Bit Quiet, Innit ?

Apologies for a lack of updates lately, I’ll explain at a later date why.

Meanwhile, if you’re looking for a good read on Dahon folding bicycles, here’s a rather good blog from a Dahon owner in the UK :

Read and enjoy !!

Posted in Press articles | 3 Comments

Losing my bearings

Thursday evening Curve and its owner were caught out in a torrential downpour on the way back to the station from the office. Incidentally, the journey from the station to the office and back now is a tad longer than before due to the fact that the local municipality is in the process of repairing the ageing footbridge that spans the busy N10 road. They haven’t bothered to put a temporary bridge in (the work is supposed to last three weeks) so what was once a 350 metres walk is now turned into a 1300m walk. For the cyclist the situation is worse – it involves a section along a very busy main road which narrows over the bridge over the N10 – not enough room for a motorised vehicle to safely overtake a cyclist if anything is coming in the opposite direction. So, the footbridge is realy useful.
After the drenching the bike was dried down as per usual. Friday the Curve wasn’t requried for the commute (worked from home) – Saturday it rained, so the bike wasn’t used. In the evening the bike was given a once over and the rear wheel turned badly and sounded a bit rough. Obviously an ingress of water. Time to service the hub again.
Compared with the old Sturmey hubs, which took everything that was thrown at them, the Sram T3 is a bit fragile and the water seals aren’t that good. As a youngster I owned a Raleigh Wayfarer – built like a tank and ideal for the hard life it had to endure. The Raleigh had a Sturmey three-speed hub and apart from dropping a bit of oil through the oil valve (now long gone) the hub required zero servicing. This is the second time that the Sram T3 has been dismantled, which seems a bit excessive for just five thousand kilometres. So the hub was stripped and regreased and re-assembled.

Just some comments on hub servicing – other than it being a messy job, it is a medium to hard task. Sram do provide exploded diagrams of the hub assembly but I found their text explanations somewhat confusing. Nevertheless I managed. The drive side cone is fixed and should be screwed down on the axle as far as it will go and will then be locked with a locknut. On the non-drive side there are a pair of locknuts which should be tight but not too tight otherwise the wheel won’t rotate.
So the bike was used for the commute to work on Monday but by the end of the day the bike didn’t sound healthy at all. After being nursed back home, it was time again to drop the wheel out and examine the hubs. It was then that I realised my mistake. The hub bearings are actually held in a round cage affair (see the diagram below – taken from the Sram technical database) and what I had done was to put these the wrong way round in the hub shell. Normally the balls protrude one side and on the other the cage is flat. The balls should go into the shell first, the flat will be on the outside of the hub shell. I had put the flat in first so that ball bearings were on the outside. No wonder the hub was rough. Still, no visible damage done and now the hub runs fine.

Exploded diagram of Sram T3 hub, taken from the Sram Technical documents database. Arrows indicate the bearings

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Well that didn’t last long, did it ?

On the Sunday morning bread run, and noticed a horible intermittent cracking noise from the transmission… further roadside investigation revealed imminent failure of the right-hand side pedal bearings. Got home ok, took the pedal off and by hand the pedal only turns 180° on its axis. Put the original Dahon-supplied right hand pedal back on for the time being. Could the MKS make their return ?

Pretty dreadful quality of bearings… the Suntour ones have lasted two months and around five hundred kilometres.

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GTA : Great Train Adventures (?)

During my daily commute I have to change trains twice, once at Saint-Lazare and a second time at a sub-surface station in the suburbs. The change at Saint-Lazare is relatively easy, although it involves lugging the bike about 50 metres along one platform, down a flight of stairs into the underpass linking the platforms, then about 50 metres in the underpass before climbing another flight of stairs to my seond train of the day. The bike is relatively light and easy to manoeuvre, although the stairs are narrow and awkward if I meet someone coming in the opposite direction.

The second change, however is a different kettle of poisson. Theoretically it should be easy; the train arrives at one side of the island platform, the next train is waiting on the opposite face. In reality, the platform is narrow and very crowded. It is even worse when someone forget basic manners and tries to board the train before the passengers have alighted. Still, if a tyre comes into contact with trouser leg then it can’t be helped.

The platform is blighted by all manner of objects; billboards, rows of metal seats, vending machines, bus-shelter affairs to name but a few, and of course waiting passengers. Trying to navigate a  folded bike through all this lot can pose something of a logistics problem.

Early doors and a lot of passengers are still half asleep which doesn’t help. The worst has to be the passenger whom suddenly and for no reason whatsoever appears to awaken from a state of torpor and decides to move into my path just as I arrive. This makes me think of a well-known video game, hence the title of this posting. An early version of this game had passers-by in the street sort of wander around aimlessly until you either shot them or ran over them in a stolen vehicle. Folk at this train station appear to have similar movement patterns or so it appears to me. But then again, maybe not.

Posted in Commuting | 1 Comment

Back to Square One

After fitting the new pedals, I needed to give them a proper testing. Wednesday evening I had a meeting at head office, and afterwards, seeing as how it was a lovely evening, rather than taking three trains home I decided to cycle back, 25km all in all.

Nothing major to report on the ride, part of which involved a few kilometres along the Seine, on a traffic-free road. But just before attacking the last major climb of the day, about three kilometres from home, on a road leading up from the river, I decided to have a rest. On stopping I had bad cramp in both feet. I put this down to the crenellations on the pedals. So, for work at least, I decided to put the Suntour pedals back on, and keeping the MKS for lengthier rides, when not at work and when I would be shod with shoes with thicker soles.

The problem is that for work I have shoes with relatively thin soles and these really aren’t comfortable with the MKS pedals. So until I change shoes then the Suntours are back.

Posted in Commuting, Technical | 1 Comment

More underfoot

Just to add, following on from yesterdays’ article about pedals, when the Curve was undergoing its pedal woes a few weeks back, to keep it on the road I “borrowed” a pair of pedals from my other folding bike. These were the old VP VP-112 model single-sided folding pedals, probably unobtainable now as new (try one of the on-line auction sites).

As mentioned these are single-sided but in practical use the pedals generally position themselves right-side-up for easy recovery. Folded, they are actually smaller than the MKS ones (50mm instead of 55mm).

Time has taken its toll on the left-had side one, and it has lost the springiness that used to keep the pedal in the unfolded position. There is a little device under the pedal that you can turn and it locks the pedal unfolded, but it’s a bit of a nuisance having to do this all the time. Grip is nothing special and I did once take the skin off my ankle on the way to Belgium – painful.

VP-112 folded…

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Changes Underfoot…

After the problems experienced with the original Suntour folding pedals (see I decided, after a bit of research on the web, to try the MKS FD-7 folding pedals. These were obtained from a shop on Pentonville Road in London, just a couple of (windy) minutes walk from Kings’ Cross station. Actually, I had e-mailed the shop and they had kindly put them to one side for me ready for collection.

Pedals in their packaging

The pedals aren’t the lightest available, it had to be said, but they look well-made and the finish details are good. The bearings appear to be free, rotation is good without any of the rough bits felt as per the Suntour ones. The pedals come with an Allen key to fit them; there isn’t enough space between the pedal and the crank to fit a standard spanner, so you insert the Allen key in the end of the pedal axle to screw them into place. Don’t forget that the left had side one has a left-hand thread, so you turn the other way in order to tighten them. Don’t overtighten the pedal, either. In all it took me a matter of minutes to change them. Old ones back into the spares box, of course.


…and after

In an ideal world, I would have preferred clipless pedals; MKS do a rather nice pedal which unclips from the bike, and takes a special cleat very similar to but not quite like Shimanos’ SPD. I like being attached to the bike, but for a folding commuter there are several drawbacks – either I have to wear the same cycling shoes all day to the office, complete with cleat or carry a spare pair of shoes to get changed into. Secondly, as the bike gets folded and unfolded several times in one journey, not really practical to constantly fit and remove the pedal. Finally, the problem of obtaining replacement cleats when they wear out. Probably ok for some but not for my circumstances.

The pedals have “teeth” for the shoe to grip; one of my complaints about the Suntour pedals is that when in rains and the pedals are wet, they are notoriously slippy and I have had the foot slip off one more than one occasion, with painful consequences. I had a concern about being able to feel the “teeth” through thin work shoe soles, but I will put this to the test, hopefully this week.

The folding action is rather elegant; simply push the end of the axle and the pedal folds neatly with no straining; I will test this over time once the pedals become a bit dirty.

Folded, the pedals protrude  55mm as opposed to the Suntours’ 60mm, so 5mm gained there.

Hopefully this week I can carry out the first road tests. Will post here, of course.

The pedal as folded. Neat neat neat.

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