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  1. #1
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    Brompton overhaul help...

    Hi, I have a 1999 brompton with stock standard parts from the time... It sat in a shed by the bottom of a roller door for almost 10 years so it was a little exposed by whatever moisture etc got underneath it... I sold my bike friday pl after touring asia for 2 years as it was not a convenient fold and the brompton i can put in my tent with me when sleeping in built up areas etc... although the ride of the bf was excellent.... Anyway i now plan to overhaul this brompton completely and will have many questions along the way as i am definitely no bike mechanic and i would like to draw upon the expertise of some of you guys... Right now i these are my questions....

    1. I want to put double chainring on it, i know there are threads about it but i couldnt really get it and most were talking about square taper cranks... Can i put a different type of bb on a brompton? Why wont any kind eg octalink fit? Also is there a specific length of bb you can reccomend or does it depend what particular double chainset i get?

    2. The hub... This hub hasnt done many km as i know the previous owner bought it, had some problem with it (which after my own research i guess wouldve been from cable) anyway they took off the tensioner n toggle chain which is now missing & i didnt get the chance to even ride it yet... Tried to open it gave up and then put it in the shed n forgot about it.... The whole bike n hub was covered in a kind of mouldy dust mixture but not really rusty so im wondering if this will effect the hub, if so can i put the internals from an old aw3 into a brompton hub? As they are cheap and so many of them conpared to expensive brompton hubs.

    3. The brakes... Like i said i didnt get to test yet but they are the old calipers if i get these shimano bl 550 levers and some pads (im thinking these as they are cheaper than the kool stop) Clarks 72mm Alumium Triple Contour Brake Shoes | Chain Reaction Cycles.... Will it improve much?

    4. The wheels... My bfri had xt hubs, dt swiss spokes on a alex dm18 dw rim... And these old brompton wheels look erm... Fragile... Will they stand up to 100km a day rides with 25kg of gear? As they are small maybe theyre stronger than they appear, brompton owners how did your old single wall rims hold up?

    Thats a lot i know, and im sure as i go there will be more questions, im learning as i go from internet and my local bike shops are unfriendly, very money hungry and uninterested in this bike they said they "don't touch those old internal hubs" so help me out guys....


    Thanks in advance

  2. #2
    Senior Member bhkyte's Avatar
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    Hi if you have the single pivot calipers they are not great. I recommend upgrading the innercable to Teflon lined. I don't when brompton started fitting them as standard. Also, I went for Teflon lined outcable. Koolstops work very well but so do other makes of premium pads. Upgrading to current brompton twin pivot cost about 90 pounds. You can modify standard brakes but it's a pain to find the parts to reverse the pull direction.
    Bottom braket is square tapper, you can swop the crank over no problem as far as I know. You will need a Steven perry or simular bracket if you want a front mech, else go for a dirty change(manual shift).

    Many SA hubs models about. Make sure before getting internals. Its not difficult job to oil or replace the internals of a IHG. I am clueless about their black magic, but I managed to swop over the internals of a dual drive hub easily enough.

    Your rims are strong enough but jur recomemds using just the front brake for routein braking to extend rim life.
    Last edited by bhkyte; 05-04-14 at 04:37 AM.
    Dual drive Mezzo (GOLD), Dual Drive Mezzo with bullbars (black), White Brompton thingy with Dahon Androes stem and bull bars. Birdie (old sytle) 7 speed. Downtube NS8. Birdie red.

  3. #3
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    Thanks, i wont be spending that kind of money though, i got lucky with an upgraded llama for 250 when visiting london before that i was touring with a chinese 7 speed mountain bike from a scrap heap until it fell apart... The brompton seems much more durable than the bf frame was which is why im gonna use it but this will be as cheap as possible upgrades... Right now im in australia so limited availability on parts... Why cant a different type of bb go in brompton to allow more choice of cranks?

  4. #4
    Senior Member bhkyte's Avatar
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    You can use another Bottom bracket. Just make sure the width is the same otherwise you may interfer with the fold.
    Dual drive Mezzo (GOLD), Dual Drive Mezzo with bullbars (black), White Brompton thingy with Dahon Androes stem and bull bars. Birdie (old sytle) 7 speed. Downtube NS8. Birdie red.

  5. #5
    Senior Member Ed in Toronto's Avatar
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    If you don't want to spend money on it, than probably it might be better if you just leave it as a single chainring in the front and just peddle harder when you come to a hill. That way you can put your budget into doing a proper job of rebuilding, replacing or upgrading the wheels, and brake parts or new cables and rubber.

    After you get it working smoothly. Then down the road or next year you can look at putting in an extra chainring. But for now you'll have one less thing to worry about.

  6. #6
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    Oh i will have to spend some money but 90 for a set of brake calipers seems like a bit of a killer if i can get away with only replacing levers n pads which i suppose needs to be done either way... A double crankset seems relatively inexpensive as i have access to some free double cranksets from old bikes right now so im just looking for advice from others who have done this mod and what size bottom bracket they used and anyone who has tried swapping hub internals should need be as the shed this brompton was pulled out of got flooded once im told... next year ill be far from any western country (and never returning to one if i can help it) and back to using sign and body language... Or possibly be road kill by then ive got 8 weeks more in australia so im trying to do what i can now...

  7. #7
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    One more thing... The headset removed from the bike friday (chris king gripnut)... This is a 1 1/4?? So cant be put onto the brompton?

  8. #8
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    What are other high quality headsets for the brompton? Thanks

  9. #9
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    Brompton uses a 1 1/8" threaded headset and very few of those are made nowadays.

    The hub will be fine, run some oil into the hole where the indicator chain goes.

    I'd change to decent brake levers (not V-brake levers), cables and pads. Make sure the length of each cable isn't too different from the originals.

    Check the rear triangle, they tend to rust through.

    Some folk used to bolt a smaller ring to the outside of the existing chainring (instead of the chainguard) and hand shift when they got to hilly regions.

  10. #10
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    Thanks a lot for the advice mate, will do.... Can anyone say if any of these headsets will fit a brompton? Thanks

    Cane Creek Tank Hit EC34 Conventional Headset | Chain Reaction Cycles

    http://www.chainreactioncycles.com/m...3/rp-prod39820


    Or one of the old shimano 1 1/8??? Thanks

  11. #11
    coprolite fietsbob's Avatar
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    step 1: buy a caliper to accurately measure the part of the headset that inserts in the frame head-tube .

    that is a significant piece of data, the other is the fork crown race seat diameter .

    armed with that data you can ask better questions of the sellers..



    My old Mk2 Brompton I removed the axle bearing cones and used Grease on them and put it back together ..

    Then did the oil down the hole where the indicator chain goes , for the gears inside.

    + I put KoolStop's continental model salmon compound brake pads on .
    Last edited by fietsbob; 05-05-14 at 10:55 AM.

  12. #12
    Senior Member smallwheeler's Avatar
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    Quote Originally Posted by Homeless View Post
    Thanks a lot for the advice mate, will do.... Can anyone say if any of these headsets will fit a brompton? Thanks

    Cane Creek Tank Hit EC34 Conventional Headset | Chain Reaction Cycles

    Ritchey Pro Logic Threaded Headset 2013 | Chain Reaction Cycles


    Or one of the old shimano 1 1/8??? Thanks
    sometimes it is difficult to accurately measure tubes even using a digital caliper. below is a pic of a brompton that has a chris king gripnut headset. the dims for this headset are listed as:

    weight
    (g)
    total
    stack

    height

    (mm)
    lower
    stack

    height

    (mm)
    cup
    skirt

    (mm)
    head
    tube

    I.D.

    (mm)
    base
    plate

    I.D.

    (mm)
    fork
    crown

    O.D.

    (mm)
    1-1/8" 109 33.9-38.9 13.7 34.0 33.9 30.0 30.1

    you can use this data as a guide. it's possible that the 90's era brompton had some different dims but, most likely any conventional threaded headset with dims similar to the king headset will work for your bike.


    here is a generic headset that's listed as a "scooter" headset. although it is probably just a conventional standard 1 1/8" threaded headset. you can contact the seller for dims. coincidentally, they are based in australia.
    if it works, it would be cool as they are sold in a variety of anodized colors..

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