BiKenG

There is absolutely no need to drain the final drive hub when replacing the shaft. The hub is completely sealed and not dismantled at all. It is removed and re-fitted intact when the shaft is replaced so the oil shouldn't be touched.

The replacement shaft is largely identical to the original. It's just a small change to the bearings and how they are installed in the universal joint. I cannot see there's anything that can have noticeably changed the balance. Any stiffness or drag would need to be MASSIVE to be able to actually slow the bike down. There's a lot of power going through that shaft and that much drag would likely cause it to tear itself apart. I cannot see how the shaft could have been installed wrong. Either it's on the splines at both ends or it's not and the latter would prevent final assembly. The only issue could be if the cir-clip on the front end was not engaged, but it's very unlikely. Assembly is actually very straightforward (provided you have 3 hands :-) I realise you won't want to hear this, but it is very easy to convince yourself there are strange noises etc when you are specifically looking for them and perhaps expecting them, when in fact it is just the same, but you'd got used to them and so no longer noticed. Obviously I cannot judge for myself what you say you are experiencing with your bike, but bear in mind how easy it can be to misinterpret how the bike feels. Any vibration due to out of balance wheels tends to be lower frequency than the buzzyness one gets from the engine. Anything felt through the seat as you describe does sound like a badly balanced wheel, but a rear usually needs to be very badly balanced for it to be even noticeable. I find different road surfaces have a greater effect on vibrations I can feel than any minor imperfections in engine/drivetrain/wheel balance.

I have just done my recall work, but yet to ride and confirm any noticeable difference. First of all, the reason for the recall. This is because they discovered that the UJ at the front of the shaft can have a problem. In the production process, the main/outer body of the UJ is staked over the bearings which keeps the entire assembly together. But the staking (pressing the metal over to fix the bearings in) pressure was too high and crushing the needle bearings too tightly, causing a high risk of failure. What they did. The recall was issued and bikes checked. Any that had a suspect UJ had a new drive shaft assembly - just the same part. Meanwhile they were redesigning the part and production process, with lower staking pressure to prevent bearing damage and also for good measure, slightly larger bearings. As these 'countermeasure' parts became available, bikes were to be checked again and suspect shafts replaced (with the countermeasure part). But bikes that showed no problem were NOT to have the new shaft. Then finally when the countermeasure parts were in good supply in sufficient quantities, ALL bikes that had not yet been fitted with the countermeasure part will have that done, no question. Personally, I can't see how Honda could have handled it any better. It's unfortunate that they had the problem, but FFS there's a lot of parts involved and Honda's technical prowess and manufacturing abilities ensure such recalls are VERY rare. The downside for me is that I had a spare driveshaft which I thought would be handy to have, long term. But this recall now makes it junk, worthless. There's no way I can get it swapped as it's not in a bike and recalls are done by the VIN. So I'm stuffed there. However, I took it in to the dealer for him to check. There was NO play in the UJ. In fact it seemed almost too new, still being slightly stiff. Aha said the dealer tech. This is already on the way out. The test for failure is either slack in the UJ or excessive stiffness and that really means any stiffness. So it's actually pretty easy to check, although no longer necessary as it'll get replaced anyway. But in this case, stiffness was irrelevant as the main UJ body was in fact cracked. Yes, an actual hairline crack running across and so in danger of flying to pieces under load. Phew, at least that was never in my bike. I soon received the countermeasure replacement and I can confirm that the new part looks identical, so no obvious way to tell the difference. There probably is a way, but it's not obvious. I was keen to remove my original as I was sure there would be a lot of slack in the UJ because the bike is dreadful at low speed on a neutral throttle. If under even very slight acceleration or on the overrun, no problem, but as soon as there is no actual drive, it rattles like a bastard. Must be a failing UJ I've been telling myself while awaiting the replacement. But no, the old shaft has no slack whatsoever. The backlash is actually all within the gearbox. If I rotated the output shaft (onto which the shaft/UJ fits) back and forth by hand, the loud clunking seems to emanate from the clutch area. As if the entire basket is loose. I doubt that it is though, it's just normal backlash in a gearbox. All bikes have it. So why is my bike so bad? On further examination of the original UJ, it is not stiff as much as notchy, like badly pitted and worn steering head bearings. What I'm surmising from this is that when under even slight load, this notchyness wouldn't be noticeable, but on a neutral throttle with no actual drive though the shaft, it will manifest itself as rapid fluctuations in speed of the shaft and gearbox, causing the gearbox to rattle more than if the UJ were completely and uniformly smooth. Well that's my theory, but not had a chance to check it out. It is however interesting to read here that several owners say their bike is smoother after the recall, which backs up my theory. Some other things to do first, but then I'll be finding out if there's any improvement. If replacing the shaft yourself, some advice. Follow the procedure in the manual. This states that the shaft should be fixed onto the final drive unit (so the snap ring has snapped into place) and then insert that whole assembly into the bike. However this means holding the final drive unit with one hand while trying to push aside the rubber boot and feed the UJ onto the gearbox output shaft, while holding the snap ring at this end open with a pair of circlip pliers. Well if you've been counting, that's 3 hands at least, not to mention the impossibility of holding the final drive unit up with one hand. Man, it's heavy. So I took the obvious alternative method of installing the drive shaft shaft into the swingarm and onto the gearbox shaft first, then pushing the final drive unit onto the CV joint output spline and finally onto the swingarm studs and avoid having to manhandle the final drive unit and shaft together as one assembly. Ha... I thought. Don't bother even trying. It is IMPOSSIBLE to push the final drive unit onto the shaft spline. Even with plenty of good grease, it simply won't go on and just pushes the shaft into the swingarm instead. There is no way to hold the CV joint to stop it all disappearing into the S/A as soon as you try to push on the final drive unit. If only they'd put a small step in the CV joint or shaft to hold it while pushing on the final drive unit... But they didn't. So after pulling it all out again, if fitted the shaft into the final drive unit and then installed it all together as one assembly. A box, or something similar onto which the final drive unit could rest approximately in position, while working on getting the UJ onto the gearbox output shaft is I'd say essential, but then it wasn't actually as bad as I expected. The rest is a piece of cake anyway, so overall it's not a particularly hard job - if you follow the manual Well, it all helps to pass the time while it rains outside

A bit late to the party again, but thought I'd chime in. Has nobody considered the rear wheel from a Ducati Diavel. I think they're 8" and there's a ready made Pirelli (240 width) to suit that rim and it's certainly not detrimental to the handling of that bike. Just seems like an obvious option to try if you want a fat rear wheel and tyre on a motorcycle. You'd need to re-work the rear axle to suit the Ducati wheel's mounting, but plenty of people have done that to mount all sorts of other wheels. At least you wouldn't be up against the bike/car bead incompatibility issue.

Doing my usual - resurrecting an old thread, but it is an interesting topic. As has now been pointed out, a 'screamer' is a more even firing order, whereas 'big bang' means lumped close together. The latter used to mean more than one cylinder firing together, but now as was pointed out, it can mean just close together. Honda have used 360° AND 180° configurations on their V4s, the former being oft referred to as 'big bang', but I've not heard the latter being called 'screamer'. In either case, they're not totally true to the name, whereas when Ducati entered MotoGP with their Desmosedici, they did try a real 'big bang' with pairs of pistons firing together, so rather like a V-twin, but with each leg of the V actually 2 pistons and cylinders, moving and firing together. So a 360° crank and firing as a real 'big bang'. Ultimately not successful and apparently had a tendency to throw its motors into pieces. I don't think they ever raced it. It was tried with an R1 in British SuperBikes, but I think Yamaha nixed that when they introduced their 'cross plane' crank. An easy engine to make into a 'big bang' was the CBX1000. Each camshaft was in 2 halves, split in the middle with an Oldham coupling driving them together. It was of course just a matter of installing the second camshaft halves 180° from how they were supposed to be installed. With wasted spark ignition, nothing else needed to be done. I did hear of someone who did it by mistake and said it ran very rough, but then I also heard that it was tried by some teams in racing. I never tried it, I liked the CBX the way it was intended. While looking into the crank angle used by Honda over the years, I have come across some information that I consider inaccurate, concerning V engines. One particular video clearly implying that the engine balance of a V8 is down to each bank being balanced in itself, whereas in fact, it can be wildly out of balance without problem since balance is attained by each V pair. Let me explain:- In a single cylinder engine, the piston dashing up and down would create a terrible balance problem. Just thrust one fist up and down and feel how it shakes the rest of your body. The answer to this is balance weights on the crank. So at the top and bottom of the stroke, the force of the piston changing direction is balanced by the balance weight on the crank pulling in the opposite direction. If those 2 forces are equal (by adjusting the balance weight - i.e. balancing the crank), that is perfect PRIMARY balance and stated as a 'balance factor' of 100%. But there's a problem... We have perfect balance at TDC and BDC of our single cylinder engine, but what about when the piston is half way up or down the bore. At this point, there is NO force exerted by the piston, but the crank is now at 90° from T/BDC and that balance weight is exerting just as much force as at T/BDC, that cannot change. So all we've done is change the terrible up down vibration due to the piston to a sideways vibration of the same magnitude, because of that counterbalance weight, which at the 90° position of the crank has nothing to balance it out. This is secondary vibration and in this case we have zero secondary balance. So the balance factor of a simple engine like this is usually chosen to be something like 60% or 70% or something close that gives the best compromise of primary and secondary balance, but however you look at it, it's a shitty result. Put 2 of these cylinders side by side, operating together, with nice smooth evenly spaced power pulses and you've just made the balance situation worse. Well done all the British bike manufacturers who foisted those jackhammers on us for so many years. Honda realised that uneven power pulses was not really a problem and used a 180° crank for their twins so the pistons were not going up and down together and you get a much better balanced engine. Mind you, that didn't have anything to do with them also being oil tight. Bear in mind that ANY form of 'out of balance' vibration can be mollified or even eliminated with the use of balance shafts or reciprocating weights which can be designed to throw weights around exactly as required to keep a motor smooth. But let's just ignore those for now. But what about V engines I hear you ask, they must be very difficult to balance. Nope. A 90° V has PERFECT primary and secondary balance. Here's how:- Go back to the single cylinder example with the counterbalance weight on the crank providing perfect primary balance but no secondary balance at all at 90°. What we need is some form of balance weight whose effect varies as the piston goes up and down, so we get balance at T/BDC, but also half way up. Something that acts just like our piston but 90° away. Hmm, what about another cylinder and piston at 90° from the first one. With a 100% balance factor we have perfect primary balance for each piston, but the secondary imbalance of each piston is now completely balanced by the other piston. So a 90° V provides perfect primary AND secondary balance. It's a great configuration for an engine. Of course a horizontally opposed (Boxer) engine can provide the same perfect primary and secondary balance without any counterbalance weights on the crank. But we always need some weight there to smooth out the power pulses etc anyway, so both engine configurations are very good for mechanical balance, whereas any in-line engine is in trouble with no way to avoid it completely without using balance shafts. For both the V and the Boxer, it is each adjacent pair of pistons, that balance each other. The relative position of the other pairs is largely irrelevant. So our V4s might have a 180° crank where each pair is half a rotation away from the other, or 360° where the 2 pairs are side by side. This is usually termed 360° apart but of course could be termed 0° (although due to firing order etc the former is more applicable overall). As far as crank balance is concerned, you could have any angle between the pairs. So if these engines are perfectly balanced, why do we feel any vibration at all? Well, not everything is balanced. Cams for example are lumps of metal flying around with nothing to balance them out and generally throwing lumps of metal around at such a speed, it would be very hard to eliminate vibration entirely. Think about it, at 10K rpm, the piston is changing direction at 300 times per second. You try and count that fast. There is also the problem of 'rocking couple'. With each power pulse hitting the crank, unless these are evenly spaced along the crank, it can cause the crank to try and rock slightly. Obviously it cannot actually move so this translates as a vibration. If power pulses could occur simultaneously on either side of the centre of the crank, we could avoid these couples, but for other reasons of balance that's not really practical, so we have to put up with this rocking couple which fortunately is minor compared to the piston and crank balance described above. So finally, what about about 'cross plane' cranks. As is easy to read elsewhere, these look like a cross when viewed from the end and breaks up the firing pulses into an uneven order. For an in-line 4, it also requires the use of balance weights as decent primary and secondary balance is otherwise impossible to obtain, but for a V8 it doesn't really matter as each crankpin has 2 conrods and pistons attached and they balance each other out as explained above. So each crankpin could be at almost any angle relative to the others, but in practice either flat (like a typical in-line 4) or cross plane (at 90° to each other) are used. So that's what a cross plane IS, but why? Well there's been almost as much guff talked about this as there has been about radial brakes. There was much talk about a V engine giving better traction due to the longer interval between some power pulses allowing the tyre to regain grip. This always seemed like nonsense to me. We're talking in thousands of a second here and rubber just don't move that fast. What has now become apparent is that it's more to do with vibration. If rubber is vibrating, it is less able to grip and evenly spaced power pulses can set up a harmonic oscillation in the rubber that causes sufficient vibration to reduce grip. But the uneven spacing of the power pulses of e.g. a V engine prevents any such harmonic, which reduces the vibration and allows more grip. Yamaha's cross plane crank in their in-line 4s does this. The uneven power pulses allowing the same grip levels as the V engines. There are now several examples of cross plane twins (270° cranks), like Yamaha's Super Tenere, Honda's new Africa Twin and Triumph's new 1200s among others, but whether that is for any supposed enhanced grip or just because they sound cool is anyone's guess. But annoyingly Yamaha have started applying the term 'cross plane' to their 3 cylinder engines which just use traditional 120° cranks. So a case of marketing triumphing over the facts I think. So that's it. Whether your VFR would provide greater grip if it had a 360° crank is a mute point, for 2 reasons. 1, you're stuck with it and 2, you'd never notice on the road. Realistically, the only difference is the sound and all the above configurations with their different power pulse intervals will sound different. To each their own. Personally I like the sound of a V4. Any V4 will do. Anyway, hope this is of some help. If not, sorry I bored you.

Thanks for that. I think I want to go black engine, so good to get the low down on how you did it.

Seb, could you explain more about refinishing the engine. You said "soda blast", but was that something you did, or did you take the engine somewhere? Was all the cleaning and painting done while the engine was complete?

Thanks Phantom. We could do with some more info on rads from previous generations. Anyone?

Indeed. All the CBR1000RRs use the same wire colours for each cylinder and probably 929 and 954 and maybe even CBR900RR before that. In fact i'd say it's a fair guess that Honda always use the same colours on their 4 cylinder bikes. As an example of why we tend to moan about prices here in the UK, I just bought a suitable harness - from the US. It was cheaper to buy one from all the way over there AND ship it here AND pay any duties, than I could find one here. Greedy UK breakers want 3 TIMES the price. I made a reasonable offer, but was declined. Their loss. It is immensely frustrating (not to say costly) to constantly see stuff available in the US for so much less than the UK. We don't call it "rip off Britain" for nothing. BTW, we're allowed to call it that, no-one else is. I've already got some RR11 CoPs on their way to me. Bought from outside the UK of course as it was cheaper.

The problem I see with the standoffs is that it pushes the whole thing away and off the plug. Normally the rubber end of the CoP is a snug fit around the plug and keeping it sealed. With the standoff you won't have that seal and more chance of problems if anything gets past the upper seal. Not saying you will have problems, but it's something to be aware of. I have also become aware that some VFRs use plugs with the exposed screw thread at the top and others use a plug with a solid top and any cap or CoP is only going to really fit properly on the plug type for which it was designed. Otherwise it will either not actually clip on or will be loose. Maybe these differences only apply to later VFRs already with CoPs and so fitting CoPs to earlier bikes shouldn't have this problem, but if the plugs have also been changed... It might be an idea if thinking of doing this, to be sure the top of the plug is compatible with the CoP being installed. Finally, I think the primary connections ARE polarity conscious. Get it wrong and I cannot but think it will fail to work correctly as the HT from the secondary coil will be trying to find ground through the primary. The negative side (earth) of both primary and secondary coils must be connected together. The secondary coli MUST be connected at both ends or current cannot flow. The high side is to ground via the plug (and the spark), but the low side has to be connected to ground to complete the circuit and without any other possible route, it must use the same ground terminal as the low side of the primary. At least, that's how I see it. If anyone thinks differently, please chime in.

On the basis that gig says they fit, I've ordered a set from an RR11 (same as RR8) off eBay. I suspect they're actually the same coil as the VFR1200, but with a different top seal which is not available separately, hence the different part number. I'll confirm that when I receive them,

Ah, thanks for that. Did they fit down inside the head round the plug. The VFR1200 ones I tried were very tight before they had engaged on the plug. Did you have to shave the lower rubber section at all?

Can anyone confirm how the later CBR CoPs fit to a 5th Gen? I tried VFR1200, but they seemed too short. The CBR1000RR4-7 Cops will fit, but slightly long. The above picture looks perfect, but hard to tell and as far as I can see looking at pictures, the later CBR ones (RR8->) look very like the VFR1200's, but impossible to confirm either way as I don't have any on hand to check. Well I do, but they're on the bike and even without fairings, they're a ba****d to get to. Anyone have an RR8-> CoP they could measure?

Old topic I know, but in discussing the merits or otherwise of CoP vs normal coils, no-one mentioned ignition interference suppression. This is a very big deal and manufacturers put a lot of effort into passing the strict regulations. Resistive plugs were a BIG improvement, but stuffing the coil right on top of the plug has to offer the best improvement of all. I doubt performance or even emissions really has anything to do with it. Ignition suppression is probably the biggest factor, but packaging now plays a very big part in vehicular design. Just trying to cram everything into the available space can be tricky and with bikes they need to be able to place everything for optimum weight distribution. CoPs are simply better at all these. Whether it's worth doing on an older bike is just down to personal preference. I like the idea of freeing up some space and saving a bit of weight. As long as they work correctly it'll make bugger all difference to the performance though.

From now on, playing around with forks like this will be known as "Fork Swappage" (thanks JZH)

Lots of people playing with fork changes etc, but without any real data to judge what effect the changes may or may not make. So I set up a spreadsheet and entered some typical examples to illustrate what happens. But first... This is done for the 5th gen 800 and it relies on original spec in order to be able to calculate what it does. If anyone needs data for a different model, providing the original spec is available, just let me know. I have based everything on the suspension being fully extended as that's the only reliable and repeatable state. Hard to measure in practice of course, but that doesn't matter as what we're concerned with really is changes away from standard, which is the line in red. The fork length is from the upper surface of a flat top yoke/triple clamp to the centre of the front axle. Gull wing yokes and/or forks not being flush with the top of the yoke will have to allowed for as it's impossible to build-in all possible variations. E.g. the standard forks I believe are 780mm overall. But they should extend above the upper surface of the (flat) top yoke by 41mm, plus the top cap which is about 2mm so the length to use is 737mm (780 - 2 - 41). In case that disappears geom800.tiff It can be seen that reducing the OFFSET has a significant effect on the TRAIL which suggests that it's not a good idea to replace with forks with a very small OFFSET. It can be counteracted by dropping the front and/or raising the rear to steepen the RAKE, but there's a limit to how far you can go with this. Anyway, hope this is of interest to others.

Hmmm. Food for thought. Thanks Seb (I assume it's Seb, correct me if I'm wrong)

Thats exactly the info I wanted. I can't see that not being the best option to convert a VFR800 to single front mounted rad. Thank you for that. Ah one more question, which exact model is that from?

Understood. In truth, Honda don't make the best looking bottom yokes. I like the idea of a wide clamp with 3 bolts entering from the rear and hence largely hidden from view. So having a bottom yoke made is an option I have considered. Can you confirm though the CB1000R uses a 35 mm offset? The VFR is 40mm and the CBR/RVT etc is 30mm IIRC, so the CB1000R is in between? I have no data on that bike (apart from using handlebars and other things on my FireFighter). I wasn't aware it is not the usual 30mm. Or maybe I was and simply forgot. Now where was I...

The fork colour certainly looks great. I guess I'll find out how fragile. Regarding the fork offset, surely if the CB1000R has the 35mm you want (as it must be if you use that top yoke), could you not have used the CB1000R bottom yoke also? Was there a reason why that would not fit?

Thanks for your confirmation on the fork parts. Why make your own bottom yoke though? Surely you could have used one from a CBR1000RR (or even 929 or 954) or RVT? Not criticising, just wondering if there's any reason and that I should look out for. Also, what preparation did you perform on the fork outers prior to spraying? Did you sand them down at all and/or use any primer? I've long wanted to find that colour for forks. Now I have to find a way to obtain that paint in the UK.

Hey SEBSPEED, looks like you used CBR1000RR4/5 fork legs, what about the yokes/triple clamps? Top looks like CB1000R, yes? What about the bottom, same? Are your forks at 214mm spacing/width? Any problems with the rad and tyre clearance with those shorter forks?

Anyone done a comparison of radiator sizes of the 750s. Quite a few 800 owners are interested in a single front rad conversion and the obvious candidate would appear to be a rad from the 750, but what are the sizes and inlet/outlet orientation of those models? Anyone got the dimensions handy?