://www.mijnalbum.nl/Foto-YSBV8CR4.jpg)
Whats happening here?
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 :)
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
pardon the ignorance but whats a cupping tire? the pic looks fine to me :dunno_white:
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.
To make the topic even more exciting: :o
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? :dunno_white:
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 :)
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"
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
Quote from: ls 64086 on June 01, 2008, 01:15:51 PM
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.
Quote from: MArkRD on June 01, 2008, 01:24:20 PM
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.
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.
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?
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.
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 :)
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
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 :cheers:
Left click on the tire log to enlarge it so you can read.
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"?
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.
Quote from: ls 64086 on June 01, 2008, 06:42:11 PM
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 :cheers:
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.
Quote from: ls 64086 on June 01, 2008, 06:42:11 PM
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?
Quote from: ls 64086 on June 01, 2008, 06:56:12 PM
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"?
I liked them all for various reasons, it all depends on what you want from a tire and how much you want to spend for it. I used Dunlop K291 and K491 touring tires on my four old 400-750cc Hondas and got 25-30k miles from the rears, don't think you can beat them for miles for the dollar if that's what you want. Tried one K491 on my first GS and it just didn't want to go around the corners as fast as the bike did.
At the other extreme are the supersport radials like the Pilot Powers which are popular with many GS/EX500 riders. Super sticky and great handling but most expensive per mile since they give shorter life than touring or sport touring tires. I don't use supersport radials myself settling for good sport touring tires but there are others here that use them.
I made an attempt to rate the ones I used a couple years ago and updated it about a year ago and it's in the FAQ section. But this is just what I thought was best for my needs, your needs may vary, it's in this thread:
http://gstwins.com/gsboard/index.php?topic=16501.0
I'm starting to really like these Roadriders I'm using now, they are good enough in performance for my current needs and really nicely priced. Not as good as the Lasertecs I used but about $40 per tire less at my local place. They replace the Avon AM51/52 tires I used previously and are noticeably better than them. Don't be surprised if I go back to a sport touring radial rear next though, time will tell.
Yea I am replying to myself ...
The GS forks are kayaba items. The Kat forks are showa. Now in the old days 80-90's japan had a long history of protectionism for their native equipment makers. The govt mandated the manufacturers to use all the available sources. That lead to GSXR 750's being fitted with showa, and GSXR 1100 fitted with kayaba among other random things.
The 2 bikes weighed close enough and had identical geometry that there was no need to fit them this way ... yet they were. Now sooner than later the public figured out the 750's had better shocks and they would drop in to the 1100's ... ergo, the 750 shocks were a hot item, and 1100's shocks went to sheite. The difference from outside is that the 1100's had a remote reservoir the size of a red bull can, while the 750 was closer to the coke cans. The front ends for these 2 bikes were also the same showa/kayaba thing, but it was less of a difference than the rear and harder to really swap.
The kat forks actually come apart much much easier (no need to get that weird tool made for it) and go back on easier. Their rebound adjustments really work so well because they have concentric rotating disks that change the effective hole diameter so drastically. In effect, the Kat forks on a GS are like night and day. Those forks aren't that bad on a kat 600 itself, my 3 kats did well, with one of them having an extra 1 inch spacer and the other 2 were stock. That bike felt tight, a little too tight and stiff if you ask me. Anyway, the GS forks may be modded - I am yet to really test that part out, but as they stand, it is pitiful. I never saw it till 2005 cos I ran on a lindemann modded GS suspension. Then after 05, I never had a steady GS, I am working on putting one together but I have had atleast 3 that I borrow on a regular basis, and 2 of them are beyond useability. The clip on's on the 1 have just made it awful ... I plan to slice and dice it ... lets see.
As a upside to leaking forks, the part that is soaked in oil, usually resists weather a lot better.
Cool.
Buddha.
Do they make cartridge emulators for the GS? If so would these and progressive springs and the correct oil weight be close enough to get good handling and eliminate cupping?
I have seen them I thought in the past, They were ~90 bucks, springs are ~80, then the forks have to be split and have these fitted so you need new fork seals and dust covers, this is the time for it, then you still ahve the possibility that the forks leak with that idiotic single giant disk and anyway you're out $300 + ... Adjusting them you have to open the top and fiddle with them, you still ahve the lousy stock bars of the GS and 1 disk.
In the present context katana FE's off ebay are much cheaper ... Maybe if demand for kat FE's sky rockets because of what we're doing, then maybe the emulators are the way to go. Anyway the 41mm fork tube and dual disc I suppose help it all the way around. To the extent of like stoppie-ing it.
Cool.
Buddha.
Quotebut 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.
So, what are you saying here Buddha?
The stock front-end is more or less crap, despite 15w oil & progressive springs etc?
I have a RD500 (Yamaha) frontend lying around with the same forktube diameters and double brake disc. I'm thinking about using this in the GS.
PS I have the offer of a new BT45 only the size is 110/70/17 instead of 110/80/17. I can't imagine this being a big problem.
Jury is awaiting execution on the GS stock FE ...
2 disk FE from them FZR or old CBR may improve to the katana level, or it may not ... prolly cannot make it worse, more than likely improve it a good bit. No idea, never done it.
Now a Kat FE sealing up itself is work some research and I am on it as well. I'll post here guys you know that, even if no one wants to read it ... O0
Cool.
Buddha.
Quote from: MArkRD on June 02, 2008, 10:08:43 AM
PS I have the offer of a new BT45 only the size is 110/70/17 instead of 110/80/17. I can't imagine this being a big problem.
110/70-17 is the stock tire size for the GS.
Quote110/70-17 is the stock tire size for the GS.
:oops:
That's the 2nd time i screwed up on my tire size. First one I fitted a 130/
90/17. Glad i got rid of that one.
Buddha, I think you made your point, although the jury is still out. I'm not gonna wait on them and will start looking out for another FE. I didn't like the brake anyway.. :nono:
Ah! The joys of a good tire. I fitted a new bt45 up front. :thumb:
Only then i noticed how bad the old tire handled.
All is ok now but i'm gonna swap the front end soon
Thx for the input guys!
ive never had a tire cup, and ive ridden the piss out of bikes with completely hosed forks.... its not always bad forks...
The cupped tire is not the main reason i want to change forks.
The tire-man said that i could expect a tire change after 7000- 10.000 km of riding the way i do.
It's more the whole dual disc idea that got me thinking.
Oh well. It's gonna be a future project..
Oh for God's sake Buddha,
Enough with the "everybody needs a Kat front end" already.
Not every motorcycle is ridden 10/10ths, as I am sure yours is not also.
The stock GS500 front end has weak springs and can be made vastly safer and better with the addition of Progressive springs and 15W quality fork oil, properly measured and installed.
We don't all need Kat front ends, particularly riders who just want to ride their motorcycles and not spend their time with machinists, and eBay and the hassles of bringing it all together.
A perfect world? No, but Progressives and new oil make it a good world.
It is a much better ride and more control. A must-do GS500 fix, for sure.
And my fork seals don't leak constantly because they are weak, despite your claims. That's ridiculous too, I'm afraid.
Not everyone needs to do it YOUR way.
SO relax folks, and let's have fun out there.
Best wishes,
Todd
He relax Todd.
Buddha wasn't the one who convinced me to ditch the stock FE. It was me!
Your right about the progressiv's and 15w oil, though. It a whole different bike after these mod's. But still i want a dual disc FE :icon_twisted:
Sleep tight
Thanks, Todd. Somewhere I mentioned the very same thing, not exactly in your eloquent words, but it needed to be said.
Buddha usually has great info and I have used a couple of suggestions, except this time he is whipping a tired horse.
i like the high speed weavjing and wobbles when ive got it pegged through sweepers. seriously, keeps me on my toes.
The GS is what it is, a low end bike with low end components. The suspension is one of them. I am not saying everyone needs to replace or upgrade it, more need to than they do. It is only designed for a 120# or so rider. Upgrading to better springs (not a fan of progressives) is a start but does not eliminate the flex inherent with smaller diameter tubes. I would rather have a front end that gives me confidence.
The best you know is the best you have ridden.
I've had 6 bikes that I've put a total of 365,000 miles on since 1984; 81CB400T, 82CB750K, 81CM400A, 85CB650SC, 97GS500E, and 02GS500.
That Nighthawk 650 I traded in on my 97 GS in Mar 99 was smoking like a chimney the summer before when bogged down in traffic on a hot day with barely 60k miles on the clock. It was the best handling of the 4 modest Hondas I had. It had air adjustable front forks with hydraulic anti-dive adjustment. Besides preload adjustment, the rear shocks had rebound damping adjustment. It had dual disc front brakes and drum rear.
It was a cold day just above freezing when I rode the NH about 30 miles to the dealer and rode the 97 GS home. Not yet use to the cold blooded nature of the GS I was thinking I'd made a mistake buying it but half way home it warmed enough so that when I hit hilly twisty River Road it was finally cooking and I became completely sold on the GS during those final few miles home. It handled great and dove into the corners faster than I had intended. It felt like a sportbike compared to the old Hondas.
Now 120k GS500 miles later I'm still sold on the modest little GS500, it really needs stiffer front springs like Todd said and little else to make it a great ride for the price. No problem with those that want further mods on their GSs, go to it and enjoy. I put a set of Progressive front springs on the 97 GS and then transferred them to the 02 GS and with 100k miles on the springs they are just right for my 240# weight now, nicely broken in.
Americans now buy sportbikes and cruisers and I've never ridden either and hope not to. Don't feel the need for track designed sportbike suspension and brakes, dont want to pay twice as much for the bike to try them out. Dgyver is right on "The best you know is the best you have ridden." That's good enough for me, as much as I want to pay to know.
And on the fork seal question, both of my GSs have developed leakage around 50k miles or so, I replaced them on the 97 and will do the same on the 02 next winter unless they get worse before then. One seal change in the 80-90k miles I use a bike seems reasonable to me.
GsJack - A often used bike will have everything last longer. Fork seals die from sitting more than riding. Your numbers definitely make us look like wimps.
Cool.
Buddha.
Quote from: Trwhouse on June 05, 2008, 12:25:06 PM
Oh for God's sake Buddha,
Enough with the "everybody needs a Kat front end" already.
Not every motorcycle is ridden 10/10ths, as I am sure yours is not also.
The stock GS500 front end has weak springs and can be made vastly safer and better with the addition of Progressive springs and 15W quality fork oil, properly measured and installed.
We don't all need Kat front ends, particularly riders who just want to ride their motorcycles and not spend their time with machinists, and eBay and the hassles of bringing it all together.
A perfect world? No, but Progressives and new oil make it a good world.
It is a much better ride and more control. A must-do GS500 fix, for sure.
And my fork seals don't leak constantly because they are weak, despite your claims. That's ridiculous too, I'm afraid.
Not everyone needs to do it YOUR way.
SO relax folks, and let's have fun out there.
Best wishes,
Todd
I agree.I live in a hilly curvy mountainous area and I like to use my bike.That's my reason for upgrading to the Katana750 front end.If I was just knock around town or touring(not sport touring)I would have kept my GS front end with Progressives and 15w.Instead the built GS front end is going on Project Lite Wait.Trying to keep it as light as possible.
10/10's ... you guys kidding me ... my 240lb weight means its already @ 2 x its design weight. The normal commute I do and the bumps on the road under brakes mean the damn thing will get maxed out.
Now the Stock FE isn't a complete wash. There are FE's that constantly leak. Some as soon as you put seals in, some in few months. Its just that of late I am working with FE's. I did the same to carbs 10 years ago, and FE's are also entirely Fluid mechanics, I should figure it out soon.
There may be a way to get them to seal up more reliably, and sonics or progressives can help their tendency to collapse. Yea, I am still working on it. Now all that is a lot of experimentation. The Kat FE may just be a cleaner way to get a better result.
Anyway, I'll post the results here of my experiment. Everyone knows the kat FE ...
BTW I also started the whole Kat rear shock 10 years ago on the old mailing list, and I sold over 10-15 of them in the 00-02 time frame. The shock swap is almost sure to show up the front end.
Now here is what else I got ... no FE's for sale. I do machining and welding, essentially I have 2 guys that will do these to specs I have showed them. Basically nothing to sell. No money to make ... dont care if the GS FE's work, dont care if kat FE's work ... If GS FE's work I'll post that here too ... maybe then you can all bash me for saying GS front ends are working.
Cool.
Buddha.