I'm talking about a 50 lbs.+ rated rack that uses the frame bosses on the seatstay and holes at the dropout. I have a commuter/touring bike I use for all my errands and it has a heavier-duty rack for large grocery runs, etc., and I've toured with that rack as well. I quite enjoy the feel of the bike for recreational riding, though, when I take the rack off.

I've heard people warn against doing this with regularity, and I'm wondering (a) if that is your experience and (b) if you've tried alternative mounting methods that make it less troublesome. I'm not looking for a quick-release, seatpost rack, or other solution-- I quite enjoy my burly Tubus and just wanted to see if people ever go back and forth with their mounting.

Thanks

No. My rack came on the bike and while I have checked the attachments sometimes that’s it.

What's the supposed risk? Wearing out the frame threading?

Yes, I had an older bike, since sold, where one of them had been stripped, though no idea if that was from normal use-- I had picked it up used. I've been careful with my current bike but I wonder if I'm pushing it. I do grease bolts/torque appropriately, though.

I don't remove the rack, but I do slide my Trek bag on and off the rack and, wow, what a weight difference THAT makes!

My rack stays on the bike, but the bags come off.

No, but my fenders come off a few weeks after the time change and go back on when it changes back

Ditto.

I did take the rack off one bike 6-8 years ago. It was an aluminum rack that came with the bike, and the panniers had rubbed about a third of the way through the struts. New Tubus steel rack is shiny in those spots.

Maybe a couple times a year I'll take the rack off my crosscheck, but I really don't enjoy recreational riding on the road, so there's not much point.

My racks are there to provide service options and stay in place. Today was recycle run, so bigger panniers on front low riders with a few cans in trunk on back... smaller, back bags stayed home. Another day it was collapsed boxes on the front top rack. Or the bottled water run with all bags pitching in.

No but I keep losing the mounting screw that goes on the frame at the rear wheel. I keep forgetting to double-check it before and after all my rides or to just pour glue all over it.

I've been planning to do this. I'm currently using my original touring bicycle Trek 520 as my grocery getter. On the cheap aluminum rear rack that came with it I have a pair of Wald 582 shopping pannier baskets, which would be too difficult to remove and reinstall multiple times. The rack is held by four allen bolts in the usual places. If I wanted to put trekking panniers on the bicycle, I'd remove the cheaper rack with shopping basket panniers still attached and get a new, stronger rack for which to tour with.

Be careful not to cross-thread your bolts when re-installing your racks.

If you're afraid that the bolts might work themselves loose, use blue threadlocker (locktight, etc) on the threads of the bolts which hold it on.

Does the issue happen just with experimental materials such as aluminum and carbon fiber?

In the early days of my Pete Mooney, the rear rack came on and off as needed, Year 5, I had a replacement fork made with braze-ons for a Lowrider which also came on and off, Now the swaps are far less often and the bike has not toured for many years but it spent the '00s and first half of the teens as a farmers market bike so those racks saw real use.

With carefully done threading and care starting bolts, those dropout eyes should handle the changes many many times. And when the threads do go, a slightly longer bolt and nut works just fine on most bikes. I've had bikes that came without threading and older bikes that had them no longer. Small PITA but far from a frame killer.

Oh , my experience is all with steel and titanium frames, I've never owned either aluminum or carbon fiber. (The ti frames have only seen fenders, not racks but the fenders come on and off a lot.

Not at all! Braze-ons made of flint are known to be particularly brittle, even more so than cast iron.

What issue are people having with this?

hermanchauw, is that just a grub screw in a standard braze-on, with a bolt and washer as locknuts? Or did you drill&tap your seatstay to screw that in?

I've taken my rack on and off maybe 20 times? doesn't seem worse for wear.

I’ve done this but had a threaded eyelet located at the seat stay stripped after a while so stopped taking off the rear rack.

standard braze-on.

I take mine on and off, maybe 3x a year so not much. My theory from general mechanical knowledge is you have a higher risk of damaging your threads from:
1. The screw working itself loose and moving around gradually damaging the threads
2. Over tightening
To prevent 1 people often use 2. Use a threadlocker to reduce the risk of both of those greatly and can fill in some voids and reduce vibration and movement. Racks put very little force outwards on a screw, the screw is just "there" to provide something to suspend the eyelets from falling. The tightness required is only to prevent the screw from vibrating and falling out which threadlocker does. A $5 tube can last you years if it doesn't leak out first.

Also, use the softest screw available (aluminum?). Allow any potential damage to happen to the screw instead of the boss.