Perhaps a crazy idea. I’ve got two steel frames and one mudhugger rear guard. I want a quick option for swapping it between either bike (quicker and less wasteful than zip ties). Been thinking of getting some neodymium magnets and bonding them to the mudguard. Would be about 15cm long x 3-4 mm wide of magnets on either side. Is that likely to be enough to hold the mudhugger on securely?

How long is a piece of string? A magnet is only as powerful as the amount of magnetism that has been induced into it.

“Very” is the answer you’re looking for, but they’re heavy and they slide quite easily. So you may find that they slip down over the course of an off road ride.

about 15000 Gauss as a maximum. Well you did ask 😉

i reckon you could hold on a mudguard – but you’d need to get the arrangement/ placing just right.

You might need opossing magnets on the bike, otherwise the margnet might slide down the seatstay – if that makes sense.

Not as simple as I thought then. I’m assuming you mean some trying to pull the mudguard down and some to pull it upwards.

It’d be strong enough to stick it on, but it’ll probably slide. But you could counter that with some sort of sockety deal to prevent movement

Having an end stop permanently attached to both frames would be fine. It’s the moving of the guard itself quickly that I want to achieve.

Don’t know how to solve your problem, but if I may share an anecdote?
I saw something shiny at the end of a woodchipper discharge chute and struggled to get it off with work gloves on, but managed to pull it off bare-handed (stop sniggering at the back). It was the strongest magnet I’d ever come across and was the size of a pea. I concluded it had been picked up off the road and worked its way through the chipper and amazingly slid up the chute and clung on at the end.
So, they are very strong but will slide.
It now holds up my Singletrack calendar in my work locker.

A cable tie around the seat stay would work as an end stop to prevent the magnets sliding.

velcro?

Another anecdote a builder friend of mine found some super strong magnets while working in an old factory and somehow figured out if he puts it on his electric meter it stops reading any usage…

I used those stick on frame cable holders when I fitted my dropper. They came unstuck so i used a magnet in a blob of sugru moulded around the cable.
Works fine for that. Shame my other bike is ally so it cant be used on that.

Reusable cable ties.

Massively strong!

I’ve got a few, ranging from 90kg to 200kg that I use when magnet fishing!! :0)

A cheap/free source of small, powerful neodymium magnets can be found in old, defunct hard drives. Ask nicely down your local tip, as they are worth nothing now and can be fished out of tower units easily

Magnetic force calculator

As magnetic forces diminish so rapidly with distance, I think you’d find that it will either be impossible to remove, or, drop off unpredictably when you hit a bump.

Reusable cable ties are a faff and I don’t find they don’t do up as well as non reusable ones (also its not exactly that much quicker). After seeing what a loose mudhugger can do to a frame I’d not want to leave it loose.

We have a huge stack of old HD’s in the office that have been kept back from old machines. Given that they really need to be gone I may have a fish in them.

gfs, not being able to remove it was my main concern!

Sweepy, that’s a neat little trick. Would be great for swapping a dropper between steel frames.

Aren’t those guards about £20 ?
I’d just buy another for the second bike I reckon and save myself the hassle 😉

Velcro as mentioned above.

The ones that loop through themselves similar to a ziptie.

They are yes. Part of it is also wanting to be able to remove it quickly when I don’t want in on (and then put it back on quickly when its wet and my forward planning has failed). The peculiarity of where I store the bikes also means they are easier to store minus the guard.

Velcro zip tie?

https://uk.rs-online.com/web/p/products/0216034/?grossPrice=Y&cm_mmc=UK-PLA-DS3A-_-google-_-PLA_UK_EN_Cables_And_Wires-_-Cable_Accessories_And_Ties_And_Tools-_-PRODUCT+GROUP&matchtype=&gclid=Cj0KCQiAmITRBRCSARIsAEOZmr53rgZOstL51roOQMG0noxueK7vq68OoyAWUwP-x3YUCdoQf_Oe9eMaAoPYEALw_wcB&gclsrc=aw.ds

the special vecro stuff they use for fixing the latest version of crudcatcher Road Mk3’s is pretty stable? Duotech Interloc

That stuff does look like it would be worth investigating.

P clips round the seat stays with wingnuts/nyloks?