How to buy classic bike parts
Provenance | Part numbers | Motorcycle parts | NOS | Quality
In the "good old days", buying classic motorcycle parts was a lot different to how it is today. There was a time when you went into your local AMC, BSA, Norton, Triumph, Royal Enfield (or whoever) shop, tramped to the parts counter, waited in line, checked your watch half a dozen times and finally shuffled forward and told the parts man (or, occasionally, parts woman) what you wanted.
These characters were a mixed breed. Usually they were ex-mechanics and knew their stuff and were happy to demonstrate their knowledge. So you'd ask for a left-handed widget for a 1933 250cc Dirigible (or whatever), and you'd reach into your bag, pull out the one you'd just removed from your bike, and bang it down on the battle scarred counter.
The parts man would perhaps pick up the item and examine it cursorily, then promptly tell you that, from memory, it was part number 6678-4, and he'd duly resurrect one from the parts bin. Or, if he wasn't sure (which was unlikely), he'd grab a factory parts book and flick to the necessary page and check the listing. Either way, he'd return with the widget and slap it down for inspection.
And at that point, where appropriate, you'd reach into your pocket for your vernier gauge or micrometer, and you'd compare the dimensions with the new part. You might umm and ahh a little. It was generally required. And then you might decide that you'd like to see a couple more of the same. This one, you'd explain, was too near the maximum tolerance. So the parts man would give you a dirty look, then saunter off, have a ciggie maybe, and return with the entire box and let you take your pick of the widgets.
That's almost never done anymore. Most parts are probably bought online or by telephone. Any measuring you need to do therefore has to be done after you've got the item in your hand. And if you've waited a day or so, and if you're impatient to get the part on the bike, you might overlook the fact that it's near tolerance, or is blemished in some other way. You might even be prepared to take a file or a hammer to it if you're desperate. Most of us have done all of that.
The point is, circumstances have changed so much over the past few decades that we've become necessarily sloppy. Not all the time perhaps. But certainly some of it. Classic bike parts dealers are an increasingly endangered species. Correction: good classic bike parts dealers are an increasingly endangered species. The world is full of people who have no significant knowledge of motorcycles, classic or otherwise, but are contentedly running parts businesses from their bedrooms, garages or possibly a lock-up shop.
We're not condemning these traders outright, mind. You've gotta eat. We understand that. But as a buyer of classic bike parts you've got to be very careful with what you're prepared to accept. Plenty of classic motorcycle spares are sub-standard in terms of fit, finish and materials quality.
To mitigate this problem, here are a few tips to help you get the right item in the right condition.
1. Ask the trader about the provenance of the part. As a general rule (but not a cast-iron rule), British built motorcycle parts are usually superior to motorcycle parts made in India or China. But that might change in the coming years as the Indians and Chinese up their game.
Japanese parts are usually very good; the Japanese take a special pride in getting things precise, and they love classic motorcycles; not least British bikes. Parts from Taiwan can also be good, but sometimes not so good. Ditto for Italian parts. We've less experience with German spares, but the few we have bought for our BMWs have been pretty good, if not very good. But that's based on a small sample. American parts are also generally pretty good if not very good. But at any one time, a given part from anywhere in the world might be high quality or low quality. You need to check further. So ask the trader where the part was manufactured. If he or she can't tell you, walk away—unless, that is, you've exhausted other suppliers and are desperate. Then make a decision if you want to take a chance.
2. Try buying direct from a dealer; not online or by mail. That, of course, means visiting the shop (or garage if you must) and checking the part before you buy. Alternately, try buying from an autojumble—but you might first have to find an attending dealer and have them bring the part to the event (usually, autojumble dealers carry only fast-moving spares). Look for a dealer with some history, if possible. You really want to trade only with committed parts suppliers, ideally guys and girls with their own classic bikes or racing background, or similar.
3. Inspect the part thoroughly. For engine components, you need precision measuring instruments. That could mean investing in a vernier caliper or micrometer, or at the very least a steel ruler. These items don't have to be that expensive. Second hand will do. And once you get into the habit of measuring and checking spares, it becomes second nature. Moreover, it helps educate you about the importance of precision.
A piston, for instance, is only a piston if it satisfactorily compresses an induction mixture in a cylinder bore. If it can't do that (because it's oversize or undersize), it's scrap metal, and that's all it's worth. It's the same thing for valves, springs, shafts, whatever. For all parts, including seals and other rubber items, handle them thoughtfully—and where possible—compare them to any used items you have.
Check chromed parts too, but be careful. We've seen flaking chrome on new parts many times, and those flakes can easily get into your skin. In general, use your eyes, use your ears (it's interesting how good parts often sound right and bright, and how poor quality parts often sound dull), use your sense of touch, and use your measuring devices. Check flatness too (for clutch plates). Spin bearings and listen and feel. And remember to check nuts and bolts. If your money is 100% good, you expect the same of your motorcycle parts, don't you?
4. Ask if there's a more expensive item. Many classic bike dealers sell cheap parts only because most buyers want cheap. These buyers are not necessarily riding their bikes, after all. They're often just parading them. Or displaying them—and okay, maybe once in a while they'll motor around a showground and/or take their wheels for a Sunday bimble. But they probably won't be riding it far, or in anger, and certainly not in the rain.
Or maybe they've bought the bike to repair and sell onto to whatever mug happens along. Consequently, inferior quality parts aren't necessarily a problem for many bike owners/builders. They're not looking for longevity. Just cheapness and superficial looks.
Many dealers, however, would like to sell better parts. They want to develop good reputations, and they don't want any aggravation from disgruntled customers returning broken items and complaining about rebuilds. As such, it's possible that they know where to get higher grade parts, and it's possible they'll be able to acquire them. So if top quality is important (and it ought to be), ask if anything better is available. The trader might say yes and offer to supply it. Or they might send you to a competitor. Or they might sell you an inferior component. Beware.
5. Ask if there are any other parts needed to support the part you've just bought. Once upon a time, parts men (and women) used to tell you this automatically. You'd buy a carburettor, and they'd suggest a new gasket. Or maybe a Tufnol spacer. Or a new air filter. Or maybe they'd suggest that you need to think about changing the jets.
Or maybe you'd buy a new set of cylinder head valves, and they'd ask if you need guides, or springs, or valve seals. And if the head was coming off, do you need a new head gasket and seals for the pushrods?
Back then, it wasn't so much that dealers were trying to up-sell you. They were probably also just being helpful. Or maybe they were showing off their expertise. Regardless, they were an asset when you were repairing your bike and buying spares.
However, these guys (and girls) are mostly gone now. A new breed of parts men/women is out there, and many don't really know their stuff at all, or just haven't developed the habit of exploring other items that the customer needs. So today, we have to do that for ourselves.
Therefore if you're replacing fork seals, or swinging-arm bushes, ask if there are other parts needed to complete the job. It can save a lot of time and trouble later when you suddenly realise that you should have bought a supporting item, but the shop is closed for the weekend (and you end up re-using an old part that's barely fit for purpose). In short, get into the habit of up-selling yourself.
6. Remember to also ask about second hand parts. And note that we're referring to quality second hand parts. After all, some second hand spares are better quality than new, repro items. Most of us routinely throw away motorcycle components that are still fit for purpose. Yes, they might be old. They might be a little knocked about. They might need re-chroming. But you shouldn't write-off these parts. There's often life there still, and you'll buy safe in the knowledge that the items was built to the original manufacturers specifications.
Be careful when you buy. Ask questions. Check that the parts man/woman knows why the item is better quality. He or she should not only be talking about superficial qualities, but also about the underlying qualities. Chrome plate directly on steel, for instance, is not ideal; it generally needs copper and nickel. A cast iron item is rubbish (and possibly dangerous) if it really needs to be forged. A clutch pushrod needs hardened ends. Piston rings need to be made from the correct grade of cast iron. Bearings need to be properly graded. Etc. In short, know what you're getting.
Finally, ask about warranty. You have certain legal rights under basic consumer law, but a two-year guarantee on a rebuilt magdyno or dynamo or a re-spoked wheel tells you much about the faith the dealer has in his or her products. Just remember to get that guarantee in writing. It might help later.
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