Fork seals

Pete Roper wrote:

Sadly my bulk has nothing to do with too much food and everything to do with buggered lungs from fifty years of smoking so I can't excercise properly and a terrible love of beer.......

It is what it is. There are no Purple Hearts for self inflicted wounds......

Ah. I feel your pain. I too have buggered lungs for the same reason. Thats the technical term - colloquially, it is COPD.

As much as people hate vaping, switched 8 months prior to my stroke. Prob saved me lots of f*cked body parts. The way I put it is 10 years ago walking the quarter mile up hill to my garage required a lengthy rest to recover as breathless. 10 years later nearly 3 stone heavier, older joints significantly less fit takes me mere moments to recover. A lung X-ray after a few years showed all traces of shadows gone. Only downside to vaping is that crutch what calms you down with smoking is non existant with vaping.

OK, I'll explain.

It is straightforward to calculate the local expansion. Since we have the potential expressed as a n-order polynomial, we only need to plug in the value of (dx, dy, dz) for each beer to obtain the potential for it.
The local expansion of the potential is a polynomial of the belly's coordinates. Taking the derivative of the potential with respect to a beer gut, one can obtain the (p − 1)th-order polynomial for the field on the respective direction.
The variables in the belly expansions are analytical functions of the coordinates. To calculate the field by the beer expansion, we take the derivative with respect to the guts by the chain rule, and we obtain the expression of the belly expansion as:

Ex={∂ϕ/∂dx⋅d²/2dx²+2∂ϕ/∂dy⋅dxdy+2∂ϕ/∂dz⋅dxdz+ϕ/⋅dx⋅d}

QED.

beetle wrote:

OK, I'll explain.

It is straightforward to calculate the local expansion. Since we have the potential expressed as a n-order polynomial, we only need to plug in the value of (dx, dy, dz) for each beer to obtain the potential for it........and we obtain the expression of the belly expansion as: Ex={∂ϕ/∂dx⋅d²/2dx²+2∂ϕ/∂dy⋅dxdy+2∂ϕ/∂dz⋅dxdz+ϕ/⋅dx⋅d}

Of course the "d" factor is a complex result of the interaction of variables
For example the input excercise quotient (IEQ) which subtracts from the expansion co-efficient according to the excercise required to get the beer into the mouth.
Thus Light Ale is obviously less work to lift than the Scottish Heavy
and beers with a large mass of foamy head reduce the workload for a given volume e.g. Johns Smiths & some lagers.

Updates to accepted IEQ values

• The standardised glass for all IEQ is a Nonic Linky to Nonic Weight: 335g;  heavier glasses will upset the calculation
  

• There is no longer an accepted IEQ difference between opening flip-top bottles and opening crown caps
  

• Manually drawn beer (Real Ale in English) has no addtional IEQ as all excercise goes to the bar-staff and not the drinker
  

If you take a piss does all that change?

I’ve gone over all this and can find no fault. The mathematics is sound and holds true, at least theoretically. One does have to wonder if it can be proven in the real world where random interactions could deviate results, such as GuzziSteve’s query about taking the piss.

Interestingly, Mark’s formula is also the basis for propagating the reactive resonance of one’s own belch and, as noted by lcjohnny, the ‘d’ factor is highly significant to the result.

Taking Mark’s Ex as a function of time, ∂(Ex)/∂t, and performing a Fourier Transform results in a complex valued function of frequency, whose magnitude represents the amount of that frequency present in the original function, and whose argument is the phase offset of the basic sinusoid in that frequency.

Clearly the differing ‘d’ factor in the differing brews results in a differing frequency when gaseous expulsions occur.

Marvellous isn’t it!

Ok. I can't find the parts at a sensible price. So I'm going to rechrome. Problem is my tame Guzzi mechanic doesn't have room to store the bike while the forks are away for some work. So I need to get the forks off at Trog Towers. What's my best option for lifting the bike? Will a Becker lift and a car jack work for dropping the forks out?

Yes. I do something similar. You only need to get the front wheel a wee bit off the ground. Loosen the front wheel nut beforehand.

I'd avoid any sort of hydraulic jack as they have a tendency to bleed down. If you want to you can use one under the sump but chock the sump when it's high enough to get the front wheel off the ground.

Ideally use a scissor lift under the sump with a piece of wood between it and the sump.

I'm really struggling here. The specialists appear to be Brook Suspension, but they won't do it. They say that they have less than 50% success rate with getting the knuckle off the tube, and it's not worth the risk. I can't find second hand forks, and I do t fancy the price of new tubes which are in the £mental range.

Any ideas?

Brook suspension are good people - but in Yorkshire so will have to send the fork legs - they charge £220 for usd fork rechroming Brook usd rechrome linkand 180 for a fork strip service and rebuild Brook Showa rebuild link

Lots of places on the web offer re-chrome i guess it depends which side of London you are

Looks difficult but wonder what Brooks failure point is (that can't be worked around somehow) ?

The tightwad old farmer in me would make a clamp out of wood, slightly undersize, and clamp it in the vise.
And yes, gentle heat is your friend.

Also, he mentioned using red Loctite. Ummmm, there are at least 6 different red Loctite products. Make sure you use the lowest strength, which I believe is 242. DO NOT use 271 !!!!

lcjohnny wrote:

Brook suspension are good people - but in Yorkshire so will have to send the fork legs - they charge £220 for usd fork rechroming Brook usd rechrome linkand 180 for a fork strip service and rebuild Brook Showa rebuild link

Lots of places on the web offer re-chrome i guess it depends which side of London you are

I've tried Brook. They are not able to do it, as they say there is too low a success rate in getting the hub knuckle off the tube.

I've spoken to another localish suspension specialist, who did all the boy's race suspenders. He says he'll have a go but rates the chances of success as 50% or less. He says you often need to drill the grub screw, and that often shags the threads. He'd do it, but at my risk.

Yeah, but surely you just need to drill a bigger hole and fit a bigger grub screw when you refit the (re)chromed stanchion ???

(after tapping a bigger thread)

Trogladyte wrote:

I have a sudden fork oil Niagara situation.

It must be catchung - same here

Ordered most stuff now just awaiting a seal driver and some longer spacer tubes to give me 14mm more preload.
If my calculations are correct that should make it ride the bumps better

Im still in the market for some forks, or tubes with knuckles if anyone has a line on such wonders.

I also sprang a leak on one of my forks a couple of weeks ago. I used Guzzi Steve’s recommendation of the home made seal mate from a plastic milk jug. Ran it up and around a couple of times. Had to pump the forks a lot and actually the second day it was dry. I even slid some molykote 55 up around the seal. But at the end of the day, about a week later, I took it to the MG shop, as the bike is 8 years old and has 23k miles on it and has never had the oil changed. Cost of 4 hours labor at $120/hr plus oil and seals etc so about $550 USD total. Glad it is done.

Eek!

$30 for fork oil. $30 for fork seals. Home made compression tool. Couple hours in the garage.

That's Australian dollars..so not many US dollars.

$550? Oh my giddy Aunt!

Only the second trip to someone else in 8 years besides tire changes, thanks great instructions here. I would have liked to do it but felt it was beyond my capability and I didn’t want to be without the bike for a month….

maybe useful, if you are around London area

[You must be registered and logged in to see this link.]

not sure how good they are as I haven't used them