DIY 69er

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  • DIY 69er
  • the_pilot
    Member

    Having done the numbers, I was thinking of building a SS 69er from a 2009 Orange P7, all british, well as far as poss.

    Designed for a 140mm, so approx 520mm axle to crown, use an on One carbon fork at 470mm, + 38mm for the additional radious, 12 mm shor, so perhaps a third of a degree steeper on the head tube would give 73deg seat and 69.3deg head, which seem like pretty good angles to me, very close to 73/70 norm.

    Any thoughts/comments.

    The reason I like the P7 idea is the flexible dropouts, I don’t want a mech hanger spoiling the view, I could also run a rohloff if I really wanted.

    I want to run my SS rigid, so a 29 front wheel makes some sense to me, but I am not sure I want to go the whole hog to 29.

    I have a rohloff hardtail and full suss so I kind of need a reason to ride a SS given I have no winter/maintenance issues so different is good…

    It is either a 69 or 29er I think, I like the niner but loadsa cash for something I’m not sure of, I want steel….discuss

    I_Ache
    Member

    Im sure Brant said the other week to put the 26″ carbon forks on a DIY 69er. Cant be bothered to work out which is the 470mm length but there you go.

    rolfharris
    Member

    I’ll be honest, since I got a Rohloff I stopped SS’ing except for the champs. The rohloff has all the advantages of SS with gears. It’s great.

    Premier Icon BillOddie
    Subscriber

    I have seen a diy 69er using 100mm correctyed frame, surly 1×1 forks (which are short) and a 29in wheel in Dirt Rag. Worked well apparently.

    http://www.dirtragmag.com possibly

    Premier Icon brant
    Subscriber

    Designed for a 140mm, so approx 520mm axle to crown, use an on One carbon fork at 470mm, + 38mm for the additional radious, 12 mm shor, so perhaps a third of a degree steeper on the head tube would give 73deg seat and 69.3deg head, which seem like pretty good angles to me, very close to 73/70 norm.

    520mm = unsagged length. With sag it’d be 520-(140/4) = 485mm ish.

    440mm + 38mm extra = 478mm = goodtimes = as near as dammit/touch steeper which = good, as bigger wheel = more trail so steeper head angle = less trail = quicker steering.

    with 470mm you’ll be a good 30mm too high = badtimes.

    qwerty
    Member

    singular do some short a2c forks

    Keef
    Member

    RC 31’s 440’s are what you want.

    the_pilot
    Member

    Thanks chaps, I was thunking about this and even considered contacting Brant…no need.

    I had, until altruism got the better of me (let my mate have my SS inbred/RC31 combo) thinking of adding a 29front to it because there is easily enough clearance.

    My concern was making a bike corrected for 100/120 forks too slack, so options appeared to be around 456 or P7

    I even thought about trying it on my Ti456 but like it as set up with Rohloff.

    Rolfharris is right, I don’t need a SS, the rohloff solves the maintenance issues but….well there is something about riding one that puts your mind in a different place.

    Many thanks, seems like it might be a plan 😆

    mmmm or go the 29er, problem is I don’t know anyone with a 29er to ask for a ride!

    YoGrant
    Member

    thepilot…if you are near the north or south downs then you can try either of my singulars out.

    I have proto hummingbird 69er (with the configuration of fork you are talking about so that it can also run a 26 inch front wheel and 120mm sus fork). See this months singletrack for a review.

    also have proto gryphon which is a drop bar 29er.

    email: yoeddygrant at hotmail dot co dot uk

    STATO
    Member

    YoGrant – what length and rake are they? and any idea when sam will be releasing them?

    YoGrant
    Member

    dimensions are on the website I think.

    don’t think sam is releasing the fork separately…i meant you can have a go on my singular bikes to get a feel for it if you like.

    can measure the forks for you later…never know, sam might be able to sort you out with some.

    the_pilot
    Member

    I do like the singular, and it ticks most of my boxes, I was going to take a punt on Swiftaculars when he put it up for sale, but he changed his mind 🙁 the only ‘worry’ I have is the ebb. My concern is not based on any direct experience, but I do have an engineering background and can see why there could be issues with ovalisation of the BB or slippage/creak on the designs I have seen.

    The niner solution appears to be logical to me, but I do not know whether the size of ebb’s is universal.

    Thanks for the offer YoGrant, I do not live near you, but that doesn’t mean to say I couldn’t travel down 🙂

    Phil

    Premier Icon brant
    Subscriber

    don’t think sam is releasing the fork separately…

    if sam doesn’t, I’m going to.

    the_pilot
    Member

    And I should’ve thanked Brant for chipping in with the advice, Brant Thanks 😀 for your advice, your services to design (my Ti456, and teaching me that frame designers when they quote angles invlude forksag, although they don’t say how much and for what fork..I have had experience of two different forks recently that required quite different sag to work properly,Magura Thor and DT Swiss EXC150, which did change the way my 456 handled noticeably even tho the axle crown was within a knats wotsits.

    Still most tempted by a P7 experiment…maybe I will try it on my 456 first…doh

    Sam
    Member

    I will have some extra Hummingbird forks for sale separately when they arrive, likely in a more neutral colour. My forks are 445mm with 55mm of offset. They are really intended for the conversion of a 26″ bike with a 100-120mm fork, might make something designed with longer in mind a bit too quick even with the big wheel.

    richc
    Member

    What sort of price will the fork retail at Sam?

    I rode my mates 29er and it felt like riding a gate I was up so high on top of the bike. It was great once you had it going but never felt right to me. I stuck a 26″ wheel on the back to see the difference and it immediately felt better even with the angles all to cock so I bought myself a custom built Carver 69er.

    I absolutely love it. It really flies over little bumps and I hardly notice the lack of suspension.

    I then decided to still a big wheel on the front of my Scott Strike but the short front fork meant I had to run a skinny CX tyre. I have no idea what this is meant to have done to the geometry but rides extremely well. The front wheel lifts a bit on climbs but other than that it just feels faster.

    I am not claiming it is the new niche and I only did it to wind up some people at Swinley but as 67ers go, it is pretty good.

    richc
    Member

    So if I am reading this correctly if I want to try a 29er wheel on the front of my 100mm corrected hardtail I need to get 425mm ish corrected fork, or will that not give me enough clearance for the wheel.

    Also WCA that Scot looks wrong, and doesn’t it clog something awful in the mud

    Yeah, I know it looks wrong but it does actually work on the Swinlet and Lordswood trails. Amazingly it doesn’t clog even though there is less than 4mm of clearance.

Viewing 19 posts - 1 through 19 (of 19 total)

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