Inconsequential ramblings of an Old Git

[Mr. Dazzle]

Straight cut gears sound awful though

You can make helical gears narrower than straight ones, all other things being equal. Maybe it was a space saving thing, or allows them to use a lower grade of steel or something.

[mangocrazy]

Straight cut gears are available (at a price) if you're chasing the last fractions of horsepower, but I imagine Yamaha left that for the TZ racers. As Mr D sez, noise would also be a consideration for street bikes.

When Honda fitted gear driven cams to the VFR they fitted anti-backlash gears to the main straight cut cam gears, mainly to quieten them down, but also to reduce shock loadings on the gears. Racers experimented with removing the anti-backlash gears in a quest for more power, but all they got was a lot more noise and wear and very little in the way of more power.

[Mr. Dazzle]

It's not as though the gear losses in the cam drive are that large! Nearly all the losses are overcoming the springs and the friction on the cam/valve interface, the gears themselves must be a tiny fraction.

Main drive is different of course, all the engine output power goes through that.

[A_morti]

Nearly all the losses are overcoming the springs and the friction on the cam/valve interface

Forgot what thread you're in, I think

[Mr. Dazzle]

Two stroke VFR sounds fun

[mangocrazy]

It's not as though the gear losses in the cam drive are that large! Nearly all the losses are overcoming the springs and the friction on the cam/valve interface, the gears themselves must be a tiny fraction.

Completely agree, but tuners will always look for marginal gains. In this instance the marginal gains were outweighed by the drawbacks.

Main drive is different of course, all the engine output power goes through that.

All parts of the engine/transmission contribute to frictional losses, so all parts are legitimate targets for improvement.

[Taipan]

Straight cut gears sound awful though

Why I oughta!

[mangocrazy]

Well, the puller arrived in the break between Xmas and NY and it did its job, easily removing the starfish from its shaft. But in that time The Plan had changed. Originally The Plan had been to smooth the points off the starfish so that the selector mechanism had less of a mountain to climb, and thereby make gear changing easier. If you can't visualise this, there are pictures further down. Or as Lux Interior of The Cramps would have said:

I'll teach you how to read the book of Life,
You can just look at the pictures if you like...

But in the intervening time period I had discovered that some canny person had done all that hard work for me by machining the part (with modifications) out of billet. For fifteen of your English pounds. So it would have been rude not to buy one. And I'm not a rude boy. It also means I have the OE parts as backup should anything go horribly wrong (not that it would, of course...) Here is the explanatory picture:

DSCF4599a.JPG (633.37 KiB) Viewed 893 times

New parts are on top, old parts below. As you'll notice, the new part machined from billet has much gentler-radiused 'peaks' between gears which means that the jockey wheel (left of picture) has less of a hill to climb between gears. Also the spring on the new part is made from thinner gauge wire, so won't exert as much force on the starfish. And lastly the roller on the jockey wheel is a real bearing (small but perfectly formed) on the new part, not just a circular piece of metal. Here's a top down view comparison of parts:

DSCF4608.JPG (320.59 KiB) Viewed 893 times

New roller (with bearing) is on the left, old metal disc is on the right. And witness mark from the old roller disc on the starfish is clearly visible. Here's a side on view:

DSCF4604.JPG (362.12 KiB) Viewed 893 times

So all it needs is for the shed to stop doing its impersonation of a chest freezer and I'll be back in there fitting this stuff. In the mean time I need to find a suitable clutch plate sized receptacle in which I can soak the new EBC fibre plates in oil prior to fitting them.

[mangocrazy]

I finally located my man card earlier today and ventured out into The Shed - an arctic hideaway at the bottom of the garden. Even with a fan heater on full chat the temperature only rose to a balmy 9 degrees C, but still better than the sub-zero temps outside. First job on the list was to fit the new billet starfish to the end of its shaft. This was fairly easily achieved, with a pleasingly snug fit, requiring a little persuasion with a hammer and wooden drift. The OE made-of-cheese cross head screw was replaced with a stainless countersunk allen head screw and a dab of anti-seize paste.

The next item on the agenda was the new jockey wheel and brass washer/stand off. Before the mounting bolt would pass through, both brass parts needed careful attention with a round needle file to enlarge the centre hole. I decided against trying to drill the parts out to 6mm, having visions of parts being sent spinning into the darkest recesses of the shed. Filing the centres out only took about 5 minutes, so no big deal. Then it was time to fit the jockey wheel, spacers, bolt and spring to the crankcase lower. I was expecting a big fight with the spring, but it all went together on only the second attempt, which was nice. This is what it looked like afterwards (neutral currently engaged):

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After that it was time to re-fit the gear selector shaft and make sure it engaged with the dogs on the starfish. With that in place the clutch outer and inner could be mounted on their shaft and the lock washer and nut fitted. Here they are in place (but not yet tightened up):

DSCF4625.JPG (843.76 KiB) Viewed 887 times

And lastly it was time to put the clutch plates in a bath of oil so they could have a good soak. They'll stay like that at least overnight before being fitted to the clutch. So progress is being made, despite the inclement weather conditions.

DSCF4630.JPG (829.79 KiB) Viewed 887 times

[Buckaroo]

I'm muchly enjoying this thread!!

[mangocrazy]

Taking a brief break from the LC (but will be returning to it in a couple of days), I visited the new(ish) to me Falco to take photos of the general grime and cack that needs to be cleaned off. This picture of the swingarm, hugger and wheel illustrate my point pretty well, I think. It's minging...

DSCF4640.JPG (857.24 KiB) Viewed 1199 times

I could never understand why the PO had taken the time and expense to get the swingarm powder coated black when the bike has a bare aluminium frame and the Mille swingarm would have been a perfect match, colour-wise. I shall be reversing that piece of visual fuckwittery. And one of the first things on the 'to do' list is to turn down the Scottoiler from its 'max' flow rate. There's probably as much oil on the tyre sidewall as there is on the chain. And that wheel is supposed to be a lovely bright blue anodised finish, but you'd never know it.

DSCF4641.JPG (589.71 KiB) Viewed 1199 times

And lastly, the electrics will need attention, mainly to remove all the fucking power-sapping gizmos that festoon the bike and are Scotchlocked into the main loom. There's an intercom, sat-nav and home-brewed tail tidy that need removing and throwing in the bin, not to mention tiny chavvy little indicators. I'll also want to tidy up the Power Commander installation as well. So when the weather is amenable to working outside I'll be donning full biohazard gear and getting to work removing the layers of grime.

DSCF4644.JPG (661.21 KiB) Viewed 1199 times

But for now it's back to the LC...

[BBB]

Are the falcon frames hard anodised the same as the mille? It's a pain of a finish to match

[mangocrazy]

Are the falcon frames hard anodised the same as the mille? It's a pain of a finish to match

It's either hard anodising or some kind of super-tough factory-applied lacquer. Either way it will be a pain to replicate and I really wish the OP had left well alone...

[mangocrazy]

So as promised, it's back to the LC.

I'd left it last time with the fibre plates bathing in oil, prior to being thrust into action (as it were). In actual fact I'd bolted the clutch inner and outer baskets together, fitted the fibre and steel plates and buttoned the whole clutch up, ready to re-fit the clutch crankcase cover.

But something was nagging at me, and the nagging didn't lessen, it got worse. This was the basis for the nagging:

DSCF4651.JPG (714.51 KiB) Viewed 1118 times

Yes - the clutch centre tab washer. Yamaha thoughtfully provide you with a raised lip that you can use to lever/hammer/pry upwards and inwards to provide a mechanical lock for the clutch centre nut. It's already torqued up to 65 Nm, but the consequences of it loosening off don't really bear thinking about, so it's a case of belt and braces. When I was using the OE Yamaha outer clutch basket, it was always the case that the raised lip on the tab washer aligned nicely with a flat on the centre nut, but with the Mitaka outer basket the raised lip coincided with a point on the nut, not a flat. So you wound up with an unholy mess like this:

DSCF4647.JPG (921.69 KiB) Viewed 1118 times

And to add insult to injury I was deeply unsure that the torque wrench I was using had given me the correct torque when tightening up the centre nut. It just seemed to 'click' far too easily and early. So I ordered up a new tab washer and blagged a torque wrench off a mate to get a comparison. I also decided to give myself options when it came to the tab washer. I decided I would bend up a second tab on the washer, but one that was off by 90 degrees from the one provided. They say a picture is worth a thousand words; in this instance I think it's very true:

DSCF4654.JPG (516.53 KiB) Viewed 1118 times

The smooth shiny tab is the Yamaha-provided one. The 'rough as a badger's arse' one is my doing and bears the loving imprint of my vice jaws. But hopefully you can catch my drift...

Saga continued in a later post, to get around the limit of 3 pictures per post.

[mangocrazy]

Using my mate's torque wrench the centre nut was tightened down to 65 Nm, then it was time to turn my attention to the lock washer. As it turned out, my DIY lip was in pretty much exactly the right place to align with one of the nut flats, so that was worth doing. If I ever do it again I'll take a slightly bigger bite out of the washer and turn it up further so that I can get a better surface to use the cold chisel and pin punch on. This is how it looked after I'd finished hammering and banging:

DSCF4660.JPG (893.92 KiB) Viewed 1100 times

The aluminium of the inner basket suffered a bit, mainly due to the fact that one of the bosses for the clutch spring was exactly in the way and I had to go in at angle to get at the lip that needed flattening against the side of the clutch nut. Had I been more aggressive in creating the lip that would have helped as well. With that done I could populate the basket with fibre and steel plates one by one, making sure the cut-outs in the steel plates were at 60 degree offsets to the previous one.

DSCF4663.JPG (889.26 KiB) Viewed 1100 times

Then it was just a case of fitting the ball bearing and mushroom into the centre of the clutch, fitting the clutch centre plate and fitting the new OE clutch springs and tightening down the nuts and washers to 10 Nm. With that the clutch was finally complete and this is what it looked like:

DSCF4666.JPG (792.33 KiB) Viewed 1100 times

That was as far as I could go, as I'm still waiting on a new clutch crankcase cover gasket. The guy who makes these on the RD LC Crazy forum had lost his Mum only a couple of days ago so his priorities are understandably elsewhere. So my next task is to figure out where I'm going to put all the bits that will need to come off the bike so I can fit a new set of taper roller head bearings. I may need to get creative in trying to hide the various parts in the house, as there's simply no room in the shed.

If I'm not seen on the forum for a while you may need to look in A&E. Mrs Mango knows where I keep the hammers...

[Sadlonelygit]

You need better mates!
I hid an entire bike from my wife. She only suspected something when I went on a track day and left my roadbike behind.

[mangocrazy]

You need better mates!
I hid an entire bike from my wife. She only suspected something when I went on a track day and left my roadbike behind.

Haha... My wife recognises bike components but strangely not whole bikes. It's probably because I have 5 or 6 bikes and she can't really tell the difference. Last weekend I asked her to help me put the 'new' Falco on the Abba stand and she didn't say a thing, even though it's the first time she'd seen it. But it is black, so probably not significant.

If it had been green or blue she might have noticed something was up (I have 3 red bikes and one orange, they're all part of the herd).

[mangocrazy]

As I was waiting on the clutch cover gasket the other day I started to dismantle the stuff hanging off the forks/steering head and realised quite quickly that modern faired bikes are in many ways easier to work on than those with a headlight nacelle that is the meeting point for nearly all of the bike's electrics. It's always great fun trying to cram all the wires in the headlight housing before you can jam the headlight itself back on, and even more fun trying to fit the speedo/tacho unit back on its mounting points. But that lies ahead, taking stuff off is a lot easier than refitting stuff.

So today when I walked into the shed, this is what greeted me:



With the steering head nut loosened off, I was able to remove the forks from the yokes, being careful to catch the headlight brackets and indicators. With nothing now hanging off the top or bottom yokes it was time to remove the steering head nut and top yoke. This left me with just the castellated nut and dust cover to remove. Before I reached for the hammer and drift I tried loosening the nut by hand and it just came orf in me 'and guv... This wasn't what I was expecting and the slackness was almost certainly responsible for the flappy steering I'd noticed last time out.

The next thing that surprised me was the nature of the head races; I'd been expecting standard ball races, but instead found taper roller bearings. I have absolutely no recollection of fitting them, but at some point I must have, as it's a one owner (me) bike. When I looked closely at the bottom race, this is what I saw:




Made in England, FFS! This very definitely dates them as they are pre-Chinese tat (which is good, obviously). Looking more closely I then noticed this:




If you're not able to read small upside-down writing I'll translate for you; it spells 'TIMKEN'. This is also good. It means that these bearings were made prior to 2002, when Timken moved production from Northampton to Poland. So the next thing was to clean off the old grease and see what kind of state the bearing surfaces were in. This is the top race:




Now to me that looks pretty much as new, so no concerns there. But all the real load in steering head bearings is taken by the bottom race, and this is what that looks like:




Now here there is definitely evidence of something - whether it's just 'polishing' or whether it's genuine wear I wouldn't like to say. But when I ran a fingernail over the marked parts I couldn't feel any indentation or lip; it just felt completely smooth. So I'm very tempted just to give all the bearings and seats a damn good clean, slather them in new waterproof grease and button it all back up.

But this time, torque the bearings down to the correct preload.

What says the RTTL massive?

[Skub]

You could see what it feels like with the stem lubed up,refitted and tightened. If you won't be doing a lot of miles it might do. I'd want to do it right,because I'm lazy and hate doing the same job again,when I can avoid it.

[mangocrazy]

I know what you mean about doing the same job twice - I hate that as well. With a passion. I'll give it a good coat of looking at tomorrow, but I honestly couldn't feel any indentation or irregularity when running a fingernail over the marked parts. There's also the consideration that it's going to be a proper twat to get the bearing cones out of the headstock; there's no lip to get a drift on to. And I do wonder if I'd be replacing high quality Timken bearings with questionable made in China tat.

I'll sleep on it and have another look tomorrow...