Front end issues, suggestions?

[XS11NEWROSS]

Upper bearing/race Greg, I thought I had not got it into the frame correctly so I cut it out of it this afternoon Still not clear why top tree is a bit high but I'm sure lower race is good from your pics and lower bearing is seated on shaft (this I will check again on reassembly). The 9 page motion pro thread is impressive!

[XS11NEWROSS]

Road test and update

So it has taken me a while to get everything back together! Been so busy at work and a holiday to Italy (super). Got her finally on the road and she is greatly improved at the rear end but the front while better is still not right. Still getting a bouncy vibration feel, I checked carefully oil level in both forks used ATF10 , all cleaned out and new bearings in wheel and headraces. I measured the spring length and both were spot on but it feels saggy. I wonder is it possible that the springs are tired and old but still measure up OK without compression? They are non progressive. Anyway, I have now ordered a set of progressive springs from Germany which will be here in a couple of days, may try 15w oil? Any views on them old springs?

[bikerphil]

If you can do it safely, reach down to the left dust seal when the rough condition is happening and see if the stanchion is sticking or if it is bouncing up and down too rapidly. Bouncing rapidly indicates lack of rebound damping (oil is too thin), sticking may indicate binding, due to improper alignment, bent components, worn bushing, etc.

I'm sure you have checked to make sure the tire is in balance, yes?

[jetmechmarty]

15W oil will slow the high speed damping as compared to 10W.

[skids]

15W oil will slow the high speed damping as compared to 10W.

I used 15W fork oil in my 78 and when it gets cold out it is stiff but not unreasonable.

[XS11NEWROSS]

Thanks all ...

On reflection, I may just continue for now with the ATF oil, the new springs have arrived from Wirth and they suggest using 15w in the instructions as the springs are stronger but I think it may be a good comparison to first try the same oil, easy to change it out later if it is not working well.

Thanks very much for all your inputs.

[motoman]

On reflection, I may just continue for now with the ATF oil, the new springs have arrived from Wirth and they suggest using 15w in the instructions as the springs are stronger but I think it may be a good comparison to first try the same oil, easy to change it out later if it is not working well.

Thanks very much for all your inputs.

Problem I see is ATF is like WAY 'old school'(used to use it some 4decades ago in our moto-cross bikes). The issue ATF has is it aireates a lot, loosing decent dampening affects. Fork oil IS your best choice!
Wieght to use IS dependant on the fact that dampening orfices slightly enlarge over the decades of use(yes, oil transferring at high speed wears on metal pieces, and THIS is what causes the increase in temperature of front forks). Have had the front forts so hot on my YZ250 after a moto heat, they were too hot to touch for long.
Having said that, in my Venturer front forks( original factory progressive springs), I've went to 15w Silcolene fork oil. Dampening of front of bike is like night and day compared to the 10w Silcolene. All fork rebuild/oil change done by complete dis-assembly, everything cleaned with new, clean solvent and blown dry before assembly. I also used to run 5-7psi in forks, but now, zero air pressure.

[TopCatGr58]

Hey Brant,

Not trying to pick an argument, but do you think that they have engineered the ATF a little better over the last 4 decades?? ATF is supposed to be non-foaming which I think is equivalent to what you call Aerating?? It's also fairly high detergent which I think can help keep those ports open and not allow them to clog.

T.C.

[motoman]

Hey Brant,

Not trying to pick an argument, but do you think that they have engineered the ATF a little better over the last 4 decades?? ATF is supposed to be non-foaming which I think is equivalent to what you call Aerating?? It's also fairly high detergent which I think can help keep those ports open and not allow them to clog.

T.C.

Agree, using DextronII or III, if only convenient for a start. just keep the F type ATF out of forks.

[XS11NEWROSS]

Was going to chance this, very hard to source any oil out of the ordinary here in Ireland.

Thanks again for your inputs..... I would definitely like to put 15w type in as it has been very soft on atf but I guess with the latest springs it's a bit of trial and error, I only use the bike for a few slowish miles around locally, more of a hobby now but I have put so much time work and money into restoring it, I would like to actually drive it and feel solid and tight. We will see, this has been a great refresher course and learning experience, has kept my head sane when all around me has been difficult. A great bike and a great community.

[XS11NEWROSS]

Finally progress on front end issues

Well guys a big hello, it has been a long summer of work and hardship and a few heatlh issues so have had no time, things are calming down now and had the chance to re-commit to XS lady! Before I tried to change the fork oil again, I wanted to try her with the new springs and same oil etc. Definitely a stiffer feel, better but still loose and high vibration, giddy. I changed the oil again and this time got the 15w oil in the forks. Very hard to source here, had to get it online. So new progressive springs from Germany, Zero pressure, 15w oil and ....magic. For the first time, it feels tight at the front and the most striking thing is a hugh reduction in the vibration through the bars. I would say it's the first time it has felt good since I bought it. There is still some shimmy/wobble but I have not yet changed the swing-arm bearings (ran out of patience ) but all others have now been done. I am hoping this will again improve things, all other bearings were bad, looks like there was nothing done for years with this machine. Maybe the swing ones will be the same although I could detect no play in them when I checked so did not make them a priority. I have the bearings, so that will be done over the next couple of weeks.

[motoman]

Paul, good to hear your making positive progress on that bike.