Friday, 26 May 2017

L1e-A Type Approval - Missed Opportunities

1 - L1e-A Type Approval - Missed Opportunities - Intro

The L1e-A class of vehicle is at at present described in European Directive 168/2013, at the moment there is no way of obtaining UK type approval for this vehicle. If you built a 15 mph 1000w ebike it would need to undergo the same inspection process as a Motor Bike.

But for now let us imagine that the DVSA had the resources to publish a list of requirements. If they followed the requirements set out in European Directive 168/2013, then the below list (Chapter 2) would be required, and uptake of the L1e-A vehicle class would be minimal. 

If we are to release to full environmental benefits of electrically assisted pedal cycles then we must allow a higher power rating under existing EAPC regulations, whilst maintaining current 15mph speed limit. 

If one has to tax and insure these higher powered, but low speed (15mph) vehicles what is the incentive in operating one? One may as-well opt for a "real" motor bike or a car.

In my various emails shared with the Department for Transport (Chapter 4) no reason for the current 250w limit has been given, the USA have a 750w limit which has been in use for over a decade. 

In short this could be a very useful, zero emission, transport solution. We need to clean up our air, we need to reduce our carbon emissions. 1000w 15mph EBikes and ETrikes could take over many of the jobs that Small Vans and Car currently do in our cities. 

Passengers . . .
. . . post. . . .
. . .  or freight.
Most of these heavier cycles are popular in the "low countries" such as Belgium and Holland. In the hilly UK, if these pedal powered vehicles are to be success then we will need a 1000w power limit on an assisting electric motor.  

2 - L1e-A Type Approval - Missed Opportunities - Requirements

L1e-A - Horn

You will not need am audible warning device. AKA a Horn.

L1e-A - Brakes


According to UNECE Reg. 78 unless the vehicle weighs less than 35kg. In which case normal bike brakes will be OK.

Rim widths must be kept under 45mm to avoid stopping distance requirements.

L1e-A - Endurance

Needs to be able to last for 5 years. Which bits this applies to I do not know, likley the frame I should think. 

L1e-A - Lights and Signals

A headlamp, a side reflectors, pedal reflectors. Headlights can be switched automatically or manually. No rear light is required.

This is rather silly. A rea light is one of the most important safety features on a bicycle. . . . the mind boggles.

L1e-A - Saddle

A normal bicycle saddle.

L1e-A - Tires

Normal bike tires provide loaded weight is below 150kg, and the tires are less than 67mm in width. This translates to 2.35" cycle tires being OK, which is pretty wide. 

L1e-A - Anti Tamper

The vehicle user should not be able to alter the vehicle speed above 15mph, with (i am guessing) an off road switch or similar.

L1e-A - Vehicle structure integrity

Must conform with EN 14764:2005. This is a bicycle standard realting to "City and trekking bicycles." So if you are converting a modern bike of the correct type then it should comply. However, this standard does not apply to:

"It does not apply to mountain bicycles and racing bicycles, tradesman's delivery bicycles, recumbent bicycles, tandems and bicycles designed and equipped for use in sanctioned competitive events."

L1e-A -Passenger handholds and footrests

These are not required. However this would suggest passengers are allowed. . . 

L1e-A - Registration Plate / Number Plate

10cm by 17,5cm space is required for mounting. This is annoying. This is large un-aerodynamic thing to fit on to a bicycle. 

L1e-A - Kick Stand

Yes you need one of these. A kick stand, or two foot stand for example. 

L1e-A - Propulsion Unit performance

This is a little complex, and will depend on the type of system. If a pedal assistance system then there are standards to be met (EN 15194:2009 &  UNECE Reg. No 8)

L1e-A -Electric energy consumption and electric range

There are no minimum range requirements. 

3 - L1e-A Type Approval - Missed Opportunities - - Conclusions

One of the great joys of owning a ebike is the lack of legislative burdens. No tax, no insurance, no requirement to wear a helmet. . . . 

The L1e - A category has the potential to revolutionise inner city transport if implemented correctly and sensitively. But if regulators are too heavy handed this form of vehicle will be relegated to an obscure and underutilized form of transport. 

4 - Type Approval Requirements L1e-A - Letters to DfT

I have had various contacts with the the Department for Transport. I would rather see this L1e-A bracket included under EAPC regulations.

Letter 1

An initial enquiry, brought boiler plate response. So . . . my response.


I think in the days before the world wide web, the response may well have been a useful one. But it is repetition of information that I have already read, and already have access to. It is all very well to choose 250 watts as a maximum power rating, but I fear this figure has been chosen at random with no true understanding how an electric motor works.

How will this be enforced? – We have a enforcement system that measures speed, not power.


Practicality? – Would you place a power limit on a Tractor?


Worthy Contribution? – A moderately fit rider can produce 800w power when cycling. 250w as an addition is rather small.


I summary I am trying to investigate why this 250w figure has been chosen. I would like to think there was some science behind it somewhere. . . . but I have a strong suspicion it was plucked from the air.


DfT response to Enquiry on why current limit is 250w.

Directive 2002/24 made type approval compulsory for all two wheeled motor vehicles,  except powered cycles not exceeding 250 watts. 
Unfortunately we have no detailed information on why that threshold was chosen. It may  have come from a prior threshold in an EU country where such cycles were common eg  Netherlands.

Letter 2 - Higher Power for Low Speed EBikes 

My Letter - Enquiring About Power Increase

Now that we are leaving the EU could we open a dialog on how best to increase max allowable power on pedal assisted EVs? To be clear 15mph speed limit would be maintained, with increased assistance level and torque.



Since our last communication we have heard that diesels will likely be banned in cities, and I think it is likely that electrical assisted vehicles can fill this gap.



With the price of electric cars and vans being inhibitive for most, I think now is the time to investigate this possible review of the EAPC regulations. Here are some links to some vehciles that would benefit from a change to the regulations: 




For Passengers



http://pedalistcycles.com/

https://blogvelocity.wordpress.com/2016/10/14/excellent-piece-of-cargo-bike/



For Cargo



http://vrachtfiets.nl/

https://twitter.com/fahrradwien/status/800967612108783616?s=09



Surely this is worth looking at? We have an air quality and emissions mountain to climb in the next decade and this can only help. . . .

Dft Response to Increasing 

Thank you for your e-mail of 27 April concerning electrically assisted pedal  cycles (EAPCs). I have been asked to respond as I work in the Department  for Transport’s cycle policy team and lead on EAPCs.

As we are currently in the pre-election period, known as purdah, new policy  decisions cannot be taken until after 8 June when a new Government will  have been elected.

You may be aware that prior to the beginning of the purdah period detailed  guidance on compliance issues affecting certain EAPCs was published on the  Department for Transport’s website. For ease of reference here is a link to  the guidance.

My response to This

Thank you very much for you informative response. I had seen a draft of your linked document last year, I am worried that if these slow, low powered cycles are grouped with motor vehicles that the added administrative burdens will prevent their uptake.



I have recently read that there is a directive 168/2013 that introduces the category L1e-A for type approval. That is a 15mph top speed but with a 1000w power allowance.



This is exactly the type of bicycle I think that would prove useful for passenger and load carrying, and would provide a real alternative to cars and vans. Especially in hilly areas, were the current 250w allowance does not contribute meaningfully.



These types of cycle would also allow individuals and businesses to opt for zero emissions transport at a fraction of the cost of an electric car. This would accelerate the inner city air quality improvements required of the UK, whilst adding to the fitness and wellbeing of those using the cycles.



I believe that the DfT are updating type approval regulations at present, I would ask that the L1e-A category is merged with the EAPC regulations. I am of the opinion that attempts to classify these cycles as motor vehicles would severely restrict there up take, and thus limit the myriad of positive effects that they would bring for those using them, and air quality.



Finally, it is very difficult to enforce a system based on power ratings, at present our enforcement system favours speed as an enforcement mechanism, which most police can measure easily. If a bicycle is limited to 15mph, then there is very little point in having any more than 1000w power, any more and it is surplus to requirements. 

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Monday, 8 May 2017

Thorpy's Grass Track Dilly Cart Build

Thorpy's Grass Track Dilly Cart Build - Intro


This is a brief write up of the dilly cart / box cart that my kids and I have built for the National Trust, Landhydrock, Dilly Cart Race. I am not racing in the kart, instead my wife, and two daughters are entering because I enjoy building things, but not driving.

The race is a grass track race, and as such the rolling resistance is quite high. For this reason the race organisers suggest the use of 24" wheels or bigger.

Normally a box cart, or dilly cart track is paved in some way, and on these tracks a smaller 20" BMX wheel will serve you well, they have more spokes and are generally stronger.

I chose large wheels, because I think it will be annoying if the cart does not roll well. I think my kids will use the brake quite a lot, and not gauge the track ahead very well in terms of the momentum, required. Bigger wheels will reduce the likelihood of stalling on a grass track. So that is why I think the bigger the better even if you are not out to win.

Watch the length. 2.5 meters is soon used up!

Thorpy's Grass Track Dilly Cart Build - Specifications / Rules


For Landhydrock, Dilly Cart Race 2017 the carts have to meet the following requirements, unlike many cart races, you only need 3 wheels, which makes things a lot easier in terms of steering!


  1. Carts must have a minimum of three load bearing wheels.   
  2. We recommend a wheel size minimum of 24 inches, as you will be racing on a grass track.  
  3. Carts must have effective steering. 
  4. Carts must have effective brakes. 
  5. Carts must fit within the following dimensions:  


  •     Maximum length 250cm, 
  •     Maximum width 150cm, 
  •     Minimum track width 60cm 
  •     Maximum weight of vehicle, ballast and driver 150kg. 


  1. Carts must not have any sharp edges, glass or loose parts.   
  2. Carts will be examined before racing, and any carts considered  dangerous or unsuitable for the course will not be allowed to race.   However, inspection does not constitute a warranty of safety.   Drivers are solely responsible for the safe construction and operation  of their vehicles. 

Wonky but Functional



Whilst I found the width allowance to be very generous, you will have the watch you length. The 26" wheels add a lot of length as there are approx 60cm front to back so there is 1.2 meters straight away. The pictured cart is 2.4 meter long approx.

Thorpy's Grass Track Dilly Cart Build - Ingredients


Two bikes will provide moist of the stuff you need, they will have mounts for brakes, wheels, and other handy bits saving time and trouble. To summarise, try to get hold of two old mountain bikes. The recycling centre is a good place to start, where you could get 2 bikes for £20.

To Weld or Not to Weld?


If you buy a welder, then I am pretty sure you will be able to learn to use it pretty quickly. A cheap gasless mig welder can be had on ebay for £120. A welder is such a handy thing to have, by the time you have spent £50 on an alternatives such as epoxy, rivets or bolts etc. then  you may as well make the investment.

If you were to building from wood, that is OK.  I have done this before and the results are not as good. And even then we used some welded parts for brackets etc. I have seen some good wooden carts built with wheel barrow wheels, but with larger wheels it become more difficult.

Extra Tubing

The best source for cheap tubing I have found is electrician's conduit which you can get from any plumbers store or electrician store. Not B&Q, somewhere like plumb-base. It come is 3 meters lengths so unless you have roof rack, take a hacksaw with you.

Seat


You will need something to make the seat, this could be a canvas only deck chair type thing, or as I have done a plyboard jobby with a bit of cushioning (roll matt).

Foot Rest

This could be wood, tubing of net / mesh as used in pictures.

Paint


I used water based exterior paint, with an undercoat. It was left over from our front door. Metal paint would do a better job, but it is very smelly (high VOC content) and I wanted my kids to help paint it.

Tires 

I am just using the tires that came on the bike. But you could opt for fatter tires with a shallow tread if you were really keen.

Ballast

Ballast is a heavy lump of something that you attach to the cart to make is go quicker. Heavier thing have greater momentum, and so speed gained down steeper sections will be maintained through flatter sections.  I am not putting ballast in the cart, I just want my family to have a nice day and I am not bothered about winning. If the dilly cart were to tip over with 25kg or 50kg of ballast in side then I do want a family member underneath that kind of fast moving weight.

Brakes


Hopefully you can use the brake son the bike. A front wheel break is not ideal as there will not be much weight of the front wheel, causing it to skid easily, at which point the steering will stop working! Not ideal.

1 Break on one side of the rear, will cause a little skewed, when braking, but is an ok option, if you have time then brake both rear wheels.

A very simple solution is a ground bearing break. Pull up a handle and a piece of wood hit the ground slowing the cat in the process.

Thorpy's Grass Track Dilly Cart Build - Design


Perhaps this should have come before ingredients. . . . . 

HAVE FUN. Do not worry too much about your design, unless you enjoy that part of it. Just try to keep the wheels aligned, and think about the human that has to fit inside the dilly cart. A good way would be to sit on your garage floor and draw around you required seating area, with a permanent marker. Then build the cart around this. 

Two Bikes Stuck Together make the Job Easier


Make sure the cart is strong enough. I will test out our dilly cart before I put my kids in it. I am double the weight of my wife, so I consider that an adequate test. 

So many things in life are prescriptive, why not just make it up as you go along!

Thorpy's Grass Track Dilly Cart Build - Extra Bits


Some extra bit s that might be considered . . . . . 

  • Flags 
  • Streamers 
  • Roll Bar - Stops youngsters getting squashed.
  • Horn
  • Spokey Dokeys
  • Spoiler
  • Mudguards - Stop debris front front wheel going in eyes. 

Thursday, 6 April 2017

Shimano Alfine 11 Hub Gear Review

Shimano Alfine 11 Hub Gear Review - Why?


There are a number of reasons why you might want a hub gear, for most is is the lack of servicing required. For others it is the clean look it provides.

For me it was to avoid the waste of replacing my chain and cassette every 9 months, as they get coasted in mud from rural cycling that I rarely have the time to clean off.

They is also one other bonus for me and that is the reduction in noise level. No chain slap. No crunching of gears. It makes for a relaxing ride.

A neat set up (please ignore pipe lagging!)


I live in a hilly area, and a 1 x 9 set up does not really provide enough range (300%). Whilst the alfine hub, gives a little extra range (400%) and make the steeper hill possible without walking!

Shimano Alfine 11 Hub Gear Review - Gear Range


The Alfine 11 speed hub has a gear range of approx 400%, by comparison here are some other systems:


  • Alfine 8 Speed - 300%
  • 1 x 9 (11 - 34) - 300%
  • Sturmey Archer 3 Speed - 130%
  • 3 x 10 Triple - 550%
  • Rohloff - 520%
So you can see that the 400% offered by the alfine 11 is fairly large. You will need a front mech, rolhoff, or new fangled wide range 1 x 11 set up to match it.

View from above drive side.


Whilst a front triple ring setup will offer the same range for less money, the other two will cost the same if not more. 

Shimano Alfine 11 Hub Gear Review - Cost 


Compared with systems that offer similar or better range, at time of publishing.

  • Alfine 11 - £350
  • XT 1 x 11 Groupset  - £350
  • Rolhoff Speed Hub - £935
  • 2 x 10 Groupset Shimano - £260
There is one extra cost which must be added to hub gears and that is the building of the wheel. Which can be done for around £25 plus cot of rim (£30). 

Used with sliding dropouts in this instance.

Shimano Alfine 11 Hub Gear Review - Fitting 


The alfine 11 can be fitted on pretty much any bike with a 135mm rear dropout spacing. PERFECT INDEXING IS A SINCH. But there are a few extra things to consider.

The instructions although excellent but are split between 2 documents for:

When buying your parts just watch out for:

Chain Tensioning

If you have slot drop outs or horizontal drop outs then, you will be able to run the Alfine 11 without chain tensioners. Sliding dropouts are also an option. 

If you have vertical dropouts then you will need to use a chain tensioner. This slightly defeats the object of having a hub gear as it add complexity to the system, but is not too much of a burden. It will also stop you using a chain cover. 

An eccentric bottom bracket would allow the use of vertical dropouts, with an Alfine 11, without the use of the external tensioner. 

Fitting Kit / Small Parts Kit


In order to fit your alfine 11 hub, you will need to obtain the correct "small parts fitting kit" there are 3 or 4 to choose from. The main difference between each will be the non-turn washers, which have lugs at different positions for horizontal, standard and vertical dropouts. For example:

Be sure to buy correct fitting kit.
Wheel Building

If you intend to build you own wheel (and I suggest you have a go) then head over to "Ed Spoke Calculator" and tap in you hub and rim options. Then buy correct spokes.

Go for a 3 cross lacing, and opt for the 36 hole hub. The high the number of spokes and the thicker the rim, the more redundant strength you are building in to make up for amatur wheel building. 



Shimano Alfine 11 Hub Gear Review - In Use


In use the hub is very pleasant to use, but as with so many things it is a matter of preference as to whether the pros outway the cons.

Pros

  • Very snappy gear changes.
  • Shifter several gears at a time
  • Shift at a standstill  - this is really handy
  • Silent whilst pedaling and coasting
  • Perfect indexing very easy to set up
  • large range with no front mech
  • perfect chainline always


Cons



  • slightly spongy feel whilst pedalling.
  • rear wheel removal slightly more difficult
  • no quick release
  • slightly more complicated to fix a puncture

Shimano Alfine 11 Hub Gear Review - Conclusions


Whilst lacking the direct feel of a typical derailleur system, the Alfine 11 hub is an excellent bit of kit. 

If you are a utility cyclist, a tourer, a commuter or a rural rambler, then the quiet hassle free nature of the hub will suit you very well. It is set at a good price point and delivers plenty of range for nearly all situations. 

Time has proven the Alfine 11 to be a reliable component, and I look forward to the reduced service intervals, and quiet riding that is to come.


Shimano Alfine 11 Hub Gear Review - More Pictures 

Line up upper marks for perfect indexing. . . .

. . . .  or the bottom yellow marks.

Cable routing. . . a few zip ties required. 

Rapid fire shifter. . .

Upper indicator window is replaceable if cracked.

Shifter units is rather bulky. . . 

. . . bulky. 


Tuesday, 14 March 2017

Commencal El Camino Frame Review

Commencal El Camino Frame Review  -  Intro


Commencal are an ANdorran company that market this frame. The El Camino is billed as an everyday frame, and it a tough, versatile offering which might be considered for building up a commuter or a touring bike.

It is designed for 27.5 wheels up to 2.2" diameter, but I was running is with 26 x 2,34 tires, and it then has room for mudguards / fenders also. Fork is Salsa Firestarter Fork. So the bike can be built like this:


Or like this:

Which makes for a pretty versatile frame.

Commencal El Camino Frame Review  - The Ride 


This was my only negative. The ride is fairly solid, I think this is because I switched from a reynolds steel frame, to this one. Some may actually prefer this it certainly feels very solid and reassuring. I was not zinging this thing down alpine mountain sides so I'll leave any further comments here to those more qualified.



The frame has a lowered top tube by means of the gusseted upper seat tube section, which is a nice features and allows for a low step over height whilst using high vole 26" tires or 27.5" tires. The seat post is 31.6mm which allows for the use of dropper seat posts, although you can get normal seat posts in this size.

Commencal El Camino Frame Review  - Mounting Points


Excellent. There are threaded mounting points a plenty. Lots for mudguards, and the pannier rack mounts near the drop outs, are very deep so should withstand punishment. Unfortunately these do have to be shared is you are using fenders / mudguards, but this can be got round with a simple plate to add an additional hole for mounting fenders / mudguards which after all do not require much strength in the way of mounting points.



Commencal El Camino Frame Review  - Finish


The decals are beneath the lacquer and so are unlikely to be come scuffed. The frame I think is powder coated rather than painted and is a very high quality finish.

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Salsa Firestarter Fork Review

Salsa Firestarter Fork Review - Intro


A lot of the nicer MTB frame nowadays come with geometry to match a high travel suspension fork. If you want to then fit a rigid fork this limits you options, as you will need a long fork, to match the sagged height of your suspension fork, so as to not alter you head angle and relative saddle  / bar height. You can see Thorpy's Guide to Rigid Forks for more detail.

Used here with 26" wheels. Ideal for emulating long travel forks. 

Salsa Firestarter Fork Review - Ride


The fork visibly flexes as you ride, and has a lovely soft feel to it. I do not ride hard or fast, so I can not tell much more than that. My main requirements are that stuff is strong and comfortable, and the fork is certainly both of those.



As the pictures show I was using this fork with 26" wheels with 2.35 tires. It did not feel odd in any way, and I think the fork is good quality.

Salsa Firestarter Fork Review - Length


One of the best features of this fork is the 300mm steerer, but if you are listening salsa why not make this 400mm. Combine this with the axle to crown length of 483 and the whole fork is 783mm long, which is not a million miles away from the Thorn Forks (Mt Tura / Nomad), which measure in at around 830mm combined.

Salsa's "Enabler" Fork has a 350mm steerer, which would be nice, but the drop out spacing =130mm.

Uncut this fork will provide a ride that is considered up right for most.

Salsa Firestarter Fork Review - Mounting Points


There are mounting points everywhere, but not for low riders. There are 6 bolts holes (all supplied with M5 hex bolts) which are to be used with "Anything Cage Mounts". These are like giant water bottle cages in to which you can strap stuff like dry sacks or stoves.

In the arid expanses of the US I can see this being a OK, if rather clique concept. But in the UK. Everything would end up covered in mud for 60% of the year. Not Ideal.

"Classic" Fender / Mud Guard & Pannier Rack Mounts


Disk Brake Mounting point is present with rotor sizes up to 203mm accepted.

It is a bit of a faff using huib brakes with this fork, as the stanchions are so wide, but I doubt whether many will be doing this.

"Trendy" Anything Cage Mount Points


Mudguards or fenders can be mounted, but you will require some kind of fudge to bridge the mounting point at the crown. On my 26" wheel this gap is large, but on a 29 inch wheel or a 27.5+ it will be less of a problem.

Bodged Torque Arm Mount for Hub Brake. 

Salsa Firestarter Fork Review - Salsa Blurb


  • 100mm Suspension Corrected CroMoly fork
  • Suitable for Fargo and El Mariachi, and many others
  • Specifications*Steerer type: 1-1/8" straight(300mm)
  • *Axle to Crown: 483mm
  • *Fork Offset: 45.0mm
  • *Stem Clamp Diameter: 28.6mm
  • *Crown Race: 30.0mm
  • *Wheel/ Tire Compatibility: 29 x 2.4" max. tire fitment (but I had no trouble fitting Surly 3.0 tyres)
  • *Disc Brake: 51 mm I.S. Mount, 160 mm rotor Min, 203 mm Max.
  • *Fender Mounts:yes
  • *Rack Mounts: at Droput and Mid-blade*
  • Water Bottle Mounts: Anything Cage mounts of front of fork
  • *Dropouts: Stainless steel, forward facing
  • *Front Axle and Hub Info: 100 x 9 QR
Usual Warning 

"Dropper Plate" for Mudguards Required

Saturday, 4 March 2017

Drag Wood with Quad Bike

Drag Wood with Quad Bike - Intro


If you do not have a trailer, or in may case the ground is too boggy for the use of a trailer then you may consider dragging wood behind the quad bike. This is a stupid idea, and I do not recommend that you do it.

This is probably quite dangerous for the following reasons, and some other reasons that I can not think of:


  • The wood could dig in the ground causing you to stop suddenly.
  • The wood could dig in temporarily and then spring forwards hitting you in the spine, neck or skull or the bike.
  • The wood could carry on sliding when you stop and bash in to the quad bike.
  • The ropes could slip of the wood, and spring forward under tension hitting your spine, neck or skull.
To this end consider the following:

  • Use thinner rather than ticker rope so it is will snap easily, avoiding build up of tension.
  • Do not use chain or wire.
  • Do not use hook on the end of the rope. 
Like I say this does not cover everything but is better than nothing in terms of safety precautions. You might try wearing a a helmet and horse rider's body armour if you have it. 

Drag Wood with Quad Bike - How I Did It


I dragged about 300 lengths of wood, about 400 meters across a muddy field. I made slip knots in four length of rope, and put these around bundle of wood.

It worked OK, but the knots slipped off the wood occasionally. It is better to drag smaller multiple bundles than one big one. 

The wood gets covered in mud, and is tricky to work with thereafter. 

Muddy Business

Small Bundles are Better

Drag Wood with Quad Bike - Conclusions


Messy and dangerous but possible. 


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Tuesday, 28 February 2017

Specification vs Strategy

Specification vs Strategy 


What is the difference between a Specification and a Strategy?


Specification



noun

1.
the act of specifying.
2.
Usually, specificationsa detailed description or assessment of requirements, dimensions, materials, etc., as of a proposed building,machine, bridge, etc.
3.
a particular item, aspect, calculation, etc., in such a description.
4.
something specifiedas in a bill of particulars; a specified particular,item, or article.
5.
an act of making specific.
6.
the state of having a specific character.

Strategy


NOUN


  • 1A plan of action designed to achieve a long-term or overall aim.
    ‘time to develop a coherent economic strategy’
    mass noun ‘shifts in marketing strategy’
  • 2mass noun The art of planning and directing overall military operations and movements in a war or battle.
    ‘he was a genius when it came to military strategy’
    Often contrasted with "tactics" (see tactic)
    1. ‘non-provocative defence strategies
  • 2.1count noun A plan for directing overall military operations and movements.

Conclusion


Whilst a a strategy may explain what you are intending to do, a specification will describe how you are going to do it. 


Surface Water Drainage Strategy 

Thursday, 23 February 2017

Rigid Forks for Commencal El Camino

Rigid Forks for Commencal El Camino - Intro


The Commencal El Camino Frame has lots of mounting points for fenders / mud guards, racks etc. and as such make a great rough stuff touring, utility frame. To increase loading option still further, you may consider rigid forks from surly or salsa. But what length of fork is right.


Rigid Forks for Commencal El Camino - Axle to Crown


The axle to crown measurement is the one to look for. This is some time listed as AC or A/C. It is the measurement from the axle to the crown of the fork, the crown is where the crown race sits.

The Commencal El Camino full bike is supplied with a RST Blaze 27,5" Fork, the  axle to crown measurement for this fork is 495mm.

Rigid Forks for Commencal El Camino - Sag


When you hop on a bike with suspension forks the forks squash down a bit. This is called sag. Racing bikes are set to have about 10% sag, whilst non-racing bikes might have 30% sag. An average of 20% is usually used. So if you apply this sag figure you are looking at a length between


  • 445mm (10%)
  • 396mm (20%)
  • 346mm (30%)
Bear in mind that the radius of a 650b wheel is 325mm. So allow for clearance, fenders, and mud space. 

Rigid Forks for Commencal El Camino - Shopping


Most forks available from surly or salsa are at least 460mm in length. It is better to go longer than shorter, perhaps adopting the 10% sag figure from above. 

So based on the above we would be looking at the below fork options.

  • Surly Instigator (447mm) - Lots of mounting points. 
  • Thorn Mount Tura (430mm) - No disc brake. Lots of mounting points.
  • Thorn Nomad Disc Fork (420mm) - Excellent Choice. 
  • Gusset DJ26 Fork (430mm) - Cheap. But no mounting points. 

Rigid Forks for Commencal El Camino -  Good luck.

Have fun and cheerio. 

Monday, 20 February 2017

Thorpy's Guide to Rigid Forks

Thorpy's Guide to Rigid Forks - Intro


A great many of the features on modern mountain bikes are aimed at racing, and going really fast and doing stunts and stuff. People used to do all this stuff on rigid forks, and probably break their wrists in the process, but now we have entered the marvelous age of suspension forks.

BUT if you are a luddite, troglodyte or hairier than average you may want to stick with a rigid fork. But where does this leave you? Can you buy a frame that is design for massive 150mm travel suspension forks, and run rigid forks on it?

Exec. Summary - If you are running a high travel 26er or 650b, you will likley be able to find a long rigid fork to replace, but for a long travel 29er, you will struggle to find a mass produced fork to cover forks above 120mm travel.

I have produced the below table to help you decide method used is to follow (click to enlarge).





Thorpy's Guide to Rigid Forks - Length Matters

Obviously you will need a fork that fits your wheel, but there is also the ride characteristic of the bike to think about. 

An over long fork will give a "slack" ride. Some people actually like this as it makes for a relaxed steering feel. However, and fork that is too short will result in a steepening of the head angle of the bike, and the steering will become "twitchy". Unless you a slightly delusional and masochistic this is not a very nice thing. 

As you change the height of your bike front, it pivots around the rear axle. This means that sever changes in height at the front end will change the position of the pedals relative to the saddle, the taller you have the saddle set, the more difference this will make. 

Thorpy's Guide to Rigid Forks - Travel


The bike below has 150mm travel suspension forks. The frame was designed (i should think) to run with forks of this sort of size, because it looks really cool. . . and some other reasons.

There are a lot of reasons why you might want to run the above frame with rigid forks. The list is long, and might includes mounting panniers or fenders / mud guards for a practical use, whilst still allowing for the use of high volume (fat) tires and a low step over height.

But can you really put rigid fork on a bike like this? Of course you can but do some maths first.


Thorpy's Guide to Rigid Forks - Maths for 27.5"


The above bike takes a 150mm fork. We need to find the "axle to crown" measurement for that fork, or any other 150mm travel fork, of the same wheel size, which in this case is 27.5" or 650b.

If we look at Axle to Crown Lengths for 150mm travel forks is we can see that axle to crown length is typically around the 550mm mark.

So we will need to find a rigid fork the same length?  NO

We also have to account for "Sag". This is when you sit on a suspension bike and it squashes down, under your weight. For different travel forks you would apply a different sag:


  • 100mm = 20%
  • 120mm = 25%
  • 150mm = 30%


So for a 100m travel fork, you would subtract 20mm. And for the above bike we would subtract 30% of 150mm . . . .  45mm . . . which give a rigid fork length of 505mm (for the above bike).

What sorts of forks are that length?. . . , not many:

There are some high end fork with 500mm axle to crown measurements such as the:


  • 3tcycling rigid-500-mm-team (tapered headset - see below)
  • Carbon Cycles Exotic 49cm


Thorpy's Guide to Rigid Forks - Headset


So you can get a fork the right length, you now need to attach it to the bike.

Some of these bikes designed for high travel forks have a 44mm headset in which case you may already to running a straight steerer tube (Commencal El Camino), but a 44m headtube can also accept tapered forks, the above list are not tapered forks (although you may find some which are).

If you have a tapered headtube, then you may need to fit an adaptor to allow for the 30mm crown race on the above forks.

Thorpy's Guide to Rigid Forks - Mega Table


Based on the above method please find below table showing required fork lengths.









Travel 100 120 150
Wheel  Sag % 20% 25% 30%
Axle to C
26" 440 490 540
Sag 20 30 45
26" w. Sag 420 460 495
27.5" 470 510 550
Sag 20 30 45
27.5" w. Sag 450 480 505
29" 480 520 560
Sag 20 30 45
29" w. Sag 460 490 515



In general I would recommend choosing a slightly longer fork (10mm - 20 mm), rather than a shorter one. A shorter fork will result in twitchy steering. Feel free to browse for forks of the correct length, but you might opt for:


Yellow = Gusset Jury 29er or Surly Karate Monkey

Green =  Thorn Mount Tura (26")

Orange = Surly Krampus (483 mm) Salsa Fire Starter (483 mm)

Blue = Exotic 29er


Thorpy's Guide to Rigid Forks - Conclusions

Is you are riding a high travel 29er then you may well have to suffer a drop at the front end (shorter  forks) in order to swap over to rigid. However, for most other bikes with 120mm travel or smaller wheels, you will no doubt find an off the peg solution. 



Thorpy's Guide to 44mm Headsets

1 - Thorpy's Guide to 44mm Headsets - Intro


The 1 1/8" headtube has been a constant in my life for the last several years, and I have enjoyed that constancy. Unfortunately, some clever people have decided we all now need a 44m headtube, which is bigger than the "old school" 1 1/8" headtube. The redeeming feature of the 44mm headtube is that it will accept 1 1/8" straight steerer forks, and 1 1/2" taper forks. Provided you choose the correct headset. So:

Good News - You forks will 95% likely fit.

Bad News - Choosing the Headset will be tricky.

Skip the Waffle? Scroll down to Sections 5 and 6

2 - Thorpy's Guide to 44mm Headsets - Sheldon Brown


First stop of information is Sheldon Brown's excellent website. But when you consider the variety of 44mm headsets for sale on the internet, the below list of just 2 options seems a little short.

Even Sheldon does not have all the answers. . . . 


3 - Thorpy's Guide to 44mm Headsets - The 44mm Family



The frame I was upgrading to, said is requires a "ZS44 Semi Integrated". A quick search for this term will bring up a selection of suitable headsets, however I was still curious as to what is a "ZS44". I came across a very handy PDF published by problem solvers:

44mm EC or ZS? - What is that?



The above paired letters EC or ZS may precede the "44" in any 44m headset, and this relates to whether the headset will have:


  • External Cups (EC) - Like most Older Headsets
  • Zero Stack (ZS) - Think trendy.
The important difference from here on in is that the lower headset can be designed for:

  • 1 1/8" - For the upper cups.
  • 11/8" OR 1 1/2" for the lower cups. To allows for 1.5" taper on modern forks.

4 - Thorpy's Guide to 44mm Headsets - EC or ZS



ZS or Zero Stock will normally be for the upper / top or the lower / bottom of the headset.

Whilst the EC or External cup is generally only used on the bottom.

5 - Thorpy's Guide to 44mm Headsets - For Straight 1 1/8" (1.125") Steerer



Choose the following:

ZS44/28.6 - For the top.

ZS44/30 or EC44/30 for the bottom. (30 relates to the 30mm crown race).

A note: The EC bottom cup set up will add about 10mm in height to the front of the bike. This may result in a "slacker" ride, and can be useful to make up height if swapping from high travel suspension forks to rigid forks. 


6 - Thorpy's Guide to 44mm Headsets - For Tapered 1 1/2" (1.5") Steerer



Choose the following:

ZS44/28.6 - For the top.

EC44/40 for the bottom. (40 relates to the 40mm crown race).


7 - Thorpy's Guide to 44mm Headsets - Conclusions 


The 44mm headset is here to stay, as it allows the use of both straight and tapered steerers. However, you will need to spend a bit more time thinking about what combination of headset parts you need.

Many shops now supply 44mm headset parts on a mix and match basis, so you will need to know more than just the one number. 

The flip side of this added complication is that if you buy a frame with a 44mm headset, you can run pretty much any fork in it. . .  .for the time being. . . . .