revtothelimit - motorbike forum

It's called 'doing a Yorick'...

On the subject of 'weird things you see on French roundabouts' I submit this for your delectation - a giant privet dinosaur...


And just to give an idea of the bar position as the Falco left the factory, this pic from the same French trip:

Quite a lot of roundabout entertainment round our way

The paper boats one was always popular for my kids because it signified we had arrived on our holidays.


And this one a bit further up the road.

The figurine is about 15ft or so high.

Re french structures, I liked this one in Salbris...

We returned from La Belle France last week and I've spent most of the intervening time getting over the drive back (800 miles door to door, excluding the ferry crossing) and catching up with stuff from the last 4 or 5 weeks. The VFR was ferried back in the van and is now sitting on the Skylift awaiting investigation of the front end 'clonking' issue. I'm not in any hurry to start...

Today I took advantage of dry weather, blue skies and mild temperatures to wheel the Duke 690 out, warm it up, change the oil and paper filters and inspect the gauze filters. All seemed in order - there was a slight build up of fine metallic swarf on the magnetic drain plug, but nothing excessive. The oil had only done about 1500 miles but was looking a bit dirty, so it was worth changing it. I replaced the mega-expensive Motorex oil that KTM recommends with some only slightly less expensive Motul 10w60. I really like Motul oils and as the Duke's engine only takes a paltry 1.7 litres of lubricant, it pays to use the best. This stuff was a quite dramatic burgundy-red colour and the engine was noticeably quieter than before once the oil had circulated fully. It's probably not fair to compare used oil with new in that respect, but there was a noticeable difference.

It's now getting to that time in the year when you wonder if every ride will be the last for a few months. I'd like to get out for one last blat on the Duke before it goes on SORN. One odd thing did occur while I was warming the bike up prior to dropping the oil; for no real reason I just pulled the clutch in a couple of times and the bike started surging from tickover up to 3-4000 rpm and then back to tickover again, over and over. I tried opening the throttle, but it was completely unresponsive, it had obviously been over-ruled by the ECU. So I hit the kill switch, left if for 5 seconds or so and then started it again and normal service was resumed - very odd.

Has anyone had any experience of this?

Nopes. Fraid not sorry.

Nope never had that on mine either

I have had some weirdness on a few bikes before and turning off and on again has cured it. I guess the ecu doesn't get the signals it expected at the right time and has a brain fart?

Potter wrote: Wed Oct 18, 2023 1:45 pm

mangocrazy wrote: Mon Oct 16, 2023 5:43 pm
It's now getting to that time in the year when you wonder if every ride will be the last for a few months. I'd like to get out for one last blat on the Duke before it goes on SORN. One odd thing did occur while I was warming the bike up prior to dropping the oil; for no real reason I just pulled the clutch in a couple of times and the bike started surging from tickover up to 3-4000 rpm and then back to tickover again, over and over. I tried opening the throttle, but it was completely unresponsive, it had obviously been over-ruled by the ECU. So I hit the kill switch, left if for 5 seconds or so and then started it again and normal service was resumed - very odd.

Has anyone had any experience of this?

I'm sure I remember a KTM tech telling me that if you leave your bike on tickover for a long period without touching it then the bike recalibrates itself, IIRC I had to do this when I replaced a TPS. I'm sure it was something like leave it on for 15 mins and between 5-15 mins it recalibrates, but the cycle only starts at the 5m point, so it doesn't do it every time you start the bike and ride off.

When it's doing this you're not supposed to touch it, so perhaps it was mid calibration and it didn't like you pulling the clutch in and it sent it off on one a bit until it gathered it's senses.

Good point - it's the '15 minute idle reset', and it's definitely A Thing. I had left it idling to fully warm up prior to dropping the old oil, so could have been anywhere between 5 and 15 minutes, before i pulled the clutch in. That's definitely the best explanation so far; I'll go with that.

When we came back from France I brought with me the steel 'ace' bars, so I could try and make them work with the OE Falco anti-vibration system. Last week I dug out one of the OE bars as a reference and took that, the 'ace' bars, an M18 x 1.5 tap and one of the complete OE anti-vibe inserts and headed down to my local engineering emporium. One of the guys there jokingly suggested I ought to have a clock card with my name on it, I visit that often...

Paul, the head honcho, had a good look at all the parts, did some measuring up and pronounced that they should be able to make up suitable inserts, get them welded in and then tapped to the correct thread (M18 x 1.5, unsurprisingly) to accept the hollow mounting bolts. So that's a good piece of news to start the week off with.

But as I always like to have a Plan B, I'm also going to order in some aluminium tube in 7/8" and 1 1/8" x 10swg (3.2mm) wall thickness and make up a duplicate set of bars in aluminium. That way I can do an A/B comparison of steel vs. aluminium bars and decide which material suppresses vibration the best. Or not.

Do you find it annoying when someone answers their own question? I do...

With the Falco bars handed over to a third party, it was now time to give the old VFR a good coat of looking at. So up on the Skylift it went and out came the front wheel and the forks. As soon as the front wheel touched the floor, it became very apparent where the clonking noise was coming from - the discs were making a right old racket. On closer inspection there was very very slight sideways movement between disc and bobbins, but plenty of radial movement ; i.e the bobbins were allowing the disc to float excessively. This is the disc in question:


It's not yer ornery 320mm disc, in fact I've never seen another one like it. It's very definitely a Honda disc, the six M6 mounting points tell you that, but it's ventilated axially and radially and the original carriers were magnesium. It has all the hallmarks of being a kit or racing part; I wouldn't be suprised if it wasn't a RC30 kit part, as it slots into an RC30 front end perfectly. OE Honda RC30 discs were 310mm diameter, but kit parts were 320mm. The carriers you see now are 7075 aluminium replacements/copies as the magnesium items suffered an untimely demise. I'd always assumed they were aluminium, and sent them off to be plated thinking as such. It was only when I received an irate phone call from the production manager of the plating plant telling me my f***ing parts had contaminated a brand new batch of chemicals that the penny dropped. Apparently magnesium reacts quite violently to the plating chemicals they use. Here's a rim shot for all you perverts out there...


To confirm my suspicions about radial play, I dug out the feeler gauges and started measuring clearance under the bobbin heads. Minimum clearance was more than 0.2mm and maximum not far off 0.3mm. This was in addition to the existing 0.5mm shims/washers that were fitted under the circlips. So I hit google searching for 14mm x 20mm x 0.2mm stainless shim washers and bugger me if I didn't come up with a perfect match on the accu.co.uk website. A few minutes later and 30 (2 x 12 plus a few spares) of the little buggers were winging their way to me.


The Plan is to fit the new 0.2mm shims underneath the existing 0.5mm items, so they face directly to the disc/carrier. I'll also be putting a wipe of silicone sealant on each bobbin to further reduce any extra play. I'll effectively be converting fully floating discs to non-floating discs. Not very rock'n'roll, but if its stops that bloody clonking it will all be worth it. This is scheduled for tomorrow. What is it they say about tomorrow?

Well, tomorrow actually arrived and the two discs have had their end float reduced by means of the 0.2mm shims and their rights to free movement curtailed by application of RTV silicone. There was an early panic when I re-used a tube of silicone that had previously been capped off using cling film, and when I applied force in the shape of a mastic gun it steadfastly refused to budge. I then foolishly poked a screwdriver into the plugged end and released a torrent of silicone everywhere. Cue frantic clean up operations and black silicone all over bench, vice, hands and God knows what else. That stuff really does stick like sh1t to a blanket...

Anyway all 24 bobbins have been done and the two discs (and more importantly the silicone) are currently sat on a living room radiator and quietly curing away. Prior to this work the discs rattled like a bag of spanners when shaken. Now they're as quiet as a church mouse...

I've bought stuff from Accu for the bikes and car, quality fasteners at a good price, postage can be a bit high if you don't have a big order. Fancy blue envelopes soften the blow.

BBB wrote: Sat Oct 28, 2023 8:30 pm I've bought stuff from Accu for the bikes and car, quality fasteners at a good price, postage can be a bit high if you don't have a big order. Fancy blue envelopes soften the blow.

Yeah, I have actually kept the fancy blue envelope - normally it would get tossed... They provided exactly what I wanted in super double quick time, so will be using them again.

Coming soon to a thread near you!
Why do my brakes pulse

mangocrazy wrote: Tue Oct 24, 2023 8:57 pm There was an early panic when I re-used a tube of silicone that had previously been capped off using cling film, and when I applied force in the shape of a mastic gun it steadfastly refused to budge. I then foolishly poked a screwdriver into the plugged end and released a torrent of silicone everywhere. Cue frantic clean up operations and black silicone all over bench, vice, hands and God knows what else. That stuff really does stick like sh1t to a blanket...

I did similar this week when using a tin of aerosol glue. When I pressed nozzle the glue shot out in a snottery stream at 90° all over the seat of the H1..fuckity fuckity fuckstix. It was like the Fred Gassit cartoon when he pisses all over everyone because he has a hair on his knob.

Demannu wrote: Sun Oct 29, 2023 1:56 pm Coming soon to a thread near you!
Why do my brakes pulse

There's still some end float, just not the excessive amount there was previously. If there are any problems they should become immediately apparent on the first test ride.

Skub wrote: Sun Oct 29, 2023 4:20 pm

mangocrazy wrote: Tue Oct 24, 2023 8:57 pm There was an early panic when I re-used a tube of silicone that had previously been capped off using cling film, and when I applied force in the shape of a mastic gun it steadfastly refused to budge. I then foolishly poked a screwdriver into the plugged end and released a torrent of silicone everywhere. Cue frantic clean up operations and black silicone all over bench, vice, hands and God knows what else. That stuff really does stick like sh1t to a blanket...

I did similar this week when using a tin of aerosol glue. When I pressed nozzle the glue shot out in a snottery stream at 90° all over the seat of the H1..fuckity fuckity fuckstix. It was like the Fred Gassit cartoon when he pisses all over everyone because he has a hair on his knob.

I bet there were some pretty frantic clean up operations going on there... And a good helping of profanity...

New Year, New Mandlebars


A trip to my friendly local welders is indicated for tomorrow, I think...

Couldn't help but think of these!



Will they be going on the MT09 risers?