The best lightweight tyre insert for protecting your rim?

I have not tried them but the Rim Saver appears to be the best.  I would love to try them.  They just make sense.

I'm currently running the XC Cushcore in the downhill bike solely for rim protection.  I will probably switch to rim saver eventually.

Plus they have a great story and are made in Vermont.

Rim Saver for sure. If you don't want the squish of a foam insert (like many do not), but still want to protect your rim, Rim Saver is by far your best option. Plus Ryan lurks around these parts, super good engineer, really nice guy.

This. Only one flat since I started running rim saver, and that was entirely a combination of user errors. Easier to install than cush or rimpact too.  

Protecting your rim and preventing pinch flats are two different things even though they are related and might seem similar just to be clear.

It seems like a good number of world cup XC race guys run the Vittoria one - Air-Liner Light XC Trail - MTB Tire Inserts | Vittoria  

55g added which is a not bad compared to other options. Can't speak to how effective it is at rim protection but it's light and claims to help prevent pinch flats if that's what you are after. 

If you’re not getting pinch flats then the rim likely isn’t getting much abuse. What rim are you trying to protect?

I’d also lean towards Rim Saver for your use case. If you’re not trying to run super low pressures, I don’t think a heavy insert is worth the extra weight and changed feel.

from my experience, there is no preventative maintenance on an alloy rear hoop.  You simply admit that you're into a new rear hoop every 12-24 months depending on how many times a year you Ef around and find out.  I do that a lot... so I go through 1 alloy reserve or ex511 hoop per year.  

I was thinking about posting this exact question two weeks ago. I run DH tires on EX511’s and go through at least one rim a a year… I write cheques that my skill can’t cash sometimes. 

I get zero pinch flats running 24 F and 26 R PSI and was looking into stretching lifespan of a rim if possible. Tried inserts but prefer the feel without… might have to try the Rim Saver. 

I will preface everything I am about to say by mentioning that I work for a wheel company, and as such I have an unusual capability to replace wheels. I  am very very lucky to be where I am and as such this can be taken with a grain of salt. With that being said...

Inserts for alloy rims are a tough sell for me. I am not an exceptional rider, nor am I particularly heavy rider(165lbs with kit), and I have destroyed an aluminum rim despite running a heavy Cushcore insert. Somewhere on this website there is an excellent write up from the guy who owns/founded rim saver. It is an excellent read regardless of if you are in the market for an insert or not. In the write up he acknowledges that the expectation placed upon tire inserts by consumers are a little lofty. He states that the reality is that an impact that is going to cause a catastrophic rim failure is likely going to do so regardless of an insert's presence. He mentions that what initially caused him to look into inserts in the first place, was an incident in which he has a sudden carbon rim failure (JRA) likely as a result of unseen damage to the carbon fibers, which became exacerbated by continued riding and eventually resulting in a complete failure of the carbon fiber. This is where the tire insert shines. Inserts can absorb small amounts of force that would otherwise be transferred into the material of the rim, which could theoretically prevent unseen carbon damage and thus unexpected rim failures. 

I should also mention that in all of the carbon rim failures I have seen, almost none have been a dramatic collapsing of the rim. Most carbon rims fail by cracking in a very loud fashion, and then promptly letting all of the air out of your tire while still retaining their general structure. It is still expensive as the rim is now unusable, but I think it is worth noting that carbon rims from any reputable brand rarely disintegrate in dramatic fashion. 

Alloy, isn't like this. Alloy rims bend when they are hit, and a little foam may lessen the dent slightly, but the reality is that if you transferring force directly into your aluminum wheel, you are asking to dent it. That  doesn't make you a bad rider, and it doesn't make the wheel a bad wheel. Aluminum is meant to bend when impacted, and it very seldom breaks. This means that hitting your wheel on a rock typically doesn't result in a loss of air from your tire. The rim bends, but it tends to take the tire with it and keep the tubeless set up intact. The alloy rim is meant to hit a rock or two. Knocking an alloy rim a little out of true and/or putting a few dents in the rim horn isn't really going to change its performance so long as it keeps holding air. If you are impacting the rim hard enough to make it incapable of holding air, then there is little chance of an insert changing that outcome. Alloy is nice because the worst case scenario is putting a tube in, and riding a little more gingerly. Throwback to Jack Moir beating his alloys wheel with a rock in order to tube them, which played a huge part in him winning the overall that year. 

My point is this, the only way to keep your wheel in perfect condition, is to not use it, just as the only way to ensure you never get injured is to never leave your house. Inserts have a place for sure, they can help prevent flats, they can act as bead locks, and you can ride on them if you flat which is surprisingly novel. What they won't do is stop you from denting your alloy wheel, or knocking it out of true, and you are likely better off making peace with the fact that alloy rims are a long interval wear item, and that they are meant to be beat, not babied. 

All of this is said with the context that you aren't someone who usually flats. It goes without saying but if you slam a rock into your rim, there is a decent chance of blowing a hole in the tire and you shouldn't be surprised if that is the outcome and it likely has nothing to do with the wheel. Final disclaimer- I run alloy rims on my enduro bike. 

some friends report being pretty happy with the lighter vittoria airliners.  I have a trail set that are quite light, like a tube. I aim to throw them in this weekend.  They won't offer the protection of a full cushcore, but they're far lighter, so maybe the ride quality is more similar to tubeless.

I still like Tannus, but they do change how your tire rides (in a positive way)

I started using inserts to protect my fancy rims, but now I find that the biggest advantage of inserts is that they act as volume reducers. I can run low pressure and still get the ramp up of a much narrower tire or the equivalent tire at higher pressures. I get tremendous traction and corning with pressures around 20psi and still have the support going into going into jump faces or doing berm slaps. The rim protection has become secondary, but an added bonus. After trying 5 different brands, I like Tannus for all-around and Cushcore for DH/park riding. Airliners and other pool noodle types seem to me to offer too much ramp up/ too little volume. The thin, low volume Rim Savers don't appear to offer the ramp up, low psi and support benefit.

Reserve carbon HD's are incredibly durable and I have had the same experience where they last so much longer and are so much less maintenance that they are arguably cheaper in the long run when compared to most AL hoops.  I used to be an inserts in everything guy... but recently I've reduced my usage of inserts to my ebike and light weight inserts on my light duty trail bikes that run exo/exo+.  Everything else gets a thicker casing tire instead of an insert.  

I love that insert in the rear tire of a hardtail. They changed design though, it used to take up more volume. It used to be like this

the newer ones are t-shaped, i‘m on the new enduro one after having used the older ones for years. you need their mounting tool to break the bead when you changing tires and using dh casings. couldn’t get the off any other way

If you guys ever see a tire insert that needs to be made but doesn't exist, let us know.

Happy to prototype it and share learnings here. 

Could do it live on here to see what we learn as well. We are making a custom insert for a team for next season, will see how it goes!

I've gone around the houses with tyre and insert combinations, currently on an XC cushcore and DH casing DHR II.  A guide of ours in Finale still rides tubes in DH tyres on his guiding rig. I got back into riding in 2016 and i've just rode tubeless. Does anyone else still ride tubes or newer style TPU ones. What combo's? I've had issues keeping wheels sealed lately, new rims, new tape blah blah.... go to the garage....fffflat

I picked up a set of Reserve 30HD AL wheels for the downhill bike last season and have been nothing but impressed.  I dented the rim so bad the paint flaked (no insert at the time BTW) but it never came out of true.  I still haven't had to touch a spoke with well over 30 park days on them.

I need to get one of the Sledgehammer tools soon.  Think that would be helpful for an aluminum wheel guy.

Tannes for me , soon bikes I have the light version and others I have the pro. I have not , will probably never run the full fusion system.