Bike fitting: valuable service or fit up?

Last weekend I went along to the fabulous ‘Bespoked Bristol‘, the UK hand built bicycle show. The beauty and quality of many of the bikes on show was amazing and UK custom bike building enterprises seem to be growing well alongside the general increase in cycling. Even the BBC website now features this piece on the trend so the show’s PR team is doing a good job.

On a couple of the stands, I encountered the issue of bike fitting. One renowned custom frame builder insisted that I really did need a detailed fitting session before they could possibly consider building a bike for me. Another stand offered a 2-hour fitting session for £120 (about $180 US).

This got me thinking, not least because within my modest collection I have bikes of varying geometries with nominal frame sizes of 21 inches to 24 inches, measured from the centre of the bottom bracket to centre of the top tube. With a little experimentation with stems, seat posts and saddles, and the relative positions of each, I have yet to come across a bike that I can’t adapt to be comfortable, even for long rides.

When I started to get sore knees on one trip, I did consult the oracle – YouTube – and quickly resolved the issue by shifting the saddle a little. A search this evening on YouTube turned up this video from Performance Cycling, which has had nearly 1 million views:

It’s very comprehensive but just six minutes and ten seconds long. There are plenty of similar ones and a whole stack of online advice about bike fitting in the forums.

Of course, the right fit is a very individual thing and depends on a number of factors, not least the kind of bike you want to ride and the kind of cycling you’re going to do. Head down on the drops is not ideal if you’re a commuter that needs to attempt 180 degree vision at all times! But whatever shape and size we are, some basic judgements on the frame and a little experimentation should be sufficient to ensure that cycling is a pleasure rather than a pain.

So next time someone tries to sell me a £120, 2-hour bike fitting session, I think I should politely suggest they “take a ride” – don’t you?

More on the Brompton 8-speed conversion….room for improvement?

I mentioned in my last post about the Kinetics 8-speed conversion kit for the Brompton that the new crankset looks rather cheap and nasty. It is. I’ve discovered that it’s a Sturmey Archer FCS30 model with 33 teeth (why it’s not called the FCS33 is a mystery), which retails for about £16. So we now have a bike that’s cost the best part of £1000, with a somewhat poorly matched crank that’s ugly.

The Sturmey Archer FCS crank - cheap, ugly and no way to change the chainring
The Sturmey Archer FCS crank – cheap, ugly and no way to change the chainring

Worse still, I found that the chainring fouled intermittently on the rear triangle, preventing the bike folding properly. I started looking around for alternatives. The first thing to note is that the Brompton bottom bracket has a 119mm ISO square taper axle. By far the majority of today’s cranksets are JIS taper, so the choice is more limited. The differences are explained most clearly here by Sheldon Brown. According to Sheldon, “if you install a J.I.S. crank on an ISO spindle, it will wind up about 4.5 mm farther in than it would on a J.I.S spindle of the same length.” More about chainline in a moment.

It seems relatively uncommon to find a single-speed chainring with less than 39 teeth, and the most commonly available versions start at 42 teeth or bigger. I need to stay close to 33 teeth to achieve the gear range of the original, which seems ideal for the rather hilly countryside around here. The hub has a 20 tooth sprocket on the back, so according to the online gear calculator, it produces a range from 27.3 to 88.7 gear inches.

Chainline is the next consideration. According to the Sturmey Archer spec, the 8-speed hub with flat 20-tooth sprocket has a chainline of 39.7mm. I measured it and came up with about 38mm, so that checks out. At the FSC30 chainring, I found the chainline to be around 40mm – not perfect but not too bad either. If I’m going to cure the folding problem, the front chainline will need to be bigger at the front, about 41mm. Again, it won’t be perfect, but 3mm difference between front and back doesn’t seem to likely to be much of a problem.

There is no easy way to correct the chainline at the back. You can buy 25-tooth dished sprocket to fit the 8-speed hub. Reversing it would add about 1.5mm. However, the chain tensioner is so close to the sprocket that it’s not possible to use one with more than 20 teeth.

There's not room to fit a sprocket with more than 20 teeth, and you can only get that one in a flat version
There’s not room to fit a sprocket with more than 20 teeth, and you can only get that one in a flat version

The solution at the front may well be to fit a JIS taper compact double crankset and remove the outer chainring – changing the fixing bolts and using washers to adjust the exact position of the inner ring to get the desired 41mm chainline. This will give me a chainring of 34 teeth, rather than 33, so I’ll need one more link in the chain to take it to 101 links. Fitting a new chain at this point seems like a good idea anyway. The gearing will move up very slightly to a range of 28.1 to 91.4 gear inches.

If it's possible to get a reasonable chainline, the inner ring of this compact double would be a much more attractive and flexible  alternative to the Sturmey crank
If it’s possible to get a reasonable chainline, the inner ring of this compact double would be a much more attractive and flexible alternative to the Sturmey crank

It may even make sense to change the bottom bracket for a JIS taper version at some point – Shimano sells them in 118mm and 122.5mm axle widths, so it’s likely I can achieve a fit one way or the other. The FSA Vero compact crankset looks infinitely better than the Sturmey one, so it’s on order and I’ll know if it’s going to work later this week.

Incidentally, the 6-speed parts taken from my Brompton fetched over £100 on eBay, after deducting the costs and PayPal commission, so the final cost of the upgrade will be £200 plus whatever I end up spending on the crankset and/or bottom bracket.

Kinetics Brompton 8-speed conversion kit

I’ve not done many miles on my 6-speed Brompton, despite owning it for several years. It’s not that I don’t like it; I simply don’t do many of the sort of miles for which it’s designed – short commutes around the city. Nevertheless, I had two niggles with the bike from new – the cheap and grotty handlebar grips and the rather ugly and fiddly gear shifters. If you don’t know the Brompton, the 6-speed version has a Sachs 3 speed hub to which a pair of sprockets is attached. The left hand shifter selects the sprocket and the right hand one the  internal gear. To go up and down the gears one by one, you use the shifters alternately.

The 8-speed Brompton chainset and tensioner installed. Note the much smaller front chainring
The 8-speed Brompton chainset and tensioner installed. Note the much smaller front chainring

While on holiday over Christmas, I found out about the possibility of converting the Brompton to an 8-speed bike with just one twist grip shifter. A kit is offered by Edinburgh-based Kinetics and, in a slightly cheaper form, by Tiller Cylces. Both firms offer other hub options, but I decided on the Sturmey Archer X-RF8(W) 8-speed kit. I ordered it from Kinetics over the Christmas period, paid my £300 plus postage, and waited for the 2-week delivery stated on the web site. By the middle of the 3rd week of January I’d had no acknowledgement of my order and nothing had arrived. I called Ben, the owner of Kinetics, and he explained that he was just building up a batch of wheels with the hubs and my kit would be despatched later in the week. It wasn’t. I emailed and got a quick reply and apology, saying that it would be sent the following week. During the last week of January it arrived.

The Sturmey Archer 8-speed hub at the centre of the new wheel
The Sturmey Archer 8-speed hub at the centre of the new wheel

The web site stated that the conversion takes about 30 minutes. The Kinetic instructions were reasonably clear so I set about the conversion. I’m not quick, but not that slow either…you might do your 100th conversion in 30 minutes, but I challenge anyone to do their first one in that time. It took me several hours, but I was not too familiar with the peculiarities of the Brompton, having never worked on it before. You take off the existing wheel and tensioner, plus all cables and other parts associated with the drivetrain. Then you remove the chainset and replace it with the new, smaller one.

I followed the Kinetics directions to the letter but the tensioner jockey wheels were about 5mm out of line with the sprocket on the hub, so the chain wouldn’t stay on. I emailed Ben at 10pm on a Saturday evening and got a reply within minutes. One of the changes during the conversion is to replace the tabbed washers on the wheel axles with thicker ones from the kit. Ben suggested I revert to one of the original thinner ones in order to move the tensioner closer to the frame. It was bad advice because it caused the tensioner to press against the edge of the hub, preventing the gears from changing. I went back to the original washers and packed out the jockey wheel fixing bolts with some washers to move them the required 5mm. All was well and the gears change smoothly.

The new gripshift if much neater than the original Brompton shifters - just need to find some new grips to go with it now.
The new gripshift if much neater than the original Brompton shifters – just need to find some new grips to go with it now.

SUMMARY: This is a nice conversion and, if you don’t mind the extra weight (perhaps a kg or so?) it makes for a more rideable bike with a slightly wider range of gears. The bike looks neater, has cleaner lines and is not quite so quirky, although quirkiness is something that few Brompton riders will worry about. I was disappointed in the service, the hassle of having to modify parts to get the conversion to work, and the rather cheap and nasty looking drive side crank and chainring supplied with the kit. In my view the latter is nowhere near as nice as the one shown on the converted bike on the Kinetics web site. At £300 plus postage, enough to buy a reasonable bike, the kit is expensive, but I’m hoping to raise £100 by selling the original parts, so that eases the pain a little.

The joy of hubs…my next project

Last year I bought a restored A.S. Gillott frame from a dealer in South London. It has one or two very minor marks from where it was packed for delivery, but it’s pretty near perfect. A 1948 model, it may well have been built by Ron Cooper, who worked for Gillott, and I know that Ron was involved in its restoration, replacing one of the drop-outs.

A.S. Gillott frame
The beautifully restored 1948 A.S. Gillott frame

What I didn’t realise until the frame arrived was that the dropouts were designed for an Oscar Egg “Osgear” set up. It’s not possible to fit a conventional derailleur freewheel or cassette. I decided to make it a single-speed bike and found a nice pair of Charge track wheels, the rear one of which had a flip-flop hub, so I was able to build up the bike to be ridden either as a fixie or with a single-speed freewheel.

Oscar Egg dropouts
Oscar Egg dropouts are only suitable for Osgear, single-speed or hub gear set up

I decided that this was going to be my prettiest bike, so matched the brake and gear cables to the red of the decals and even bought a red and black saddle to complete the work of art. Looks lovely….rides like a shed on wheels!

I think the problem is partly the razor sharp saddle (back to a Brooks B17 any day now) but also the geometry of the bike. I haven’t measured it but the top tube seems particularly long. I feel like I’m stretching over the bike, even to ride on the tops of the Cinelli drop bars. And my feet feel as though they’re too far forward, wherever I position the saddle. It’s time to try a new set up – one that will make the bike as good to ride as it is to look at.

A.S.Gillott bike
The Gillott frame with as a single-speed set up with flip flop hub. Very pretty, note the glossy bar tape, but strange to ride!

Having appreciated the joys of Sturmey Archer hub gears last year, when I road my Thanet Silverlight with a 1949 4-speed hub from Barcelona to Bristol without a hitch, and inspired by the sight of the restored Bob Jackson bike mentioned a couple of days ago, I’ve decided to rebuild the Gillott frame.  Even though you have to stop pedalling for a second to change ratios with internal hub gears, each change is precise, silent and perfect – not like the rather crude process of dragging a chain across a bunch of sprockets to end up with yet another imperfect chainline. So the frame will be fitted with a Sturmey Archer S-RF5(W) 5-speed hub in the rear wheel (with a downtube shifter as a nod towards vintage styling), a B17 saddle and either a Mary bar or Mungo bar from On-One.  The bars are on offer at the moment and are so cheap I decided to buy both and try them out. The Sturmey Archer was chosen because Shimano hubs and others aren’t suitable for the relatively narrow dropout spacing of vintage bikes (125mm OLD). This combination should give me a lot more flexibility in setting up the bike for greater comfort, and make it practical for commuting. I’ve bought a couple of 27 x 1 1/4 wheels, which is the size the frame was originally designed to accomodate, and I’ll rebuild the back one with the new hub – that was a cheaper option that buying a pair of rims, a front hub and all new spokes.

The bike in 5-speed form will appear here soon….if all goes well.

Now you don’t need to wear lycra to be a real cyclist

Lycra has its upsides – it dries fast after a shower, it reduces your wind resistance and it shows off your figure. But having seen a few thousand cyclists at various events this year, its clear to me that not all figures are ideally suited to lycra. In fact, I’m on a bit of a mission to get everyone over 40 out of lycra, so to speak. The problem for the mature road cyclist is that there isn’t that much choice, at least in terms of dedicated cycling trousers, if you don’t want to wear lycra or the ridiculous baggies worn (inexplicably) by mountain bikers. But I have found one supplier of cycling clothes, some of which I’ve come to really like.

Let’s put this into perspective. First, my idea of a designer brand has always been M&S. In fact, I’d struggle to name more than a couple of designer clothes brands, assuming that there are more than two. Second, I have no commercial connection with the company and it’s apparent that its clothes are designed for a younger generation, but some Rapha stuff is terrific. My favourites are the 3/4 trousers, reminiscent of plus-fours but tailored for cycling with a lower front and higher back, and Rapha denim jeans, which seem to be a perfect fit for me. Also, I recently bought one of the company’s inappropriately named ‘hardshell’ winter jackets – great fit, warm and waterproof – and nothing ‘hard’ about it at all.

Me modelling a lycra alternative - Rapha tailored plus fours and waterproof jacket. A new career beckons....
Me modelling a lycra alternative – Rapha tailored plus fours and waterproof jacket. A new career beckons….

Rapha gear is not all good. I tried the padded undershorts and they gave me serious thigh chaffing due to the poor placement of the pad stitching, so I returned them. But when riding a Brooks B17 saddle, which I do most of the time, I find I don’t need undershorts if I wear decent cycling trousers. (I’ve never understood why a saddle, or a Hercules aircraft, would be called a B17?) The other product that I’ve found to be completely useless is the Rapha’s fingerless leather gloves. In the winter it’s too cold to wear them and when you get sweaty hands in the summer, they just stick to you in a very uncomfortable way. And beware, the sizing is a bit on the Italian side – I’m about 77kg and 5 ft 11″ but need a large size. No wonder all their SALE items are small.

Like a lot of people involved in marketing, I am of course totally immune to the wiles of advertising and brand promotion in general. But for the most part Rapha has won me over, despite one cycling friend of mine dismissing it as “over-priced crap”.

Bifocal cycling glasses – why don’t bike shops sell them?

With the dramatic rise in the number of older cyclists (the definition of ‘old’ being 15 years older than you are today), there must now be millions of riders around the world who need reading glasses. For cycling, these would ideally be wrap-around bifocals so that you can read both road signs and your GPS screen or map.

But what do you find when you go to your local bike shop, or any of the major online cycling kit dealers? Absolutely nothing.

I found a solution on eBay by searching for “safety bifocals”. This turns up a lot of options, some of which are indistinguishable from sports glasses and do the job a treat. I wear clear ones all year round for protection against flying debris and insects but you can also find dark tinted versions and glasses with yellow lenses. Prices start from about £5 per pair, a fraction of the price of designer sunglasses that appear to be almost identical, bar a logo.

Cycling bifocals
These bifocal safety glasses from eBay are ideal for cycling, eliminating the need to carry a separate pair of reading glasses and providing good eye protection. You can find dark or yellow tinted versions too.

Searching on “bifocal sports glasses” brings up even more options, although my impression is that adding in the word “sports” seems to make exactly the same products about 50% dearer, and one that boasts “Italy Design” is around twice the price of most of the others, but looks no different.

Nearly all of these glasses come from the US, so it’s worth buying a few at the same time so that postage doesn’t add too much to the cost of each pair. In my experience, every time you show them to another cyclist who’s long-sighted they’ll say, “you don’t happen to have a spare pair, do you?”