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Conference noted::bicycle

Title: Bicycling
Notice:Bicycling for Fun
Moderator:JAMIN::WASSER
Created:Mon Apr 14 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:3214
Total number of notes:31946

1776.0. "double-walled rims??" by DCC::URBAN () Thu Nov 08 1990 16:39

    Hi,
    
    I have a bianchi 1989 "Tangent" (a hybrid).  It has suntour parts.  I
    recently had a accident where the front wheel turned 90 degress and I 
    came to an abrupt stop.  This caused the front rim to be bent farther
    than is correctable by simply adjusting the spokes.
    
    I have two questions:
    A. Has anyone successfully bent his rim back into shape after something
       like this? If so, how?
    B. I went to a bike shop and the propriator told me that because
       it was as expensive to buy only a rim and remount it on the old hub as
       it is to buy a whole new wheel.  He recommended some kind of a double-
       walled rim. Can anyone give me more info on this? Is it better?
       stronger?  I use this bike for some fairly rugged city riding (hopping
       onto curbs and riding off them).
    
    thanks,
    
    -Rob Urban
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1776.1my .000000000002 cents worth....SUSHI::KMACDONALDIronFish Tamer.Thu Nov 08 1990 17:4715
>    A. Has anyone successfully bent his rim back into shape after something
>       like this? If so, how?

This is generally not a correctable condition.

>    B. I went to a bike shop and the propriator told me that because
>       it was as expensive to buy only a rim and remount it on the old hub as
>       it is to buy a whole new wheel.

This is generally not true. You might want to talk to a different 
shop.... If you have a reasonably good hub, you should be able to 
rebuild for a lot less than a new wheel, especially if the spokes are 
re-usable (often the case). Maybe it's time for you to learn 
wheel-building? :-)
                               ken
1776.2and from Alaska...SHALOT::ELLISJohn Lee Ellis - assembly requiredThu Nov 08 1990 19:1516
    
    I agree with Ken on both counts => trash the old rim, rebuild
    the old hub with new spokes and new rim.
    
    Some rims are stronger than others, obviously.  The Weinmann
    concave rims are or were hard to destroy - it's hard to get
    them nowadays.  But the accident you describe is not something
    you should expect any rim to stand up to.  And if it did, i.e.,
    if the rim weren't the "weak link," then the next weakest
    component might go, the fork for example, which would be worse.
    
    Anyway, for the really indestructible, Iditabikers may have the
    answer for you: not double-walled rims, but rather double rimmed
    wheels!
    
    -john
1776.3Sure. How? (or where?)DCC::URBANThu Nov 08 1990 19:1610
    re: .-1
    
    I'm game.  How does one build a wheel? (or rather, where does one learn
    how to build a wheel?).  Can you recommend any books? (although this
    time around I'll probably take it to another shop as I'm in germany and
    it difficult to find english books around here...however, this is
    something I've always wanted to be able to do, so your advice won't be
    wasted...)
    
    -rob urban
1776.4q & d wheelbuilding lesson...SUSHI::KMACDONALDIronFish Tamer.Thu Nov 08 1990 19:5036
>    I'm game.  How does one build a wheel? (or rather, where does one learn
>    how to build a wheel?).  Can you recommend any books? (although this

Well. Starting with a front wheel is the place to start, along with having 
a truing stand. You're fortunate on the first count. :-). There are 
recommendations for truing stands in here somewhere. Choosing the proper 
length spokes for your hub/rim/pattern is next, your shop can help you there. 
Lacing the wheel is first - choose a correct lacing pattern. There's a note 
on lacing in here too, I'm sure. With the wheel loosely laced, gradually 
tighten by hand until it's still loose but each spoke has the same amount 
of threads showing. Mount the wheel on your stand, and starting at the 
valve hole (or some reference spot, the hole's my fav.) tighten each spoke 
1/2 turn until you complete a circuit. Repeat until wheel *begins* to be 
firmer. Start checking for true-ness and round-ness. Now you begin an 
iterative process where you cure trueness problems by tightening spokes 
opposite the bulge (but just a little, since this affects roundness) and 
cure roundness problems by tightening the spokes at the bulge. Do it 
gradually, keeping your adjustments spread over a number of spokes in the 
offending region. Remember that in roundness, pulling a section of rim in 
will cause it to bulge somewhere else. When it's close to round&true, 
tighten the whole wheel a bit more, Repeat the last few steps ......
when the wheel is finally getting firm, start checking the dishing. If the 
wheel is not centered, move it over by tightening all the spokes on one 
side while perhaps (depending on..) loosening the other side. Repeat the 
above stuff as many times as are needed. Mount a tire, ride the wheel....

And yes, there are books, though I don't recall the names. The biggest 
problem as a novice wheel-builder is that you tend to tension the spokes 
unevenly. Keep working around the wheel, doing gradual changes - don't try 
to force a section all at once, move on and pick up on it later. If you 
sense a spoke is too tight, loosen it and re-adj. its friends....

Anyway, that's the basic process. Not too hard, just go at it leisurely. 
There's more on wheelbuilding here in the notes, but that's kind of a 
overview.... have fun!
                       ken
1776.5TALLIS::JBELLZeno was almost hereThu Nov 08 1990 20:086
    The Bicycle Wheel by Jobst Brandt.

    Does Nashbar ship to Germany?
    It's in the catalog.

    -Jeff
1776.6Fahrradheilkunde by Ulrich HerzogKBOMFG::KLINGENBERGFri Nov 09 1990 06:3414
    Rob,
    
    how good is your German? There is an excellent book, called
    "Fahrradheilkunde" by Ulrich Herzog. Building wheels is explained in
    detail as well as most other things you might need to work on. It is
    fun to read and even more fun to work with.
    
    It may be ten years old by now, so at least my issue (there might be
    newer ones) doesn't talk about indexed shifting etc. But the basics
    haven't changed yet. And in case you need translations for special
    descriptions, just ask here...
    
    Have fun,
              Hartmut
1776.7clearly a must-have bookSHALOT::ELLISJohn Lee Ellis - assembly requiredFri Nov 09 1990 10:136
    
    "Fahrradheilkunde" - I love the title!  
    
    ("The Craft of Healing Bicycles")
    
    -john
1776.8Es geht scho'DCC::URBANFri Nov 09 1990 10:408
    re: .-2
    
    Mein Deutsch is wirklich schlecht! (Aber ich sollte versuchen, es zu
    verbessern.)  Ich werde nach dem Buch suchen. 
    
    Danks,
    
    -rob urban
1776.9truing stand vs. on-bikeDCC::URBANMon Nov 12 1990 14:267
    Ken,
    
    Is there some distinct advantage of a truing stand over simple truing
    on the front forks?  I have had moderate success doing the latter...
    
    -rob urban
    
1776.10Best reason to use a stand: if you OWN one :-)SUSHI::KMACDONALDDrywall Poster Child for 1990Mon Nov 12 1990 14:4511
>    Is there some distinct advantage of a truing stand over simple truing
>    on the front forks?  I have had moderate success doing the latter...
    
Well, I find it simpler, especially when building wheels which require a
lot of adjustment. Putting the wheel in round is especially easy on a stand
since you need a reference on the outside of the wheel (as opposed to the
sides, where a brake block works fine). As pointed out, though, you can
build dandy wheels without a stand. Depending on how fancy you want to get,
stands may have centering thingies, dial indicators, and all manner of
stuff, most of which is pretty unnecessary....
                                                 ken
1776.11ok, i did it.MUNICH::URBANWed Jul 03 1991 12:049
Hi folks,

I just thought I'd mention that I finally got around to building my first wheel,
using your (collective) advice.  It wasn't that hard!  I've got the wheel as
true and round as I care to get it. ( 0.3 - 0.5 mm, i'd say).

thanks again.

-Rob Urban
1776.12and the rest of the story is...NOVA::FISHERRdb/VMS DinosaurWed Jul 03 1991 12:475
    Tell us more after you've ridden 200km on it.  :-)
    
    (And good luck.)
    
    ed