Foam inserts for XC bike?

[michaelbiker]

I run a tubolite sl in my back tire and it’s allowed me to run lower pressures (1.4-1.5 bar) and lighter tires (Rekon Race 120tpi or Kenda Karma SCT). It also seems to dampen vibration quite a bit which is probably the main reason I’ve left it in there. It’s only a 60g weight penalty and I have heard the back wheel ping a few times on rocky descents. So it’s nice to have the peace of mind.

It does go through a bit more sealant though.

[Stephan]

Thanks for all the replies, everyone. 

So IF I wanted to go this route, the https://ridepanzer.com/xc-marathon/ (~100grams) and https://tubolight.bike/shop-bike/tubolight-evo-sl-hd/ (~58grams) seem to be the two best options. 

Does anyone know if these brands are sold in SA? 

[DieselnDust]

14 hours ago, SSCC said:

There is a test somewhere online - inserts are only 1 to 2 watts slower than no inserts. So basically they make almost no difference to rolling resistance. 

That’s lovely. Can you post the link so we can examine the test methodology?

[SSCC]

4 minutes ago, DieselnDust said:

That’s lovely. Can you post the link so we can examine the test methodology?

Don't have the link but google has all the answers. Maybe on bicycle rolling resistance dot com but can recall.

[DieselnDust]

Ah ok so it’s my problem to investigate your claims……

Filing this one in file 13

[Stephan]

Maybe this one? http://www.morespeedlesspower.com/2022/02/do-foam-tyre-inserts-degrade-rolling.html

[Headshot]

21 hours ago, Scalpel said:

Theoretically you can also run slightly lower pressures on a gravel bike!

 

You can run much lower pressures and actually have to to avoid super bouncy tyres. The insert acts like a volume reducer in your shock and makes your tyres more progressive i.e they wont bottom out even at lower pressures. 

[Headshot]

18 hours ago, Andrew Buckley said:

The tyre/sealant combo on MTBs these days is so good it just doesn't seem necessary to run inserts.  In 7 years I have never had a puncture which didn't seal on the trail.  Schwalbe Racing Ralph/Rays, Maxxis Recon/Recon Race, Maxxis Ardent/Ardent Race, it doesn't matter, they are all great.

Running between 1.2 and 1.4 bar.

Andrew

Inserts are not primarily designed to allow you to ride home on a flat. While they will help prevent rim contact induced snake bite punctures, the primary purpose is to allow lower pressures for added traction in situations where you'd usually want lower pressures but can't risk it because of the risk of rim and tyre damage, per my example on the Missing Link trail earlier in the thread.  If you only ride smooth gravel and hard pack, then inserts are probably a waste of time.

[Headshot]

2 hours ago, DieselnDust said:

Ah ok so it’s my problem to investigate your claims……

Filing this one in file 13

Sounds like built in bias towards inserts rather than a desire to learn.

[DieselnDust]

2 hours ago, Headshot said:

Sounds like built in bias towards inserts rather than a desire to learn.

No not quite. My comments earlier were very specific. I’ll use them for general riding when rolling resistance is not a problem.

when riding at threshold for 3-4hrs I want all the watts going into propelling me forward. 
 

so for XC is won’t use them in a race. Maybe for an XCO where I’m taking more risks for a shorter duration and the course warrants,  but for a marathon where I can’t ride the wheel on an insert for an hour without destroying the rim or tyre completely no I won’t I’d rather fix the tyre there and then.

the rolling resistance is noticeable no mater what the marketing says. It’s rubber inside the tyre than has more hysteresis than an inner tube and the difference between inner tubes and tubeless can be felt. Now someone says he may or may not have seen a video where the watts lost is 1or 2 so I’m wrong…?. That’s not a reasonable argument to debunk every review on inserts that says yes there’s extra rolling resistance but the trade is worth it (in the reviewers opinion) not to debunk my personal experience and decision based on that experience.

for gravity and e-bikes I would definitely use inserts everyday 

 

[Headshot]

Do you mean rolling resistance or rolling mass. Lower pressure in tyres have been shown to roll better on rough terrain and this is exactly what happens with inserts when using the lower pressures they permit. I speak from firsthand experience.

[DieselnDust]

21 minutes ago, Headshot said:

Do you mean rolling resistance or rolling mass. Lower pressure in tyres have been shown to roll better on rough terrain and this is exactly what happens with inserts when using the lower pressures they permit. I speak from firsthand experience.

Rolling resistance.

this accounts for mass, hysteresis which is informed by tyre casing design and air pressure. The insert is held in place by the tyre therefore it will always influence the tyres rolling resistance. The only way to get way from that is to have it completely free of the tyre and there are no inserts design that functions without contact unless the tyre pressure is so high as to negate the function of the insert. In a road application with the Vittoria inserts the rolling resistance is less impacted because the insert is compressed under the tyre pressure. Mtb inserts don’t function this way. They are always mostly in contact with the tyre casing .

inneglected to mention that the widely held belief that high volume delivers less rolling resistance is being contradicted by assertions that the insert does not impart RR. This is impossible since it occupies volume in the tyre.

< makes pop corn while waiting for pseudoscientific assertions that inserts are exempt from physics>

Edited October 10, 2023 by DieselnDust

[Jewbacca]

@DieselnDust I love it when you speak foreign.......

I 'believe' there is merit in having a proper insert while trail riding and smashing down things, but otherwise it becomes something that gets in the way of a simple trailside repair and more to carry or discard if the system completely fails 20, 30 or 50km from the nearest relief point.

 

[DieselnDust]

3 hours ago, Jewbacca said:

@DieselnDust I love it when you speak foreign.......

I 'believe' there is merit in having a proper insert while trail riding and smashing down things, but otherwise it becomes something that gets in the way of a simple trailside repair and more to carry or discard if the system completely fails 20, 30 or 50km from the nearest relief point.

 

Agreed

[Scary Rider]

1 hour ago, DieselnDust said:

Agreed

All of it, or just the part where Jewie said he loves it when you speak foreign?😜

[Fred van Vlaanderen]

I run cushcore on a trail bike and it works brilliantly. The benefit vs weight penalty on a trail bike is an absolute no brainer for me. I think it depends on whether you mind the extra weight, and if you don't, it would make absolute sense to do inserts. You can run tyres at lower pressure, which results in more grip, with the lower risk of puncture... what is not to like about that.

I never ever ever ever thought that I would run inserts... but having used it for a year now, I can't imagine riding without it.