The biannual Bonhams auction takes place on Sunday as part of the Stafford Show. While most people will be watching the posh lots, we're more interested in the bidding at the bread-and-butter end of the business...

Buying at a traditional auction does involve some faffing: ideally you need to view the lots beforehand to set your top price for your intended purchase. It's best to turn over the engine (and check that there are actually some lumps of metal inside those shiny cases…), check the paintwork for bubbles and hidden rust, and review the paperwork in person. Then you have to hang around the auction hall at exactly the right moment, acting nonchalant until leaping in with the winning bid. Thereafter, you've got some more hanging around to do until the sale finishes, whereupon you must remove your new P&J pronto, before you're charged a storage fee. It probably won't be in ride-away nick, so make sure your mate with the van or trailer hasn't gone home early. Oh, and don't forget to register before you bid, and make sure you have cash or enough instant credit on your card to pay in full.

Phew. Sounds like hard work, but it's just a matter of being patient, really. And there are times when patience pays off. The big posh sales tend to attract big posh bidders for the big posh lots; the Vincents and Inters and Broughs and such which go for huge money. Yet the early part of the auction always contains a motley crew of more mainstream motorcycles, many of which are overlooked. We regularly see some of these bikes offered for private sale some weeks later, sometimes with an MoT, frequently with a grand or two added to the price tag. So here are some of the classic bikes we'll be watching this weekend...

Lot 274: 1971 BSA Thunderbolt
The 'too tall' frame of 1971 doesn't suit everyone, but we'd certainly give this single-carb 650 twin house-room. It's been recently rebuilt including the wheels (that's at least £500 you won't need to spend) and should be an easy starter with an electronic ignition system fitted. Similar machines are available from dealers for around five grand; this one is estimated to fetch between £3500 and £4000. At three it would be a snip.

Lot 292: 1964 Triumph TRW
The military sidevalve 500 twin provides a neat combination of rigid rear end (so low seat height) with tele forks and a decent front brake. Roadworthy ones sell at dealers for a sniff over four grand. This machine looks to have been stood for most of its life - it's not even registered - so will need some careful recommissioning. (If you're lucky, that could just mean fresh petrol and consumables). It's been through very few hands since its demob in 1977, and is estimated to fetch £2500 to £3500. Worth a punt if the bidding stalls low.

Lot 359: 1989 Ducati Paso
We've got a soft spot for the fully-faired 750 desmo L-twin, even with its 16-inch wheels. This one is estimated to fetch between £1500 and £1800 which would be a fair price for a roadgoing concern. However, it's been part of a collection and is being sold alongside some rather more awesome examples of Italian exotica, so there's half a chance that a silly bid would be successful. Two grand usually gets you a Paso from a dealer with a three month warranty; don't confuse the 750 with the 906 because the bigger bike usually sells for a grand more.

Lot 352. 1954 Matchless G3LS
Solid, sturdy and reliable, the AMC heavyweight singles make an excellent introduction to traditional Brit biking with proper swinging arm suspension on the LS, combined with the firm's well-regarded Teledraulic front fork. The G3LS is no road-burner, but possesses it owning chuffing charm and is ideal for gentle trundling. There are a couple of examples in the auction, with estimates between £2000 and £3000. This one was restored in 2001 and then only covered 1500 miles over the next decade before the owner passed away. It comes with masses of history and paperwork: most dealers will charge around £3500 for similar bikes.

Lot 274: 1969 BSA Starfire
In RC102 we happened to mention that 250 unit singles were looking like a lot of value for a little money at the moment, and here's one to the prove the point. However, you shouldn't pay the £1800 or so that an up-and-running example is worth. This one needs 'reconditioning', so you'll need to walk around it to see how much it'll cost to put through an MoT. The estimate is around £1100; if you can shave a couple of hundred pounds off that then it'd make a nice winter runaround.

There's another 350-plus lots to view here: www.bonhams.com/auctions/19768

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