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  1. #1
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    M6R - 76mm skate wheels on one side, 78mm on other?

    After installing 76mm wheels, the bike seems to favor the handle side when rolling along folded. It tilts somewhat too easily due to the handlebar, so I'm thinking of switching the handlebar's side wheels to 78mm to tilt it slightly back towards the non-handlebar side and keep it more balanced overall.

    76 76
    == ==
    ======----//
    ======----\\
    == ==
    78 78mm
    -Handlebar drops on this side, so the 2mm difference could make the folded bike favor the non-handle side a little more.

    Would that make any sense?
    Last edited by keyven; 03-18-14 at 12:28 AM.

  2. #2
    The Recumbent Quant cplager's Avatar
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    Huh.

    Not completely crazy. Try it and take pictures.
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  3. #3
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    Quote Originally Posted by cplager View Post
    Huh.

    Not completely crazy. Try it and take pictures.
    A bit tough to find 78mm wheels in Singapore... no one carries them anymore so I have to pick them up from Amazon... sigh.

  4. #4
    coprolite fietsbob's Avatar
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    1mm difference in radius doesn't seem significant..
    If 76&78 are both diameters. given r=1/2D

    NB: only the bottom half will affect the tilt, and that by definition is radius ..
    Last edited by fietsbob; 03-19-14 at 11:03 AM.

  5. #5
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    Quote Originally Posted by fietsbob View Post
    1mm difference in radius doesn't seem significant..
    If 76&78 are both diameters. given r=1/2D
    The total difference (diameter) is 2mm, which hopefully will be sufficient to correct the minor tilt. I worry 80mm is overkill.

  6. #6
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    Quote Originally Posted by keyven View Post
    The total difference (diameter) is 2mm, which hopefully will be sufficient to correct the minor tilt. I worry 80mm is overkill.
    If you are trying to raise one side, the 1mm difference above the centerline doesn't count.. only the 1mm below .. 76mm/2 =38mm 78mm/2=39mm 80mm/2 =40mm .. so if you want to raise one side 2mm, then 80mm is what you want to use to go with 76mm .. I'd start thinking heel strike though..

  7. #7
    coprolite fietsbob's Avatar
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    the EZ wheel is bigger than the standard roller
    perhaps leave the standard rollers front and rear on the left side

    Bromfication custom machines a roller that is thinner so less heel strike is a second gain..
    & they are pretty .. anodized Aluminum with a thinner O ring 'tire'

  8. #8
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    Quote Originally Posted by BruceMetras View Post
    If you are trying to raise one side, the 1mm difference above the centerline doesn't count.. only the 1mm below .. 76mm/2 =38mm 78mm/2=39mm 80mm/2 =40mm .. so if you want to raise one side 2mm, then 80mm is what you want to use to go with 76mm .. I'd start thinking heel strike though..
    Yeah heelstrike is definitely a problem even with 76mm wheels so I'm not quite prepared to try any bigger than I need to.

  9. #9
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    Quote Originally Posted by fietsbob View Post
    the EZ wheel is bigger than the standard roller
    perhaps leave the standard rollers front and rear on the left side

    Bromfication custom machines a roller that is thinner so less heel strike is a second gain..
    & they are pretty .. anodized Aluminum with a thinner O ring 'tire'
    Hmm that sounds interesting... maybe I'll look up their site.

  10. #10
    Senior Member bhkyte's Avatar
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    Its not the size of the wheel To avoid heel strike afaik . Of you use a rollerblade wheel just use the outside bearing and glue the wheel to the bearing. I think 2 mm makes sense from memory to keep stable without going around in circles.
    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.

  11. #11
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    Quote Originally Posted by bhkyte View Post
    Its not the size of the wheel To avoid heel strike afaik . Of you use a rollerblade wheel just use the outside bearing and glue the wheel to the bearing. I think 2 mm makes sense from memory to keep stable without going around in circles.
    That's good to hear. Thanks.

  12. #12
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    20140404_202310.jpg

    Well, I've been using it for more than 2 weeks and it's everything I hoped for.

    Fantastic stability regardless of whether I'm pushing or pulling it. I can run with it on most flat surfaces without feeling like it's going to tip over suddenly.

    It actually pushes in a straight line noticeably better than when it was 76mm for all four sides.
    Last edited by keyven; 04-08-14 at 11:35 PM.

  13. #13
    The Recumbent Quant cplager's Avatar
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    Quote Originally Posted by keyven View Post

    Well, I've been using it for more than 2 weeks and it's everything I hoped for.

    Fantastic stability regardless of whether I'm pushing or pulling it. I can run with it on most flat surfaces without feeling like it's going to tip over suddenly.

    It actually pushes in a straight line noticeably better than when it was 76mm for all four sides.
    Nice!

    Thanks for the update.
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  14. #14
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    Np, I'd highly recommend it and may even try 72-76 4mm difference in the near future since I have the wheels on hand.

  15. #15
    coprolite fietsbob's Avatar
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    Yeah heelstrike is definitely a problem even with 76mm wheels so I'm not quite prepared to try any bigger than I need to.
    the issue is width- wheel thickness , not diameter .. Brompton's EZ wheel is 10mm thick 60 in diameter.. width 140 mm overall.

    the bromfication ones are stated as 51mm Dia and thinner (not here to measure)
    Last edited by fietsbob; 04-09-14 at 12:28 PM.

  16. #16
    Senior Member bhkyte's Avatar
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    Re 78 mm hockey wheels.

    you need to skate around in a set on 80mm untill they become 78mm!!
    A good skater can reduce them in about 2 mins doing hockey stops and turns.
    I can shred them in about 10 mins to the core.
    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.

  17. #17
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    Quote Originally Posted by bhkyte View Post
    Re 78 mm hockey wheels.

    you need to skate around in a set on 80mm untill they become 78mm!!
    A good skater can reduce them in about 2 mins doing hockey stops and turns.
    I can shred them in about 10 mins to the core.
    I can only hockey stop perfectly on one side. The other still feels somewhat unnatural. As such, most of my wheels become very lop-sided and I don't bother to change them until it's too late. I find T-stops are better for 'burning off' the rubber though.

    Kinda feel the 76/78mm are still too prone to heelstrike and now I'm aiming to get as small as possible. The extreme low end would be 62/64, but 64mm is very hard to find in Singapore. I may have to settle for 68/70mm which are far more common.

  18. #18
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    Quote Originally Posted by fietsbob View Post
    the issue is width- wheel thickness , not diameter .. Brompton's EZ wheel is 10mm thick 60 in diameter.. width 140 mm overall.

    the bromfication ones are stated as 51mm Dia and thinner (not here to measure)
    Well, that is true but unfortunately that would mean the only choice would be the Bromification ones since I'm never going back to Eazy wheels.

    Wheel thickness definitely plays a part in heelstrike, though not as much as diameter. A thinner, slightly smaller wheel just means I can shimmy my feet a little more onto the pedal while reducing the chance of heelstrike as well.

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