Custom lots-of-titanium Brompton

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  • OK, so it's a Brompton, and therefore deeply uncool, but bear with me...

    While riding to the train station the other day, I had something of an epiphany - I realised that (1) I ride my Brompton more often than any of my other bikes (not in terms of mileage, obviously) and (2) it was shagged. Obviously the sensible option would be to rebuild it. Rather than doing that, I've decided to build a new one. And to make it a bit special.

    Starting point - a new clear matt laquer frame:

    But I wanted a titanium seatpost, and Brompton no longer make one. Happily, a nice Dutch chap living in Thailand trading under the name Brompfication does make one. And rather nice it is too, along with the other bits he makes. All the components on the seatpost are titanium, even the clamps and bolts:

    The saddle's a Charge Knife - like a cut-down Spoon but with titanium rails, sticking to the must-have-titanium theme. Seeing as it's a long way from Thailand, it seemed worth buying a few more bits of Brompfication Bling from him, such as the bronze release clamps:

    (which are rather nicer than the Brompton ones since they're cunningly designed so that the V-clamps stay in the right position rather than spinning around in an annoying fashion) together with the aluminium roller wheels and the titanium rear frame clip kit:

    Added to this so far is a titanium rear frame and some Campag carbon Record cranks (fitted with a Centaur 115mm sealed bottom bracket). It's early days, but after waving a tape measure over the cranks, I think it'll work. I'll only have the 53t chainring, which I'm planning to swap to the inside of the crank spider.

    Next step, some wheels...

  • liking the glass of wine.

  • This is exciting me

  • This is looking very interesting, what are you going to do about forks/bars? Can you get them in titanium too? I am beginning to wish I still had my brompton.

  • This is looking very interesting, what are you going to do about forks/bars? Can you get them in titanium too? I am beginning to wish I still had my brompton.

    Yep, front forks will be the titanium ones, the handlebars will be some flat 25.4mm straight bars I got from Taiwan via eBay. Can't fit either yet as I haven't got the stem or the headset yet.

  • This might be good reference if you're planning on going fixed

    flickr.com/photos/littlepixel/2173983253/

  • When I was in Thailand, met the Bromptification guy at a restaurant by the train station, cool guy
    #csb

  • I'm sitting next to my colleague's titanium Brompton.

    He fancies a re-spray. Is the original spray powder coat? I assume these bikes must be prone to chipping.

  • ^ the paint on bromptons is very tough - I've always assumed PC.

    From my searching the Brompton ti forks are around £270.

    For that money would it be worth having some custom light weight steel ones built? There may even be enough spare to work out a cleaner a-head alternative to the bulky stem fold section.

    Oh and these look great. My dad's ones are quite wide (stake wheels I think) and sometime catch on my trousers.

  • i have a brompton with ti bits too - for bars you may as well go carbon but if i were buying the forks for it i'd probably just go steel too - you could get some sexy custom ones made for less than the price of ti and you can sort it to run better callipers more easily ( i run campagnolo TT ones but they required a dremel and some patience)

    flickr.com/photos/tomcutting/7888900910/

  • What wheels/rims are you going to use?

  • OK, time to 'fess up, it's not going to be fixed - I've got a 5 speed SA hub for it. Even applying Rule No. 5 as much as I can, I need some gears for the routes this'll be doing (like South End Green to Whitestone Pond).

    I hadn't thought about getting some custom forks made up. Not a bad idea at all, but I've already got the ti forks, so I think I might as well use them. Personally I've never had any issues with the Brompton brakes. They're not brilliant by any means, but given a good hearty tug I can lock up either wheel if I want to.

    My understanding is that Brompton frames are all powder-coated except for the clear laquer finishes which, as the name suggests, is a wet paint.

    As for wheels and tyres, all will become clear! Working on the front at the moment, rear will follow shortly. However, I need to make some mods to my wheel-truing stand before it can take weeny 349 wheels.

  • This is brilliant. I love Bromptons and think they are cool no matter what anyone else says. Shouldn't you be worried about overtorquing carbon bars, as the handlebar bolt design looks rather old school?

    Also, what stem are you going to use - M, S, P or H?

  • This is brilliant. I love Bromptons and think they are cool no matter what anyone else says. Shouldn't you be worried about overtorquing carbon bars, as the handlebar bolt design looks rather old school? Also, what stem are you going to use - M, S, P or H?

    Shouldn't be an issue, as the bars are titanium too. They're flat bars, so I'm going to be using an S stem. I'm currently waiting for the stem (2 week order time) but the main problem at the moment is trying to source a Chris King Gripnut headset. It looks like I'll have to order to headset specially, which leaves one burning dilemma - pewter or gold for the headset?

  • Has there been a mostly cabron Brompton? If not, why not? Steal the design, lay it up yourself at home (not a euph). No? Okay nevermind.

  • OK, time to 'fess up, it's not going to be fixed - I've got a 5 speed SA hub for it. Even applying Rule No. 5 as much as I can, I need some gears for the routes this'll be doing (like South End Green to Whitestone Pond).

    I just built an Airnimal with a fixed wheel, but when I was having the wheels built I had an extra one built with a 5 speed SA hub for touring, so it will be interesting to compare the Brompton to the Airnimal. Mine rides SWEET as a fixed.

  • what bars are you using?

    *ignore me. Ive just read it

  • It's early days, but after waving a tape measure over the cranks, I think it'll work. I'll only have the 53t chainring, which I'm planning to swap to the inside of the crank spider

    That's not as simple as it sounds, the Campag carbon cranks use non-standard chainring bolts and you'll need to make a spacer to replace the outer ring where it's sandwiched between the inner and the back of the crank, and if I were you I'd make some washers to spread the load of the chainring bolts on the outside of the spider arms too. Aesthetically, it would be better to use a shorter BB and leave the rings where they are, just cut off the teeth and ring part of the inner and leave the tabs to do all your spacing and load spreading duties. Somebody on here did exactly that for a UltraTorque Pista conversion on some carbon cranks recently.

    Also, the outer ring is ramped, pinned and has lowered teeth, so expect frequent chain drop. For all of the above reasons, I can't help thinking that Record is not the way forward, and a 130mm pcd crank with 5 arms will provide more options, including this commuter friendly 57t chain ring with integral guard.

  • I'm tripping balls on the final cost of this setup. I like it though.


  • Also, the outer ring is ramped, pinned and has lowered teeth, so expect frequent chain drop.

    Surly if he's going to be using a hub gear the chain line won't be changing? But I agree, although very cool, these cranks could creat some issues like chainring bolt lengths.

  • Surly if he's going to be using a hub gear the chain line won't be changing?

    No, but the chain still flaps about, and it's going to need a sprung tensioner to accommodate the variation in chainstay length when folding, which will probably make matters worse. There is an increasing number of chain guides on the market serving the 1×n MTB and CX crowd, so it's not the end of the world.

  • 5 speed? Two speed deraillieur ftw. Though I recall bmmf saying the mech is rubbish...

  • A two-speed derailleur set-up might win me points for style, but it won't help get me up to Whitestone Pond - not with gearing that'll help me crack the 40mph barrier (I've wound the current Brompton up to 37mph with the assistance of gravity, so 40mph is the next step).

    I'll be using a chain tensioner, the standard Brompton one. As mdcc_tester has correctly identified, the effective chainstay length on the Brompton changes when you fold the rear wheel under, so some sort of tensioner is necessary.

    As for the chainrings/cranks, the plan at the moment is to dig out a suitably-sized sheet of titanium from my stores, give it to a nice man with a water cutter, and have a titanium chain guard made up and fit that in the outer ring position. I can't see that the ramps and pins will have any effect, but if the lowered teeth are a problem (and at present I suspect they won't be) then a combination of another sheet of titanium, said nice man, and my CAD package (which has a function for plotting chainring teeth) will result in a new titanium chainring with full-height teeth. All other issues should be capable of being overcome with time, and the assistance of my milling machine and lathe...

  • Has there been a mostly cabron Brompton? If not, why not? Steal the design, lay it up yourself at home (not a euph). No? Okay nevermind.

    I asked them that very question on the factory tour, and they said they don't have time/resources to devote to a full carbon Brompton. Basically, they can't be arsed.

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Custom lots-of-titanium Brompton

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