Over the Rallarvegen on Bromptons

[syklist]

After our Brompton tour this summer around 1000km in Germany and Denmark we decided to take a trip over the Rallarvegen last weekend. The price of shipping our bikes from Myrdal back to Haugastøl plus that you cannot reserve a bike space online meant that we decided to take the Bromptons on this trip too. It makes travelling by train more convenient. We went from Haugastøl to Finse on Friday night and then all the way down to Flåm on the Saturday. Our Bromptons have been modified somewhat: a different handlebar stem and handlebars and we built Nexus 8 hubs into the rear wheels and fitted double chainrings to give us the gears we need for longer cycle camping tours.

A gallery of the Rallarvegen trip is here and a bit of background on the Bromptons is here.

[John Holiday]

Just shows that a Brompton can be a realistic solution to Touring.
I too have fitted a second smaller chainring (thirtyeight tooth) which provides an excellent low range for steeper hills.

[shane]

Love your baggage solution, though I doubt my knee's would fit.

For a longer trip I'd consider a trailer for the brommy so that the basic bike stays light and compact.

[hoogerbooger]

Thank you for posting. Great blog. I have just fitted Schlumpf speed drive to my brommie for touring, but am interested in your double chainset solution for my partners brommie. What parts exactly did you use to fit the front derailleur ? how well does it work ?

[syklist]

Love your baggage solution, though I doubt my knee's would fit.

For a longer trip I'd consider a trailer for the brommy so that the basic bike stays light and compact.

Damae's legs are quite long, a lot longer than mine and she has no clearance problems when cycling. The other advantage of this baggage solution is that it puts weight on the front wheel. Without that weight I find it all too easy to pull the front wheel of the Brompton off the ground, particularly when climbing in first gear. The weight of the Brompt-o-lieb and bar bag also create a damping effect. This removes almost all of the buzzing through the handlebars you get on a normal Brompton on rougher surfaces. The ride at the front end is generally smoother and the bikes feel more stable and controllable.

[syklist]

Thank you for posting. Great blog. I have just fitted Schlumpf speed drive to my brommie for touring, but am interested in your double chainset solution for my partners brommie. What parts exactly did you use to fit the front derailleur ? how well does it work ?

I plan to post some pictures on the Mistymornings.net blog but here is a quick explanation. Both bikes were bought in the period 2003 to 2007 and are fitted with the then standard bottom brackets.

I used the cheapest double chainset with steel rings with 50/34 chainring. The inner ring on both bikes clears the rear fork. The Brompton six speed chain tensioner seems to cope with the changes in angles between the two rings but does not cope well with the difference in diameter of the two chainrings (a known problem with the Brompton chain tensioner). Care is needed when back pedalling when the chain is on the 34t chainring.

I used this front mech (FDM-360) on Damae's bike and something similar on mine. It is a top swing mech with a steel mounting bracket suited to oversize bike frame tubes. It is a short cage mech for MTB (IIRC) and the cage has been cut so that it does not foul the chain when the Brompton folds.

I had to bend one side of the mounting bracket with mole grips and used a Drehmel on the other side to open it up so that it fitted the Brompton downtube. The angles for the bolt holes changed so I used a smaller diameter bolt to fasten the mech to the downtube. I also put a layer of plastic cut from a 4l meths can between the downtube and the front mech mounting bracket to protect the Brompton frame.

The combined brake lever/derailleur changer were used parts left over when I fitted hub gears to our old touring bikes. I used only the left hand changer as the rear hub has its own Nexus twist grip changer. The indexing on the front mech works fine with the double chainset using the 1 and 2 chainring position.

Damae's changer setup can pull the chain off when changing to the 50t chainring despite being adjusted but mine never does this. I put this down to minor differences in the front mechs and the fact that the chainset is slightly close to the frame on Damae's Brompton. If she changes up slowly then it doesn't pull the chain off.

[edit- corrected URL for the link to the front mech]