Pannier rack failures

[Slowroad]

I had a strut on my rear pannier rack split at the weld whilst on my recent tour - the pic shows the road repair... no harm done, but made me think. One, I need to make sure I get a new pannier which is rated to carry a load far more than I actually carry. Two - that weight bears down on two screws attaching the pannier rack to the bike. It seems like a good idea to change these screws every year or two to forestall metal fatigue. Also, are there any particularly strong screws to get for this job?
I know it wasn't the screws that failed this time, but it just made me aware of a possible weak point.
Cheers!

[reohn2]

Rack replacement =Tubus.
I think you're safe with stainless steel bolts,but I beleive steel screws are stronger.

[rotavator]

As a matter of interest, what make and model of rack was it? Is it Al alloy?

[Sweep]

Kind of related

Have often wondered.

If there's room, (ie no interference with gears on the inside) is it advisable to use a bolt that goes all the way through the bike frame mount, out the other side, and stick a nut on the end?

ie - does this distribute the forces better?

I assume that even if there isn't room on the inside it's advisable to use the longest bolt possible?

For heavy touring use I'd always use a tubus.

I understand that certain designs of rack "feet" are best avoided, but will leave enlightenment on this issue to the more engineering qualified.

Am also interested in slowroad's question about whether it's a good idea to swap bolts out.

[foxyrider]

looking at the pic it was a 10kg mwl rack no doubt loaded with 20kg or more!

I have had standard steel bolts break in the past so my default these days is Ti but if I can't find them (the racks aren't always fitted and get moved between bikes) stainless do the job. Never had the need to swap any out but there again my fully loaded riding is no more than 10% of my riding and my fully loaded is under 20kg on a 35kg rated Ti or 45kg rated steel Tubus rack.

[mercalia]

I have wondered about using some plastic ties around some of the welds so stop any cracks developing due to strut flexing?

[mjr]

looking at the pic it was a 10kg mwl rack no doubt loaded with 20kg or more!

I have had standard steel bolts break in the past so my default these days is Ti but if I can't find them (the racks aren't always fitted and get moved between bikes) stainless do the job. Never had the need to swap any out but there again my fully loaded riding is no more than 10% of my riding and my fully loaded is under 20kg on a 35kg rated Ti or 45kg rated steel Tubus rack.

Stop messing about with those pansy racks (as in they're good for carrying some flowers) and get a thick-as-your-stays axle-mounted 75kg rated steel rack with a passenger seat cushion

[Psamathe]

Rack replacement =Tubus.....

+1

Ian

[NATURAL ANKLING]

hi,
When I mount racks I always bend the legs carefully where they meet the frame.
There should be no springing of the legs when you put the rack on the frame.
Where the mounting holes are make sure the face of the rack fits nice and flat on the frame lug.
Despite not liking stainless screws much for stressed points, I found using stainless ones here perfectly okay assuming that you have done the above correctly.
On the plus side the stainless bolts will never seize in a steel or aluminium frame.

Don't forget the rack top mount strips, everything should be perfectly flat and not stressed when you bolt it up

[horizon]

I had a strut on my rear pannier split at the weld whilst on my recent tour - the pic shows the road repair... no harm done, but made me think. One, I need to make sure I get a new pannier which is rated to carry a load far more than I actually carry. Two - that weight bears down on two screws attaching the pannier rack to the bike. It seems like a good idea to change these screws every year or two to forestall metal fatigue. Also, are there any particularly strong screws to get for this job?
I know it wasn't the screws that failed this time, but it just made me aware of a possible weak point.
Cheers!
DSC08615.JPG

Hi Just for clarity, could you add "rack" to "pannier" in your post? I presume you are talking about your rack, but you say pannier. Thank you.

[horizon]

weight bears down on two screws attaching the pannier rack to the bike. It seems like a good idea to change these screws every year or two to forestall metal fatigue. Also, are there any particularly strong screws to get for this job?

The Spa tourer hads larger screws for this job:

6mm threads in
the bottom rear carrier eyes. They’re
much less prone to loosen and strip
under the weight of a touring load. The
usual 5mm are adequate for the upper
fixings and lighter front panniers.

[Bmblbzzz]

I don't see any evidence that the rack was only rated for 10kg, or that it was rated for more. Nor what sort of load it was actually carrying at the time (or in the past). Perhaps Slowroad could inform us, so we don't get led astray by random guesses from others?

[Slowroad]

Thanks all, very useful. I'll definitely look at Tubus. And the comments re screws are very useful.
It's a Blackburn MTN rack, came with the bike second-hand - some mixed opinions here http://www.bikepacking.net/reviews/rack ... mtn1-rack/
My luggage weighs around 15kilos, comprised of two panniers and a tent. Do bear in mind that it's a very small frame with 26" wheels so the panniers look bigger than they are!

[mercalia]

just get it re welded? Why the expense of a new Tubus rack? Things do break?

[Slowroad]

just get it re welded? Why the expense of a new Tubus rack? Things do break?

I'd quite like a different design anyway, it has got slightly bent, and I'm not sure how cost-effective aluminium welding would be?