Generational learning in the workshop: Part II

Mark Hallinger
Generational learning in the workshop: Part II

Many thanks to those of you who noted that last month’s story on “generational learning in the shop,” was not masked “millennial bashing.”

Well, maybe it was a bit. But laughing about differences and stereotypes is not always a bad thing. It’s often a good thing that helps you understand the very real perspective of others, even if gentle humour is the vehicle to learn and appreciate differences. 

One millennial colleague from my other life that pays the bills read the article and opined in a text to me – I like texts not Twitter of course – that the story was “witty and informative and only slightly condescending to millennials without being too ‘get off my lawn,’” in tenor.

But he admitted he understood only half of the article, as he speaks the languages of “pro audio”, and “broadcast production” from his work life, not “bike shop”. So does his opinion matter? He doesn’t even know what a PW-4 is. 

Once again, a plea. In the spirit of generational learning, I’d love smart-thinking, younger mechanics to make some suggestions on tips and tricks going the other direction. Not obvious things, but tricks you know that the average Gen X mechanic might not yet have figured out. If I get enough of them, I’ll do a story. I already have the headline: Teaching the
Old Dog

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Now, some housekeeping. I note that the structure of the first Generational Learning story included something obscure (Helicomatic hubs); something big-picture helpful (; something practical (don’t use a blade to unwrap tyre bundles); something esoteric (install toe straps correctly please); and finally something funny but real (the fact that a 30ish head mechanic could not be reached by cell phone on his day off, but he responded right away to Snapchat).

I like consistency. So it will be more of the same here. Structure and consistency make life easier. 

Like having your tools in the same place all the time, rather than distributed across three work stands. Like building ten of the same model bike in succession, using the same step-by-step procedure. The latter is a good practice that makes the unwrap and the silly little problems associated with any build easier to manage. I could do a whole article on the theme of consistency. Hmmm. But let’s do today’s work today and tomorrow’s work tomorrow, which is another good habit. 

The obscure: Flat-sided rims

There are things you will only very occasionally see in a bike shop that you should recognise: the obscure. When I was just a tadpole mechanic, I noted that some of the 27 x 1 ¼ tyres (which I would carefully unbundle without the use of a sharp knife) had something like “Inflate to 90-100PSI, 80 PSI on flat-sided rims,” written on them. 

This would have been the late 1980s, a good ten to 20 years after “flat-sided” rims had been supplanted by the much better “hook-bead,” rims. The former looked like a flattened-out letter U in profile, and the latter looked like a flattened U with a little inward-turning “hook” at the top. These hooks grab the bead of the tyre and allowed higher inflation PSIs. 

I knew what a “flat-sided rim” was because some kindly Baby-Boomer mechanic who had lived through the transition of flat-sided rims to the more modern “hook-bead” rims had told me about this before I blew a tyre off a rim through overinflation.

This came to mind a few years ago when a young mechanic had twice blown a tyre off a simple repair and could not figure out why, as the tyre was seated well and he was only putting 100PSI in a tyre rated at 105. I looked at the rim, told him about how tyres used to spec lower pressures for these rims, and then we got the tyres to hold just fine at 80 PSI. 

Then I wrote a little sticker on the rim at the valve so the customer wouldn’t blow the tyres off when he went to reinflate them in the future. And I made a note of it on the repair tag as well. I think I’ve only seen flat-sided rims on repair bikes three times in the last decade. Still, it’s good to know about this if you’re working on a 40 to 50-year-old bike.

The big picture: BCDs 

Here’s a big picture thing that makes a shop look more professional. BCD stands for bead circle diameter and is a measure of tyre size far more important than 26 x 1 3/8 inches or 700 x 32. The bead is what a hook bead rim hooks on. 

Most of the time the “diameter x width” measure written in inches or metric on the side of the tyre will get you what you want. But if it’s an obscure size like on a folding bike or a kid’s bike or something that might be 650B or 26-inch and you can’t tell, look for a BCD number written on the tyre. If you look at a distributor’s website or order book, they’ll often have the stated size of the tyre (26 x 1 3/8) listed next to a bead circle diameter (590 in this case). 

Here’s where a knowledge of BCDs makes you look brilliant. In the US, at least, there are two wheels/tyres that say 26 x 1 3/8 on them, and they are not compatible. The 590 BCD 26 x 1 3/8 was used on (mostly British) three-speed bikes, and then by the 1970s on crappy department store ten-speeds. A 597 BCD tyre and rim was used on a variety of very common Schwinn three and five and even ten-speed bikes for a decade or three. Everyone assumes it was a way for Schwinn to sell its own tyres or control that long tail of occasional income.

These tyres are not compatible. I once saw a highly-paid shop mechanic (who was also a car mechanic, I was told) trying to pry a 590 tyre on to a 597 rim. I set him straight, and was only mildly annoyed that he was making 50 per cent more than I was. 

I also had a shop manager chew me out one time for keeping the 26 x 1 3/8s of both sizes in the back of the store where customers would have to interface with shop personnel to get at them. My presumption was that we would get the customer the right tyre this way and not sell “British three-speed” tyres to a Schwinn owner and vice versa. 

A month or two after we had put the tyres on the floor, they went back in the shop where people who (presumably) know a bit can help a customer get what they need. Very few customers knew the 590/597 BCD issue, and it was it was usually just luck if they got the right tyres. I think I took three returns on these tyres in two months before we finally convinced the manager that these tyres needed a level of shop interaction before purchase.

This 590/597 problem may be a US issue, where Schwinns and Raleighs and Dunelts and Robin Hoods were and still are common, as they are tough bikes that last forever. I doubt that the UK ever saw an influx of Schwinns. But know your BCDs, or at least take the time to find a BCD on a rare tyre size like some of the 24-inch tyres, the weird folding bike sizes etc. 

And know that tubes are far more forgiving than tyres in terms of using the exact size. I once saw a mechanic holding up a repair because he didn’t have a 27-inch tube. He had multiple 700 x 32 tubes he could have used, but he was concerned they wouldn’t work.  

The Practical: Stretching a bit 

Tubes that work on 700 x 32 tyres can also work on 27 x 1 ¼ tyres, as the BCDs are very similar at 622 and 630. Modern tube boxes are usually marked as such. 

At some point, you will be unable to do a repair because somebody will bring in a kid’s bike that has an 18-inch tyre, and maybe you only have the more common 16 and 20-inch tubes in stock. You can make these work, just slightly overinflate the 16 or underinflate the 20 for the install process. You can do it, trust me. Inflate to recommended pressure once the tyre is firmly on the rim.

Similarly, a 12 or 16-inch tube can work on a 14-inch tyre.    

I’ve also recently noted that plastic rim strips designed for old 26-inch mountain bikes can be stretched to work on 700 or 27-inch rims. It takes a small effort but they pop on and fill that rim channel very nicely. Not all plastic rim strips are that flexible, but it’s worth a try if the alternative is a half-done repair or sending a customer away empty-handed.

Something esoteric: A freewheel story 

If an old bike has a two prong freewheel that needs to be removed, be very careful and consider getting somebody who knows the difference between a Suntour freewheel and one of the French or Italian two prong freewheels that exist from companies with names like Regina and Atom and Maillard. 

I’m not even sure that each of these continental freewheel makers had two prong freewheels – they surely had more modern-looking splined units in a variety of diameters from so small that a partial axle disassembly was required to nice and big and easy to deal with. They likely had both over the decades based on the massive collection of freewheel removers most old bike shops have.

Last year I got a call from my main mass market shop asking if the vintage shop I was working at two days per week had a “Campagnolo freewheel tool” for a repair. I immediately told them that it was probably not a Campy freewheel, just a nice old Campy Record hub with some European freewheel on there they did recognise and with no visible name.

But no, it was Campy, they said. Really? To my knowledge, Campy made one freewheel out of aluminium (!) in the 1980s and I had never seen one in person. They were not around long as they were expensive, and the world had just started to shift to cassettes. And aluminium is a bad material for cogs.

I told them repeatedly that just because it was a Campy hub did not mean it was a Campy freewheel but they insisted. Fortunately for them, the vintage shop I worked at also doubled as the US distributor for VAR’s very nice line of tools. And VAR still sold this tool. Better yet, I could just borrow the vintage shop’s remover as the likelihood of ever seeing another Campy freewheel was very very low. Wait for me, I said.

They didn’t. A very young mechanic with more confidence than skill or knowledge attempted the job and butchered it, breaking the customer’s vintage Campy skewer in the process. This leads to a further tip: Use an old skewer to hold a freewheel remover on, not the nice vintage skewer that has survived 40 or 50 years so far. 

The customer took his wheel to another shop that got the freewheel off, which is embarrassing. I fixed the skewer mess as I actually had access to a bin of 20 1980s Campy skewers at my other shop job, and bought one on the cheap. But what a mess. When the customer came to pick his skewer up, it was the first time I saw the wheel. Maillard freewheel, not Campy. I had that tool at home.

When a customer comes in with a modern press fit bearing issue or an electronic shifting problem, I know what I don’t know, and pass this to somebody who might manage this better than me. There’s nothing wrong with admitting lack of knowledge on a subject and getting the right person for the job. 

Aromatherapy & Enya

And a final note of humour from a very real shop. Aromatherapy machines have no place in the shop. Lava lamps, maybe. Dogs are fine. Cats even. But no aromatherapy, no Enya. The Kinks, yes. I have very distinct memories of Skip the Pagan, the mechanic in the first shop I worked at, explaining the song Lola to me on multiple occasions. Today, Lola is on the playlist of the piped in “music to buy bikes by” mix we listen to every day. Orinoco Flow is not.   

You can read Generational learning in the workshop: Part I here

Mark Hallinger’s collection of freewheel removers has topped 20, although they are not displayed on a wall as they should be, but kept in a drawer.

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