How to lose 390 grams from a hundred.- Mtbr.com
Results 1 to 30 of 30
  1. #1
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313

    Wink How to lose 390 grams from a hundred.

    Here is a study in obsession. I have a set of 100 mm rims (aka "hundies") that I will build up at some point this winter. They are heavy. Three and a half pounds apiece, in fact:



    To remove some material from the rim, I first decided to get rid of the center inner channel. The rim is a double wall with two vertical stiffeners in the extrusion linking the inner and outer channels.



    I needed a guide for my circular saw, so I made to shallow cuts in two blocks of wood:



    They fit the rim sidewall hooks, so that the blocks would slide on the rim:



    Next I screwed the blocks to my saw, set the depth shallow, and cut the inner center channel next to each vertical stiffener:



    I cleaned the cuts up with a flap wheel:





    The result was pretty clean and I lost 140g of material in the process:



    Next it was on to the drill press and a 1" hole saw. First I went to town on what was left of the center channel:



    Then I drilled just the inner wall of the outer channel sections:





    The result was shaving 390g off the rim (that's almost a full pound, FYI):



    It now basically weighs the same as a Large Marge:



    But it offers a bit more float:



    Now I just need to clean up the holes a little and put a bit of rim strip over the holes after lacing the wheels up.
    Last edited by tscheezy; 01-17-2010 at 08:31 PM.
    My video techniques can be found in this thread.

  2. #2
    Self-defeatist
    Reputation: CLONG's Avatar
    Join Date
    Nov 2006
    Posts
    965
    Oh HEELLLLLLL YEAH! That is friggin' beautiful. I can't wait to see it built up.
    I'm covered in beer.

  3. #3
    Fatback
    Reputation: thirstywork's Avatar
    Join Date
    Dec 2006
    Posts
    705

    Nice job Phillip

    That's about the same method I use, with the exception of a tablesaw instead of a Skilsaw (Ryobi). I like your rim guide jig, you even used VG Fir. Top shelf.
    Man, I've eaten lots of alumium over the last few years, so I'm glad it's you and not me.
    It's not easy to use a holesaw without a pilot bit.
    That is about the maximum mod you can make to that rim-it needs those vertical ribs (and box section) to remain stable. Without those, the rim will invert or crack eventually.
    Speedway Cycles owner http://fatbackbikes.com

  4. #4
    mtbr member
    Reputation:
    Join Date
    Aug 2007
    Posts
    4,667
    Hopefully you'll adjust your spacing so the holes will be equal distance from the valve hole but otherwise it looks good.

  5. #5
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    Quote Originally Posted by Schmucker
    Hopefully you'll adjust your spacing so the holes will be equal distance from the valve hole but otherwise it looks good.
    Uh-oh. Busted by the fashion police.

    Actually, it ended up that way because I put 1.5 holes between adjacent spoke holes. That means that one big rim hole sat next to a drive-side spoke hole (for instance) while the next non-drive-side spoke hole sat between big rims holes. That was the tightest spacing of big holes that would work. Since this is an uneven spacing relative to the spoke holes, it did not end up even at the valve stem or rim seam, though the big holes are still perfectly evenly spaced and balanced across the rim.

    I just did the second wheel. I figured I may have gone a little too crazy on drilling the first wheel so on this one I only did ONE big hole between adjacent spoke holes (instead of 1.5 like in the first rim). There is a bit more material bridging the two halves of the rim now, and I think it actually looks a little less Swiss-cheese-like. The weight difference is only 10 grams.

    The new wheel is on the right (I will use it in the rear) and the first wheel (I will use on the front) is on the left. You can see the difference in drilling pattern easily:

    My video techniques can be found in this thread.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Aug 2007
    Posts
    4,667
    The second looks much better.

  7. #7
    Alaska Turner Mafia
    Reputation: EndoRando's Avatar
    Join Date
    Sep 2004
    Posts
    1,116
    Quote Originally Posted by CLONG
    Oh HEELLLLLLL YEAH! That is friggin' beautiful.
    I agree, that's fantastic! So these won't go on the initial bike build?
    Deceleration Trauma is my middle name

  8. #8
    A Surly Maverick
    Reputation: Dr Feelygood !'s Avatar
    Join Date
    Jun 2006
    Posts
    2,623
    They look great !

    Life IS a Beach and then you Corrode :)

  9. #9
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    Quote Originally Posted by EndoRando
    So these won't go on the initial bike build?
    These require 36h hubs, and I think the next batch of hubs don't include any 36's. They may also spontaneously fold on the first pedal stroke, so I'm not sure I want to commit to these as my main wheelset from the get-go.

    Quote Originally Posted by thirstywork
    It's not easy to use a holesaw without a pilot bit.
    That is about the maximum mod you can make to that rim-it needs those vertical ribs (and box section) to remain stable. Without those, the rim will invert or crack eventually.
    The first set of holes I drilled with a pilot bit, but I got a bit annoyed cleaning the resulting scrap out of the bit so I tried it without the pilot (and the scrap just fell out) and with the big beefy drill press the bit never wandered. I had the rim locked down very well too, so that makes a big difference. It would never work hand-drilling.

    I am a little concerned about how thin the remaining bridge material between the two rim halves is. The rear rim (the one I drilled with less holes) may be perfectly fine, maybe the front too, but time will tell. Not drilling any holes completely through would probably only add 20g and it would eliminate the need for the rim strip in the center, which will probably add 20g anyway.
    My video techniques can be found in this thread.

  10. #10
    Ologist
    Reputation: Valhalla's Avatar
    Join Date
    Mar 2004
    Posts
    963
    Nice work!!

    I don't know anything about engineering and was thinking about doing something like this with my double walled 80s. At what point do they lose integrity? Like you mention you are concerned about the bridge material - if you weighed 50-75 lbs more do you think they would still be strong enough?

  11. #11
    mtbr member
    Reputation:
    Join Date
    Aug 2007
    Posts
    4,667
    Quote Originally Posted by Valhalla
    Nice work!!

    I don't know anything about engineering and was thinking about doing something like this with my double walled 80s. At what point do they lose integrity? Like you mention you are concerned about the bridge material - if you weighed 50-75 lbs more do you think they would still be strong enough?
    I think you'd be fine doing what he recommended and not removing the center channel center wall and just drilling through it and leaving the inner rim wall intact. It shouldn't change the strength of the rim at all.

  12. #12
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    I haven't a clue. The main thing is not to compromise the spoke bed. That is not an issue with the drilling I have done. I have tried to picture what forces are at work, but wheels are mysterious creatures. Once they are built (if they even survive the tensioning process ), the longevity test will begin. I may not get a chance to lace them up for a while though. I think they will be for snow and sand only though.
    My video techniques can be found in this thread.

  13. #13
    mtbr member
    Reputation:
    Join Date
    Jan 2010
    Posts
    5
    Nice job they good.......

  14. #14
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    681
    Amazing! Props to you for attempting such a thing.

  15. #15
    mtbr member
    Reputation: gomadtroll's Avatar
    Join Date
    May 2009
    Posts
    76
    Wow, bold move. My first thought was : they will fold in the middle.

    Never have drilled or owned a drilled rim it seems the middle could use a little more support, the outer strips are much stronger, weakest link et al.

    Put me down for $5 on 'folding in the middle' when you get them built up and tested ;-)

  16. #16
    mtbr member
    Reputation: damnitman's Avatar
    Join Date
    Jan 2008
    Posts
    1,288

    I tried...

    ...something similar with mixed results...rather, my mechanic tried something similar and I had the mixed results...The rear had the entire inner wall cut out (no remaining box section) with just enough left near the sidewalls for the tire to seat w/o breaking loose at LOW pressures...The hole-saw was not used in the center "bridge" section...The wheel worked great until I was airing a new tire/tube up to 45 psi to fully seat the bead...the concave bridge section "panged" and became convex in a couple of areas, between the holes...It was enough for me to cancel the trip from Aniak to Bethel I had planned for the next day-D'oh!! I kept riding it, though only within easy walking distance of town, for the remainder of the season w/o any problems...it even stayed almost completely true...so maybe not that big a deal?

    The front wheel had only the inner wall cut out...to accomodate my 100mm hub / fork we had to move the spoke holes inboard...no problems till a nipple pulled through last month...damnit! Oh well, I guess that's what innovating is all about, trying things till they work...I've got a set from a friend to fall back on for now, though I havn't needed anything but umma's and studs since the first part of December...

    -edit-I do not know what the final weight of either hoop was...
    Attached Thumbnails Attached Thumbnails How to lose 390 grams from a hundred.-rearsl.jpg  

    How to lose 390 grams from a hundred.-frontl.jpg  

    Last edited by damnitman; 01-19-2010 at 09:09 PM.
    If Huffy made an airplane, would you fly in it?

  17. #17
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    Great beta, damnitman. Much appreciated.

    It looks like your holes span (cut across) where the vertical stiffening ribs were, and yet all that went wrong was that sections of the center concavity popped out into a convexities. Not too shabby. I am using the stock spoke holes which are in a thicker rim material area.

    The rim I over-drilled will probably pop inside out fairly easily since there is so little (and such thin) material left. The other one, with the fewer holes drilled, should withstand that tendency a bit better I think. I also never go over 20psi to seat the tire, so maybe I will be ok. I will certainly let folks know how I make out.

  18. #18
    mtbr member
    Reputation: pbasinger's Avatar
    Join Date
    Dec 2004
    Posts
    777
    Sweet.
    I have some rims I'd like to send you.

  19. #19
    mtbr member
    Reputation: dmx1's Avatar
    Join Date
    Dec 2008
    Posts
    424
    Great job. Those rims now look like circular Gruyere cheese.
    Last edited by dmx1; 01-20-2010 at 05:50 AM.

  20. #20
    Self-defeatist
    Reputation: CLONG's Avatar
    Join Date
    Nov 2006
    Posts
    965
    Quote Originally Posted by damnitman
    ...The wheel worked great until I was airing a new tire/tube up to 45 psi to fully seat the bead...the concave bridge section "panged" and became convex in a couple of areas, between the holes...
    For some reason...that's so cool. Props to you guys for trying this out. damnitman, I was worried when you mentioned the spoke pulling through, but I see you drilled new spoke holes in the thinner extrusion. I thought about doing that, but now I'm glad I didn't.

    I'm a heavy mother** but I think these rims could stand up to some simple mods even under someone my weight.
    I'm covered in beer.

  21. #21
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    Quote Originally Posted by pbasinger
    I have some rims I'd like to send you.
    I don't know if you were serious, but I could work up a set for you. You guys have been very generous about handing out loaner bikes, and I can do a rim pretty fast now that I have things dialed in. Shipping within AK is cheap too. Greg has my email if you really want a set done.

  22. #22
    mtbr member
    Reputation: damnitman's Avatar
    Join Date
    Jan 2008
    Posts
    1,288

    We kinda...

    ...figured the wheels would fail in the ways they did, for all the reasons they did...but again, that's innovation...it's called research and DEVELOPMENT for a reason...
    If Huffy made an airplane, would you fly in it?

  23. #23
    mtbr member
    Reputation: Velobike's Avatar
    Join Date
    Jun 2007
    Posts
    7,171
    You still using these rims?
    As little bike as possible, as silent as possible.
    Latitude: 57º36' Highlands, Scotland

  24. #24
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    Actually I have yet to lace them into wheels. I have not gotten my hands on hubs yet. Hopefully this winter...

  25. #25
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    I'm finally making some progress, mostly thanks to Mikesee and Greg.

    I welded up some wiiiiiide hub adapters for my Park stand a while back:



    A nice symmetrical spread to keep a 170mm hub centered:



    Soldiers lined up for battle:



    Lacing it up:


  26. #26
    How much does it weigh?
    Reputation: Borgschulze's Avatar
    Join Date
    Nov 2007
    Posts
    1,169
    You lace funny.

    I do one flange at a time.

    How do you like the Import hubs? Can/did you weigh them?

  27. #27
    Fatback
    Reputation: thirstywork's Avatar
    Join Date
    Dec 2006
    Posts
    705
    [QUOTE=tscheezy]I'm finally making some progress, mostly thanks to Mikesee and Greg.

    I welded up some wiiiiiide hub adapters for my Park stand a while back:



    I like your adapters. We use the 29er extensions and a couple of fneder washer per side for the extra clearance.
    Speedway Cycles owner http://fatbackbikes.com

  28. #28
    No, that's not phonetic
    Reputation: tscheezy's Avatar
    Join Date
    Dec 2003
    Posts
    14,313
    Further progress:







    Front clearance? Check!



    Rear clearance? Check-check!







    Now we just need winter to make up its mind.

  29. #29
    M8 M12 M15 deez nuts
    Reputation: Leopold Porkstacker's Avatar
    Join Date
    Apr 2010
    Posts
    8,163
    Dunno man… something about that anodised orange aluminum just gets me all giddy like a Catholic high school girl doing a kegstand!
    Don’t frail and blow if you’re going to Braille and Flow.

  30. #30
    Self-defeatist
    Reputation: CLONG's Avatar
    Join Date
    Nov 2006
    Posts
    965
    So bada$$. Clearance looks a bit better than on my Pug by a mm or two.

    Reflexite rim tape?
    I'm covered in beer.

Members who have read this thread: 1

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.