R1 USD front Forks

[SDN]

Has anyone got any idea of whether there is a right way to press the steering stem out of the TRX and R1 yokes. I have just tried using a large fly press to no avail. Do I need a hydraulic press and if so what sort of force is needed. I'd rather check before resorting to more force

[Mincehead]

They are MF`s!!!!
The usual path is through destruction of the alloy bottom yoke, it`s what I had to do.The steel ring that`s fitted in the stem is also overkill, when a steel stem is pressed into alloy and the fit is good a steel retaining ring is really unnecessary.
Remember torsional forces are minimal and when forks/yokes are all up together it`s really going nowhere!
So, mill or grind the alloy yoke away to release the stem, it`s the simplest approach.

[SDN]

Thanks MH, what about pressing the R1 stem out, how hard is that?

[Mincehead]

Again they are fitted at the factory using similar methods, very high tonnage of pressure.
Likely it`ll be easier to get someone with a lathe to hold the stem in the chuck, then utilise a boring bar to carefully machine it out.
Don`t worry too much if you have to `eat` into the bottom yoke a tad, the TRX`s stem can always be built up a little with weld or indeed sleeved.As I said in my earlier post the way stems are pressed in by the factories really is overkill.
You could even make the stem a machine fit in the bottom yoke then drill through the two, tap the hole and utilise a securing screw (grub screw/recessed) around the back of the yoke where it`s not obtrusive.
Remember the assembly of stem, yokes and forks when installed on the bike really cannot go anywhere.

[zednine]

Ive pressed a few out on Suzukis ......... takes around 6 tonne of pressure

Yamahas may be different but a fly press wont be up to it

Any local engineering shop with a bench mounted press ........ very cheap I have one in my garage should be able to pop it out in a few minutes

On Suzukis the stem is stepped so make sure you press it the right way

Chris

[Mincehead]

I had a ten ton press try to get a stock TRX stem out, nothing, the alloy of the bottom yoke started to deform!

[Kayla]

You need a hydraulic press, but before you try to press it out, warm the yoke (gently, not too hot) and give the stem a waft with plumber's freeze spray. You will probably need to run a few beads of TIG around the TRX stem and then machine it down to suit the R1 yoke as there's a 0.3mm difference in diameters. Before you refit the stem, put it in the freezer and warm the yoke.

[trixi]

Yep . never underestimate the power of heat and cold /expansion/ contraction. The Aluminum Alloy on the yoke has a significantly higher coefficient of expansion than the the steel stem. Use that to your advantage and the job will be easier. Just be careful with the amount of heat you use. Too much and the Aluminum melts with little warning, before that point is reached however you will be altering the hardness and temper of the steel in the stem. You don't want to change the color of the stem. Heat the yoke. Not the stem. Cool the stem, not the yoke. Just like the previous post said. And be quick and ready to press out the stem before heat transfer undoes your good work.

[Quan-Time]

Dont they have a circlip retainer in the bottom ? i cant remember. Ive done it, but it wasnt overly hard.. With that said, i have access to a 50t press.. made light work of it without even trying.

[dandywarhol]

A good tip to use when heating aluminium alloy is to heat it until the varnish on a matchstick melts or until soap turns black - any more heat than that and you're liable to alter the properties of the alloy.
These aren't old wife's tales

[Quan-Time]

A good tip to use when heating aluminium alloy is to heat it until the varnish on a matchstick melts or until soap turns black - any more heat than that and you're liable to alter the properties of the alloy.
These aren't old wife's tales

I use a digital temp gun personally.. Much more accurate. Ill add that the varnish DOES hold true, for certain brands. Many brands dont have varnish anymore. And can you please define "soap" ? Sure its (roughly) 50:50 detergent:grease, but what sort of grease and detergent are you talkin about ? Liquid soap, stick soap you rub on, shavings of bar soap... Specifics are key here.

For the record, "paper", non gloss, non recycled A4 writing paper, photo copy paper, just about everything EXCEPT "printed news-paper" will scorch at 70degC. That means it will turn brown, but not catch on fire at 70degC. Its a fairly good witness mark on some thing.

[dandywarhol]

A good tip to use when heating aluminium alloy is to heat it until the varnish on a matchstick melts or until soap turns black - any more heat than that and you're liable to alter the properties of the alloy.
These aren't old wife's tales

I use a digital temp gun personally.. Much more accurate. Ill add that the varnish DOES hold true, for certain brands. Many brands dont have varnish anymore. And can you please define "soap" ? Sure its (roughly) 50:50 detergent:grease, but what sort of grease and detergent are you talkin about ? Liquid soap, stick soap you rub on, shavings of bar soap... Specifics are key here.

For the record, "paper", non gloss, non recycled A4 writing paper, photo copy paper, just about everything EXCEPT "printed news-paper" will scorch at 70degC. That means it will turn brown, but not catch on fire at 70degC. Its a fairly good witness mark on some thing.

I find the non perfumed 250g bar of Parmolive's finest to do the trick......................