16 speed Bromptons: part 6 – now properly tested

Our summer tour to Germany and Denmark was a great success. Not only did we follow the route we had planned (with two minor deviations) but nothing broke on the bikes or our luggage systems. We didn’t even get a puncture. The rear wheels were still true at the end of the trip and the gears, both the Nexus 8 speed hub and our front derailleurs worked as intended. The Nexus 8 in particular was much appreciated by the both of us, freeing us from the irritation of the Brompton two-shifter-for-six-gears system. Our two shifters now give us pretty much all the gears we need, with a total range that approaches that of a Rohloff Speedhub.

The range of the Nexus 8 (around 300%) means that we have two usable gear ranges. For general use we can stay on the 34t chainring up to speeds of 20km an hour before shifting to the 50t chainring at higher speeds. Using the gears this way gives six gears (low 6,7,8 high 6,7,8) with roughly even gaps between them. Although not as convenient as a Rohloff, the two chainring system with a hub in the rear wheel is a lot simpler to use than a three chainring derailleur system.

The Brompt-o-lieb luggage system worked well without any failures and the luggage blocks screws did not loosen off. I put this down to the fact that with a Brompt-o-lieb system the forces on the luggage block are much better balanced. This also means that the bike handles much more securely, there is none of that disconcerting wagging you get with a heavily laden Brompton bag as it wobbles on the luggage block.

We both liked the adjustable handlebars: I used them in the “foldable” position when cycling into stiff headwinds. In this position I was surprisingly comfortable. When we had a good tailwind I tended to put the bar ends up vertically so I could sit bolt upright on the bike. In variable conditions I had the bars in the horizontal position facing forwards. Damae usually just had the bar ends raised to around fifteen degrees above horizontal occasionally raising them more when we had a tailwind. But we had no problems with numbness in hands or fingers. I am considering getting some more of these bars for two of our other bikes.

One thing that surprised us was the brakes. I’ve never been terribly impressed with the Brompton brakes and have investigated getting V-brakes bosses and brakes fitted to the front forks. While we were still living in Holland our LBS at the time (SNEL tweewielers) suggested we tried some cartridge brake blocks usually used on racing bikes together with some ‘salmon’ brake blocks. I also fitted V-brake levers to both bikes as the old style Brompton brake levers, whilst light, just flexed too much for my liking. On this trip we did not have any problems with the brakes. Either we got used to them or they work well enough now. On a steep descent we still need to pull harder than with V-brakes or Magura rim brakes but the bikes stop quickly enough.

The only thing we are planning to alter is to fit new hard suspension blocks to both bikes. Even with a jubilee clip on both suspension blocks we were wasting too much energy making the bikes bounce up and down. The new blocks have already been ordered so I look forward to seeing how that improves the bikes.

We will definitely be using the Bromptons in this way again in the future. They are comfortable for long days in the saddle and can now carry all the gear we like to take on holiday. With the improvements to the gears we now have bikes that we can use here in Gol or anywhere else in Norway, instead of having them sitting on shelves gathering dust.

8 Responses to “16 speed Bromptons: part 6 – now properly tested”

  1. McKay Says:

    The new firm suspension blocks…are these the regular firm Brompton bits? And, I am very interested in the handlebars…who makes them and where did you get them?
    Awesome mods!! Also very interested in your drivetrain upgrade….
    Thanks and Happy Trails! McKay

  2. syklist Says:

    Hi, thanks for your comments. The firm suspension block is a standard Brompton part. I bought mine from SJS Cycles in the UK.

    The handlebars I found at the Rose online bike store and are called “ergotec MTB/ATB handlebar AHS Basic”. You need a long allen key to get to the adjuster screws. None of our standard multitools had an allen key that was long enough.

    The plan is to put out some more pictures of the gear conversion, but don’t ask when, as I am a bit busy at the moment.

  3. bat Says:

    Hi. Just to say there is a Brompton club in Norway, in case you did not know: http://norskbromptonklubb.wordpress.com/

    Would like to know more about what you had to to to rear frame and or chaintensioner to install the hub and make it run smoothly.

  4. Jon Says:

    Hi,
    I’ve just read the tail of your modifications with great interest. I would like to improve the steep hill climbing ability of my 2013 s6 brompton. I am seriously considering a manual move double chain ring. Are you able to advise the make and model of your chainset (from sjs I note) and bottom bracket? Any issues with chain line, or clashing when folded?
    Many thanks 🙂

  5. syklist Says:

    Hi Jon,
    I chose the cheapest 50/34 chainset with steel chainrings that I could find on the SJS website (the link may well break at some point in the future). I bought the chainsets at different times (three years apart) and there some minor differences between the two.

    Both Bromptons (a 2004 and a 2007 model) have the standard bottom brackets fitted at the time of manufacture. We don’t have any clearance problems on either bike when cycling nor when they are folded. However, our rear forks have been opened slightly to allow the Nexus hubs to fit which makes a small difference when folded.

    We have no chainline problems with the Nexus hubs. Given that your bike is a 6 speed one it should have a more flexible derailleur chain which is more tolerant to chainlines that are not perfect. A bigger problem is that the Brompton chain tensioner does not cope very well with the difference between the two chainrings. We have to be a bit careful when back pedalling when the chain is on the 34t chainring. The problem is much less pronounced after around 1100km of cycling.

  6. Jon Says:

    Hi, Many thanks for the response and the details of your chainset. Unfortunately I cannot use the same model without a change of bottom bracket; 2013 Bromptons (like mine) come with a JIS taper bottom bracket rather than the previous ISO taper that earlier bikes have. Also, I guess your chain line may be different following the 8spd conversion. (Can’t recall if you covered this in one of your earlier posts). For now I think I’ll keep waiting in the hope that I come across someone else’s success story for fitting a double to a 2013 bike….

  7. Leonidas Says:

    just a reply to Jon,

    you can get a phil wood bottom bracket which allows a 5mm movement of the axle in order to achieve the desired chain line alignment, with any double chainring of your choice. That’s what I did on mine.

  8. syklist Says:

    I suspect it would be significantly cheaper to buy an original ISO bottom bracket for a Brompton from SJS and fit that. I have tried a couple of other cheap double and triple chainsets and never had any significant chain-line nor clearance problems with the original ISO bottom bracket. An adjustable bottom bracket seems to me to be a solution looking for a problem.

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