Monthly Archives: January 2014

Riding fixed gear in London

So I’ve been riding fixed gear in London for two solid weeks. What can I say; it has definitely been a very interesting experience.

I’ve been “kicked” by the pedals a fair few times (about 6 or 7). I soon learned my lesson – just keep spinning those pedals!

The first week of the commute had its horrible moments. Not only was I a bit unsure of how to handle the fixed gear bike, but the gearing that was provided on the built pompino was altogether too high, Perhaps not for some people out there, but I’m willing to bet it was too high for most people.I will discuss the gearing again further down, but for now let me just say that riding fixed gear is very interesting indeed.

In short – riding the bicycle feels like a lot of fun on fixed gear, It brought back those feelings I had when I learned to ride a bike for the first time as a child. There is a cetain purity to fixie riding. At first I thought to myself – I can’t coast over rough road, I can’t coast as I turn, I can’t change gear, etc. However, as nice as coasting and changing gear is, after a little while riding fixed, when you start to forget about coasting and changing gear, the part of the brain that used to think about those things all of a sudden is freed up to think about other things, or not at all. It’s nice not to faff around trying to decide anything to do with your pedalling, you just have to keep pedalling and that’s all there is to it! The rides have become somewhat more serene. Now, I can imagine that this sounds like a load of tosh – really the only thing to do is to try riding fixed for yourself. Doing it for 5 minutes doesn’t count as trying, it takes around 2 weeks or so to acclimatize.

Back to the gearing; the chainring originally was 48 teeth whilst the sprocket that was provided was 16 tooth. Coupled with the 170mm cranks and 700C wheels, this gave a gearing of 81 gear inches (or 6.1 gain ratio). This gearing is commonly used on velodromes as a warm up gear, so no good for the road at all really.

Sure enough, I ordered a 20 tooth sprocket and a KMC Inox track chain from velosolo. This arrived and I mounted it, and things have improved greatly! I’ve been riding in this new gear (65 gear inches, or 4.8 gain ratio) and my knees haven’t felt anywhere near as strained as before, my average speed went up and overall I feel much more confident on the bike. If anything, the gear is ever so slightly low, but all that means is that I can adjust to an increased cadence for a while – and there’s always the option of going for a 19 tooth sprocket in a few weeks.

This is what the mounted sprocket looks like:

Cromoly track sprocket Andel

20 tooth Andel Cromoly steel track sprocket.

And this is the drivetrain in all its glory:

Stronlight 48T Andel 20T drivetrain

KMC Inox stainless steel chain. 48T Stronlight chainring. 20T Andel cromo sprocket

As you can see, the sprocket is actually larger than the flange of the hub, which is hilarious and (to me) aesthetically pleasing at the same time. The KMC Inox chain feels really very sturdy and I am very happy I picked it. As a graduate engineer – stainless steel makes me hot under the collar so it was a natural choice really!

All in all, my drivetrain feels very solid, both due to being fixed, having easy gearing as well as being adjusted and tightened correctly. How to adjust the chain tension and rear wheel position took a surprisingly short time to learn and feels very intuitive.

On tyres and their diameters

Tyre width is an important aspect to think about, and opinions vary on the subject, with two rather polarized camps. You get the weight weenies that are running those skinny pencil-thin tyres (usually 23mm – and this diameter can even get lower!). They run them whilst claiming that thin tyres roll faster due to less friction on the road, or some similar excuse.

This has been proven to be a myth, and in fact wider tyres roll faster because of a reduced tyre casing deformation and hence a reduced loss of energy. Detailed info can be found here: http://www.bikeradar.com/gear/article/bicycle-tires-puncturing-the-myths-29245/ The same is true for larger tyre/wheel combos, bigger tyres/wheels roll faster too. 29″ tyres roll faster than 26″ tyres.

I am definitely in the camp of bikers who like to run fat tyres on our bikes. Fat tyres provide comfort, they have TONS more grip on the road. Ask anyone, ask your nan, even she knows! I recently acquired a pompino, which has a more aggressive riding position than my other bikes, and running the fattest tyre that I can find helps with the amount of shock travelling through the handlebars and into my hands and wrists. Not to mention – running a fat tyre means that I don’t need to worry about my front tyre skidding out sideways from under me as I take some of those aggressive turns. And I DID have a couple of wobbly moments where this happened using the original tyre that came with the pompino.

On the weekend I changed the original tyre (Vittoria Randonneur Cross Pro 32mm) for a fatter tyre I had lying around (Innova 40-622). The main reason I changed the original tyre is that despite it being advertised as a 32mm diameter tyre, on my rims (which has 13.6mm internal width) the tyre actually measured 28mm in width:

Vittoria Randonneur Cross Pro 32mm

Vittoria Randonneur Cross Pro 32mm only measures 28mm on 13.6 mm rims

The Innova tyre, which is marked with ETRTO (which is meant to be the most accurate system) of 40-622 actually only measure 34mm on my rims:

Innova 40-622 tyre

Innova 40-622 measures 34mm on 13.6mm rims

Now, I can tell you that riding the Innova tyre feels really very nice, despite the fact that the tyre came free on a Halfords bike. It is much more sure-footed, as well as absorbing shock very well, providing me with a sort of front suspension.

Another thing to keep in mind is that in a similar way to clothes and shoes, not all 35mm tyres will actually measure 35mm. Some will be much thinner in order that the manufacturer can boast a lighter 35mm tyre, when in reality they’re flogging a 32mm tyre as a 35mm. All about this here (http://sheldonbrown.com/tire-sizing.html) The best indication of tyre size is usually given by the ETRTO sizing, which looks like this: 622×40 which denotes a 622mm bead circumference (i.e. 700C wheels) and a 40mm tyre diameter. For mountain bikes, the ETRTO sizing is 559×40 (for example). The 559mm part will stay constant, as that is the bead diameter for a 26 inch mountain bike tyre.

So, if you want to ride more comfortably, on tyres that give you better grip, more suspension and generally a safer/better ride, then I would suggest that you consider some wider tyres when the time comes to get some new ones. Or, in fact when you’re looking for some nice winter tyres, they’re really great on wet roads and those rotting leaves.

Some things to look out for:

  • The real tyre diameter will depend on the size of your rim (as shown in the pictures above)
  • The real tyre diameter will also depend on the brand which is making the tyres. I find Schwalbe to be quite honest in their sizing.
  • Make sure you have the clearance in your frame for a wider tyre. Some road frames are limited to 23-25mm.
  • Check the internal width of your rim and don’t go over the maximum tyre width recommended for that rim.

Go on, try some wide tyres!

The new bike is here! On-One Pompino

So it appears that I have been a good boy this year and Satan got me a new bike for Christmas/New Year!

It’s a fixed gear bike, which has always been something that I’ve been intrigued by. Over time I have heard various opinions, the full spectrum from “fixies are lethal” to “fixies are the best thing since sliced bread, and also the safest possible type of bike”. I’m not sure why people believe that sliced bread is that a great a thing, but that’s a tangent, for another day. In the meantime I have taken the advice of an experienced cyclist I know as well as Sheldon and decided that I would get a bike that is fixed, but with the option of a flip-flop hub should this be necessary.

Now, the bike in question is a On-One Pompino fixed that I got from Planet X. I originally hit the “buy it now” button on a custom clearance Pompino from the Planet X eBay store. It was a bargain price, and this was the main reason I went for it despite some drawbacks, namely the size was a medium, which is a tad small for me, and the rims were aero rims (we’re talking very deep, around 40mm at least) – which I really do not like. Through no fault of their own, Planet X sold the bike to someone else in the time between me comitting to buy the bike and paying for it (yes – I took my time). Credit to them for offering me a brand new Pompino in Large (which I prefer) – obviously for the same price. Happy New Year indeed!

The bike arrived by courier on Friday (Jan 3) and I spent a bit of time over the weekend “pimping it out”. I’m sure I’m using that phrase inappropriately, but I just don’t care 😛 Either way, the bike is now fitted with full length SKS Chromoplastic mudguards, a Topeak Super Tourist DX rack, an Ortlieb QL3 bag mounting kit, and Cateye mounting brackets so that I can use my Cateye lights.

Enough rambling, here are some pictures!

On-One Pompino Large White

First look at the On-One Pompino

The SKS mudguards were taken from a bike which originally had them but they were never used. The front mudguard was badly warped and so I had to cut the worst section off – and the upside is that (in my eyes at least) it’s aesthetically more pleasing than it was before:

Pompino front wheel

Pompino front wheel, Tektro canti brake and SKS mudguard

This Pompino build features the On-One midge handlebar which is reasonably unique in its shape. On paper it sounds much better than traditional handlebars, but only time will tell.

It’s fitted with brakes front and rear (as a matter of course) as well as my usual set up of full length mudguards and my favourite pannier rack:

Pompino rear wheel and topeak rack

Pompino rear wheel, mudguard and Topeak rack

That saddle is unlikely to stay on the bike for too long, we’ll see if I can find something suitable in the stable. Enough rambling, this has been the first look at the bike, the maiden voyage is tomorrow and I shall update the blog as soon as I’ve had a bit of time on the saddle. I’m off to bed :)