Friday, 30 May 2014
Tour of Cambridge.
On Monday 7th July, the world's biggest bike race is coming to Cambridge. Whilst most people may think this is just a bike race, my experience of it over many years of going to see it in France, is somewhat different. It's a pageant, a festival, a celebration of all things good about being outdoors in glorious summer. Locals do their utmost to show off their neighbourhood, to let the world see why coming to their part of the world is more than desirable, it's essential for wellbeing.
With that in mind, I set out to record the route through town and celebrate, with a little British panache, the places that it passes. I've created a guide to the route with some musical accompaniment (of fanciful quality) and listed places of interest with links for further interest.
I'd recommend watching the video in full screen with the sound turned up. This has lots of twists and turns that's worth staying around for!
Places of Interest.
Cambridge has many places of interest. I attempt to give you a brief guide to the more famous ones as they appear on the clip. If you need more, Wikipedia has all these places listed and tourist sites, such as Visit Cambridge, contain much more information.
There are many further curious corners, along with hotels, restaurants, and a large selection of independent shops, throughout the location of this film. This is all easily accessible along verdant paths and quiet streets by bike, the quickest way to get around!
0:42 to the right. Parkers Piece. 25-acre common, now regarded as the birthplace of the rules of Association Football.
0:51 visible ahead to the left. Our Lady Roman Catholic Church. An imposing example of the 19th Century Gothic Revival, it was built to the designs of Dunn & Hansom of Newcastle between 1885 and 1890.
1:47 on the left. Entrance to Downing College. Downing College was founded in 1800 and is often described as the oldest of the new colleges and the newest of the old.
2:03 on the left. St Andrew’s Street Baptist Church. The Bunyan Window is a notable feature of the building.
2:10 on the right. Emmanuel College. The college was founded in 1584 by Sir Walter Mildmay, Chancellor of the Exchequer to Elizabeth I.
2:33 on the left. St Andrew the Great Church. Informal evangelical church with elegant iron interior pillars and a typical Victorian exterior.
2:33 on the right. Christ's College. The college was founded by Lady Margaret Beaufort in 1505 and was the twelfth of the Cambridge colleges to be founded in its current form.
2:45 on the left. Holy Trinity Church. Started in 1189 and built on up to and during the English Reformation (1550–1750).
2:56 on the right. Sidney Sussex College. The college was founded in 1596 under the terms of the will of Frances Sidney, Countess of Sussex (1531–1589).
3:04, on the left. Wolfson Building, Trinity College (see Trinity below).
3:21, on the right. The Holy Sepulchre (Round Church). The church was built around 1130, its shape being inspired by the rotunda in the church of the Holy Sepulchre, Jerusalem.
3:35, on the right. St John's College. The college was founded by Lady Margaret Beaufort in 1511.
3:53, on the right. Trinity College. The college was founded by Henry VIII in 1546, from the merger of two existing colleges: Michaelhouse and King's Hall.
4:17, on the right. Trinity Lane, public access to The Backs. The Backs is a picturesque area to the east of Queen's Road where several colleges of the University of Cambridge back on to the River Cam.
4:18, on the right. Gonville and Caius College (pronounced "Keys"). It was refounded in 1557 by Royal Charter as Gonville and Caius College by the physician John Caius.
4:19, on the left. Saint Michael's Church.A valuable social centre.
4:33, on the right. Senate House. The Senate House of the University of Cambridge is now used mainly for degree ceremonies and was built in 1722–1730 by architect James Gibbs in a neo-classical style using Portland stone.
4:35, on the left. Great St Marys. The present building was constructed between 1478 and 1519, with the tower finished later, in 1608. The cost of construction was covered largely by Richard III and Henry VII.
4:35, ahead on the right. The iconic Kings College Chapel. The building of the college's chapel, begun in 1446, was finally finished in 1544 during the reign of Henry VIII. King's College Chapel is regarded as one of the greatest examples of late Gothic English architecture. It has the world's largest fan-vault, and the chapel's stained-glass windows and wooden chancel screen are considered some of the finest from their era. The building is seen as emblematic of Cambridge.
4:54, on the right. Kings College. King's was founded in 1441 by Henry VI, soon after he had founded its sister college in Eton. The screen and gatehouse of Front Court was completed in 1828 under plans drawn up by William Wilkins.
5:14, on the left. Corpus Chronophage Clock. Translated as "time eater", this clock was officially unveiled to the public on 19 September 2008 by Cambridge physicist Stephen Hawking.
5:26, on the right. St Catherines College. The three-sided court was built during the period 1675 to 1757 and is one of only four at Oxbridge colleges.
5:31, on the left. Corpus Christi College. Founded in 1352 making it the sixth-oldest college in Cambridge. The only college established by Cambridge townspeople.
5:38, on the left. St Botolph Parish Church. The church was by the south gate of medieval Cambridge. The existing church was built in 1350.
5:42, on the right. The Pitt Building. Neo-Gothic building designed by Edward Blore, & completed in 1832. Named after William Pitt the 18th Century Prime Minister.
5:49, on the right. Mill Lane to Mill Pond and Coe Fen. A large part of the green swathe through Cambridge following the river Cam, often with cattle grazing. Coe Fen forms a natural area that was once important for the commerce of Cambridge.
5:51, on the left. Pembroke College. On Christmas Eve 1347, Edward III granted Marie de St Pol, widow of the Earl of Pembroke, the licence for the foundation of a new educational establishment in the young university at Cambridge.
5:54, on the right. Emmanuel United Reformed Church. The current church was built, opening as Emmanuel Congregational Chapel in 1790.
5:58, on the right. Little Saint Mary's. The current church was built in 1352, having the dual purpose of College Chapel to Peterhouse and Parish Church.
6:03, on the right. Peterhouse College. It is the oldest college of the University, having been founded in 1284 by Hugo de Balsham, Bishop of Ely and granted its charter by King Edward I.
6:14, on the right. The Fitzwilliam Museum. The museum was founded in 1816 with the bequest of the library and art collection of the 7th Viscount FitzWilliam. The "Founder's Building" itself was designed by George Basevi, completed by C. R. Cockerell and opened in 1848; the entrance hall is by Edward Middleton Barry and was completed in 1875.
6:33, on the left. Old Addenbrookes. Addenbrooke's Hospital was founded in 1766 on Trumpington Street, but in 1976 it relocated to larger premises further out of the city to the southeast at the end of Hills Road, hence the name of this site now.
7:09, on the left. Hobson's Conduit Monument. Hobson's Conduit is a watercourse that was built from 1610 to 1614 by Thomas Hobson to bring fresh water into the city from springs at Nine Wells.
7:59, on the left. Botanic Gardens. The garden was created for the University of Cambridge in 1831 by Professor John Stevens Henslow (Charles Darwin's mentor) and was opened to the public in 1846.
8:11, on the right. Coe Fen. A large part of the green swathe through Cambridge following the river Cam, often with cattle grazing. Coe Fen forms a natural area that was once important for the commerce of Cambridge.
10:53, on the left. Wingate Way. Not currently historical, but will be when the bike race really starts at this point, having been neutralized through the streets of the centre.
11:21, on the left. Trumpingon Village Hall. Trumpington is a village on the outskirts of the city, with a long tradition of agricultural learning centred at Anstey Hall is a former country house built c.1700 within its own parkland.
12:22, underneath. The Guided Busway. It is the longest guided busway in the world, and was opened on 7 August 2011.
12:35, on the left. Addenbrookes Road to Addenbrookes Hospital and Nine Wells. The springs at Nine Wells is the source of Hobson's Conduit, bringing fresh water into the city.
13:52, ending in Great Shelford. Great Shelford is a village located approximately four miles to the south of the city. President of the United States Barack Obama traced his ancestry to the village in 2009.
And to Come. The route out from Cambridge to the Cambridgeshire border....
A guide to the musical whimsy behind the video, with a fantasia of popular British classical pieces. Although it's interesting to note the wide variety of European influence included!
We start with the 1812 Overture (Tchaikovsky) with it's use of La Marseillaise (French national anthem) to mark the entrance of this great French race. But are we in France? No, this is Britain!
So, we quickly despatch Tchaikovsky and move to the central piece in The Planets Suite, Jupiter (Holst). Holst, of mixed Swedish, Latvian and German ancestry, composed it in 1915 whilst living in nearby Thaxted. The piece has long been associated with traditional English culture having been influenced by folk music. It takes us from Our Lady Roman Catholic Church at the north end of Hills Road (locally referred to as Hyde Park Corner), up Regent Street and St Andrews Street, with the final crescendo as we enter the centre of town.
In town, we switch to a short phrase of A Young Person's Guide to the Orchestra (Britten), written in 1945 to be an inspiration to youngsters by another East Anglian composer. Then, as we pass through the historical, collegiate centre of town we go through an inconic classic, The Pomp And Circumstance March No.1 in D Major (Elgar). This is called "The Graduation March" in some parts of the world, so it seems appropriate here, especially at the surge of "Land of Hope and Glory" as it passes the Senate House where Cambridge graduation takes place. And it's no co-incidence that this is where the most iconic sight of Cambridge, Kings College Chapel, also appears!
As we start to pass out of the centre, we move into Zadok the Priest (Handel). Handel was born in 1685 in Halle, Duchy of Magdeburg (now in Saxony-Anhalt, Germany), and moved to London in 1712. He composed Zadok the Priest for the coronation of George II of Great Britain in 1727, and has been sung at every subsequent British coronation. Again, the rousing vocal entrance happens as we see the stunning Fitzwilliam Museum in all it's glory.
As we start to move out of town, the riding will speed up in anticipation of the bike race to come. And the music seeks to follow this excitement with The Sailors Hornpipe from the Fantasia on British Sea-Songs (Wood). It was written in 1905 by Sir Henry Wood to mark the centenary of the Battle of Trafalgar. The hornpipe is a traditional Irish, Scottish and English dance.
Finally, we come back to France with Boléro (Ravel), knowing that we are on our way there! Ravel was born in the French part of the Basque country and was influenced by Basque-Spanish heritage, including local folk songs and dances. The piece, which premiered in 1928, is based on traditional Spanish dances. It seemed very appropriate.
Map of Streets.
View Cambridgeshire Tour de France Route in a larger map
0:10 Gonville Place, http://en.wikipedia.org/wiki/Gonville_Place
1:24 Regent Street, http://en.wikipedia.org/wiki/Regent_Street,_Cambridge
1:58 St Andrews Street, http://en.wikipedia.org/wiki/St_Andrew%27s_Street,_Cambridge
2:37 Sidney Street, http://en.wikipedia.org/wiki/Sidney_Street,_Cambridge
3:10 Bridge Street, http://en.wikipedia.org/wiki/Bridge_Street,_Cambridge
3:30 St Johns Street, http://en.wikipedia.org/wiki/St_John%27s_Street,_Cambridge
4:02 Trinity Street, http://en.wikipedia.org/wiki/Trinity_Street,_Cambridge
4:37 Kings Parade, http://en.wikipedia.org/wiki/King%27s_Parade
5:16 Trumpington Street, http://en.wikipedia.org/wiki/Trumpington_Street
7:08 Trumpington Road, http://en.wikipedia.org/wiki/Trumpington_Road
11:08 Trumpington High Street, http://en.wikipedia.org/wiki/Trumpington,_Cambridgeshire
12:02 Shelford Road, Trumpington, http://en.wikipedia.org/wiki/Trumpington,_Cambridgeshire
12:46 Cambridge Road, Shelford, http://en.wikipedia.org/wiki/Great_Shelford
Cambridgeshire County Council have given much encouragement and support to creating this film. Please do note, no taxpayers money has been spent! I've done this to celebrate the city of Cambridge and it's bike culture.
Simon, my trusty companion during the main ride. He had my back as I was trying to get the best camera angle on the road. A job not without the odd jumpy whistle!
Outspoken, for the loan of some of the camera equipment and for general support in getting this project underway.
Cab, for the loan of more of the camera equipment.
Explosion at 0:49 courtesy of Mark DiAngelo.
And to Come.
The route out from Cambridge to the Cambridgeshire border....
Monday, 17 February 2014
After the weather of the past few weeks, it's good to be able to get out in better conditions. Here are some pictures from around town on a lovely lazy Sunday afternoon with lots of people out enjoying the break in the storms.
Remember when riding amongst lots of others, including those on foot and with animals and children: patience, eye-contact, and give space.
New and Neville's Court, Trinity College from Garret Hostel Lane (click to enlarge)
Clare College from Garret Hostel Lane (click to enlarge)
Fellows Garden, Trinity Hall College from Garret Hostel Lane (click to enlarge)
Trinity Bridge, Trinity College from Garret Hostel Lane (click to enlarge)
Avenue of London plane trees on Jesus Green (click to enlarge)
Slightly flooded path under Victoria Avenue Bridge (click to enlarge)
There's a video clip of this, including riding in the water.
Riverside from the North West end of Riverside Bridge (click to enlarge)
Logan's Meadow from the middle of Riverside Bridge (click to enlarge)
Logan's Meadow and river willows from the middle of Riverside Bridge (click to enlarge)
River willows from Riverside Bridge (click to enlarge)
View on YouTube here
Saturday, 26 October 2013
This roundabout is a crucial part of a major motor route going south - north in the east of Cambridge city. It's also part of a cycle route going east - west and, more importantly, a hub of a local community with nearby schools.
Recently it's been noted that the current design causes considerable conflict between different transport modes with the inevitable damage to the more vunerable road users.
There have been 16 reported accidents involving cyclists on the Radegund Road roundabout in the last five years, three of which were serious.All the STATS19 accident data I can find (which may not cover the same years as the above note) shows it's people driving going into people cycling from behind, short of one report which was someone cycling falling off on their own. Not a single instance of anyone cycling without lights or weaving/jumping out into traffic. It also should be noted that there's a trail of further accidents up Radegund Road and a little on Perne Road (south) but nowhere else.
So, changes are proposed by Cambridgeshire County Council.
Here's the diagram of the changes. It consists of a two main changes.
- Reduce the size of the motor vehicle space, including widening the pavements and putting a central "over-run" strip (to allow larger vehicles to get round but discourage fast use of it)
- Allow the pavements around the roundabout to be shared-use
Whilst the speed reduction measures are useful, this is a proposal woefully short of delivering a decent cycle infrastructure that this junction demands. This has been written up by others so I won't go into all that here.
There are a few notes to make about the general ideas here. The slowing down of people driving here is good. I'd suggest it doesn't do enough of this. This is because a lot of people worry that vehicle journey times may be increased by slowing the peak speed through the roundabout. The ARCADY analysis has been done to suggest this will not happen. And to an extent, it's clear that speed through this area in general is not going to be reduced greatly by changing this one junction. It's simply a question of getting to the next queue of cars at the next junction a little later.
The ARCADY analysis of the junction is quite a tome and peppered with analytical terms and a lot of acromyns making it quite a hard read. A few notes.
- It has only been done with the proposed change in mind. Nothing has been done to look at any other proposal, like the one I make below, which would seem to follow the Dutch model more closely. So, this isn't looking for the best solution is just comparing the current situation with the new proposal. Who's to know if there's a better model out there?
- Analysis like this simply assumes the same activity by all transport modes before and after. Again, I'd like to suggest an "improvement" should be designed to improve the status quo. In fact, the idea is to make this more appealing for people doing active travel.
- Most of the analysis work here seems to completely and only focus on the capacity of people driving. Again, this means any gains from converting people to active travel is simply not included.
- It, quite rightly, notes that there is no cycling facilities along Radegund Road with just traffic calming at points. This is where a school exists and the arm with a greater number of further accidents (see hostility of this road below).
- It also highlights that the roundabout has no facilities for people walking.
- It incorrectly refers to the new plans as segregated cycle facilities. They are not, they are shared-use, which does increase conflict between people walking and riding.
- It does say that it does not expect all people cycling will use the shared-use paths, so makes no change to the data analysed for people cycling in the carriageway.
- And finally, the really SHOCKING bit. The analysis final figures say that the car capacity of the junction will actually improve. And how is this delivered? By changing the way in which people drive into the roundabout. In fact, this looks like it SPEEDS up people driving onto the roundabout and not the claimed "slowing down". To me, speeding up entry whilst slowing down traversal is likely to increase danger here.
The only postive note for people cycling is that it will allow people who find the roundabout itself unappealing and give them space to ride out of it. This sounds like it's a great idea for the local school kids. However, as anyone whose been near this junction when the schoolchildren are riding to or from school will say, the already use the pavements. Perhaps legitimising this behaviour is a good thing, it's just not a great deal for people cycling in general.
So, the entire analytical section of this junction proposal is to show that vehicle interaction is not impaired, and actually shows that it's improved. There's nothing in this to look at how this junction can be improved for people cycling. It may, it may not. There's just no analysis of it.
So, how about some analysis of the cycling infrastructure of the anecdotal nature? After all, that's all we've got.
For those people who don't want to cede way at 3 occasions (going straight on) or 5 occasions (turning right), they are left in a narrow lane. Well, it's just narrow enough for some people driving to feel they can pass someone riding leaving a metre or so of space. This is in a turning, twisting space. And effectively a cut back in at the exit of the roundabout. Hardly very safe. The design here looks to make things less safe for people riding in the carriageway.
Looking at how the junction works brings up several things. Here's a clip.
Or link to it here.
The clips bring up two items from a cycling point of view.
- Worn out cyclelanes. Currently people driving are cutting back into the cyclelane on the entrance and exit of the roundabout. This is highlighted by the damage caused in the cyclelane.
- Parking near to the junction on Radegund and Birdwood Roads.
Worn Out Cyclelanes
Not all the damage caused is a direct result of people driving over the cyclelanes. The obvious direct damage is the missing paint. This quickly gets removed by car tyres. The broken up surface is more indirect. Vehicles heavier than a bike create a lot more wear on the road surface and sub-structures. That, in turn, allows water in and weathering has a strong effect on the break-up of the surface.
Well, the cyclelanes are being taken out of the Perne Road part, so why does this matter. The near miss on the clip illustrates a big issue. The cyclelane exit onto Radegund Road is quite close to the junction. It's all too easy to see that the cyclelane here will be run over. Just in a place where people may be riding back out into the road space in what would normally be considered a safe space not intruded on by motor vehicles.
This really isn't helped by the shared-use path also crossing the exit of the shops parking spaces. It means people riding have to focus on both directions to avoid being hit. The route needs adjusting and protecting. This has already been done elsewhere in Cambridge, why not here?
And it's not the boy (and girl) racers that are the big concern here, it's the poeple whose focus is not entirely on the road. Thinking about what to cook for dinner, or what that meeting was about, and not considering that slightly slower lump of person just off to the left. It's a well researched phenonomen that after a few minutes of driving people stop focussing as much as they should.
Destroyed cyclelane on Perne Road (south)
Worn out cyclelane on Perne Road (south)
Cyclelane wear on Perne Road (north) and some obvious reasons
Parking on Radegund and Birdwood Roads
Getting onto and off either of these roads is distinctly hostile. And it's down to the on-road parking that occurs. This needs removing and enforcing.Let's not confuse that with the off-road parking as it's is good and useful if it's for someone with limited mobility.
The obvious and pretty limited change would be to remove it up to the schools at either side of the junction. It's not obvious why any local homeowners need on-orad parking. The houses are large with considerable open space in the front of the private properties.
Additionally, it should be noted that the last parked car o nthe video clip before the exit of Birdwood Road is illegally parked in the verge. The double-yellow line restriction applies all the way the other side of the pavement. This needs education and if it continues to occur, enforcement.
Hostile environment coming from Radegund Road
The off road parking north of Radegund Road (limited mobility parking?)
Hostile environment going onto Radegund Road
Hostile environment on Birdwood Road
Improving the Scheme
The thing is, this scheme actually isn't far away from something that would deliver those benefits to all parties. Well, improve it for the community and only slightly impact those needing to drive through here.
1. Protecting cycling entry into the on road cyclelane. On all cyclelane exits from the "pavement" there should be a kerb protecting the lane from motor vehicle encroachment. In the case of the Radegund Road exit, it also should be moved further along the road to allow for a prioritised cross of the shops side road to occur before moving out into the road.
2. The speed dilemma. Whilst the proposal of an over-run strip is welcomed as a way of limiting faster vehicles, the devil is in the detail. This needs to really work and not be some attempt. There are examples of it hardly being any different from the main road surface and the result is that all motor vehicles run over it.
3. Priority crossings. The ultimate mechanism to slow people driving down to a reasonable speed is to ensure they do not have priority on the roundabout crossings. This also works well for people walking around here. These crossings are not limited by traffic lights, so it must be assumed that the crossing rates are low. Perhaps thats because this is not a very friendly environment? Perhaps it's just there ar less people crossing. Whatever, improving the friendliness here would help bring people back to more active travel choices. And if it's just not used much, it won't impact people driving much! It's win-win.
This change should not go ahead without updating and possibly more research. I hear that Dutch engineers were consulted during this process, but it can't have been anything to do with cycling. Although some will say that further changes will take more money, and I'd agree, the current proposal is essentially more of a waste than spending more. The simplistic and minimal research, wholly based on car capacity and not looking at the fuller picture, really doesn't justify anything.
I'm aware that council officers have worked hard to get as far as they have with the current proposal and have had to balance the needs of a lot of different groups. Sadly, they are having to take into account people who have very little understanding of the situation and how financially beneficial active transport is for local areas both in terms of medium to long term reduction in road costs and massive health savings (as well as making communities a lot more pleasant). It's proven that for every £1 spent on properly improving cycling infrastructure (so not this scheme) returns £4 in savings. This ends up simply giving the worst of both worlds to all parties
It's not like we don't have examples from round the world (The Netherlands, Paris, New York, Chicago, and now even in some part London) of how when you do plan for a better world, the naysayers often stop grumbling very quickly afterwards, especially when a change of transport mode choice reduces the need to maintain (in in this case improve!) car capacity.
Subnote: I've used terms such as "people cycling" and "people driving" rather than "cyclists" and "drivers" to highlight a few simple issues.
- We are all people underneath it all. And all just going about our daily business.
- Often us people doing it are capable of doing both driving and cycling. We don't fit into one camp or the other and we are not defined by the current choice of transport.
- Last, when we drive or cycle, our behaviour can be vastly different at different times. We have good behaviour, something most would aspire to, and we have bad behaviour, something to be a bit embarrassed over. We can choose which pattern to follow. There is no such thing as a "bad driver" or "good cyclist", just behaviour that can vary. It'd be good to reward ourselves for good behaviour and encourage towards that when we see bad behaviour, we are all capable of it.
Wednesday, 23 October 2013
Whilst the good folk of Paris where keen to find out which French cities the beloved bike race known as Le Grand Boucle was going through, us UK folk where keen to find out the stage 3 route from Cambridge through Essex to London. And to have a little non-lycra bike fun at the same time.
The good folk at Outspoken Cycles (which as of very recently includes me!) set up to run Scalectrix bike races powered by, of course, actual pedalling. And behind, the big pull, free smoothie making again by pedal power.
Here are a few photos just after set up with people from all cycling backgrounds coming to join in the fun before the Tour route is announced. And yes, there is some genuine Tour de France paraphernalia littering the place. That sign came from Briançon during the 2006 Tour (swag picture and blog of the day).
Bike race table with (genuine) Tour de France route sign
The racing was great fun and taken up by all kinds, see clip below.
But that wasn't the big pull of the stand. The bicycle-powered smoothie maker was a big hit with many more! In the morning it made a great diversion for those who needed a free bike check. Drop the wheels off with the mechanics explaining the joyous foibles of it's current state, then meander along to a bike on a roller and power through a few bits of fruit to get a free drink!
Both bike race table (mountains classification!) and smoothie maker stand beyond, but where are we?
This was all done whilst waiting for the official announcement happening just along the road in front of the world famous Kings College front.
Ah, the familiar landmark of Cambridge city centre!
So, how did that fun go down? Here are a couple of short clips from the morning showing people engaging with the great idea of this fantastic race coming to Cambridge, bringing a wealth of tourism publicity.
Bicycle Powered Smoothie Making!
Or link to it here.
Bicycle Races are Coming to Town!
Or link to it here.
Sooooo, now we know what to do during that wait for July 7th when the Le Grand Boucle does indeed arrive in Cambridge. Here's the Cambridgeshire Route in Cyclestreets.net.
Friday, 18 October 2013
Sometimes something strange happens whilst you are riding. The top chain loosens when you stop peddling, and if you look it's because the rear cassette is continuing to move a bit after you've stopped. Alternately, and a bit more upsetting, when you leap majestically on, start peddling and everything goes round except the rear wheel. Often this can be followed by a squark, a slight topple and you sprawled across the ground as you've not antipated this rum behaviour from your trusty friend.
Cause from Effect
The cause, a gummed up freehub. Simple actions like taking it off the wheel, thoroughly lubricating, then returning is only going to hold it for a little while. It needs to be taken apart, properly cleaned, regreased and reassembled.
Looking at Wikipedia there's a good diagram of what the mechanism is (or roughly, bikes have more than one red pawl!). The spring or space between the light green inner and turquiose outer has become gummed up.
This means the red pawl sticks in against the green inner (allowing the rear cassette to not power the wheel and you to fall over) or the red pawl sticks out against the turquiose outer (allowing the chain to keep moving).
Let the Maintenance Begin!
This is where it get's a little tricky, especially if you're British. I do scan for help on how to do bike maintenance quite regularly and know where to look. Also, Google is quite good at finding things. However, finding a site that covers this is quite difficult.
Well, I was at my workshop with a whole load of others enjoying being outdoors. And I had a bike I was maintaining for a charity for which I work. A good friend and trained engineer wandered (and wondered) in looking for things to do and I said "Let's play with a freehub!". Well, we scanned again for web pages. Not even the great Sheldon Brown's freewheel disassembly page (or here) seems to have the exact details.
Well by now my mate had the cassette off, an easy "year 7" task shown in many places.
Now comes a a slightly sticky bit which is also quite well written up, but I thought I'd share my mechanism (well, the one my mate did with my kit!). I have a "travel" bike tool box that has a good lid with edges that means upsidedown it acts as a good tray. Get spanners set on either side of the axle and give it a turn to get it loose. Now turn the wheel to being horizontal and put this tray under the wheel axle. Finish by unscrewing the axle preferably pulling it up and eventually out. This will leave the hub with loose bearings, some of which will have dropped into the tray.
Freehub on wheel with bearings showing
Now knock the remaining bearings out into the tray. If you don't have a tray, a cleaning cloth makes a good replacement. You can buy cushions or pillows that do the same thing. Move the bearings tray to somewhere safe.
A 10mm Allen key is all that's needed to remove the freehub fixing bolt as Sheldon Brown says.
Unscrewing the Freehub Fixing Bolt from the Wheel
Now you have the freehub. What a thing of beauty it is. This is what it looks like from the wheel bearing side. You can just make out a small notch in the inner assembly. Ah. Hmm.
Freehub from Wheel bearing side
And here it is from the side that attaches to the wheel. The cog on this side neatly slots into the opposite grooving on the wheel. Like a Connection. I'm going to call it a Connecting Cog.
Freehub from Connecting Cog side
The Connecting Cog is part of the inner mechanism, it that it goes round separately from the cassette mounting but with the notched bearing holder on the other side.
Now the fun begins. We've still not found any websites helpfully telling us how to take this bit apart. We're distinctly rueful as we know there's going to be numerous bearings, probably a lot smaller, and possibly some springy things, likely to fly out at any moment of disassembly. We've tighened and pulled and twisted lots of parts to no effect. Actually that was pretty good, this bit of a bike is pretty indestructible.
Then, a Swedish page pops up. Yes, Swedish. And then a Polish one! Wahoo! Er, neither of us spoke either language. But hey hoo, there's a picture and I think it's obvious we need to focus on those notches.
The Notches are the Key
So what to do? We didn't have any kind of tool that'd deal with that. Well, we did have a well stocked workshop and quite a bit of rough metal odds and sods. My mate hack-sawed a piece to fit. The steel has to be pretty tough, it's going to twist something super tightened.
Well, we tried, then thought and tried left-handed, that is reverse to how you expect it to loosen (the adjective confuses me as I'm left handed). With the Connecting Cog firmly in a vice and a good long pair of pliers it started coming undone!
Tool Pushed into Freehub
Once it was loose it was quite easy to move, holding the Connecting Cog and the makeshift tool in the notches. Again, we transferred work to in the tray. Eventually it came loose and some bearings meandered, but in the tray.
And this is what you get. An Inner Hub with pawls, which are the moving rachet parts. The bearings here are sitting in new grease, but many will be here in the old stuff.
Inner Hub with Pawls
This is the notched section turned the other way up showing the bearings at this end (again in new grease).
Inner Hub Lock Ring and bearings (notches on underside)
And this is the Outer Hub on which is mounted the cassette. Note the circular rachet facing in on the inside.
Outer hub with circular rachet facing in
Well, the next bit is pretty easy. A good clean up, oil up, and test the pawls.
Inner Hub with cleaned pawls
Then re-grease, especially where the bearings are so they can be stuck in place. These are all in the above pictures. The unit goes back together easily after that, although still worth using the tray.
Again, we re-mounting and returning axle bearings to the wheel, the tray is useful.
Hub on Bike with Bearings
Finally, tighten the axle cones until it moves freely but doesn't shift through the mounting. Again, this is shown in many places.
Full Hub on Bike
Now, searching for that tool. It's meant to be a Shimano Cassette Hub Race Remover. But they seem awkward to find. Even in a Google a TL-FH40 search doesn't seem to give many places to buy one.
Then, a French Blog with Park Tool gives a different ID. And in Google a FR-2 Park Tool Search gives a lot more places! After finding them in a Random Place and another Random Place there's loads of places in Ebay that will give them, with the cheapest here.
And subsequently, I found posts about lots of different Freehubs and a slightly strange-but-useful-pictures blog about cleaning without taking apart. Not really sure about the amount of chemicals being used once here, though.