Baggage on a Brompton

Carrying two full size panniers.
This is really just a proof of concept for the idea of an upward extension for the Brompton rack with two 10mm rails for mounting a full sized pannier on each side.

 

 

Add-on frame provides pannier rails at the right height.

As you can see, the panniers sit well clear of the road but very likely lower than the combined centre of mass of a rider on a loaded larger wheeled bike. The extension is made of 6mm marine plywood with 10mm aluminium pannier rails epoxied in at an appropriate height and it fastens securely atop the factory rack with four easily released clamps. Modern polyurethane wood glue enables very strong butt joints in thin plywood if the joints are close fitting and glued according to the manufacturers recommendations.
This version is 150mm wide, 215mm high and 330mm long. It weighs 790g and the lightening holes do save a little weight besides looking very technical. It's measured specifically to suit my Ortlieb back-roller panniers.
The cut-outs in the edge of the base let the adjustable hooks on the backs of the panniers fit over the side rail of the Brompton rack. The 10mm rails are placed so the panniers lean inwards by 10°.

It would be even better if it could be folded up and packed flat. That wouldn't be difficult with plywood if the vertical central spine simply dropped into slots to stiffen and lock the whole thing together once the ends were unfolded and the removable 10mm rails inserted. I'm thinking about that. It must have been much harder for Brompton designer Andrew Ritchie to figure out the fold for the original Brompton.
Someone should steal this idea and adapt it to TIG welded aluminium rod, the way many actual pannier racks are made.

Prepared pieces before the end-plate shape was refined.

Bottom view.

Wooden cleats on the base positively locate it inside the Brompton rack perimeter.  They are made just the same depth as the rack rails so that the round clamping devices bear equally on rails and locating cleats. The clamps are simply discs of plywood waste left over from the 50mm hole-sawing binge with bolts and wingnuts added. I smeared them all over with excess epoxy resin from another project to seal the end-grain edges and bond the bolts in place.

Baggage on a Brompton

Making a saddlebag mount. 
The remarkable Heinz Stücke tours this way on a Brompton. A capacious Brompton T bag on the front and a hikers backpack perched on the rear rack. Heinz left home to see the world on a bicycle in 1962 and fifty-three years later he is still traveling. The Brompton was supplied by the company in 2009 to help him achieve his plan to cycle in every single country of the world.

Heinz Stücke and his Brompton M6R

The backpack on the rack seems to be quite common among Brompton tourists, usually attached at the top to a bar fastened to the bag loops on the saddle and bungeed to the rack at the bottom.
I thought I could adapt pannier bags that I already use on conventional diamond frame bikes.
My first goal was to mount one bag behind the saddle for around town shopping and short tours. The bags I have are Ortlieb back-rollers. When carried  athwartships, I think they look better without the angled "front" some bags have to avoid heel strike when clipped fore and aft on a pannier rack. These bags would be symmetrical and identical, no "left" or "right" bag except that I retro-fitted one Ortlieb outside pocket to the "rear" of each one. The bag loops on the Brooks B67 saddle are steel which seem more trustworthy than the moulded plastic loops provided on many other saddles.
Here's what I came up with.

Pannier mounting loop

It's a simple rectangular metal loop attached to the bag loops with ultra-strong nylon zip-ties. At 270mm wide, it suits the widest spacing of the two adjustable attachment hooks on the bag.

Bag sits on the rack. Stabilized by a cord lashing.

The depth of the loop is 145mm. This allows the bottom of the bag to rest on the rack. It also allows room for a big load crammed in under the roll-top bag closure to still be below the saddle. If the cord lashing was replaced with a loop of strong shock cord the bag would be almost  as quick to unclip as on a conventional rack. The loop does not get in the way when the bike is folded.
A different bag or a different seat height will probably need to have the loop dimensions adjusted.

Side view

Materials list:

1 metre 6.3mm galvanized steel rod

250mm 10mm OD aluminium tube.

120mm 8mm OD aluminium tube

JB Weld epoxy steel adhesive/filler

I considered using 6mm aluminium rod for the loop but decided that the steel would be stronger with only a small weight penalty.

The bending jig

The bending jig wasn't too much trouble to make considering the neat result. Just a 50mm thick slab of wood with bits of 25mm broomstick in holes drilled to suit. The 10mm aluminium tube is just the right size to accept a bag hook. Many racks are made of similar diameter material. It was centered on the metre length of steel rod and I glued it in place with JB Weld, though leaving it loose would create no problem. The bottom two broomstick pegs were initially left out to permit bending of the rod well beyond 90 degrees at the top two corners. This created nice tight radius bends. The nails and later the clamped on wood blocks were progressively added to maintain the tight radius when the rod was bent back to 90 degrees. The one metre of rod stock was more than enough for this job. It's easily bent by hand using a short length of steel conduit slipped over it for added leverage. When I was pleased with the bends, I trimmed off the two rod ends with a mini hacksaw.

Job completed.

Finally, the 120mm piece of 8mm tube was buttered up well internally with JB Weld on a bamboo skewer. It is a close fit and just the right length to be slid fully over one of the rod ends, then slid back over the other end and centered to securely close the loop of rod. The loop has since been given a couple of coats of rattle-can black lacquer.

Next in this blog: A device for carrying two Ortlieb bags on a Brompton rear rack.

Installing and Removing Pedals

Crank arm holding device.
The Problem: Pedal spindle threads are very often hard to move at first when a pedal needs to be unscrewed from a crank-arm. On the other hand a pedal needs to be tightened snugly when it's being installed.
People have various ways of preventing the whole crank-set from turning when pressure needs to be applied to a pedal wrench. You can reach through the frame and grasp the opposite crank-arm with one hand while using the pedal wrench on the closer pedal with the other hand. As your finely conditioned and muscular arms tense against each other  the wrench will often slip resulting in lacerated knuckles.
I've seen the opposite crank-arm lashed to the chain-stay with a spare toe strap which may not be good for the chain-stay or the strap. And it's useless if you don't use toe-clips and have no straps.
You can put a foot tall block under the opposite crank-arm when it's horizontal which always means that you must hold the bike down while pulling up on the pedal wrench.
Full time professional mechanics seem to manage it with no more than their two arms, a wrench and long practice but it's the amateurs can often use a little help.

My Solution: It is inspired by a veteran mountain biker I knew who had an eight inch tall stub of stout hardwood fencepost with a slot cut into it sticking out of the ground outside his workshop.

Fairly good pedal wrench (left) Better pedal wrench (right)

I made my variation on the slotted fencepost out of 19mm plywood that was once a shelf. The pieces are simply glued and screwed together. It's 190mm high with jaws 40mm apart which suits all the bicycles in my fleet. Bikes with non-compact chain-rings may need it to be made a little lower. Measure before settling on a height.
It hangs on a nail when not in use and makes a handy place to drape inner tubes under repair while the patch glue is drying.

In place on the drive side

Stand on it with both feet

You can hold the bicycle steady with one hand on the top tube and use the other on the pedal wrench. If you need to tap the end of the wrench with a mallet just to get things moving, bend down and wedge the top tube under an armpit to get both hands free.
That's about it really. The wooden jaws won't mar the crank arms but if you are fastidious you can always pad them with shop rags. And make sure you have a properly fitting and substantial pedal wrench.

Headset Spacer Tube

Replace a stack of individual headset spacers.
This won't interest athletic folk with handlebar six inches below seat height and only a couple of centimeters of threadless headset spacers. However there are plenty of home tinkerers who love long steerer tubes and handlebars level with the seat or even higher. They finish up with this look.

8cm of spacers

I first considered the possibilities of replacing half a dozen spacers with a single long tube spacer when fitting a cheap new fork to a ratty old MTB. I wanted the bars high and my junk box was devoid of 20mm spacers. Repelled by the idea of a teetering stack of 5mm and 10mm spacers, I soon discovered I had a likely looking length of scrap 32mm aluminium tube. Yes, it was a close sliding fit over the steel 28.6mm steel steerer tube.
The scrap tube was roughly hacksawn to a fraction over-length then finished with file, vernier caliper and engineers square so that the ends were both parallel and square to the tube axis A final check with a surface plate and square confirmed that the simple hand filing job was accurate enough for the purpose. It would be simpler and quicker to face the spacer ends in a lathe with a big enough spindle hole behind the three-jaw chuck but the  machine I have isn't that large.

The idea worked so well on the ratty MTB that I soon decided to extend it to nicer bikes in my herd.
A visit to a Capral Aluminium warehouse secured 6.5 metres of 32mm round tube for $17, enough for a lifetime of bicycles. It's 6060 T5 aluminium with a smooth mill finish.
32mmO.D. minus 2x1.6mm wall thickness = 28.8mmI.D. It seems to be a common size in other metric nations besides Australia.
Citizens of places persisting with Imperial units of measurement should start by looking for inch and a quarter tube with a suitable I.D. Take a vernier caliper with you and look for a touch greater than 1.125" I.D. or a sixteenth inch wall thickness.
The 1.6mm wall thickness of my chosen tube is somewhat thinner than a bought headset spacer. The spacers I have measure anywhere between 2.3 and 3mm depending on where they came from. But I believe that my thinner walled single tube spacers are in no danger of being crushed by the forces developed in ordinary road or bike trail use. Persons engaging in extreme off-road riding are unlikely to want tall steerer tubes and won't be trying this mod anyway.

Marking jig, 200mm double cut bastard file, engineers square, 32mm aluminium tube stock.

Pictured above is a simple wooden marking jig. The length of roughly cut tube is rotated against a sharpened drywall-screw scriber. This provides a line to file down to before I start checking for squareness with the steel square.

Raw or Painted

 
The mill finish of the tube is quite attractive. It could be left as is, mirror polished and clear lacquered or simply given a coat of rattle-can gloss black.

8cm spacer tube installed

My tube is actually a closer fit than my assortment of bought spacers. I put plenty of grease on the steerer tube to avoid corroded steerer/stuck spacer syndrome in the future.

Cotton Bar Tape

When you can't buy cotton handlebar tape.
I like it because it's resistant to damage, weatherproof if shellacked, quite grippy and lasts longer than a year or so. It also has that endearing retro look that goes well with twine for securing the ends.

It isn't easy to get here in Australia and I certainly don't see it in my LBS. The good tape from Newbaum's  has inflated to $12 a roll by the time it's reached the few Australian online bike shops that carry it, and you need two rolls for a typical drop handlebar. Add the cost of a postage bag to that and it's getting to be a luxury.
Mail-order across the ocean is equally problematic. None of my preferred overseas suppliers have it. Other suppliers who do have it want from $5 to $10 a roll and have minimum overseas postage rates of $30 or even more.

I decided to do some lateral thinking and I discovered some inch wide twill weave cotton tape at a local haberdashery for $3.99 a roll. There's 9 feet on the roll and it looks exactly the same as the stuff sold as bar tape. One minor drawback is that it only seems to come in four colours, beige, white, red and dark brown. This particular stuff is made in China but packaged by Simplicity Creative Group, headquartered in Antioch, Tennessee USA.

White, Brown, Beige

 They say it's for tote bags, backpack straps, drawstrings and hemming but now it's for taping bicycle bars. Naturally, it does not have the adhesive backing found on Newbaum's and other brands of cotton bar tape. I thought I could solve that with some 12mm wide double sided adhesive tape. I use it around the workshop for various purposes and I had some on hand. This is not the foam backed mounting tape typically seen on the 3M Scotch rack. It's a very thin membrane with adhesive both sides and a layer of waxed paper on one side to stop it sticking to itself. If it can't be found in your hardware store you can get some from Jaycar Electronics, part number NM-2823. At $3.95 for a 25m roll it is amazingly cheap. Enough to convert eight rolls of cotton tape to handlebar tape.

www.jaycar.com

The best way to apply the adhesive is to lay the cotton tape out straight on a tabletop and hold it taut but not stretched with a couple of bits of masking tape. It's very easy to stick the 12mm adhesive tape with its waxed paper backing right down the middle of the 25mm cotton tape.

Laying on the double sided tape.

 Run a thumb along it to be sure it's stuck then firmly roll the prepared cotton tape back onto the cardboard spool. Does the adhesive stick? Yes, amazingly well. An inspection proved that the adhesive has almost become part of the cotton tape.

Excellent adhesion

After that you can treat it like any other handlebar tape. Wrap it on firmly with a 50% overlap and the adhesive strip ensures that it stays in place. Unlike cork filled foam bar tape, you won't break cotton tape if you pull on it too hard, nor does it unwrap itself if you let go of it.
I wanted it on the hook portion of a Nitto Albatross bar. Here it is, wrapped on, twined and varnished with a couple of coats of amber shellac flakes dissolved in methylated spirit. 

Nitto Albatross bars.

The beige cotton darkens considerably when amber shellac is applied but that was the effect I was looking for. The shellac soaks right in and binds the overlapped tape into an immovable whole. The twill weave remains grippy as long as you don't use too much shellac. And when it gets grubby in a couple of years I can lightly sandpaper it and recoat it with shellac.

Stuff I Like

BBB BHP-20 and 21 Steerer Tube Extender

BHP -21 for 1 1/8" steerer tube and 28.6mm stems

Made in Taiwan and marketed by those wonderful Netherlandish folks at BBB.
It's one way of lengthening a threadless steerer tube that's too short.
Here's another way, not by BBB in this case but they do make something similar.

Another sort of steerer extender.

This type of extender works fine but the clamp bolts are highly visible and very ugly. Clamping the separate stem as high as possible on the extension may be too high. Clamping lower leaves some of the extension showing above the stem, waiting to get you in the groin when you crash.
The BBB BHP-20/21 does not use an external clamp. It fits down inside the steerer tube and is fixed in place by a sliding wedge system just like an old fashioned quill stem. It's an especially good solution for a threadless steerer but it can also be used with a threaded steerer, 

When using this extender with a threadless steerer you will continue to set the preload on the Ahead type headset bearings by selecting a stack of headset spacers below the stem and adjusting the top cap. Using the standard preloading process is one of the  great conveniences of this product.
 
With a threaded steerer, the preload is set as usual by the headset's threaded top bearing cup and locknut. The extender acts only as a quill with a maximum height of 75mm. You have a choice of separate stems with various rise and reach but the quill height is fixed during the fitting process. There are quill type extenders from other makers which allow more height than 75mm and can be raised or lowered at any time. Many users of threaded forks will still prefer the classic look of a one piece quill stem.

How it is made.

 Here are its components. It's claimed to be all 6061 aluminium alloy except for the long stainless steel wedge clamp bolt and the shorter top cap screw. The main body of the quill has a 10mm wall thickness which makes it acceptably strong and rigid. The 75mm stack of shiny rings adapt the quill to the stem clamp diameter. They range in depth from 20mm to 5mm. You decide how much longer you want your steerer tube to be and slide off rings as necessary to suit. The less length you need, the more the quill sinks into your steerer tube. I guess that the minimum insertion depth is at the bottom of the 75mm ring stack. Fewer rings equals greater insertion which can only be good for strength and rigidity. The rings are split to accommodate compression by the stem clamp and keyed on the inside to match a groove in the back of the quill.

Arranging the split and keyed rings for a 45mm extension

You will need to remove the star nut in your steerer tube before fitting this extender. A sharp 9mm bit in a portable drill will destroy the swaged connection between the top star shaped spring and the threaded nut core. Both top and bottom spring will then usually tilt in the tube and be easily removed with pointy pliers. You can try driving the star nut all the way through with a long drift but that gets very hard if your steerer tube is thicker walled down at the fork crown. Star nuts are cheap and you really should have a spare on hand just in case you want to change things back in the future.

This extender must not be used with carbon fiber steerer tubes. If you have an alloy steerer tube, check first to be sure the quill will fit. Sometimes alloy steerers have thick walls and a small ID.
I'm sure I would not use this or any other steerer extension on any sort of bicycle used for hard off-road work. However, I think it would be fine for on-road use.
The BBB extenders definitely work with steel 1 1/8" steerers of 25.4mm ID and steel inch steerers of 22.2mm ID. But not with old French steerers of 22mm ID.

Tightening the wedge bolt. Original spacers still in place on the steerer. Cane Creek 40 headset and Problem Solvers locking headset spacer for convenience.

Use plenty of grease when assembling, particularly on the sliding wedge surfaces and the screw threads. A 6mm allen key tightens the wedge clamp bolt. The manufacturer quotes no torque figure for the clamp bolt. Use your imagination, bearing in mind that the sliding wedge is made of aluminium with aluminum threads. The threaded hole for the top cap screw is inside the bottom of the 6mm hex.

Looks neat. Nothing visible to suggest the presence of the extension.

 It remains only to add headset spacers until the top of the stem clamp is 3mm or so above the top of the new extension. Then tighten the top cap screw with a 5mm allen key as you'd usually do to preload the headset bearings. Torque the stem clamp screws to manufacturers specs.

Summary:
BHP-20 is labelled 22.2/25.4. It fits inside an inch steerer tube of 22.2mm ID and needs a stem with a 25.4mm steerer clamp (or a stem with a 28.6mm clamp and a 25.4mm shim adapter)

BHP-21 suits most modern bicycles and is labelled  25.4/28.6.  It fits inside a standard
1 1/8" steerer tube of 25.4mm ID and takes a stem with 28.6mm (or 1 1/8") clamp.

Weighs 250g.

Available at time of writing from Wiggle UK at the following prices.
USD 13.85 GBP 9.18 AUD 18.08

Bike Light Battery

Today I added a long page about making a Li-ion battery pack for bicycle lights.
See it here