Motorcycle Classics

What to Know Before You Buy a Ducati Bevel Twin

Ducati Bevel Twins: The Essential Buyer’s Guide (Veloce Publishing, 2012) is just that–a book of everything you need to know before getting your dream Ducati. Marque expert Ian Falloon goes through information on all bevel twin models and gives in-depth analysis of each’s strengths and weaknesses. In this excerpt from the book’s introduction, Falloon gives the reasons supporting ownership of one of these bikes and tells the basics for avoiding a bad deal in buying one.

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Despite their foibles, the bevel drive family of Ducati twins has come to epitomize the finest attributes of Italian motorcycles of the 1970s and early 1980s. This was an era when Italian motorcycle manufacturing usurped a faltering British industry, and was yet to be overwhelmed by the onslaught of Japanese bikes. For some, the Italian motorcycles of this time were unsurpassed in their representation of form following function. As the production reality of engineer Fabio Taglioni’s vision, the bevel drive Ducatis were, arguably, the finest of all. These bikes formed the basis of some astonishing racing successes, and still provide a combination of suffi­cient power and excellent handling.

Why Buy a Ducati Twin?

Compared with modern production (and even contemporary Italian) motorcycles, the Ducati bevel twin was produced only in moderate numbers and, although during its 15-year lifespan it grew from 750cc to 1000cc, the basic engine and chassis remained unchanged. When it was released in 1971, the 750 set a new standard for Superbike handling, but was initially treated with ambivalence. It wasn’t until the race victory at Imola, in 1972, that Ducati was taken seriously as a Superbike manufacturer, and this milestone event eventually led to the introduction of the 750 and 900 Super Sport. Mike Hailwood’s amazing Isle of Man TT comeback win, in 1978, saw the creation of the Mike Hailwood Replica, ultimately the most popular of all the bevel twins. Although the cost of production sealed the fate of the bevel twin engine, it has continued to maintain a strong following.

Certain models have become highly prized and extremely expensive, yet some others remain unappreciated and consequently much cheaper. As all Ducati bevel twins are broadly similar, there are still bargains to be had. Distribution disruption at the time these bikes were produced also resulted in fewer bevel twins being sold in the UK than in some other countries. Fortunately, the advent of internet sales has meant that enthusiasts anywhere in the world can now find an appropriate vehicle.

As long as you’re prepared to look after it, a bevel drive Ducati twin remains a tremendous classic motorcycle. All are reasonably fast (particularly the 900 SS and MHR), have good brakes and excellent handling. There are plenty of specialists now providing the service to keep these bikes on the road, and as their popularity increases, more aftermarket components are becoming available. Any of these bikes is a fantastic ride.

Although many bevel twins are now modified, when selecting motorcycles to feature I have concentrated on original or excellent restorations. (I’m not a particular fan of highly modified bikes, believing that they should be left the way the great Fabio Taglioni envisaged them. This, undoubtedly, results in flawed jewels, but that’s the way I believe they should be.)  These are motorcycles of a different era, and trying to make modern bikes out of them is a pointless exercise; they will never perform like one. Over the last 40 years I have owned nearly every incarnation of bevel twin, and restored more than 30 examples. I have ridden all of them, some for many thousands of kilometres. There are favorites, and this will become evident, but, in my opinion, all bevel twins are great motorcycles.

Spotting a Fake Ducati

It’s easy to spot a fake Ducati bevel twin, as the different types were quite distinctive, and each model had a specific engine and frame number. Because the frame types were also quite different between most models, it’s not easy to build a fake.

A Super Sport created out of a Darmah or 860 GT will not even look close to the real thing. The main problem with fakes concerns the more valuable sporting models, in particular the early 750 and 900 Super Sports. With these models, always check the engine and frame number. The engine number is stamped on the rear of the crankcase, and the frame number on the left between the two rear engine mounts. A common method of faking is to grind off numbers from the frame or engine cases, and re-stamp them with false ones. This isn’t uncommon on the more valuable examples, so always check the stamp font.

Unlike some other classic motorcycles, the engine and frame numbers will not match on a Ducati, so this is of no concern. It’s more important that the numbers fit into the sequence for the date of the machine. A particularly desirable feature is a factory seal underneath the crankcases, which indicates that the engine has never been apart. 750 Sports can also be constructed out of a less valuable 750 GT, and as these share the same engine and frame number sequence, this can be very difficult to authenticate. There’s nothing wrong with a replica 750 or 900 SS, as long as you know what you’re buying and don’t pay too much.

How to Judge a Classic Motorcycle’s Condition

Put the bike on the center-stand so you can view both sides, and have a good, slow walk around it. If it’s claimed to be restored, and has a nice shiny tank and engine cases, look more closely: how far does the ‘restored’ finish go? Are the nooks and crannies behind the gearbox as spotless as the fuel tank? If not, the bike may have been given a quick smarten up prior to going on sale. A generally faded look, all over, isn’t necessarily a bad thing–it suggests a machine that hasn’t been restored, and isn’t trying to pretend that it has.

Look at the engine–by far the most expensive and time-consuming thing to put right. Bevel twins shouldn’t leak much oil: I have never come across a factory-assembled set of crankcases that leak from the center gasket, but they can leak from other places, notably the kickstart, and countershaft sprocket. Sometimes, this can be quite bad (and annoying), but is relatively easily remedied. Oil leaks from the crankcase center gasket indicate careless assembly.

Start the bike on the center-stand. If the ignition timing is correct, it should start easily in two or three kicks–but be careful with models with 40mm Dell’Orto “bumper” carbs, especially those with plunger enrichers. These are easy to flood and, consequently, can make starting tricky. Electric start models should start immediately, and the Sprague bearing should disengage cleanly. The engine should rev cleanly and settle into a nice idle. These are noisy engines, so expect considerable gear whine, but there should be no knocks from the bottom end. Big end failure is the bane of these engines and extremely expensive to repair. While the engine is running, check the electrical system works, lights, turn signals and horn.

Switch off the engine, and check for play in the forks, steering head, and swingarm. Are there leaks from the front fork or shocks? Are the fork tubes pitted? Pump the brakes to check that they have a good feel and aren’t “soggy.” Are details like the seat, decals, badges, and tank color correct for the year of the bike?

Check for obvious signs of repaired crash damage–scuffed axles, levers, engine covers, and exhaust pipes. Minor damage is repairable, but more serious crash damage can result in a bent frame. How many aftermarket components are on the bike? Many of these bikes will have aftermarket shock absorbers, exhaust systems, handlebars, and fairings. If you’re looking for an original bike, it can be difficult to find original items if they are missing.

Sealing the Deal: Documentation

If the seller claims to be the bike’s owner, make sure he/she is: check the registration document. An annual roadworthiness certificate is handy proof that the bike was roadworthy when tested. A whole sheaf of them gives evidence of the bike’s history, such as when it was actively being used, and what the mileage was. The more of these that come with the bike, the better.

Reprinted with permission from Ducati Bevel Twins: The Essential Buyer’s Guide by Ian Falloon, published by Veloce Publishing, 2012. Buy this book from our store: Ducati Bevel Twins: The Essential Buyer’s Guide.

  • Published on Nov 5, 2012
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