Viewing 28 posts - 1 through 28 (of 28 total)
  • EBB frame run fixed?
  • james
    Free Member

    Someone commented on another thread (on dropouts somewhere else) that you could run an EBB frame with a fixed drivetrain instead of using horizontal rearward dropouts. I’ve not come across it before and wondered if anyone has done this, I didn’t think you could fixed with vertical dropouts? Obviously you can’t with a pushing type tensioner

    ratherbeintobago
    Full Member

    If it’s got an EBB, do you not use that to sort the chain tension?

    mtbfix
    Full Member

    I’ve not done it, but you could. As said above, the EBB should allow you to get the chain tensioned. You just need to be alive to how that will affect your saddle to BB distance.

    james
    Free Member

    Ratherbeintobago yes, my query is whether under backpedal braking not having the freewheel on a fixed setup whether the wheel won’t try popping out the vertical dropouts in any instance. With horizontals obviously it has no chance

    Not many horizontal dropout mtb frames about s/h but keep seeing a few ebb options

    james
    Free Member

    Wanting to try fixed but don’t have a suitable frame. Have an on one swap out frame but don’t have any horizontal swap outs for it

    dovebiker
    Full Member

    Should work fine, but make sure you have a strong QR, or better with a DT RWS or screws if you’re inclined to skid or use leg-braking. I’ve run an eccentric hub in vertical drop-outs for yonks without encountering problems

    the00
    Free Member

    Of course EBB is fine for a fixed drivetrain. Any comments saying a vertical dropout isn’t suitable are talking about the chain tensioning, and ignoring the existence of vertical dropout EBB frames.

    kerley
    Free Member

    Any comments saying a vertical dropout isn’t suitable are talking about the chain tensioning,

    Sounds like they are actually talking about the down forces when skid stopping as it applies a fair bit of pressure which would pull down on the dropout.
    In practice I am not sure whether the forces from skid stopping are that great as although it is a sudden jolt the tyre breaks grip at the same time.

    the00
    Free Member

    And how different is it really to braking and skidding using disc brakes? If you use a proper QR or axle system then it would be fine.

    kerley
    Free Member

    And how different is it really to braking and skidding using disc brakes?

    It isn’t and I would use an EBB on a fixed gear bike if that was my only option.
    Wouldn’t do it out of preference as adds a bit of complexity and hassle to what is the simplest bike (no gears, no brakes, no modern differing standards etc,.)

    Just pointing out that they were not talking about chain tension, that is all.

    james
    Free Member

    The braking issue is what concerned me. I can’t say any ebb frames are but I know some vertical dropout frames that are slightly angled forward which must be even worse

    james
    Free Member

    26” L/XL, my current horizontal dropout search includes, what am I missing?

    On one inbred horizontal or swap out
    On one scandal horizontal or swap out
    On one whippet swap out
    Horizontal swapouts to fit my 456
    Cotic simple only upto 19” and issues with brake mount
    Genesis io
    Was there a horizontal dropout kona unit?

    big_n_daft
    Free Member

    Kona big unit had horizontal swap outs IIRC, so any Kona on the same system. I have a set of the dropouts somewhere

    I also have a MK2 scandal XL with horizontal drop outs I need to sell

    Bez
    Full Member

    An EBB will be fine. The issue with “vertical dropouts” isn’t with vertical dropouts, it’s with using a chain tensioner (as required on 99% of frames with vertical dropouts, ie those without a BB or sliding/rocker dropouts).

    The braking forces thing isn’t an issue either. That’s just a factor for a front disc brake, where the reaction to the braking force is downward on the axle. On the rear a disc brake is mounted at the downward-moving part of the rotor so the reaction force will try to push the wheel upwards into the dropout. The only other brake related issue is when using track ends (ie open to the rear) with a brake mounted on the seat stays, when the reaction force will tend to push the wheel backwards.

    When braking a fixed gear through the chain none of these are issues: the force from the chain will tend to pull the wheel forward, but then the force from the ground is pulling it backwards, so it’s all fine.

    So crack on.

    james
    Free Member

    That all makes sense Bez

    Big n daft I’m trying to remember is a mk2 aluminium rather than scandium? And that must be about the time they were offering them in pink? Are they a touch longer in the top tube than inbreds as well?
    What kind of money might you want for it?

    Andy-R
    Full Member

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    james
    Free Member

    26” L/XL, my current horizontal dropout search includes, what am I missing?

    Genesis io

    You’re missing the fact that the IO has vertical dropouts…

    thisisnotaspoon
    Free Member

    The braking issue is what concerned me. I can’t say any ebb frames are but I know some vertical dropout frames that are slightly angled forward which must be even worse

    I can kinda see your point, and trying to resolve the forces from the chain, bodyweight and braking around the rear axle you can kinda draw up a scenario where the forces almost balance.

    But then you look at the real world and people have been running bikes with forward-facing horizontal dropouts for decades and not managed to have an issue. There’s obviously massively more horizontal force, and horizontal dropouts don’t slip either.

    big_n_daft
    Free Member

    Big n daft I’m trying to remember is a mk2 aluminium rather than scandium? And that must be about the time they were offering them in pink? Are they a touch longer in the top tube than inbreds as well?
    What kind of money might you want for it?

    It will be Al I presume, this one is brushed finish. I’ll dig it out and measure. Price? Decent offer stops it going on fleabay

    amedias
    Free Member

    Have an on one swap out frame but don’t have any horizontal swap outs for it

    I may be able to assist with some horizontal swapouts if you’re interested?

    abingham
    Full Member

    This is an interesting one. I’m a long-time fixed rider, but always on track/horizontal dropouts.

    With an EBB, then yes you could run fixed fine with a vertical drop out, but I wouldn’t use that set up if I was using my legs for stopping. For skid stops or backpedalling I wouldn’t want anything in the drivetrain that could slip under those forces, and I think an EBB has a chance of rotating if you had to pull up hard to stop quickly.

    By all means run it fixed, it’s a whole different riding experience and you may love it, but I’d strongly suggest having and using traditional brakes on an EBB set up.

    krixmeister
    Full Member

    I Am Not An Engineer, but I do own a couple of EBB bikes set up as single-speed, however not fixie. Re above @abingham – I doubt that the rotational forces on EBB during fixie braking are any different than mashing on the pedals on a steep uphill.

    But – as an old fart I also think all fixies should have a front brake at minimum anyway…

    james
    Free Member

    Hadn’t considered ebb slippage. Especially just for trying out I’m not going to be splashing out on a fixed disc hub and I don’t fancy a v brake only frame as I’d like it to be able to run a disc for freewheel use

    Amedius, I’d be interested yes, what might you want for them?

    Big n daft I wouldn’t know was a decent offer atm. eBay may be fairer

    Saccades
    Free Member

    Vertical dropouts, EBB, 8″ discs ran fixed but mostly with a hub gear.

    Think it’s 12 years old at this point with no bother.

    cynic-al
    Free Member

    Given the forces on an EBB already, I doubt what you could generate by back-pedal braking would shift one.

    abingham
    Full Member

    Given the forces on an EBB already, I doubt what you could generate by back-pedal braking would shift one.

    While I’d be inclined to agree, it’s not a chance I’d fancy taking!

    amedias
    Free Member

    Amedius, I’d be interested yes, what might you want for them?

    I’ve sent you a PM…

    tomlevell
    Full Member

    The only issue using an EBB is tensioning a fixed setup. Rear dropouts are far easier as you can walk the axle back in them by tightening one side then pulling the drive side tight. If an EBB goes baggy on a ride it’ll be a ballache to sort on the side of the trail.
    I generally ran 2 brakes on mine both rim and disk bikes. Using a front brake only on steep stuff can get exciting fast when the front wheel loses traction and no amount of rearward pressure or nuance is going to bring you back under control.
    I really need to source a horizontal dropout disk 29er frame at somepoint to repurpose my fixed/disc hub.

Viewing 28 posts - 1 through 28 (of 28 total)

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