We’ll keep you riding!

As I write, a nearly-overwhelming amount of information is coming in about the approaching COVID-19 pandemic and what measures the government may impose to help slow the spread and lessen strain on our hospitals.

I’ll leave that stuff to the experts, but I will be updating this blog over the next few weeks to give what useful information I can on how you can keep riding if it all starts feeling a bit like a zombie apocalypse. We know that cycling’s good for your health in general, but for many people it’s also closely linked to good mental health; a bike ride can be a much-needed antidote to the anxieties caused by current news.

First I want to say that we’ll stay open as long as legally and humanly possible. We’ve seen plenty of people visit us for the first time in the last few days because they’re starting to ride their bikes instead of use public transport – long may that continue! – but we’re aware that shops may be shut down very soon.

We’ll keep our normal opening hours, 7am-7pm weekdays, for as long as we can; we’ll stay open on Saturdays from 9-5 and we’ll try and fit every service in as soon as possible. We generally try and fix punctures and do small tweaks and adjustments on the spot, while you wait, and we’ll continue that although we might ask you to wait outside the front of the shop just in case (under the awning, if it’s raining!).

I’ve got a separate blog to write about the pleasure and sanity-restoring solitude of riding on your own, and how to stay safe, but we’ve got stock of saddlebags, multi-tools, pumps, tubes, and all the other stuff you’ll need to take with you, in the shop.

And for those who are already self-isolating or quarantining, there’s another blog on its way about how to set up your turbo trainer if you need or choose house-bound cycling; we have turbo trainer tyres (yes, they’re a thing) and those bike protector things that are generally known as “bike bras”.

We’ll also be offering a turbo trainer setup service. Like servicing your bike, it’s not rocket science but if you’d prefer it done quickly and properly by someone with a bit of experience, we can help out. Give us a shout for more details, or watch this space.

And in the meantime, take care of yourselves. And each other.

Why do I need to replace my chain and cassette?

(Originally published 16th October 2011)

When we service your bike, things like oils, grease and hydraulic fluid are included in the price. However, some things aren’t included and the most common extra charges are for brake pads, chains and cassettes.

The brake pads are fairly self-explanatory, and you’ll certainly notice if they’re not replaced in time. But it’s not always clear why the bike’s chain, and sometimes the cassette, need replacing.

newchain bw

As a bike chain is used, something called “chain stretch” occurs. This isn’t a great term for it, because the chain parts don’t actually stretch. At each point where the chain pivots, the constant rub of metal on metal starts to wear the parts away. Although this happens very gradually, this wear means that that pivot point starts to become a little looser. As it wears down, the distance between two consecutive chain rivets becomes very slightly further apart.


The image above shows a very worn chain link and a brand new link. You can see the wear on the rivet, the inside of the roller and the inner edges of the inner plates.

The chain and the cassette (the set of sprockets on the rear wheel) are designed to align perfectly with each other. When both are new, this is what happens; the teeth on the sprockets all mesh equally with the links on the chain, and the force you put in when pedalling gets spread evenly to each tooth in contact with the chain.

But as the chain wears, the length of each link gets very slightly longer. Only by a tiny amount, but this can mean that the pedalling force gets transferred unequally to the sprocket on the back wheel. Because of the way the chain transfers force to the sprocket’s teeth, the teeth at the “bottom” of the sprocket will have more force on them than those at the “top” at any time in the sprocket’s rotation. In turn, this wears down those teeth very slightly. As the teeth wear down, they match the wear of the chain, the chain’s load is spread more evenly across the teeth and the wear lessens.

This isn’t a huge dramatic process (unless your components are made of very cheap metal, or you run your chain dry), but it is a gradual process that occurs steadily all the time you use the bike. In time the chain, and also the cassette, become slightly worn.


I use a very handy tool to measure this “chain stretch”. When new, all bicycle chains will measure exactly 1″, 25.4mm, across one link. (“one link” is the repeating unit – one inner pair of links, one roller, one outer pair of links, another roller). As the chain wears, the very slight lengthening of each link is hard to measure but because it usually happens evenly over the whole chain, one can measure the lengthening over several links.

The chain tool pictured above is inexpensive and fairly foolproof and I’ll often refer to it as the tool that determines whether the service is going to be a little more costly or not! One end hooks into the chain and the other end will fit into the chain further along if the chain has “stretched”. It has two carefully measured sides, one that will drop into the chain if it’s 0.75% longer than when new and one that drops in at 1% total elongation. Those are important measurements.

Most chain manufacturers recommend that their chains are replaced when they have elongated by 0.75%. Because the chain wears slightly faster than the cassette, this is the point where you can usually just replace the chain (and not the cassette) if both were new to start with. As an aside, if you’re fairly meticulous about swapping chains regularly, you can usually get through two or three chains for every cassette.

Once the chain wear is approaching 1% “stretch”, it’s usually time to replace the cassette as well. Because the teeth on the cassette will have worn down to more or less match the chain wear, if a new chain is fitted to a worn cassette, it won’t mesh properly and may jump or skip, especially when changing gear. Conversely, if a new cassette is used with a worn chain it will also mesh and change gear badly and the cassette will wear much faster than usual. As chains are less expensive than cassettes of equal quality, it’s much more economical to replace them before you need to replace both.


The next logical question, of course, is “if my chain and cassette are worn but working well together, why do I need to replace them at all?”

There are two answers to this. One is, in turn, to reduce wear on your chainrings, the big cogs that the pedals directly drive. The teeth on these won’t usually wear as fast as the teeth on the cassette, because the pedalling forces are spread over more teeth on the chainring. A worn chain will still lead to unequal distribution of force on the teeth on the chainring and will wear the teeth down in the same way the cassette wears. But usually if the chain is kept below 1% “stretch,” most chainrings will outlast several chains and cassettes.

Back Camera

The second answer is simply that eventually the teeth on the cogs will wear out. I was asked to “have a look at” the bicycle pictured above because “the gears are slipping”. When people tell me this, it’s usually because the gears aren’t properly indexed and the chain is jumping between sprockets, but this chap’s chain had actually begun to slip straight over the cogs whenever he put any pressure on the pedals! There simply wasn’t enough material left on the cogs for the chain to grip on to, so it was jumping over the teeth. Unfortunately for this bike it needed a new chain, new cassette and a new set of chainrings, which worked out more expensive than the bike itself and he chose to scrap it.

The moral of his story? Replace your chain regularly, keep your bike running for longer…

The end of an era… and the start of a new one.

Last Friday we said goodbye to Joel, who’s been with me almost from the start of Rat Race Cycles. He’s moving onto pastures new (sorry, we’re already racking up the clichés and I’ve only written the title and first two sentences!). His other passion has always been for music and he’s moved up North to start a Masters course in Music Technology at the Birmingham Conservatoire. His first album is incredible, and being released on 5th October, and his next ones promise to be even greater still.

But as excited as we are for him, Joel leaves some pretty big shoes to fill. For the last five years he’s been my right-hand man and customers tell me all the time how brilliant he is, and how great he’s been with their bikes. I know I’m not the only one who’s going to miss him.

In his place, though, we’re really excited to introduce two new members of staff. They are Dax, who coincidentally has left a career as a professional musician to work in the bike trade, and Nelsy, who’s joined us from Look Mum No Hands (we’re very grateful they let her leave!). They’re both ace people and great mechanics. As they don’t yet have Joel’s expertise, I’ll be spending more time in the workshop over the next few months to help them hone their craft. They’re already well on their way.

Marlowe and Andis are still with us of course, and still keeping bikes and their riders on the road and working superbly.

Finally, our last bit of news is that we’re changing our opening hours. Earlier in the year we conducted a highly scientific Twitter poll (!), and – coupled with anecdotal customer feedback – we’ve decided to try opening 7am to 7pm on weekdays, to help those who have found it difficult to get to us during our previous hours.

As autumn approaches, we tend to see more punctures, more cyclocross bikes and more of the hardy commuters who brave the weather. Good news for you guys – we’ve recently restocked on our autumn bestsellers, so if you’re in need of new lights, reflective stuff or mudguards to fight the dark and wet come on down.

We look forward to sharing this next stage of our grand tour with you all.

Get on your bike and ride!

It’s not easy to start something new. Particularly something that doesn’t come naturally to you. It takes discipline. Courage. Determination. Commitment.

And, if you happen to co-own a bike shop, and the new thing you’re starting is cycling regularly, it takes a good dollop of humble pie, too. Because who ever heard of a bike shop owner that didn’t ride a bike?


A kick in the lady parts for equality in cycling

Some months ago, Pete did a talk on bike safety and maintenance at our local WI. Now, before you start picturing a load of silver haired ladies staring blankly at the nice young man showing them how to change a tyre, let me point out that the demographic of the Nunhead WI isn’t quite that traditional. Much of the Nunhead branch, from what I understand, is made up of 25-40 year old professionals/mothers/creatives, or any combination thereof. Women like me.

It was after this talk that Pete received the shop feedback of which I am most proud. I paraphrase, but a member told him that she loved Rat Race because she never felt patronised or embarrassed there. That she was treated no differently to any other customer, and was never sneered at or assumed to be stupid.

The beauty of hand built

One important thing we do at Rat Race Cycles is hand-build wheels. In fact, we’re about to launch a specialised wheel building service – Owen Wheels – at this year’s BESPOKED – The UK Handmade Bicycle Show.

There’s no dark art to wheel building, but to consistently build strong, durable wheels requires knowledge, skill and practice. There are many reasons to choose hand-built wheels over branded wheels like Mavic, Shimano or Fulcrum. I’ll try and outline the key ones:

Changing gear at Rat Race Cycles

If you’ve been in the Nunhead area over the Christmas break, you’ll have noticed that we’ve been making a few changes to the shop. Sure, we’ve reorganised things a bit, added in some more lights and had a tidy up and given the walls a lick of paint, but none of those is the big change. The major change is that we have stopped selling bikes.

That’s right – we are now a bike shop that doesn’t sell bikes.

Sounds crazy, right? Well, yes and no.

Small Business Saturday

Think of a massive online retailer and chances are you think of a logo; a letter, a colour scheme, a design.

Think of a small shop on your high street and you probably think of a face. The owner. The person who took a deep breath, stepped out and turned their passion – their dream – into their life’s work.

Every year, more stories surface about huge multinationals exploiting yet another loophole to skip out on tax in the UK. And yet, every year, (often despite our best intentions) we throw our hard earned money at them as Christmas descends, resorting to the easiest, the cheapest, the most obvious, over-advertised option. And every year we wonder why shops are closing on the high street, why people are going out of business, why our towns and villages are becoming soulless miniature carbon copies of huge, out-of-town shopping malls.

Well, here’s a chance to shop a bit differently. This Saturday 5 December is Small Business Saturday, and a chance to get down to your local high street and support those people trying to make their dreams pay their bills.

Le Cure de France

So, I know we all get a bit of charity fatigue now and again, but if you haven’t reached an icy saturation point in the bucket of people doing good things, you really should check these guys out.

This is not just people doing something good, this is people doing something extraordinary, for a fantastic cause: 29 guys, 4 epic, iconic* climbs, 1 week, and the Royal Marsden Hospital.

We are thoroughly impressed, and if you can afford a couple of quid for this worthy cause, you might make their climbs just a tiny bit easier…

…but probably not.



* in our opinion, iconic is an overused word.  However, in this case it’s utterly deserved.  I mean, come on: Galibier, Mt Ventoux, Col d’Izoard, Alpe d’Huez.  Fair?  Yes.