The Challenge
To ‘dump’ as much excess solar photovoltaic energy into hot water tank as possible whilst minimising impact on battery store.
Background
Our house is off-grid, powered by 6.5 kWp solar photovoltaics and a wood stove with back boiler. Being off-grid, we can’t export electricity so it either has to be used as it’s being generated or stored in batteries. Once the batteries are full, it’s a case of use it or lose it. We want to store this otherwise lost energy as heat our hot water tank.
Equipment
2x Victron BlueSolar MPPT 150/70
BMV-702
Colour Control GX
2x Phoenix Inverter 3000VA
360 Copper Thermal Store with 3x 2.25” immersion heater bosses
22kWh 48V Lead acid battery store
First question AC or DC. I think it’s better to use 48V DC immersion heater(s) so as not to use the inverters unnecessarily or even keep them on all the time (we have a smaller 1.2 kVA inverter which is on all the time). The thermal store is only about 10m from the battery store so cabling is not unreasonable.
Relays
The MPPT, BMV and CCGX all have relays with the following options available:
BlueSolar MPPT
BMV-702
Colour Control GX
Has a relay, but can only work on information provided by the other devices so maybe there’s no point in using it? However, it does have a neat way to start/stop a generator, track hours run etc. I wonder if this assistant could be used to start/stop the immersion heaters?
https://www.victronenergy.com/live/ccgx:generator_start_stop
I don’t yet own the 48V immersion heaters, but say I get 3x 1.5kW for 4.5kW total. These could take a single cable then be hooked up in parallel at the water tank. This would be around 90A, over 10m so 14mm2 (6 AWG) for a 5% voltage drop. That’s some thick cable, and a single on/off or 4.5kW is not very delicate! Maybe better to run a separate cable to each immersion (more manageable 4.5mm (11 AWG) and have the choice of 1.5, 3 or 4.5 kW depending on how much excess solar was incoming.
Questions
Which relay(s) to use?
What to trigger on?
Relay minimum close time?
Is there a way of varying the power to the heaters, such that if there’s only 500W of ‘spare’ solar, that’s all that’ll get dumped?
My initial thought was to use the MPPT’s float option. Something like when the controller enters float, close the relay for 30 minutes. But this misses a lot of energy in the absorption stage before the batteries have reached float and there’s the risk of switching on the heaters late in the afternoon, when float has just been reached but there isn’t a large surplus. So maybe the BMV’s state or charge or battery voltage are better triggers? Battery voltage is at it’s highest during the absorption stage though so any high voltage trigger would switch on before the batteries are full?
I’ll also need high current DC-DC relays, something like this?
D06D100 – Solid State Relay, SPST-NO, 100 A, 60 VDC, Panel, Screw, DC Switch
http://uk.farnell.com/crydom/d06d100/ssr-100a-3-5-32vdc-0-60vdc/dp/1213166
Anything better/cheaper?
Cell bars with cups ready for grafting.
We recently spent a lovely weekend at the Basterfields’ honey farm in Devon learning the theory and practice of queen raising and stock improvement. This is one of several courses that Ken and Dan Basterfield, both holders of the National Diploma in Beekeeping, offer to beekeepers working towards BBKA assessments or those involved in teaching at local associations. Queen raising by its very nature takes time: suitable breeder queens must be chosen and colonies prepared to raise the new queens; cups have to be conditioned for a day before grafting; after grafting it takes a day or so before acceptance by the colony can been seen; a few more days are needed before the cells are sealed; and the cells shouldn’t be moved into small mating nucs until a couple of days before emergence is expected, around 11-12 days after grafting. The process isn’t complete until the queen is mated (requiring a suitable drone population), marked, and clipped if required. To cover the process, without the course becoming reliant on improvisation, requires a bit of Blue Peter “here’s one I made earlier”. Thanks to their meticulous preparation the whole process was compressed into two days with us all able to graft a dozen larvae, asses our success rate, make up mating nucs with ripe queen cells and finally practice clipping, marking and caging.
The course is split between classroom activities, practical sessions in the apiary and lively discussions over coffee and cake. The bees can raise queens from a wide range of larvae ages, however, the quality of the resultant queens, particularly their potential laying rate is influenced by the age of the chosen larvae.
Bee larvae of various ages.
In the image above, the larva second from right on the bottom row is around 1-2 days old and suitable to graft from. Lying in the bottom of the cell, the larvae should be about a fifth to a quarter of the (5.3mm) working cell width.
Young larvae transferred into practice cups.
After experimenting with several different grafting tools (a 000 paintbrush was my preferred tool) larvae of the right age were placed into cups. The process was pretty straightforward – however, this was sitting at a bench, in the classroom. How easy would this be in the apiary, peering through the veil’s mesh?
Working outside we had to be quick, as the young larvae can be damaged by exposure to UV light and are susceptible to drying out. The acceptance rate is also very dependent on the state of the colony. One word of advice was not to give up if a whole bunch of grafts are rejected but to try again, and again – the colony needs to be in the right condition to raise queens. I was very pleased to see half my grafts accepted.
Successful grafts accepted by the colony.
Dan had been grafting the week before, not only to demonstrate that it’s possible but also to give us the experience of stocking mating Apideas. These small mating nucs require around 300 bees – a teacup full – a good chunk of bakers’ fondant and a ripe queen cell. Bees from a well-stocked colony are sprayed lightly with water and shaken from frames into a box. From there, they are scooped into upturned Apideas before a queen cell is added through the cut out hole in the crownboard. The mating nucs are kept in a cool, dark shed, with a little water sprayed onto their ventilation grill for three days. During this period, the virgin queens will emerge; ready for mating when the nucs are taken out.
Adding queen cells to recently stocked apideas.
Of course it’s possible (and recommended!) to read the books and there’s never been so much material available on-line. However, there’s no substitute for spending a couple of days with two highly experienced beekeepers keen to share their knowledge. Beyond the direct syllabus of the course, as beekeepers with fewer than ten hives it was also fascinating for us to see how an operation of several hundred hives is managed, the honey extraction and bottling equipment, the workshops, even the bespoke equipment for moving their hives.
Inspecting colonies for suitable brood to graft from.
Finally, we thought we had better put this into practice in our own apiary. A queenless hive for cell raising was obtained conveniently by removing a queen who disappointingly had started laying drones. A queenless hive is not required but does improve the chances of graft acceptance, as the bees have to be “in the mood” for queen raising. After a couple of days for the bees to wax the new plastic cups, Erica grafted 10 young larvae from another colony into the cups on Thu 19th June. Three days later (22nd), we checked them to find an encouraging success rate of 7 out of 10 cups extended into long queen cells.
Erica’s first graft, seven out of ten accepted.
On Fri 27th, one was left in the queenless hive, two of the older ones were removed, and four others went into mating nucs with some young worker bees and fondant. They spent three days in the dark garage as recommended and are now (Tue 1st July) enjoying the sun in the garden at home. Check back in a few weeks for an update on whether our new queens manage to mate successfully and graduate into a full size colony!
One of four small mating hives.
UPDATE
On the sunny afternoon of Sunday 6th July we spent a couple of hours watching the mating nucs. To our great satisfaction we saw three of the new queens leaving the nucs and taking to the wing. They flew around and around in ever widening circles gaining height, occasionally coming back to the nuc. We didn’t look inside, remaining fondant was estimated by weight.
On Sunday 13th all four were checked, the queens were seen but none had eggs. Checking back on Thursday 17th July, all four had eggs, but no larvae yet. We can now build up the following table:
| Thu 19th June | Grafted (4-5 day old larvae). |
| Fri 27th June | Sealed queen cells moved to mating nucs, left in dark for 3 days. |
| Mon 30th June – Tue 1st July | Expected emergence based on 16 day rule. |
| Sun 6th July | Queens seen flying. |
| Sun 13th July | No eggs seen. |
| Thu 17th July (early morning) | Eggs in all four, no larvae. |
From the final row in the table we can determine the queens all started laying between 14th and 16th of July so just over two weeks from emergence.
One other point, in addition to the four cells moved to the mating nucs, one was left in the queenless colony used to raise them. Checking on Monday 21st July we found three frames with brood, including some sealed! Given that it takes 8 days from egg to sealing, the queen must have been laying from no later than 13th July, slightly earlier than the four in the mating nucs.
Frame from a mating nuc with sealed worker brood.
In May we always have an abundance of rhubarb. It’s a fantastic vegetable for crumbles, jam, cakes or just stewed with a bit of ice cream. We appreciate it even more because there isn’t much else from the garden at this time of year. Here’s a cake I bake a lot when there’s rhubarb about.
This is a double mixture cake, quantities below are good for a large loaf tin.
- 18 oz fresh rhubarb
- 12 oz self raising flour
- 6 oz caster sugar
- 6 oz butter
- 3 eggs
- Sprinkle of Demerara sugar
- Pinch of salt
1. Preheat over to 180 ºC and line a large loaf tin with greaseproof paper.
2. Sieve flour and salt into large mixing bowl.
3. Add butter and rub in until you have breadcrumb texture.
4. Add sugar.
5. Cut rhubarb into chunks less than an inch long and add to bowl.
6. Crack the eggs into the bowl, break the yokes and stir the mixture.
7. Don’t be worried about how dry the mixture is at this stage, there’s a lot of water locked up in the rhubarb! Just mix it all together.
8. Transfer mixture into tin, firm it down and sprinkle with Demerara sugar.
9. Cook for about an hour or until it generally looks done! Leave to cool for at least 20 mins before turning out of tin.
Last weekend I spent a day with The Bristol Bike Project in Strawberry Cottage Wood. This is the wood Rob Penn has been managing for the BBC TV series Tails from the Wild Wood. Our job for the day was to plank a couple of ~110 year old ash logs and return the wood to the project for our new bike shed.
It was a beautiful day for my introduction to chainsaws. I was particularly impressed with the Logosol M7 mobile sawmill. It just screws to each end then the guide can be moved up and down about a foot before having to re-screw it. It can be rotated 90 degrees to release the planks. The saw has a bracket which slides along the guide. It was still a big job!
A day in the woods.
Click thumbnails below to enlarge:
 Chainsaw Mill |
 JamesP |
 JamesP |
 Progress! |
 Twin Sawing |
 Homeward bound! |
More photos on The Bristol Bike Project blog:
Planking in Strawberry Cottage Wood for the new bike shed.
I’m on my way home from my first EGU conference, taking a sleeper train from Venice to Cologne, then on to Brussels, to London via Eurostar and finally back to Bristol. It takes 23 hours with fairly slack connections. It’s a lot more civilised than flying and, especially important when attending a geoscience conference, has a lower environmental impact.
Conference Venue
Secondly, the session on Blogs and social media in scientific research. This was a panel discussion including two PhD students, a postdoc and a professor. All were passionate about blogging and tweeting their science, highlighting the many benefits; build network of contacts, raise profile, public good, improve communication skills, twitter is friendly place, can approach people, opportunity for collaboration, awareness of job opportunities, keep up with what people are doing before publications, exposure, fun, educational… but also offering some advice. Be professional – more so than in scientific life! Be measured and maintain higher ground, explain concepts carefully, invite contributions but vet them, don’t duck key issues – but don’t get drawn into unwinnable discussions, correct errors, don’t blog primary research before publication, have separate Twitter accounts for professional and personal life, think about what audience what to know and don’t tweet too much!
There are a few Twitter hash tags worth catching up on:
#EGU2013 is the main comment feed
#EGUSMEDIA for discussion arising from the blogging and social media discussion and
#EGUFrack for the fracking debate.
Videos of the press conferences are available here: http://media.egu.eu/press-conferences/
I’m in my tenth year of blogging and I’ve been tweeting for around four years. Social media has been very valuable for me. My main challenge is how to cover my science, along with beekeeping, bicycles, growing, amateur radio etc.
Sunny but windy on Wednesday
A few messages: Greenland did not contribute more than 2m of the 6-8m sea level rise during last inter-glacial according to Dorthe Dahl-Jensen’s work on the NEEM ice core. Katy Pol told us evidence from Antarctic core (EPICA Dome C) suggests a warmer climate (last interglacial) may be more variable than today’s. Contrails reduce solar power by 60% when sun blocked but small enhancement when not actually blocked, net negative effect though, P. Weihs. Alan Robock explained how a 50 nuclear bomb war between India and Pakistan would cause global cooling of ~1.5 C for a decade and devastate agriculture. 4000 bombs (most of them) would cause -8C global cooling, using nuclear weapons would be suicide through starvation/nuclear winter. F. Lott from the MetOffice used event attribution analysis to suggest the East Africa drought in 2011 was more likely as a result of anthropogenic climate change. Arctic sea ice would have reached minimum without ‘The Great Arctic Cyclone of August 2012’, Irina Rudeva. K. Kjeldsen showed how Southern Greenland been losing ice since little ice age but there’s been a factor-2 increase in loss rate in early 21st Century.
Meeting up with friends and colleagues I hadn’t seen for a couple of years was good – but especially valuable was meeting two of my co-authors for the first time. It’s great to finally meet face to face with people I’ve only been working with through email for the last few years. It’s amazing how productive ‘virtual teams’ can be but those 15 minute chats in person are invaluable.
Calm before the storm
On Thursday I had a poster presentation. We had the opportunity to give a two minute ‘poster flash’ in the main oral session. This worked really well, as it gave us the chance to let everyone know who we were and the main thrust of our work. Here’s the poster I presented:
Click for full size PDF
Surface mass balance model intercomparison for the Greenland ice sheet.
Finally, I’d like to finish with a plug for the conference I’m co-organising in Edinburgh this summer. It’s the Global Energy Systems conference, a three day event examining the challenges facing our energy system in detail including supply side constraints, energy-return, renewable energy and the rate-limit of non-conventional fossil fuel. All issues that will drive future energy prices. We have a really top speaker line up including Sir David King, Lord Ron Oxburgh, Dr. Jeremy Leggett, Prof. Stuart Haszeldine, Dr. Michael Kumhof, Dr Peter Jackson and many more. We still have space for poster presentations, register here.
First two loaves of ciabatta
Ciabatta’s wonderful, especially dipped in balsamic and olive oil. We had a go making some the other day with great success.
- 375 g strong white bread flour
- 125 g semolina, plus up to another 200 g for dusting
- 5 g fast dried yeast
- 10 g salt
- 400 ml warm water
- Olive oil
1. Mix the flour, semolina, yeast salt and water together in a large bowl, then add a good slug of oil. This will be a very wet dough, too wet for kneading. It needs mixing by hand or alternatively with the dough hook of a food mixer for 5 minutes.
2. Put the bowl in a plastic bag to ferment for 3 hours. Every half hour or so remove it from the bag, add a bit more olive oil, smooth it all over and fold the dough over itself a couple of times. Yes it’s very sticky at first but it gets easier.
3. We don’t have a baking stone or peel, we just sprinkle two baking sheets with a good covering of semolina.
4. Sprinkle the work surface with semolina and turn out the dough onto it. Separate into two equal lumps. Dust everything with semolina. Taking one lump at a time, flatten it and stretch it out into a rectangle. Roll this up into a cylinder four times as long as it is wide and place on the baking sheet to double in size.
5. Heat the oven to maximum.
6. Once risen, put them into the oven quickly, baking at maximum heat for 10 minutes before turning down to 200 ºC for another 15 minutes.
7. Remove from the oven, drizzle a little oil on top and allow to cool on a rack.
Last week our local beekeeping association ran a mead workshop. We’d never made mead before and only tasted it a couple of times. Mead, or honey wine, is an ancient fermented drink made from fermenting honey and water. It uses quite a lot of honey, so typically beekeepers use honey that might otherwise go to waste, such as the cappings. Cappings are the thin layer of honey soaked wax that’s cut from the surface of the honey frames during extraction.
Mead fermenting in demijohn.
The process we followed was straightforward. Into a demijohn we put around 3 litres of water (mostly filtered and boiled rainwater, but topped up with some tap water, not ideal). We then added ~100ml of ‘starter’, a yeast solution that had been pre-prepared for us, ~100ml of lemon juice and approximately 1 kg of honey. The starter was Lalvin D-47 yeast, water, honey and lemon juice prepared a few days earlier. The water wasn’t quite warm enough for the honey to dissolve, it just sat in the bottom of the demijohn.
Once home we sat the demijohn in a sink of warm water and gave it a stir, this was enough for the honey to dissolve. On went the airlock and for two days nothing much happened. On the third day, the yeast had got into its stride with CO2 being produced and bubbling through the airlock every 30 seconds or so.
Apparently we should now wait several months until fermentation has completed before racking into smaller bottles and leaving to age. Watch this space.
When is a mead not a mead?
Whilst looking around the Internet for mead, the first things Google found for me were Cornish Mead Wine from the Cornish Mead Company and Lindisfarne Mead. Neither of these products sound like mead to me, as they are based on a fermented grape base, making these products pyments:
Pyment in modern usage refers to a fermented beverage made with grapes as well as honey; it can be considered as a grape mead or a honeyed wine, depending on the relative amount of fermentables from each source. Red or white wine grapes may be used.
http://www.homebrewtalk.com/wiki/index.php/Pyment
My understanding of mead is that only honey, water and yeast are traditionally used. Maybe ‘mead’ is just an easier term for marketing these pyments as few people know what pyment is?
I have just one simple response to High Speed 2 (HS2). Why do we need to invest a lot of money, many billions, in further facilitating long distance national travel? This seems like a bad idea. We would be better served by re-engineering the country and economy to reduce our need and indeed our desire for long distance travel.
We’d do well to focus on the Proximity Principle as described by Dr David Fleming in Lean Logic. The principle states that the need for transport is reduced by using space more intelligently, producing goods and services – especially food – where they are needed, rather than having to transport them over long distances. The objective is to build competence across the whole range of economics and culture, and to enable personal lives to be organised so that routine travel and transport are no longer a necessary condition for material needs, nor for leisure, friendships and work.
The HS2 proposal misses this entirely, it seems to be based on the single, dumb, assumption that there’ll be more travelling in the future. To what end? I and I expect most others don’t want to travel more. In fact what we’d all really like to do is to meet all our needs as, Fleming describes above, without having to spend good time, and good money travelling.
Sadly, HS2 is another case of treating the symptoms, not the disease. Something to which transport policy is particularly susceptible.
The unanswerable question at the heart of transport is the one asked by the farm labourer standing bemused one day in the mid-eighteenth century at the side of the Liverpool-Manchester turnpike, crowded with urgently-speeding coaches: “Who would ever have thought that there were so many people in the wrong place?”
From Lean Logic ~ David Fleming 1940-2010
We have a problem. I’ve known we’ve had a problem for a long time. It’s only in the last few years though, after I left my career in engineering to take a PhD in glaciology, studying the changing Greenland ice sheet, that the magnitude and timeframe has become clear. It is now all but impossible to limit global warming, the warming of mean surface air temperature, to less than +2°C from pre-industrial temperatures [1, 2]. Understand also that temperatures over land rise more than this global average, and extremes are likely to be further exaggerated by positive feedbacks. All but impossible because to have even a fifty-fifty chance of keeping warming below that somewhat arbitrary threshold, global greenhouse gas emissions would have to peak within the next five years or so then fall rapidly for decades: “…the threshold of 2°C is no longer viable” [3].
This fall in emissions would have to happen against the trends of increasing wealth in growing economies and growing populations. Recent history, even with the largest economic slowdown in decades, offers us no hope as global emissions are currently rising faster than ever [2]. It is a fantasy to suggest that the global community is able to collectively choose to peak and decline emissions within the next few years.
The lack of action is not for lack of knowledge. The data and scientific understanding have been clear for a long time and yet over the last decade carbon emissions have increased by a greater amount than in any previous decade (between 2002 and 2011 emissions increased by 2.5 GtCyr-1 from 7.0 to 9.5 GtCyr-1 [4]). There is nothing in the data to suggest that we have recognised the seriousness of our situation. In fact the reverse is true: we are accelerating into disaster faster than the scientific community thought possible even a decade ago.
As a scientist, I’m not supposed to use emotive words like disaster; however, that is what we are facing – an avoidable disaster of our own making. Reticence amongst the scientific community has probably contributed to our civilisation’s inaction. We know enough to say, and importantly to do more. As I write this, however, my office is quiet, half empty. My colleagues are attending a conference on the other side of the planet, elevating their carbon emissions to some of the highest in the world.
Two glimmers of hope I held until recently are fading. The first was offered by researchers quantifying the Earth’s endowment of fossil fuels. Their evidence suggested there simply weren’t the hydrocarbon reserves available to greatly perturb the climate system [5]. This is the question I explored for my master’s thesis [6] a few years ago. However, as extraction of unconventional resources continues to expand and as Arctic melting unlocks probably significant northern reserves, the hope of these resource limits applying any meaningful and timely brake diminishes. Secondly, our emission growth is linked to our economic growth. Without increasing demand from the expanding wealthy population the hydrocarbon reserves will remain unexploited. The threat of economic collapse, in our case linked to unserviceable debts, is familiar and appears plausible at least for developed Western economies. Exactly three years ago I blogged, with evidence, about the economically induced 2008 emissions peak. The global economy has proved far more resilient than I imagined. In any case, were western economies to collapse, the remaining four fifths of the global population are unlikely to need asking twice before taking up any hydrocarbon supply slack and attempting to resume the emission growth trajectory.
The time for hope is over; it is simply illogical to continue believing that dangerous future climate projections can be mitigated through national and international agreements, or through pro-active action. We now have to consider life in a 4 °C warmer world, described here in a report for the World Bank [7].
Our global civilisation appears to be facing a protracted period of decline. Most likely this will be due to the damaging impacts of climate change but if, against the odds, we are spared the worst climate impacts it will only be due to decline from crippling energy shortages or global economic collapse. There is no easy way down for our seven, going on nine billion population, not from the height we’ve now reached. The first half of the 21st century is likely to represent a new peak of human civilisation, the first truly global civilisation, eclipsing our species’ many previous peaks. From here, we can only now hope the cost of climbing so high won’t be so damaging as to deny our distant descendants their own future triumphs.
—————————————————————————————————————————-
[1] PriceWaterhouseCoopers, November 2012.
Too late for two degrees? Low carbon economy index 2012.
[2] Peters, G. P., Marland, G., Le Quere, C., Boden, T., Canadell, J. G. & Raupach, M. R. 2012. Rapid growth in CO2 emissions after the 2008-2009 global financial crisis. Nature Climate Change, 2, 2-4.
[3] Anderson, K. & Bows, A. 2012. A new paradigm for climate change. Nature Climate Change, 2, 639-640.
[4] Boden, T.A., G. Marland, and R.J. Andres. 2012. Global, Regional, and National Fossil-Fuel CO2 Emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. doi 10.3334/CDIAC/00001_V2012
[5] Nel, W. P. & Cooper, C. J. 2009. Implications of fossil fuel constraints on economic growth and global Warming. Energy Policy, 37, 166-180.
[6] Vernon, C., Thompson, E. & Cornell, S. 2011. Carbon dioxide emission scenarios: limitations of the fossil fuel resource. Procedia Environmental Sciences, 6, 206-215.
[7] Potsdam Institute for Climate Impact Research and Climate Analytics, November 2012. Turn Down the Heat: why a 4C warmer World Must be Avoided. Report for the World Bank.
I last wrote about bicycle maintenance almost a year ago, here’s the next instalment.
Draining oil from the fork's damper.
Last month I spent two weeks at the wonderful Cycle Systems Academy in London. I was there to take a level 3 training course in cycle maintenance, officially the Level 3 VRQ Diploma in Cycle Maintenance (QCF). This builds on the level 2 course I completed some 18 months ago with Alf and Teresa Webb at The Bike Inn. The two institutions are quite different, not least as one is in rural Lincolnshire, the other in north London! However, the training offered from both is top notch.
The syllabus of the level 3 course spends a few days on each of the following technical areas; hydraulic brakes, fork suspension, full suspension systems, complex wheel systems and advanced groupset set up (including Campag, Sram, Shimano and Shimano Di2). First time I’d worked on the (ridiculously expensive) Di2 system and I can’t say I’m totally convinced electronic shifting is future however prices are likely to fall quickly.
Servicing a RockShox coil fork.
5ml of 15wt oil in the bottom of each leg.
There was lots of hands on experience working with the Avid, Hope (excellent British company) and Shimano hydraulic brake systems, servicing coil and air sprung forks from RockShox and Fox, X-Fusion and Fox rear shocks, building wheels from Fulcrum and the crazy ‘Cobalt’ wheelset from Crank Brothers to name just a few. Our tutors knew their stuff. I’ve never actually owned a bike with hydraulic brakes, let alone one with full suspension (wasn’t a big mountain biking scene in the Lincolnshire flatlands where I grew up!) but after getting to know the product well, I’d be very happy to run the Hope brake system.
There’s also a significant written element to this qualification with an essay on customer service and for each technical area there is a short answer exam and report to write. A multiple choice health and safety exam is also required for one unit.
Four-bar rear suspension system using a Horst link.
The workshop is very well equipped with each work area having its own high quality tool set and the bikes we were working on were modern and of high quality. Although some had unusual wear associated with being dismantled dozens of times and yet hardly being ridden! It’s a pleasant 15 minute walk along Regent’s Canal from Angel tube station to the academy, just what’s needed after a Northern Line rush hour commute!
Crank Brothers Cobalt wheel, the hub mounted nipples are are long as the spokes!
These bicycle maintenance skills complement the frame building I’ve been doing. I’ve built frames with Dave Yates, Dario Pegoretti and The Bicycle Academy this year. After all this fancy kit, I’m thinking to build myself a minimalist frame for a single speed next!
The X-Fusion O2 rear shock. Only one order works!
The certificates arrived within a few weeks.