Bending Rear Rack Hardware?

SriBikeJi said:

I am wondering how much bending I should do on my rack attachment
hardware and how I should do it.

If I put the rack on the bike, attaching it to the eyelets on the rear
dropouts, the top, front edge of the rack ends up about two inches
higher than the eyelets on the seatstays and only about two inches
behind them. To get this thing on the bike, as I conceive it, will
require me to put about a 45 degree bend in the flat metal strips that
attach the rack to the bike - or bend them in a curve that spans that
angle.

This seems to me to be a bit much. Even if I don't break them now,
aren't I risking having them snap when I have a 40 lbs of panniers on
this thing?

I could use the plastic-coated clamps but it would be awkward - the
brake bridge lines up with the top of the rack and it would be a tight fit.

I have a Blackburn Expedition rack on the back of my mountain bike.
Due to the compact frame on mountain bikes, the stainless steel flat
strips need to be bent down about 2 inches to meet up with the seatstay
braze ons for the rack. Its not quite as extreme a bend as you
mention, but the flat strips are definitely curved down. Its held up
fine and is very solid.

I've used the rubber coated P clips to attach racks to seatstays. They
work and are solid. But I'd still prefer to use the seatstay braze ons
with curved strips.

Quoted message said:

SriBikeJi said:

I am wondering how much bending I should do on my rack attachment
hardware and how I should do it.

[snip]

Quoted message said:

I have a Blackburn Expedition rack on the back of my mountain bike.
Due to the compact frame on mountain bikes, the stainless steel flat
strips need to be bent down about 2 inches to meet up with the seatstay
braze ons for the rack. Its not quite as extreme a bend as you
mention, but the flat strips are definitely curved down. Its held up
fine and is very solid.

I've used the rubber coated P clips to attach racks to seatstays. They
work and are solid. But I'd still prefer to use the seatstay braze ons
with curved strips.

Yep. It's a Blackburn Expedition, but on a cyclocross frame. How did
you get a smooth bend?

SriBikeJi said:

I am wondering how much bending I should do on my rack attachment
hardware and how I should do it.

If I put the rack on the bike, attaching it to the eyelets on the rear
dropouts, the top, front edge of the rack ends up about two inches
higher than the eyelets on the seatstays and only about two inches
behind them. To get this thing on the bike, as I conceive it, will
require me to put about a 45 degree bend in the flat metal strips that
attach the rack to the bike - or bend them in a curve that spans that
angle.

This seems to me to be a bit much. Even if I don't break them now,
aren't I risking having them snap when I have a 40 lbs of panniers on
this thing?

Bend them and forget it. You have no problem. I assume you're talking
about steel parts. They'll handle it.

Those parts restrain forward & rearward motion of the load on the rack,
and that's normally a _very_ small amount of force.

On one of my bikes, I have a Blackburn rack with one stainless steel
stabilizer at the front. For various reasons, I bent it 90 degrees
down at the front edge of the rack, about 90 degrees forward for it to
pass under the seatstay brake bridge, then 90 degrees upward to bolt it
to the front surface of that brake bridge. It's been that way for
years. No problems.

- Frank Krygowski

SriBikeJi said:

Quoted message said:

SriBikeJi said:

I am wondering how much bending I should do on my rack attachment
hardware and how I should do it.

[snip]

Quoted message said:

I have a Blackburn Expedition rack on the back of my mountain bike.
Due to the compact frame on mountain bikes, the stainless steel flat
strips need to be bent down about 2 inches to meet up with the seatstay
braze ons for the rack. Its not quite as extreme a bend as you
mention, but the flat strips are definitely curved down. Its held up
fine and is very solid.

I've used the rubber coated P clips to attach racks to seatstays. They
work and are solid. But I'd still prefer to use the seatstay braze ons
with curved strips.

Yep. It's a Blackburn Expedition, but on a cyclocross frame. How did
you get a smooth bend?

Its been 5 or 6 years now so I don't really recall. I am positive I
prebent the things before installing. I also recall they are pretty
stiff and do not easily bend. I did not use any sort of form to bend
them over. I am pretty sure I just bent them with my hands and they
stayed fairly curved and smooth. I did not try to bend them at a 90
degree angle because I did not want that.

SriBikeJi said:

I am wondering how much bending I should do on my rack attachment
hardware and how I should do it.

If I put the rack on the bike, attaching it to the eyelets on the rear
dropouts, the top, front edge of the rack ends up about two inches
higher than the eyelets on the seatstays and only about two inches
behind them. To get this thing on the bike, as I conceive it, will
require me to put about a 45 degree bend in the flat metal strips that
attach the rack to the bike - or bend them in a curve that spans that
angle.

This seems to me to be a bit much. Even if I don't break them now,
aren't I risking having them snap when I have a 40 lbs of panniers on
this thing?

I could use the plastic-coated clamps but it would be awkward - the
brake bridge lines up with the top of the rack and it would be a tight fit.

Put them in a vise and bend them. Don't worry about it. If you can, make
a few smaller radius bends, i.e. three 15 degree bends, but with steel
it isn't really necessary.

I've put racks on several bikes where I had to use a single center-mount
support on the front of the rack, with many contortions to get under
brake cables, etc, to the mounting hole on the frame (where a caliper
brake would normally mount). I've used aluminum flat bar, and you have
to be very careful about the radius of bends with aluminum, but the
steel supports are much more forgiving.

Quoted message said:

Quoted message said:

SriBikeJi said:

I am wondering how much bending I should do on my rack attachment
hardware and how I should do it.

[snip]

Quoted message said:

Quoted message said:

I have a Blackburn Expedition rack on the back of my mountain bike.
Due to the compact frame on mountain bikes, the stainless steel flat
strips need to be bent down about 2 inches to meet up with the seatstay
braze ons for the rack. Its not quite as extreme a bend as you
mention, but the flat strips are definitely curved down. Its held up
fine and is very solid.
I've used the rubber coated P clips to attach racks to seatstays. They
work and are solid. But I'd still prefer to use the seatstay braze ons
with curved strips.

SriBikeJi said:

Yep. It's a Blackburn Expedition, but on a cyclocross frame. How did
you get a smooth bend?

We mount the bottom of the rack on the bike, level the rack,
then bend the top stainless struts in a vise to fit before
bolting them in .

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

SriBikeJi said:

I am wondering how much bending I should do on my rack attachment
hardware and how I should do it.

If I put the rack on the bike, attaching it to the eyelets on the rear
dropouts, the top, front edge of the rack ends up about two inches
higher than the eyelets on the seatstays and only about two inches
behind them. To get this thing on the bike, as I conceive it, will
require me to put about a 45 degree bend in the flat metal strips that
attach the rack to the bike - or bend them in a curve that spans that
angle.

This seems to me to be a bit much. Even if I don't break them now,
aren't I risking having them snap when I have a 40 lbs of panniers on
this thing?

I could use the plastic-coated clamps but it would be awkward - the
brake bridge lines up with the top of the rack and it would be a tight fit.

Remember that the upper (seat stay) connections on a rack don't
actually carry much of the load - that's the job of the vertical
supports that run down to your dropouts. Think of the upper mount's
job as keeping the rack from falling forward or backward and you'll
start to get a better idea of what's possible in terms of bending that
hardware. If the upper mounts can survive a 0.5g stop, they should be
fine (worst case, that would be like supporting 10 pounds vertically
on each of the bent mounts, assuming that the bolts holding the
vertical supports were loose and causing no friction at the dropout).

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame