advice on *contracting* rear triangle

advice on *contracting* rear triangle

Post by John Ozcome » Fri, 03 Sep 1993 10:50:32


I just bought a frame second hand, and it has 130mm spacing on the rear
dropouts.  The thing is, I have two sets of wheels that have 126mm
spacing.
Question: Will the frame be able to handle being contracted to accomodate
the 126mm rear wheel?  I would simple crank down with the rear skewer to
do this.  I plan on building up a 130mm rear wheel, but I want to use
the bike in the meantime.  Would I be damaging it?  Thanks.
-John

--
*************************************************************************

"I have the mind of a genius.  Perhaps one day I'll have it installed."
*************************************************************************

 
 
 

advice on *contracting* rear triangle

Post by Rich Whal » Fri, 03 Sep 1993 22:01:29


Quote:
Ozcomert) writes:

|>
|>I just bought a frame second hand, and it has 130mm spacing on the rear
|>dropouts.  The thing is, I have two sets of wheels that have 126mm
|>spacing.
|>Question: Will the frame be able to handle being contracted to accomodate
|>the 126mm rear wheel?  I would simple crank down with the rear skewer to
|>do this.  I plan on building up a 130mm rear wheel, but I want to use
|>the bike in the meantime.  Would I be damaging it?  Thanks.
|>-John
|>
|>
|>--
|>*************************************************************************

|>"I have the mind of a genius.  Perhaps one day I'll have it installed."
|>*************************************************************************
|>

I recently had some wheels built up for a replacement frame (the new frame
is sized for 130mm 700C, the old was 126mm 27 inch).  When I asked the bike
shop about putting in a new axle or spacer I was told that it wasn't
necessary, just clamp it down and it will be ok.
------------------------------------------------------
Rich Whalen

You don't know where these bits have been!

 
 
 

advice on *contracting* rear triangle

Post by JIM_AL.. » Sat, 04 Sep 1993 14:44:26

Quote:
>I recently had some wheels built up for a replacement frame (the new frame
>is sized for 130mm 700C, the old was 126mm 27 inch).  When I asked the bike
>shop about putting in a new axle or spacer I was told that it wasn't
>necessary, just clamp it down and it will be ok.
>------------------------------------------------------
>Rich Whalen
>You don't know where these bits have been!

If you change the width of the rear triangle, the rear dropouts are no
longer parallel. Unless this is corrected with the appropriate tools,
when the axle is clamped into the dropouts, it bows the axle and applies
stress to the dropouts.
If you just bolt the wheel in without adjusting the rear traingle, the
same thing happens.

In my experience this results in bent axles and broken dropouts!

Find a bike shop that knows what they're doing!

Later, Jim

 
 
 

advice on *contracting* rear triangle

Post by Geoffrey Ha » Mon, 06 Sep 1993 07:17:37


Quote:
Rich Whalen writes:
>>I recently had some wheels built up for a replacement frame (the new frame
>>is sized for 130mm 700C, the old was 126mm 27 inch).  When I asked the bike
>>shop about putting in a new axle or spacer I was told that it wasn't
>>necessary, just clamp it down and it will be ok.
[...]
>If you change the width of the rear triangle, the rear dropouts are no
>longer parallel. Unless this is corrected with the appropriate tools,
>when the axle is clamped into the dropouts, it bows the axle and applies
>stress to the dropouts.
>If you just bolt the wheel in without adjusting the rear traingle, the
>same thing happens.

And the frame is stressed at the bridges.  Granted, it is just two
millimeters on each side, but it is generally not a good idea to ride a
frame for long periods while it is stressed like that.

Quote:
>Find a bike shop that knows what they're doing!

That always helps.  It shouldn't be that much trouble for them to add a
washer to each side of the axle.

Geoff