Bimota Content

When I got the Aprilia RS250, I thought (and honestly believed) that was IT.  Three bikes   Noone needs ONE motorcycle, let alone three.  I was out of space too.   One bike has to block in a car (or vice versa, I guess).  Another bike is locked in place alongside that car.

Still, the zuckerberg marketplace searches continued.  A good way to relax my mind while working through a problem at work (or so I tell myself).  And a Bimota V-Due showed up.  Zero km.  Never started.  FIVE MILES FROM ME.  (SPOILER: this isn't about that bike - I didn't buy it). WOW, now THAT is cool.  And down the rabbit hole I went, learning all about the tragedy that is the V-Due, Bimota's attempt to build a bike around an engine of their own design and manufacture.  A story for another post.

Since ZM has a terminally awful search mechanism, I would search on "bimota" to see if the bike I was interested in was still there.  And that's how I found a '99 db4 3 hours away.  My very rational self thought "As long as I have one bike behind the Ferrari, I guess I have room for another.  It's not that much less convenient, right?"  Of course not!  It is now 20 feet from where I'm sitting, which is a much cooler place for it to be. 

This bike is based around a Ducati (the 'd' in 'db') 900SS engine.  Air cooled, 2V heads.  Maybe 80hp at the wheel.  It's tightly wrapped in an 11lb aluminum frame that you have to remove to change the timing belts.  It's 60lbs lighter than the 900SS of the same year.  I came up with 390lbs full of gas on my scale.  This bike has a "Corse kit", which was installed by the dealer and includes Keihin FCR carbs, a titanium muffler, pod filters, and a unique gas tank to fit the carbs.  It's too loud but in a good way.  The carbs can't be bothered with a choke but they do have an accelerator pump so starting isn't impossible, just a little annoying.

Smaller than my Ducati 848, slightly bigger than the Aprilia.  I would describe the feel as 1/2 way between the Ducati and Aprilia.  More stable than the Aprilia, more flickable than the Ducati.  I recently discovered expensive shocks are expensive for a reason when I put a used Ohlins on the Ducati, which led to a Penske for the Aprilia.  Fortunately, the db4 comes with Ohlins in the back stock.  The fork is a Paoli (?).  

Other random things -  The fiberglass tank cover/tail section is one piece and comes off with three bolts and one electrical connection.  The subframe does not extend past the end of the seat.  I was surprised that the rest of the bodywork is actually plastic.  Fiberglass seems much cheaper overall for a tiny company making small batches (265 db4s were built).  The fuel shut off is only accessible with the fuel tank partially removed.  The brakes are standard-issue Brembos with EBC HH pads but 390lbs is not a lot of weight to slow down so they feel amazing.  The front sprocket is unique to this bike.  Apparently, they put everything where they wanted it, then machined the sprocket to get the chainline right.  The wheels are heavy.  Carbon fiber is worth 15lbs.  I learned yesterday that the fuel level sensor is a MotoGuzzi part, which is good because I need one.

There's a bit of CNC goodness and some very light and fragile looking carbon fiber bits too.  The bodywork is pretty fragile too.  I've heard it described as cracking 'if you look at it out of the corner of your eye'.  A couple of the mounting points are indeed cracked but everything else is "I can't believe this is 23 years old".  They were expensive new and treated well.  

I've put about 50 miles on it and it's a blast.  The power/weight is a real sweet spot IMHO for having fun in the real world.

The V-Due story as I understand it:

The problem with 2-strokes is emissions.  They're really bad.  Not just because they burn oil with the gas but because, since each turn of the crank creates combustion, the intake and exhaust ports have to be exposed at the same time.  Some amount of incoming fuel/oil/air goes straight out the exhaust.  Bimota designed a direct injection system that didn't inject the fuel until the ports were closed, dramatically reducing emissions.  Good enough to be legal to '97ish motorcycle standards.

The initial tests were awesome but the productions bikes were a disaster.  They ran like crap, and unpredictably.  They had designed everything with very expensive fuel injectors from Ferrari but built the production bikes with less expensive injectors that did not work as well.  In addition, there was a dodgy crankcase seal that wasn't understood until much later.  Since combustion air is routed through the case, air leaks are a big problem.  You can't set up fueling with an air leak.

Eventually, Bimota bought most of the bikes back.  Shortly after, they declared bankruptcy.  An enterprising Bimota engineer bought everything V-Due-related out of receivership, figured out the case problem, had new cases recast, converted them to carbs, and is still in business.  I think all the bikes have been sold but he still has a cache of original spares plus all the bits he's designed over the years.  There are about 450 of them in circulation.

They're available and not insanely expensive but ultimately, I decided they were just a little too "expensive science project" for me.     A zero km original bike (which means - not sorted) sold for 33,500 at Iconic in California recently.  "Sorted" - whatever that means exactly - running carb'd bikes get mid 30s as well.  There are a few people who claim to have made the fuel injection work (the ECU is rare but available and can be tuned if you know what you're doing) but I haven't found any details.  A French (I think) company sells an entire fuel injection system for $5k but it's not DI, it's port injected.

That's freaking awesome. Congrats!

Oooooh, Bimota. Wonderful bikes, and insane build quality for the time.

I still miss the YB7 that I had to sell to buy my first house in the UK, and one of these days I may end up owning another Bimota.

All good stuff. I dream of Ducatis, can't even afford Bimota dreams. Well done.

Bimota. Hello you sexy beast!

- heavy breathing -

Thanks for the kind words all.  Curiously, Bimota does not get a lot of love in the market and the db4 seems to get the least (or maybe the db3, which is just ugly).  An Aprilia RS250 in the same condition as my db4 would be worth more than I paid.  My Aprilia is extremely nice but the db4 is truly in 'lick it anywhere' condition.  For now - I'll eventually do something dumb.  :)

I guess this is typical market behavior.  People buy the stuff they loved and/or owned when they were young.  In the case of the Aprilia, reliving that period when 'me and my mates all had 2 smokers'.  They were relatively cheap and disposable so not many exceptional examples survived.  Of course, some Ducatis of the era command a big premium too and they were never cheap.  Maybe it's because Bimota isn't a 'real' manufacturer.  Whatever - it worked out for rme!

A very nice db2 Final Edition went for $14,100 on BaT recently.  https://bringatrailer.com/listing/1997-bimota-db2-edizione-finale-2/

Awwww, ugly?  Well OK, but I always wanted one.  Maybe it was just the 1200 Ducati engine that turned my head.

914Driver said:

Awwww, ugly?  Well OK, but I always wanted one.  Maybe it was just the 1200 Ducati engine that turned my head.

 

:).  It's actually a 900 like the db4.  The two bikes are substantially similar.  I think the frames are identical.

914Driver said:

Awwww, ugly?  Well OK, but I always wanted one.  Maybe it was just the 1200 Ducati engine that turned my head.

I've ugly bikes and this isn't one. Certainly unique and if you've seen the new Lost in Space series they stole the front fairing from this and turned it into a major robot character. Spoiler alert.

Hnnnggh! Nice score! I've lusted after them since I was a youth in the '90's, and Bimota is still atop my pie-in-the-sky dream bike list. I guess I'll just have to console myself with my Aprilia until I really make it...

In any case, congrats, and I'm excited to follow along vicariously! The tricolore scheme is just gorgeous!

I'm having a lot of fun with the db4.  Last week I was out on a quick ride after work when I saw my friend in his built Ford GT (800ish hp IIRC) and followed him home.  He's a total bike nut too (probably has 30 of them) and a ride on mine had him shopping for one of his own.  

The fuel level sensor wasn't working - the light was on constantly.  Some digging around showed that a Moto Guzzi part was substantially similar but too short (100mm vs 140mm).  Messing around, I figured out that the problem was that my float wasn't, er, floating.  After staring at it a bit, I realized I could probably swap the float out and I managed to do so w/o messing anything up.  I honestly don't quite understand how the circuit works.  It goes low impedance when the float rises.  How?  Beats me.

I only have one key.  A generic spare is about $10.  I have one for my Aprilia, in fact, but my local locksmith didn't have a blank.  Which is how I ended up spending $110 to have a branded blank and little leather pouch sent from bimota Classic Parts in Italy.  A totally rational purchase.

In other news, I'm learning how to set up the carbs wrong.  :)  A tiny flat spot off idle became massive backfires at 1/8 throttle the other day when I fooled with the low speed air screw.  It didn't occur to me that I might have to move the needles too.  Needles and the low speed settings are super easy.  The tank/tail comes off with 3 bolts and a single electrical connector.  No airbox.  Air screw changes take about 12 minutes.  Needles take about 15.  They're about 45 on my Aprilia if the lowers are already off.

The PO was about 80lbs heavier than me.   He had the compression damping set to Just Don't front and rear.  It rides much better now.

mfennell said:

I'm having a lot of fun with the db4.  Last week I was out on a quick ride after work when I saw my friend in his built Ford GT (800ish hp IIRC) and followed him home.  He's a total bike nut too (probably has 30 of them) and a ride on mine had him shopping for one of his own.  

Got a text this afternoon.  My buddy worked out a deal on a db2 being sold by the same guy I bought my db4 from!  Already sent a check.  Someone should be giving me a commission!  :)

Winter projects time.  Starting with the Bimota.  Assume the position:

I discovered that the continental European Bimotas got a cool projector headlight just like my Aprilia.  Since it's a Yamaha part, used in a few different FZRs and a several others in the early 90s, I figured it would be easy to just ebay one from Germany or Italy.  It was not.  The exact style is impossible to find.  So I ended up buying from Bimota Classic Parts, source of my $110 key above.  I got two - one for my buddy with a db2 - and the price wasn't totally outrageous but shipping from Italy is.

Totally worth it though, right?  Right?

I thought I'd have to do an ugly adapter from the headlight connector but the headlight has it's own subharness terminated with a cheap and easy to source AMPSEAL connector.  I needed to buy some crimping tools anyway.

Don't worry, I have covers coming for the holes in the back of the bucket.  The big ones (62mm) are a pretty standard size.

The fairing stay has a crack in it, which means dealing with a local welder/machinist who is as flakey as he is skilled but at least now I understand while the gauges were shaking so badly.  

I'm also reinforcing some of the body mounts with a little fiberglass.  I wondered above how they used plastic (expensive set up) instead of fiberglass (labor intensive) as a tiny manufacturer.  I'm guessing now that this kind of molded plastic must be as cheap as fiberglass to set up and cheaper to make.  It's not the nice, flexible, injection molded ABS you find on mass-produced bike but rather like the cheap replica stuff you get from China for $350/set.  Fortunately, the big tank cover/tail is fiberglass.

Fun times.  Seriously - fun times.  Love going out to the garage, spinning some wrenches, puzzling things out.  Motorcycles are so much more enjoyable to work on than cars.

I ended up sending the fairing stay to a friend who had thoughtlessly moved away .  :)  In the meantime, I popped the Aprilia on the lift and dove in.

I put a spring in from a company in the UK and replaced the fork seals.  I've been cleaning 26 years dirt off parts that seldom see the light of day.

During my cleaning frenzy, I noticed that the back of the Aprilia headlight is exactly the same as the Bimota/Yamaha headlight.  They were both made by the same manufacturer, Triom.  I was able to dig up a NOS Aprilia wiring harness, which includes the nice dust covers, on ebay.  I'll swap the connector for a much more OEM appearance than my own harness was providing.  Noone will ever see it but I'll know.  :)

My friend sent the stay back yesterday.  He used to weld/fabricate professionally but mostly just dabbles these days.  He did a great job of fixing the break and reinforcing it.

Going to keep going with the Aprilia for a while.  I want to put the oil injection system back on so I can stop pre-mixing, which is driving me crazy.  It's a variable system tied into the throttle and powervalves, so it will idle w/o creating a smoke screen.  Not completely sure I have all the parts yet...