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-   -   Spreading the frame (https://www.bikeforums.net/bicycle-mechanics/671847-spreading-frame.html)

John Montgomery 08-15-10 03:04 PM

Spreading the frame
 
Is this a DIY job (threaded rod, nuts & washers) or LBS? I've been told that


you have to spread the frame to fit a 6 speed freewheel in
since I'm trashing the worn out 5 speed freewheel. Is it possible I can get away without messing with the frame? Should I just find a 5 speed freewheel?

THANKS!

Jeff Wills 08-15-10 03:09 PM


Originally Posted by John Montgomery (Post 11293388)
Is this a DIY job (threaded rod, nuts & washers) or LBS? I've been told that

since I'm trashing the worn out 5 speed freewheel. Is it possible I can get away without messing with the frame? Should I just find a 5 speed freewheel?

THANKS!

I've done it at home, using nothing more than muscle power and a string for alignment. Of course, I'd learned at the shop where I worked, so I had previous experience with frame alignment. Sheldon's article goes into the process and the pros and cons in lots of detail: http://www.sheldonbrown.com/frame-spacing.html

BCRider 08-15-10 03:15 PM

Sheldon Brown's website has a write up on how to do this using a 2x4. And you don't just spread the dropouts. Instead you bend one out at a time using measurements from the other unaffected one to guage your progress on the first so you bend it half the total required. Then using the first bent side as your standard you bend out the second side until you achieve the final TOTAL spacing. So no threaded rod and nuts need apply here.

DannoXYZ 08-15-10 08:03 PM

You only need to go from 120mm to 126mm spacing. So 3mm per side is easy. Use the string-method to test alignment as you go.

Then you'll need to get the dropouts re-aligned so they're parallel to each other again. Again, fairly simple. Count on a total of about 10-30 minutes for the spreading and 5-minutes for the dropout alignment.

John Montgomery 08-15-10 08:13 PM

Thanks for the replies -

I'm confused about one thing though; I'm still using the same hub, just threading on a new freewheel. So why would that change the dropout spacing? Do I need to add a spacer on the axle because the new freewheel will be wider?

I get how to do the spreading with the 2x4 but what's the DIY method for dropout alignment? I'm not dropping $60+ on the Park Tool!

fietsbob 08-15-10 08:51 PM

yea just get another 5 speed freewheel, WABAC there were ultra 6 freewheels .
they preceeded the whole more the merrier thing , a long time ago..

essentially a narrow spaced cog stack,6 in the space of 5
then after the new frame width added to 126
to add a 6th speed to a standard 5,
was followed by a 7 speed in the space of that 6.
7 begat 8, then theres 9,10. and 11... jees !

120 is in dropout width range to make it into a single speed or something
using an IG hub, instead . no spread needed.

Jeff Wills 08-15-10 10:35 PM


Originally Posted by John Montgomery (Post 11294791)
Thanks for the replies -

I'm confused about one thing though; I'm still using the same hub, just threading on a new freewheel. So why would that change the dropout spacing? Do I need to add a spacer on the axle because the new freewheel will be wider?

I get how to do the spreading with the 2x4 but what's the DIY method for dropout alignment? I'm not dropping $60+ on the Park Tool!

Well, if you're putting on a wider freewheel, you're going to need an additional spacer on the drive side, plus re-dish the wheel to compensate for the extra space.

I've re-aligned dropouts with a big Crescent wrench: install wheel, look closely at mating surfaces of dropouts and axle nuts. Remove wheel, tweak dropouts until all surfaces are flat to one another. Lather, rinse, repeat. Shops have tools that do this in one step, but it's possible to get the same results if you're careful.

John Montgomery 08-16-10 10:45 AM

Man, that 5 speed freewheel is sounding better all the time - less wrenching, more riding!

DannoXYZ 08-16-10 01:03 PM


Originally Posted by John Montgomery (Post 11297421)
Man, that 5 speed freewheel is sounding better all the time - less wrenching, more riding!

Yeah, you need to add a 6mm spacer to the right side of the axle to gain the extra width for the 6-spd freewheel. In addition to the frame-spreading and dropout alignment, you'll also need to re-dish the wheel to recentre the rim between the locknut faces. But you'll also be able to use 7-spd freewheels as well.


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