Forks

[AllanB]

The forks on the old NVpainintharse feel a bit "squishy" in terms of shock absorption, how are they tested, please bear in mind there is no main stand on the bike, only a side stand leg?

When I first bought the bike I had a local guy change the then weeping oil seals and refill them, but it could be that he did neither, just gave me a bill, as there seems little in the way of shock absorption.

I dives like Jason Statham on any kind of front breaking, but there does seem to be some rebound damping, rather than a bang!

If they are okay can anything be done to firm things up a bit on the front?

[properperson]

i though you were buying a 250M ??

[pokerkid]

i thought you were buying a Benelli

[CarolJadzia]

If the fork seals were blown you would know because there would be oil on the forks, unless of course there is no oil - but that tends to lead to clucking when the forks bang on the stops.

He may of changed the seals but not replaced the oil or possibly used the wrong grade of oil.

Fork oil comes in different grades so you can change the dampening by using a thinner or thicker oil.

However to do that you need to know what the grade of the current oil is.

Edited October 26, 2015 by CarolJadzia

[Gonsalviz]

I recently changed the oil and seals in my HD forks. I don't pay HD prices so it was a search. I read on an HD forum that Ford Type F auto trans fluid was used with good result. Obviously, that is not available in Thailand so I bought Isuzu A/T oil. Works well. Can't say what oil you would need but that maybe a start.

[thaiguzzi]

If you can't get new or slightly stiffer fork springs, cut some pvc water pipe to give the tired springs more tension. Parallel each end. Try 1" first. As above, could try thicker fork oil ie 10w instead of 5w. ATF is generally good.

[thaiguzzi]

i thought you were buying a Benelli

I thought he was buying a Lifan...

[pokerkid]

i thought you were buying a Benelli

I thought he was buying a Lifan...

Or was it a Honda ....

[properperson]

If the fork seals were blown you would know because there would be oil on the forks, unless of course there is no oil - but that tends to lead to clucking when the forks bang on the stops.

He may of changed the seals but not replaced the oil or possibly used the wrong grade of oil.

Fork oil comes in different grades so you can change the dampening by using a thinner or thicker oil.

However to do that you need to know what the grade of the current oil is.

Wize words as usual Carol - keep up the good work.

[AllanB]

Shortly after I bought the bike, there was just a tiny amount of seepage from one of the seals, dampness I guess you could call it. So I lifted up the plastic covers and ran a cloth around the oil seals to remove some dirt and that stopped it, but then had a local company change the oil. This started the weep again, so removed the forks and drained them, only to find new oil in one and old oil in the other. mmmm.

Deciding on a full strip for new seals, I found a retaining clip at the top of the forks, which I couldn't get out, well actually didn't know how to remove it with the tools I had and asked another bike shop to fit new seals and new oil.

That was over a year ago, no leaks and there is some damping, not sure how much there should be, but occasionally I hit a big bump (2up) and they bottom out...and as I say the bike dives more than I would like.

I think I may have a go with ATF, I assume the oil seals are happy with that?

No manual, so wondered what the oil level should be.

[CarolJadzia]

I think I may have a go with ATF, I assume the oil seals are happy with that?

Automatic transmission fluid? I think that normally has a viscosity of 10W? Does your bike have that viscosity as standard?

Why not look up the proper fork oil for your bike and start with that? Does not have to be the recommended make, just the right viscosity.

http://rottenxxxronnie.blogspot.co.uk/2011/09/secret-world-of-fork-oil.html

[AllanB]

I think I may have a go with ATF, I assume the oil seals are happy with that?

Automatic transmission fluid? I think that normally has a viscosity of 10W? Does your bike have that viscosity as standard?

Why not look up the proper fork oil for your bike and start with that? Does not have to be the recommended make, just the right viscosity.

http://rottenxxxronnie.blogspot.co.uk/2011/09/secret-world-of-fork-oil.html

I found and downloaded a manual for the bike but it is in Portuguese and shows spoked wheels and chain drive, maybe options?

The only mention for the forks is on a diagram is labelled "AJF", which could be a misprint. Anyway I think ATF is a good option and is thicker than general fork oil, which is what they will have used, as it isn't red. I have only seen fork oil here, no other spec.

Thanks

[seedy]

Automatic transmission fluid? I think that normally has a viscosity of 10W?

Memory serves - 7W