Beauty is more than skin deep

As part of the deep clean down, I marvel at the way this bike comes apart. The design Genius creator that was Massimo Tamburini has a unique style which is evident in all his motorcycles. My 907ie also designed by him has so many design similarities and little elements of intricate attention to detail that cannot help but leave you shaking your head in admiration and wonder.

The bodywork features quick release Dzus fasteners allowing the side fairings to be removed in seconds…

The rear tail fairing hinges forward and removal of two pins and the loom connector allows the entire tail to lift off. The fuel tank lifts off after removing two side locating brackets and one centre bolt along with unclipping the two quick release fuel connectors and loom connector. The whole bike takes minutes to strip down to its beautiful chassis.

Stunning details everywhere include MV monograms all over,

Lest we forget…

Other neat touches such as this rubber elbow on the water pipe so it doesn’t rub on the fairing…

Or these rubber bracelets around the wiring loom…

And these remote vacuum ports for synching throttle bodies…

The quick release front nose cone is another revelation featuring spring loaded electrical contacts for the front indicators housed in the mirrors…


It’s time to bleed the front brakes, the fluid smells vinegary and there is some dirt around the cap to clean up. I flush the system through and put fresh fluid in.

While bleeding the front brakes I have another WTF moment, as I spot another problem!

This time, it isn’t something menial that has the potential to ruin the engine like the previous carb issues or potential oil feed blockage, no, this time, it’s the brake hose banjo bolts! I’m bleeding the brakes and I see leakage from the banjo.

I barely touch the hose end and the fitting spins. The same on the other side. Both hoses are barely finger tight!!!

Once again a reminder of why I do my own maintenance, it’s frightening to think in the last 200 miles this bike has had a service, a sales preparation and an MOT by a reputable bike specialist that even sponsors a race series! Between the nick in the rear brake hose covered by tape and the loose front hoses, coupled with the failed rear master cylinder, any one of these could have been very dangerous but all at the same time wouldn’t bear thinking about! I ordered some new copper washers for the banjo’s and fitted them.

We have ignition…

I’m getting to the end of the preparation now and I’m itching to go out for a ride. All of the Blogs for this bike up until now have involved thoroughly checking the bike over to preempt as many problems as possible by ensuring that this is running as it should be following it’s lengthy lay up and it’s increasingly apparent sub standard recommissioning.

Back to the invoice of the last works that were carried out, when the carbs were done, there was mention of a new plug for the ignition. I looked around at the coils and plugs and could find no evidence of any plugs having been replaced. However while working on the oil reservoir, I came across the ‘Wurth 3 pin connector’ that was shown on the invoice. I noticed it purely because it looked out of place to all the other connectors and looked uncharacteristically large. On closer inspection, the bad workmanship that I’d come to expect from the dealer revealed a wire that was ready to fall out. With no effort it does.

I re-crimp this wire with a new terminal (fortunately I find one of the same size that fits) but then notice the white wire is also similarly badly crimped.

So with this re-crimped and the brown wire checked, this block connector is good to go…or is it?

It turns out that this plug is the ignition signal feedback circuit. One of the checks I was going to do is plug in a Zeeltronic ignition controller (bought specifically for this job) to set up the power valves. Ideally the exhausts need to come off for this check so the valves can be seen in their respective positions. I have bought all the exhaust gaskets to do this work however for now I’m going to get a couple of runs in first! The power valves appear to be operating fine and even the markings line up where they should. However a quick test run with the zeeltronic unit is thwarted because this Wurth connector, happens to be the same plug that the zeeltronic connects to…

This means that the Wurth connector will need to be replaced for an OE block connector which I have now bought.

Happily, this will put the bike completely back to stock and is the last of the hashed items for me to remedy!!

More to follow once the connector is replaced!!

Oil be back!!

Yes, here we are again, this time, having topped off the 2T oil tank, I discover a leak from the level sensor. This will explain the out of place looking jubilee clip!

I take the opportunity to start fresh. Fully strip, remove, clean and refill with my chosen 2T oil, Silkolene Comp 2 Plus.

The oil filter is in a bit of a mess, and in cleaning the tank, I find the remnants of the seal tab of a previous 2T oil container.

This could have easily of blocked up the oil supply so once again, it has paid dividends to go the thorough approach and strip it all down. Also in evidence was silicone sealant that had been gummed around the level sensor, remnants of which had also made it into the tank…

I put some diesel in the tank and slosh it around to capture the final bits of debris…

New filter fitted…the old one cleaned up ok so I’ve kept it as a spare.

To cure the leaking oil level sensor, I place 2Nr 16mm x 1.5mm O ring seals on the level sensor to seal it correctly. This works perfectly.

I test this by topping the tank up to the brim and tilting the bike forward on the Abba stand into the stoppie position. Oil leaks out of the overflow/breather hole, but not the level sensor!

That’s one more thing ticked off the list. No more oil leaking down over the rear of the bike.

The final check, is to open up the purge screw to bleed the oil pump and ensure there is no air in the system…

Bad Carbs…

No, we’re not talking about too much sugar!! Rather, bad carburettors to be precise!

So the Carburettors were rebuilt 8 miles ago when the previous owner had the bike recommissioned in 2018 at a non Aprilia motorcycle dealership. The invoice shows 6 hours labour and a carb overhaul kit. I was hoping that they had just been cleaned out and new seals fitted. It turns out I was wrong and my worst fears were confirmed.

One of the carbs (the l/h) had been removed from the fuel delivery hose as this was now secured by a cable tie rather than the proprietary Aprilia click clamp. The fuel filter sits at the entrance to the carb, this one had come away from itself and would allow unfiltered fuel through.

The other looked to have never been removed.

The fuel filter shows some residue/sediment.

Unfortunately both carbs had been opened up, evidenced by some rounded off screw heads at the base of the carbs and further by some of the original (and very expensive) Mikuni parts having been junked in favour of Chinesium, one of the many Chinese full overhaul kits available on ebay, which include everything for both carbs for £32. I was dreading this! My view was the least done the better, unfortunately that wasn’t the case.

So it was time to identify what was original and what had been done. It’s not a great sight as I open the first carb, the fuel filter is split (this could have happened during the removal process) and the float looks eaten away on one side. This would be from the bike leaning on it’s side stand and probably came from being eaten away by ethanol which is corrosive.

The fuel had lots of black specs in it which had come from the corroded float, of course this is after the fuel filter so the muck could have found its way into the engine regardless. As with the air filter, I’m very glad that I’ve taken the bike apart first before being tempted to thrash it down the road. It seems like this approach is paying dividends in disaster avoidance. Curiously, this float does not ‘seem’ to have any oem markings on it, however the markings would have been on the corroded area so perhaps it is original after all! It would seem like a lot of damage for 2 years otherwise! The float furthest from the side stand is not marked despite being in the same float bowl suggesting it was not sitting in fuel.

Of even more concern is the power jet circuit which performance 2 strokes are equipped with. According to Mikuni, this can provide extra fuel at high rpm full throttle. On removing the float bowl, the elbow to the hose connecting the power jet to the carb body snaps.

There was no force applied, it just came away with no effort. The hose was completely gummed up, I had to use a drill bit to clear the hose, clearly ethanol fuel had been sat here and had corroded the metal weakening it. Thankfully this is the left hand bowl which is still available, the r/h one is no longer available. The power jet circuit on this carb would have been totally ineffective potentially leaning out the mix at high revs/full power applications which is when you need it most, again I’m thankful I hadn’t been down the road with it. Sadly I’ll never know how bad it was suffering or not as I never rode it but better this way I think.

On to the r/h carb.

This would appear to have oem markings on the float, and was also rusty, suggesting it wasn’t sitting in fuel when the bike was standing. I guess if the fuel tap was shut off and the bike allowed to run until it stalled while on its side stand, it would have run out in the r/h carb first. This would have stalled the engine leaving some fuel in the left carb bowl with only one float dipped in the remnants of fuel, which is also where the power jet pick up was, explaining the corroded elbow.

The needle has some congealed fuel on it and the throttle valves could use a clean.

I strip the carbs down, on further examination, some of the jets are not original. Both pilot jets, one air jet, both needle jets as well as both float valves and needle valves are non oem.

I lay out the parts which need replacing for oem, as well as the float bowl itself which will need renewing on the l/h carb. This little lot in the picture below represents £438 as a replacement value. Junking the Mikuni parts for Chinesium was an expensive exercise and probably an unnecessary one, I find it hard to believe they couldn’t have been restored with a little TLC. That figure includes obtaining parts from Suzuki where required as they are the same Mikuni carbs as used on the RGV and cheaper than sourcing them from Aprilia. I’m replacing the vacuum lines as they contain a jet, I have no way of knowing if they have the correct jet so decide to replace them as a matter of course. The unknown unbranded Chinesium items have no markings on them so I cannot even verify if they are the correct size.

In the meantime, after stripping the carbs, they go in the ultrasound tank for cleaning.

Before and after…

They clean up as new/

I pack them up respectively while awaiting for new parts!

The new parts duly arrive. There is a marked difference between them and the non original items. Not least they all have the official Mikuni markings and sizings on them. The float valve and needle valve in particular are very much more robust and precise.

The carb rebuild process begins. New parts and cleaned up originals now installed.

The Main jets, needles, power jets, spacers and float pin are the only originally retained parts, everything else is new. Pictured below is the new float valve and needle valve.

The float height needs to be set. As they are installed out of the box, the measurement is 10.6mm from the measuring point to the gasket surface. According to the manual this figure needs to be 8.1 +or- 1mm.

I adjust the float to the recommended height. There is a further test which is to measure the fuel level through a clear tube. The manual also provides this information, this is actually the more test and is the one I will be targeting for accuracy.

For this test, the tube should show a dimension of 7.1 + or – 1mm from the indicated points. To achieve this, I find the left carb requires a float setting of 8.65mm.

The right hand carb required a setting of 9.02mm.

The carb needs to be carefully setup at the right angle and centricity for this test. My fuel level is within the tolerance of 7.1mm + or – 1mm.

With both carb float levels correctly setup and checked, it’s time to finally fit them and reconnect the chokes, fuel lines and throttle cables.

The throttle slides need setting up next to ensure that they are in sync with eachother. The throttle cable is adjusted so both are on the same mid marking together at half throttle.

The idle position is also adjusted to a 0.7mm gap, this was pre adjusted off the bike using a cable tie that was conveniently 0.7mm thick!! This must be done off the bike as the measuring cable tie meeds to be inserted in the back of the mouth of the carb (engine side).

The new air filter is inserted, air box cover back on and all ready to go!!!

Edited to add, I have since been back and renewed all the fuel lines with new as well as replaced the carb drain hoses.

Meanwhile back at the Batcave…

Now with the MV sitting safely in the garage, it’s time to see what we have!

Having sat in a showroom for the last few months she’s looking a little unloved…so it’s time for a deep clean first of all to get rid of all the accumulated dust in all the nooks and crannies…

These stick on peripheral mirrors will be coming off!

Out with a bucket and sponge on a nice summer’s day has her looking her true self in no time….

The seat is custom made, a nod to the Claudio Castiglioni 1078 with the black leather/suede and red stitching but with the further addition of the MV logo…

The Ohlins 9.5kg spring fitted by Xbikes…

Along with +3mm swingarm anti squat pivot plates, Waltermoto adjustable rearsets….

Powdercoated silver finish rims…

MV Agusta F4 Folding levers…

An X-bikes re-cored exhaust mimics the RG3 setup, with the addition of ceramic coating for better thermal management…

DNA Air filter element…

and a fully mappable Microtec M226 ECU mapped by X-Bikes.

With her all cleaned up it’s time to look for any obvious problems…

First up, the battery positive connector was mounted diagonally instead of horizontally meaning the lovely CRC red rubber fitting was ill fitting. This gets remedied and a new charge lead is fitted so that I can charge the battery back up to full health.

Next up, she’s rather unwilling to start…the fuel it turns out has been in there for about 19 months…so this gets siphoned out and replaced with SUL. With fresh fuel she fires straight off on the button…

The throttle cables have rubber seals underneath them to keep the pivots tensioned, the seal has split under the retaining plate resulting in some movement…

The split seal is duly replaced…

The bike came to me with a Bursig stand, however it didn’t fit. It turns out that the stand was for a 1000cc bike not the 1078, I recall the owner telling me his previous F4 1000 was written off, clearly this stand was off that and therefore the fitting must have been attached to that bike. No matter, some correspondence with Bursig in Germany who were extremely helpful and pointed me in the right direction meant I ordered the correct fitting but also a couple of minor modifications needed to be made to the stand as the fittings for the 1078 are ever so different. The top one was new specifically for the 1078 now and was ordered in black as pictured below. The new fitting replacing the oem bolt.

The lower fitting required a spacing washer fitting to it to prevent the stand from catching on the frame.

The Bursig allows both wheels to be lifted off the floor and the bike to be manoeuvred around while leaving the other side free from any fittings…

The chain tension is checked and found to be ok…just needs a full clean and re-lubing…

A rattling side panel was tracked down to a rubber cushion missing on the inside of the under tank removeable panels. With a new one fitted the panel is solid once again…

A birthday present from the wife who managed to track down an original genuine F4 cover in perfect condition tops it all off!!

MV Agusta F4 1078 RR 312

Oh my! This is exciting. I have been hankering after one of these since seeing the first pictures appeared in MCN in 1997 featuring the EICMA Milan Motorcycle show when the F4 750 Oro was first unveiled. I can actually remember exactly where I was when I first clapped eyes on the picture, driving up a hill in my birthtown with my girlfriend (now wife) in a Red Subaru Impreza while she was page turning the latest edition of MCN.

Designed by the late great Massimo Tamburini, for me this was his ultimate creation and arguably the most beautiful production motorcycle ever. Executed under Claudio Castiglioni’s tenure of MV Agusta, these two Titans of the motorcycle world are responsible for many of my favourite motorcycles.

The 916 Ducati was just the warm up act for what was to be his greatest masterpiece.

It wasn’t until around 2001 that I actually sat on one at a dealer in Jersey while holidaying there. This is the last bike on my primary list of essential bikes, saving the best until last, this is likely the last bike I will buy for some time, the garage is full and what better way to top it off.

I had been on the hunt on and off for at least 2-3 years, before this particular bike came on my radar. The initial brief was that it had to be a first generation bike (the pure Tamburini design) and a monoposto. I was in fact originally looking at the special edition F4’s, however the more I researched, the more it became apparent that the 1078 as the swansong of the gen1 F4 was the ultimate incarnation, only trumped by one other bike, which was the Eur 80,00, 2007 1078 CC (Claudio Castiglioni) which incorporated the MV Agusta TSS (Torque Shift System) on top of the already enlarged capacity. The CC was a run of only 100 units fully draped in carbon fibre and magnesium. The 1078 RR 312 followed a year later, made from 2008-2009 and presumably used up the run of engines that made the CC viable and was the closest F4 in specification to the widely acclaimed CC.

This particular example is finished in the traditional Red/Silver MV Agusta racing colours as per the Oro original launch bikes and celebrate the last of the Generation 1 F4’s designed solely by Tamburini. (The later Generation 2 bikes were restyled by Adrian Morton).

Sporting 190hp in standard form and a top speed of 312km/h (hence the name), the RR 312 was the last of the pure breed Hyper-bikes, no abs, no traction control and no rider modes to tame this power. It made do without the carbon fibre add on’s and colour schemes of the special editions, however it made up for this with 78cc more capacity (3mm increase in bore), slipper clutch, longer 1-3rd gearing while sporting lightweight Marchesini’s, Brembo brakes, fully adjustable Marzocchi forks and a Sachs rear shock.

This particular bike has been further improved from stock by X-bikes who also tuned the official UK importer Moto GB’s bikes. The 1078 was known to have some snatchy fuelling issues and overheating problems. These were easily remedied, the consensus is to install a re-mappable ecu, in this instance a Microtec M226 mapped by X-bikes delivering better low range power delivery, increased hp and bringing the cooling fans on sooner at 90 degrees centigrade.

This has been combined with an upgraded water pump impeller and a re-cored exhaust pipe (akin to the MV Corse RG3 pipes) with additional black ceramic coating. The chassis has been treated to a lighter 9.5kg Ohlins rear spring and +3mm swingarm pivot plates to soften the rear for our roads while simultaneously increasing anti-squat. Further changes from factory include MV Corse folding levers, Waltermoto adjustable rearsets as well as a HID low beam, CC style alcantara/leather seat and Silver powder coated wheels.

This particular example was previously enjoyed prior to myself by 2 owners. The first one purchased her from a London dealer and had her shipped directly to X-bikes to carry out the work and run her in on the dyno. He sold the bike at 880 miles a year later. The second owner had her for 9 years before selling to me at 3973 miles.

All the servicing thus far has been carried out by X-bikes and the bike comes complete with all it’s original documentation.

The bike was offered for sale by the owners friend who owns a garage in Perranwell, Truro which is where the bike was being stored who kindly put me in direct contact with the owner. A few phonecalls, emails and whatsapps later and an offer was made and accepted. The bike was located at the opposite coast to me, a 12 hour round trip as it turned out and a rather apt 666 miles exactly to collect this jaw droppingly Devilish temptress!

All loaded up for her homebound journey…

I have been very fortunate in my travels in that every motorcycle that I have purchased directly from the owners, they have all transpired to be nothing other than true gentlemen. This purchase was no exception and it speaks volumes of the unspoken camaraderie of fellow bikers that they generally behave in such an honourable manner. The deal was sealed and I gave my word that she was going to a very good home and would be well taken care of! I am absolutely delighted and very much looking forward to the first ride…

RS….Regular Spend!

I must admit, one of the reasons I have waited so long to pick up an RS is because deep down, I always had this fear that they would require far more fettling than a regular four stroke.

With 2,600 miles, this example would hopefully have a few years of engine life left in her. It has had three services in its life, 2 were Aprilia main dealer, of which the last of those being in 1998, and the last service a ‘local to the previous owner’ renown motorcycle shop that recommissioned her in 2018 (8 miles ago!). Fortunately this should mean that the bike hasn’t been messed with too much. However being overly cautious, I have been going through her checking everything and renewing anything that I’m not 100% sure about before it hits the road to stave of any disasters.

It doesn’t take very long to find the first eye opener! To be frank, this is why I like to carry out my own maintenance. The air filter literally falls apart in my hands.

Thankfully it was complete when I removed it, but whether this would have held up under 11,000rpm load without the bike ingesting lots of crumbly foam; I doubt it. I also find a mismatched bolt on the airbox so in the name of OCD, a replacement matching bolt has been ordered.

Perhaps the highest priority is that the brakes are up to scratch, after the rear master cylinder bleed failure, I’m not taking any chances with the front one, so managed to source a NOS front master which includes the brake lever.

While there I’ve also picked up a matching clutch lever so everything looks shiny and new on the control front since these levers have a tendency to corrode over time. A front caliper overhaul kit has also arrived to compliment the new front master so they will function like new once the calipers have been overhauled.

In general tidying, a pair of no longer available bar ends in the correct 1996 grey colour has also been sourced.

Before hitting the road, it’s time to look at the engine. Spark plugs are checked, carburettors were apparently ‘overhauled’ a mere 8 miles ago/2 years ago. The invoice charges for a carb rebuild kit. I’m hoping a cheap rebuild kit has not been fitted and the customer was either overcharged or only select parts were used. This picture shows the right carb. During this supposed strip, clean and carb rebuild, the factory fuel feed clips are still in place, so it doesn’t look like the carb has been removed from the bike. It’s possible that maybe the carb was visually cleaned and new air jets fitted at the front opening.

I don’t know if this is the factory needle, I’m hoping it is!

The left hand carb on the other hand, has had the feed pipe removed, evidence by it being secured with a zip tie and not a factory connector. The fuel filters are within this pipe at this point, which looks like the other carb fuel filter hasn’t been checked, perhaps the left carb was the worst of the two and the filter was clear which negated removing the hose. Either way, I won’t be taking chances and have ordered two new fuel filters.

I don’t believe the carbs have been removed or rebuilt and I’m rather hoping that they haven’t. I plan to ultrasonically clean them and would far prefer them to have the oe parts. With the fuel hose not removed from one of the carbs, I can’t see how the carb could have been rebuilt in situ with float bowls removed etc. The £580 invoice to recommission also states that the bike was running on one cylinder which was traced to a bad connector with a new one invoiced. All the ignition connectors are still original, so again it appears work has been invoiced which may not have been carried out and was little more than plugging in a bad connection or spark plug cap.

The gearbox oil is as clean as a whistle. In the last 400 miles it has been serviced twice, the first of which was 22 years ago when the gearbox oil was changed! The last service was for the plugs and a carb overhaul and ‘light’ service whatever that means on a two stroke. I’m sceptical about how thorough the work by the bike shop was carried out. I figure the only way to have true confidence is to start fresh with the servicing in my ownership, which means new Silkolene ‘light’ gearbox oil in and new sump washer going on.

These regular NGK plugs were fitted 8 miles ago, or were they?

New Iridium replacements spark plugs for a cleaner burn, greater longevity and to help against plug fouling, also twice the cost.

A Pipercross ‘road’ air filter has been ordered, which doesn’t flow more air so as to alter fuelling requirements but is made from far higher quality materials, than the stock which just falls apart.

The two stroke oil will be drained and the recently added Silkolene comp2 replaced with a fully synthetic Silkolene Comp2 ‘Plus’ along with a new oil tank filter to give the engine its best chance of survival.

On this same theme, it is apparent from research that power valves can be problematic, they can stick, seize or disintegrate causing catastrophic engine failure as they can contact the piston. I don’t want to take any chances, this means removal and clean of the power valves and investigating the condition of the pin, which when worn causes the valve to fall apart and drop into the piston!! Many owners fit aftermarket Cougar Red valves which are an improved design making this failure impossible. A sticking valve can also cause the solenoid to fail prematurely, as powerful as the solenoid is, it can apparently still move a very sticky valve so this can go unnoticed. Due to the low mileage of this bike, I don’t plan to replace the valves just yet, I’ll defer any decision making until I can assess the condition of them first however. The relevant gaskets and seals have been ordered for this, as well as some valve retainer hex bolts as the oe philips screws can round of very easily making it a poor design. This will facilitate future valve removal.

A first check on the valves means everything looks good and appears to be moving and alignment appears pretty much there. Grounding the grey ignition wire puts the valves in calibration mode and it’s a case of checking the alignment against the markings. Apparently the markings aren’t all that accurate, nevertheless…the lower cylinder markings/valve adjustment looks spot on.

The lower cylinder looks a little out with the photo below showing the laser demonstrating where the pulley marking should be aligned to.

This has left me ordering a Zeeltronic ignition checker, this will allow me to set the valves up far more accurately by effectively setting them to the third wide open position which is the most accurate way to set these up, it means removing the exhaust and looking up the port to ensure the valve fully clears the port when fully open, but not that it hits its stop which may cause the servo to strain itself as the potentiometer in the circuit will keep the pressure on all the time there is resistance. By default the valve will then be in the correct position at its middle opening which is where the grey wire test puts it.

Finally, there is misting on the one of the front forks, a bike of this age is highly likely to require fork seals, these have arrived. I’m hoping to get through the season on these leaving a fork overhaul for the winter.

By now I have spent a small fortune on mainly mundane parts, no glossy shiny tuning parts or any of that ilk. I have sought some advice from Sean at the Tuning Works who has been dealing with RGV250 and RS’s for over 20 years and supplies many of the OE engine parts. He has a a tasty catalogue of proven tuning parts offering real benefits to performance, power and efficiency without compromising reliability which means there may be more spend yet down the line. For now I intend to get everything running as it should for the correct baseline.

Old School uncool….

Back in the day, some may remember these hateful little devices. Security was all the rage and some insurers demanded they be fitted to everything.

While the bike is stripped, I’ve taken the opportunity to remove the old immobiliser eliminating any chance of it failing and returning it back to it’s factory condition. This had an old 90’s GT immobiliser which featured the little button tab coin transponder that you press to the metal plate. The gubbins are housed in a big heavy metal box!

The wiring was also quite messy and unsightly.

This gave me the opportunity to clear up all the wiring…first off, exposing the connections;

Tracing all the immobiliser wires back…note battery positive is disconnected to prevent any accidental electrical system damage.

Below, the immobiliser wiring is removed and the factory wiring has been re-taped and neatened up, I have used velcro securing straps instead of zip ties so they don’t scuff the sub frame.

That’s much better!!

Out with the old!! I’ve managed to source a new OE carbon effect side panel to replace this one which has had the immobiliser receiver drilled into it!

I feel so much better with this all taken out, the bike is now returned to it’s factory condition 🙂

Time to slow down…

After 7 years of faithful service with me and on it’s 12th Birthday (18th April), it’s time to treat the Capo to some upgraded calipers.

On fitting the new tyres last year I took the opportunity to check the brake pads and give the calipers a clean. I had never really paid too much attention to them, it was when working on them that it came back to me how much I dislike the design of sliding calipers.

To be fair, they have always done their job, offered good brake feel and although its a heavy beast I can’t say I’ve recalled the sensation of them not being able to stop me ever, however they have always felt somewhat duller than most of my other bikes.

A chap called Ziskar was offering a group buy on custom caliper brackets on the AF1 forum, these were based on a previous design initiated by the AOTR club, which would allow the use of radial calipers in lieu of the axial stock ones. This opens up the choices to all sorts of lovely radial offerings.

I have to offer a huge thanks out to Ziskar who did an amazing job of organising, informing, updating and driving this effort. A couple of months later these lovely brackets arrived, made from T6 7075 aluminium in black anodised finish. The original mounting bolts for the axial calipers use an M10x1.5mm pitch bolt, this has been replicated on this bracket so that it can be bolted to the forks using the original caliper mounting bolts with the same thread for the caliper mounting points. I managed to locate some M10 x 1.5mm pitch bolts from work, they are 8.8 strength BZP finish so should not give any issues with bi-metallic corrosion. The bolts pictured below are 50mm.

It became apparent on looking for bolts, that most Radial calipers use a 1.25mm pitch. This would have been better as not only would there have been a greater bolt offering but also the finer pitch would be stronger and more resistant to self loosening. It also transpires that the top caliper bolt would need to be shortened as there is less material on the bracket therefore it has not been drilled as deep. The upshot is that a 50mm bolt is fine for the lower fitting which will be under more stress anyway, which would have 11mm of engagement. The upper bolt needed trimming to just under 46.5mm offering just under 7.5mm of engagement. To get this also required me to run a tap down the thread as the original machining did not go all the way.

When it comes to caliper choice, there are many Brembo offerings. There are however a couple of considerations to take into account before purchasing a suitable caliper. Bolt centres on the radial caliper need to be 100mm for this kit. It is a common size so fortunately there are many to choose from. Piston size, pad cost, swept area, body width etc all play a factor in choosing the right caliper.

I looked at the master cylinder to piston ratios. The stock ratio is 26.7:1 . The Capo uses a 12mm master cylinder and the stock 2 piston sliding calliper runs one 32mm and one 30mm piston. The shortlist of calipers for me were;

  • Brembo P4.32 (32mmx piston) 28.44:1 ratio.
  • Brembo M50 (30mmx4 piston) 25:1 ratio.

The latter is a fancy mono block offering. The M50 in particular was the preferred choice but I worry that it may be too much for the Capo. The lower ratio would mean a sharper more powerful brake feel. The P4 would offer a slightly softer feel. Both ratio options were the same difference apart in ratio from the stock setup, 1.7 (M50) vs 1.74 only one jumps one way (sharper) and one the other (softer) from stock.

The M50 is an expensive caliper, and I did not have the body dimensions to compare. The mono block rigidity would also probably add further feel to the braking. All of these calipers are wider than the skinny sliding calipers fitted as standard. I opted in the end to go with a caliper that I new would offer decent spoke clearance and also match the stock look of the rear caliper and indeed the original ones. It would be a subtle upgrade and look very much factory. That would be the P4.32 as fitted to many Ducati’s including the Hypermotard which is what mine came from. Ebay turned up a nice example of 3,500 mile old calipers.

Upon arrival, the first thing I did was offer them to the brackets to see how the 50mm bolts would fare. As can be seen below, there is a gap on the top bolt of each bracket near the bleeder. This required the tap being run in deeper but also some length taken off the bolt. To tighten down correctly I had to take approx 2-2.5 threads off the bolt leaving me with a 46.5mm bolt.

I then set about deep cleaning them. re-greasing the pistons, cleaning up the pads and retaining pins ready for service.

The pistons were extended using an air compressor blow line, they were in great order commensurate with the mileage so just needed a wipe clean.

The pads were sandpapered with 600 wet and dry and cleaned with some water/detergent spray and then a final wipe with some break cleaner.

The pistons were re-greased with some red rubber grease so that they would coat/protect the seals.

Then the pistons were reset, ready to take the freshly cleaned up pads.

The back of the brake pads, perimeter and retaining pins were cleaned and lightly coated with some ceramic grease.

All ready for bolting up…

The caliper bolts will have some molybdenum disulphide grease applied to them and torqued to 38Nm. The brackets will be torqued to a slightly lower 44Nm with the same grease (50Nm and oil in manual seems a bit high for this aluminium bracket). Banjo torque 20Nm, Bleed nipple 9Nm.

On to the second caliper. This is how the calipers arrived as they came off the bike, a little bit dirty but with a little time spent cleaning they come up as new.

First off the pads…

Next up, the body and pistons. The body is cleaned using some diesel and a toothbrush and wiped off with blue roll, finished off with compressed air to blow out all the hard to reach areas.

It’s very satisfying to see these come back like new with a relatively small amount of TLC…

Original Brembo pads are installed with plenty of life left. Part number below for future reference.

Both calipers are now cleaned and ready to bolt on to the bike once the new copper crush washers arrive for the banjos.

Fitting the brackets to the bike. The good news is it all bolts up and it appears that it will serve its function. There are some issues however. The caliper should clear the disc by a minimum of 2mm according to Brembo.

This 2mm drill bit shows that the minimum clearance has been achieved. This is at the base of the caliper, the clearance is higher at the top pf the caliper. This variance should not be more than 0.4mm however it is 4mm more, less the 0.4 allowance makes the variance 3.6mm out of tolerance.

Above shows a 6mm drill bit inserted to demonstrate the 6mm of clearance. If the bracket hole where drilled in a slightly different position as shown below, this potentially could have been corrected and the variance equalised;

Measured using a feeler gauge, spoke clearance with these calipers at its tightest point is 2.8mm which is acceptable to me.

Finally the original brake hose angle is at quite a tight angle. I may consider replacing these in due course with a 30 degree angled head hose but for now these will stop. In the meantime, here is the finished article 🙂