BiKenG

Hi Jim, long time no see. Not since that endurance race at Snetterton all those years ago. On a GSXR I seem to recall. Did the Enigma project get anywhere? Since I’ve heard nothing about it for some time, I suspect not. Oh well. Nothing ventured... Glad to see you’ve got the VFR bug. I’ve just come back from a brief trip on my eVo4 (1200 special) with 3 VFR800s, all also ridden by ex Honda staffers. Plus there’ll be another VFR800 joining. It’s still a great bike, even if the current press are bored by its lack of fancy whizz bang (and essentially unnecessary) features. I always liked that F model. It was a shame they had those cam problems. In fact it was the fairing from that 750F that I used on my CBX that MotorCycle Mechanics featured on their front cover March ‘85. Warranty return if I remember correctly. Just needed painting. Just the job. 😀 Hope to see you around here more. Look forward to seeing how your bikes progress.

Thanks gig. Just what I thought it would be.

Question for those who've used Ducati axles. On the (driven/cush) LHS what type of washer do they use under the nut? Honda like to use a dished/spring washer, but are Ducati the same or is it just a plain flat washer? I've looked at parts lists, but they just state "washer" which is no help at all.

So you got a 20.5mm offset? Is that for the 1098/1198 wheel for the larger axle? I measured 23mm on my 916 wheel and that concurs with what I have seen reported elsewhere. Which means Ducati used a different offset on their different axle sizes.

I now think that is incorrect as I misread the diagram which in fact states the 916/996 etc hub is 98mm dia. which means it would need a 3.5mm sleeve to fit in the VFR750's S/A which uses a 105mm dia hub. Possible but not ideal and I've no idea where that would position the wheel. Although being 10mm wider might allow some 'adjustment'. All in all, not a great solution I think. A bigger problem is trying to arrange a single nut fixing for e.g. the RC45 wheel as the 400's axle cannot really be shuffled sideways in the 750 hub the 7mm required to align the wheel. Not sure where I go from here. 😞

The Tuono 1100 is I think a cracking bike, but to be honest, any company that simply shuts down for the summer holidays (and to hell with customer service, parts etc) is suspect in my books. I sure love the idea of a new RVF1000, but I actually think the Ducati or Norton V4s will be better road bikes with their larger capacity and none of them can possibly allow me to go any faster as that's governed entirely by speed limits and nothing to do with the bike's performance. I've set myself a new rule. No more bikes that require tax and MOT. So apart from the VFRs, it's 40 year old classics for me. But there's a lot of interesting Hondas in that bracket now 🙂

I may not have explained that this bike is based on a VFR750 with Gen3 SSSA whose rear end is 70 wide by 105mm dia. The Ducati hub is 80 wide by 110 dia. and no matter which way I look at it, 110 into 105 don't go 😞 So the simplest solution is to stick with the 750 hub and axle and just make an extension to suit the 916 wheel.

In that case, the goal is the wheel, but I won't be using Ducati axles and stuff. Goes against the grain on a Honda (apart from the wheel of course 🙂 ) Anyone got an accurate Ducati wheel offset? Hard to measure exactly. Is it 23mm or 7/8"?

You do realise it will not be a VFR. It'll be a track weapon. I'd like them to produce a naked version, but I doubt they will. Either way, it won't be a VFR. Naked versions of the Norton and Ducati V4s are intended and will be very interesting. There's always the Aprilia. Why not that? It's a very good bike. None of them VFRs though. Either track focussed or naked. If you want a bigger VFR, you'll be disappointed. Hang on, there's already a big VFR. Without a doubt, brilliant bike. I like mine naked though 🙂

Well, for starters, I think that's a LOT of money for not a lot. Just a few brackets that are not suitable for my purposes and I'd still have to buy a complete Ducati axle assembly. Secondly, why pay for someone else to do something I can do myself (once I have all the info). Where's the fun in that 🙂 My intention is to have a 916 type nut and axle thread on an NC[30|35] axle that will provide what I need for these bikes. Same concept as Steen's, but with a different thread and no need to manufacture the actual nuts. Since I'll be using my own calipers and hence need to make my own mount brackets for those, even less reason to waste money on the EC kit which would actually provide me with nothing that I need. "Paddle my own furrow" eh Mohawk 😉

Further consideration has made me realise that my dream of using identical axles to allow swapping of RC45 and 916 wheels is not going to happen. The 916 wheel is 4mm wider at the centre AND will require a 4mm spacer, so the axle will need to be 8mm longer which is too much to allow for with a special conical spacer. No big deal though as I never actually intended to swap wheels, just thought it would be a cool feature. However I did weigh both wheels as it was clear to me that although 1/2" narrower, the 916 felt a fair bit heavier:- 916 = 6,055 gms RC45 = 5,260 gms That's bare, clean wheel with valve. More questions now. Could someone with the LARGE Ducati axle (1098 etc) let me know some measurements of the wheel/nut end i.e. length of axle from flange face to thread end and also diameter(s). Just pondering whether to use those dimensions (and hence 1098 type nut) for the RC45 wheel.

I am working through 2 conversions. One is to accept an RC45 wheel and the other a 916 wheel. Those are now set. I just need to figure out the best way to modify the NC[30|35] axles. Since both wheels rely on the conical spacer to centrally locate them, I'm thinking I might make 2 identical axle extensions to suit the (smaller bore) 916 wheel and use std. 916 axle nuts (well, Ti ones). Then a std. 916 spacer can be used with the 916 wheel and I'll make a special spacer to suit the RC45 wheel. That way, either wheel can actually be used on either bike. Actually the axles will need some slight machining to the outer end so the 916 wheel will fit, but they can be identical. Just need the special cone spacer to suit the RC45 wheel and inner spacer with longer drive pins for the 916 type wheel. I like the fact that then any RC45 or 916 (748 etc) type wheel could be used on either bike with minimal work involved. I'd still like to know though what steel Steen used for his axle extension as I presume it's suitable and I'll then use the same.

Ha, no, not code. I have been in touch with Steen, but he was heavily involved in something (business, or moving house, I now forget which) and is apt to take a very long time to reply. In any case, I'm sure he gets posts to this thread, so I figured asking here provided the best 'audience'. 😀 Did you ever mount an RC45 wheel to your modified axle? Surely someone has and can comment on its fitment and the length of the modified axle?

Regarding Ducati axle and wheel, how is the wheel located on the axle? On an NC30 the wheel is a snug fit over the enlarged boss next to the disc/drive pin flange, so the spacer and nut just hold it in place. The RC45 wheel is not so snug on the inner side, but the conical spacer is snug over the outer end of the axle and so locates the wheel. How do Ducati do it? From looking at measurements, it would appear that the wheel is actually quite loose on the axle and it is only the conical spacer that locates the wheel, centralising it and pushing it up against the flange, holding it in that central position by the clamping force of the nut. Not that different from the RC45 in fact, although the Ducati wheel is even looser on the axle as far as I can see. Is this how others see it? The only location of the Ducati's wheel is done by the conical spacer? BTW, what is the offset of the 1098 (6") wheel? Honda use a 19mm offset and the 916 (smaller axle) is 23mm, but what about those Ducs with the larger axle? What offset do they use? Same as for the smaller axle?

I think Steen is very busy. The assembly I have here is also 80mm when pushed together. But the RC45 wheel and nut is about 67 mm thick which leaves about 13mm protruding beyond the wheel. The groove and lip at the end are about 7mm, so that means 5mm of spare thread. Seems to me that with the nut on and tight, only the groove and lip should be visible so the clip can be fitted. There should be no exposed thread. If nothing else, that would mean the nut can come loose out to the retaining clip and allow the wheel to slide 5mm side to side. This cannot be a good thing as it'll just be flopping around. I originally thought it was 7mm too long, but the measurements above indicate 5mm. So let's take the middle ground and I can't help but think the extension piece is about 6mm too long. I'm not knocking Steen here, the pieces are beautifully made. It just seems I must be missing something here.

Another question about Steen's (VFRRR) conversion kit. I have one here and loosely inserted it into an NC35 axle. Strangely, it is quite loose. Doesn't rattle, but slides in and out. I thought they had to be push fit into the axle. Anyway... I then inserted it into an RC45 wheel and I cannot help but think it's nearly 8mm too long. If I hold the insert into the axle and spin the nut down until it starts to bind on the wheel, there's almost 8mm of thread protruding beyond the nut, before the outer lip with holes to take the pin. The whole threaded portion looks like it should be about 8mm shorter, otherwise it sticks out way too far. Anyone else found this? I cannot see why this is. The RC45 wheel is new and certainly not 'thinned' in any way. The axle is certainly not modified and the extension piece is how it was supplied. How can it end up being 8mm too long? Any ideas?

Regarding Steen's (VFRRR) conversion pieces, anyone know for sure the materials they're made from. Steel and Al alloy I know, but exactly what alloys? The axle extension is very magnetic which suggests it's not stainless and Steen made no mention of this so it's likely to be mild steel. In which case, how is everyone who uses one actually protecting the metal? If left bare it will surely rust badly. Paint it? And what about the alloy nut. 7075 perhaps? Or what? Anyone know? Of course Steen knows, but he's kinda busy and I hoped someone else would know for sure.

Already done that, but they're still not showing up. Never mind, I've gone off the Triumph idea. I'll be modding a 916 wheel to fit the NC30 axle instead.

Oldish topic, but found it while trying to find some info about the Triumph rear wheel. Unfortunately none of the pictures posted by YoshiHNS can be seen, so perhaps someone could help. What is the offset of the Triumph (Sprint) 3 spoke wheel? I.e. the distance from the centre plane of the rim to the hub mounting surface. All the chain driven VFRs have a -19mm offset, but what offset is the Triumph wheel?

Those sensors would stop the spark and/or fuel, so if you have those, the sensors are unlikely to be at fault. Likewise the pulse generator must be working. Is it firing at all or just simply turning over? Basically, if you have air, fuel, compression, spark, and they're occurring at the right time, the engine must run. So one of those factors must be missing or wrong. Do you have a clip-on strobe light? Really useful to help diagnose ignition/timing issues.

Good to know. Thanks for that. A typical Honda MAP sensor (I just checked for the RVT1000) is £256. So for the CBX, that would be prohibitive. I also have a VTR1000F FireStorm (er, Super Hawk in the US?) that I'd like to inject. So another project to keep me busy. Possibly do that before the CBX. Just see how everything else pans out.

Yes, I've read most of it, but a power cut here prevented me from finishing it. I will go back and read the rest though. It has encouraged me to start looking again at adding CNC capability to my mill. That would be enormously helpful in so many ways. But I digress... I understand that modifying the TBs to suit won't be trivial, but Patrik and Durbahn both use the TBs from a totally different bike and then had to totally create their own maps etc. from scratch. I am currently of the opinion that using 5th Gen TBs will not actually be as difficult although I may change my mind once I start hacking them. However, if I can get the TBs to fit, the rest of the system is essentially off-the-shelf, just by using the 800 parts and it should even run like that with just minor tuning required with a PC. All that is a BIG advantage by using the VFR800 parts. I do have to add a Cam sensor, but that's been done before. Of course the first requirement is that I can get the TBs to fit and I'm waiting on a set of 5th Gens I can start work on. Currently I'm firmly of the opinion that it will be easier than modifying the carbs, but I guess I'll soon be finding out if I'm right or wrong on that. It's all good clean fun though.

I see, so there's a MAP sensor for each cylinder. I have a funny feeling Honda MAP sensors are rather expensive, but I guess he's using a more cost effective sensor. All food for thought re the CBX, but is another reason for grafting the 800s injection onto the 750 as provided it can physically be done, then it's relatively simple as there's a ready made wiring harness with all the required sensors and just the one ECU module. No other ancillary electronics required. Well, apart from a Power Commander or equivalent. At least I assume it will need some tweaking, although just have to see on that once it's running.

Aha, I've been thinking along those lines too, using the VFR750's carbs and I believe an early Kawasaki 900/1000 (I forget which) had a similar injector rail with suitable injectors. I've not discounted it and will be looking into that and the MicroSquirt for a similar project to inject a CBX1000 (6 cylinder), but that's further down the line. For this VFR750 I kinda want to make it as Honda as possible, so priority will be to see if I can use the 800 parts. If I can't use those TBs, I'll look for alternative TBs and if that fails, then it's modify carb time and a different ECU. But it's always interesting to see what others are doing to inject their bikes, even more so with regard to my CBX project. How does the MS use MAP sensor output to detect engine position? If the MAP sensor is connected to all intakes, how does it know which pulse is for which cylinder? BTW, why did you choose the MS over say Motec?.

Aha, first of all, yes those TBs will be perfect to try and fit, thanks, much appreciated. Secondly, very interested to hear what you say about the 3rd Gen carbs being bigger - music to my ears. Since 4th Gen rubbers are too small to accept the TBs, there's hope that 3rd Gen rubbers may be better, i.e. actually fit. I need to find a good (i.e. flexible) set of 3rd Gen rubbers and try to squeeze those TBs in.