What size drill for converting to Schrader?

Johnny Napalm
Johnny Napalm Posts: 1,458
edited May 2011 in MTB workshop & tech
My mate is adamant that he no longer wants presta valves and wants to drill the rims to suit schrader valves.

What size drill does he need? IIRC he has DT Swiss Ex5.1d rims.
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Marin
SS Inbred
Mongoose Teocali Super

Comments

  • cooldad
    cooldad Posts: 32,599
    Measure the valves?
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

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  • Johnny Napalm
    Johnny Napalm Posts: 1,458
    I suppose he could do that, couldn't he.
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    Marin
    SS Inbred
    Mongoose Teocali Super
  • steben
    steben Posts: 24
    Drilled mine 10mm but they are slightly too big!! Been like it 4 years though and I can pinch beg or borrow any tube on the trail when I'm in the poo !
    Orange 5 Pro
    Orange P7
    Scott S40
  • Johnny Napalm
    Johnny Napalm Posts: 1,458
    I've just measured one at 7.66mm, so I'll let him know.

    Should've done that in the first place, eh!
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Marin
    SS Inbred
    Mongoose Teocali Super
  • nicklouse
    nicklouse Posts: 50,675
    8.5mm
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • gtd.
    gtd. Posts: 626
    Drilled mine to 8mm from presta front rim was a Spec Enduro version of a Sun SOS 32 and was presta, rear is a Sun SOS 32 which was schrader... didnt want to carry two types of tube
    Mountain: Orange Patriot FR, SubZero & Evo2LE.
    Road: Tifosi Race Custom.
    Do it all bike: Surly Disc Trucker 700c/29er
  • Gwaredd
    Gwaredd Posts: 251
    nicklouse wrote:
    8.5mm

    As usual, Nick is correct. I found 8.0mm to be too small for the rubber neck of the valve. Be sure to chamfer or de-bur the edges too.
    Cheers,

    Gwaredd

    http://www.iamkonki.com/
  • stubs
    stubs Posts: 5,001
    If you only have Imperial drill bits a 5/16th drill bit will do it. Thats what I used when I did it for a mate. Make sure you deburr the hole or it can cut the valve or tube. I used a piece of 240 grit paper rolled into a cylinder and just span it in the valve hole to remove the sharp edges and sucked the swarf out with a hoover.
    Fig rolls: proof that god loves cyclists and that she wants us to do another lap
  • Anonymous
    Anonymous Posts: 79,667
    Johnny Napalm wrote:
    My mate
    Do you talk to yourself?
  • The Rookie
    The Rookie Posts: 27,812
    8mm is not large enough, 9mm is the size of the hole in the 2 rims I checked before I drilled 2 out from presta to Schraeder.

    Simon
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Johnny Napalm
    Johnny Napalm Posts: 1,458
    Do you talk to yourself?

    Hey, we'll have less, young man. Are you insinuating that I'm the type of person not to have friends? Oh, who am I kidding...it even comes across on bloody forums, doesn't it.

    It is actually for a mate who has an aversion to presta valves. Honest! Honest! Honest!
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Marin
    SS Inbred
    Mongoose Teocali Super
  • kevolution
    kevolution Posts: 70
    I guess he worked it out from your list of bikes.lol
  • tri-sexual
    tri-sexual Posts: 672
    after drilling but still want to use presta valve tubes (they look better, :oops: )
    there are some "sleeves" which go around the presta valve so that it "fills "the hole better, can any one recommend some?
  • biff55
    biff55 Posts: 1,404
    did this job yestday , drilling out rims for schrader valves.
    no extra parts needed for continued use of presta valves , the lock nut will centre the valve within the larger hole.
  • stubs
    stubs Posts: 5,001
    tri-sexual wrote:
    after drilling but still want to use presta valve tubes (they look better, :oops: )
    there are some "sleeves" which go around the presta valve so that it "fills "the hole better, can any one recommend some?

    http://www.justridingalong.com//shop.php?product=169&jras=l2jg2ce5782gv4cpunq0e9uns5
    Fig rolls: proof that god loves cyclists and that she wants us to do another lap
  • gtd.
    gtd. Posts: 626
    stubs wrote:
    http://www.justridingalong.com//shop.php?product=169&jras=l2jg2ce5782gv4cpunq0e9uns5

    rim reducer :lol:
    Mountain: Orange Patriot FR, SubZero & Evo2LE.
    Road: Tifosi Race Custom.
    Do it all bike: Surly Disc Trucker 700c/29er
  • Northwind
    Northwind Posts: 14,675
    20mm then a bit of gaffer tape to size it back down
    Uncompromising extremist
  • wilkij1975
    wilkij1975 Posts: 532
    Is this safe to do? I had some DT rims and hate using Presta (I would change the road bike if I could) but wasn't sure it would be safe.
    Carbon 456
  • nicklouse
    nicklouse Posts: 50,675
    it depends on the rims.

    road rims tend to use presta as the land between the sides is narrower. cutting into the sides is not good.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • hairy_boy
    hairy_boy Posts: 345
    I did the exact same thing - drilled out my new rims but because of the profile it looked rubbish with a schrader valve fitted.

    Used the Mavic hole reducers which worked well - you actually fit them the other way up to the way they are shown in the picture. You end up with a flat surface to screw the presta tightening lockring down onto.

    These worked well for me and this place has them in stock:
    http://www.edinburghbicycle.com/ebwPNLqrymode.a4p?f_ProductID=6497&f_SupersetQRY=C275&f_SortOrderID=1&f_bct=c003154c003139c003528

    I would have thought any decent LBS would have a few spares lying around though.

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