Front forks - how much play is ok?

[gcos]

Hi to all from Ireland,
Firstly, thanks to all the people who have posted up topics that I have been glad to avail of over the years. A wonderful source of info. I now have a question that I hope someone can advise.
I decided to change fork oil in my ST as it was never done since I acquired it. Removed forks. All went perfectly, and checked the bushes which to my untrained eye did not show any wear. All back together, and when the wheel was fitted and tightened I decided for some reason to pull on it to check for movement in the triple tree. There is movement, but having removed the front wheel to be sure, the play is in the fork - each one. Seals were not even slightly leaking before I stripped to refill and check the bushes. So, is some free play acceptable when the fork is mounted, wheel removed when pulling on the bottom of the fork and holding the chromed tube? Hard to say how much, but possible 3mm at the axle mount point.
I also have a Yamaha Diversion, and it shows no free play when pulling on the wheel, although I am sure various biker differ.
I want to have everything safe of course, but if the bit of movement is normal, then I will leave it alone. Thanks in advance for opinions.
Gerard.

 

[Sadlsor]

How is the bike positioned when you are pulling on the forks?
In my mind, I'm picturing it on the centerstand with the front wheel removed?

 

[OkieRider]

Sure it's the forks and not the triple tree? Head tube bearings...

 

[gcos]

Sure it's the forks and not the triple tree? Head tube bearings...

Speedy replies! thank you.
Definitely not triple tree - absolutely no play there.
Bike on mainstand, jack under engine, wheel and mudguard (fender) removed. Definitely the movement is within the forks. Pulling on the bottom outer tube where the axle goes through, and holding the chrome tube below the triple tree.

 

[Larry Fine]

Keep in mind that the fork tubes are at minimum overlap when fully extended, and there will be less play when loaded.

 

[gcos]

Keep in mind that the fork tubes are at minimum overlap when fully extended, and there will be less play when loaded.

Yes, understand that. That's why I am wondering if on the ST there is a small amount of play that others have noticed and accept as normal on these bikes.

 

[ReSTored]

Just curious.........What year is your bike? how many km or miles?

I can tell you that my 2002 ST1100 had zero play on the triple tree with the wheel and fender installed and the bike on a center stand with a jack under the engine. It also had zero play or movement after the wheel and fender were removed. It also had zero play after the fork tubes were removed, flushed and refilled as per spec. and then reinstalled and the fender back on.
I can't speak to movement after complete disassembly as I never did this.

So, to answer your question there is no amount of play in either the head bearings or the forks that I would consider to be normal.

 

[John OoSTerhuis]

Hmmm…. you say you inspected the fork slider bushings. In order to do that you had to have separated the fork tubes from the fork sliders, driving the bushings in the sliders up and out by slamming the bushings on the end of the fork tubes into the bottom of them. The spec for the bushings is 50% of the grey teflon(?) worn away, showing the copper color underneath it. How did the fork tube bushings look? I find it unlikely that even worn fork tube bushings would account for the amount of ‘play’ you report, though. The only other possibility I can think of is the ID of the top of the fork slider is somehow not perfectly concentric/round, IOW worn out of spec.

But as mentioned, keep in mind that you are measuring play at full fork extension when the two bushings are close together, a condition not encountered during normal operation. Do you do a lot of very rough road/off-road riding (full extension w/high stress impact loading)?

My 2 cents.

John

 

[gcos]

Just curious.........What year is your bike? how many km or miles?

I can tell you that my 2002 ST1100 had zero play on the triple tree with the wheel and fender installed and the bike on a center stand with a jack under the engine. It also had zero play or movement after the wheel and fender were removed. It also had zero play after the fork tubes were removed, flushed and refilled as per spec. and then reinstalled and the fender back on.
I can't speak to movement after complete disassembly as I never did this.

So, to answer your question there is no amount of play in either the head bearings or the forks that I would consider to be normal.

Hi ReSTored,
Thanks for your reply. Well if you have no free play in your forks, then it's not something that is 'normal' and shouldn't the be in mine either I reckon.
Bike is 1999, mileage I am not sure as I believe speedo was changed before I bought it at 'indicated 40,000. with 49999 on it now. Never gave any trouble clunking or steering funny or wobbling. I just thought a fork oil change would be a good thing as I am hands on for stuff like that. I think I will strip again and replace the bushes anyway now, if only for peace of mind. Having discovered something I wasn't aware of, it's annoying me now.
Thank you for your answer - it is exactly what i needed to know.
Gerard.

 

[gcos]

Hmmm…. you say you inspected the fork slider bushings. In order to do that you had to have separated the fork tubes from the fork sliders, driving the bushings in the sliders up and out by slamming the bushings on the end of the fork tubes into the bottom of them. The spec for the bushings is 50% of the grey teflon(?) worn away, showing the copper color underneath it. How did the fork tube bushings look? I find it unlikely that even worn fork tube bushings would account for the amount of ‘play’ you report, though. The only other possibility I can think of is the ID of the top of the fork slider is somehow not perfectly concentric/round, IOW worn out of spec.

But as mentioned, keep in mind that you are measuring play at full fork extension when the two bushings are close together, a condition not encountered during normal operation. Do you do a lot of very rough road/off-road riding (full extension w/high stress loading)?

My 2 cents.

John

Hi John,
Thank you for your interest.
No obvious scuffing that I could determine but some showing of copper, though not much in my humble opinion. No off-roading at all, indeed I would consider myself a smooth rider rather than aggressive! I would have thought that seals would start to leak by the time some play was obvious in the bushes. That is why I was asking if others had noticed some play as 'normal'. Can't comment on the possibility of being out of round. Anyway, I think I will strip again and put new bushes and see what the difference is.
Thanks to everyone again for your help. Off to bed now 00:12am here.
Gerard.

 

[John OoSTerhuis]

PS - check the play again with the springs out, before you separate the forks again.

 

[gcos]

PS - check the play again with the springs out, before you separate the forks again.

I am going to put new bushes in over the next couple of evenings and re assemble (work interfering with play!). I will check as you suggested John, before removal of bushes and then after new ones fitted. I will report back in a few days to let all know the result either way.
Gerard

 

[gcos]

Ok, all done now.
I checked the free play John, as you mentioned above. Before pulling the old bushes out, with springs removed, there was definite play near full extension, and still some when half extended. \With new bushes only inserted, there is still slight play. Very very slight play when all is put back together on the bike. Still definitely not triple tree. However I really have to feel for the slight free play, and maybe when the oil gets pumped around even that may disappear. Bike does seem to feel a bit better on the road - not that I noticed any problem before. Just seems smoother at the front, maybe it's imagination! Old bushes still definitely did not show any particular signs of wear, unless they wear evenly all the way around (which I doubt). Maybe different makes vary. Not a hard job to do at all, just a matter of understanding what you are doing. I have a slight weep from RH seal, but I did allow some oil to get under the dust seal that I suspect is sitting on the top of the oil seal. I'll be keeping an eye on that just to make sure it quits fairy soon! Thanks for all the suggestions.
Gerard.

 

[CYYJ]

Hi Gerhard:

In case it helps you to evaluate the level of wear on the bushes that you changed, there is a post here in the forum with a lot of pictures of my ST 1300 front fork overhaul, including pictures of the bushes, both old and new.

There are differences between the ST 1100 and ST 1300 front fork assemblies, but so far as the bushes are concerned, I think the concepts are the same.

Here's the link: ST1300 Front Fork Overhaul: An Illustrated Bibliography. Below is a picture of the bushes, in case you don't want to read that whole post.

Michael

ST 1300 Front Fork Bushes

 

[jfheath]

Have you tried checking your fork free play with the steering held firmly fully left and fully right (perhaps with tension straps). This was the only way I found worked for checking for play in the wheel bearings.

 

[gcos]

Hi Gerhard:

In case it helps you to evaluate the level of wear on the bushes that you changed, there is a post here in the forum with a lot of pictures of my ST 1300 front fork overhaul, including pictures of the bushes, both old and new.

There are differences between the ST 1100 and ST 1300 front fork assemblies, but so far as the bushes are concerned, I think the concepts are the same.

Here's the link: ST1300 Front Fork Overhaul: An Illustrated Bibliography. Below is a picture of the bushes, in case you don't want to read that whole post.

Michael

ST 1300 Front Fork Bushes

Hi Michael,
Thank you very much for those pics and the link. I did read the whole post and it is very informative, slightly different in fork alignment for the 1100, but in all respects an excellent 'how to'.
New bushes all round have effectively solved my free play issue.