Notubes Crest/Iron Cross - real world experience with psi

[rasmussloth]

I'm considering Crest or Iron Cross for tubeless cyclocross in the winter and high pressure road cycling in the summer with tubes.

Notubes says max 45 psi.

Has anyone here used them with tubes and higher psi?

[mtbstuff]

Don't.
You might get away with it....but probably not.
Go with the Grails....better all around rim. Stiffer, seats a tubeless cross tire better...and can handle road pressure

[Tamu8104]

Agreed, had some Crest on my MTB for a while and definitely wouldn't have trusted them at higher pressures. They were light but never gave me the sense that they that strong. Large part of why I let them go.

[bikerector]

There have been a number of reports of the iron cross blowing tires off at the higher pressures with tubes and road tires. A friend of mine had that happen in the shop since the iron cross came on a lot of disc CX bikes as OE when they were first introduced and they came on his CX bike. He wanted to put road tires on and ended up either needing new wheels or just deal with getting wider slicks and running them at the lower pressure.

The grail seems like a better all-around option from stans. I believe a lot of people used the alpha's if they needed rim brakes.

[jooo]

I still think the Crest or Iron Cross is great, you just need to pick something a little larger to suit the rim, like a Compass or Clement tyre and run really low PSI compared to normal road pressures. It will feel fantastic and the Crr is still pretty reasonable.

[mattr]

How small a tyre will you actually get away with on an Iron Cross or crest?
I'd guess probably not much smaller than a 30 or 32mm?

So, if its a decent lightwieght tyre, you'll not be running much more than maybe 3.5-4 bar?
I'd probably risk it........

[drbobb]

I've got some experience with my Iron Cross hoops. I pumped my vittoria xg tnt 32c tubeless up to 50 psi to get them to seat and they popped off, loudly. My current set up of WTB Nano 40c run nicely tubeless at about 35 psi and I don't feel the need to get higher on the road with them and are stable on the single track. They have rather skinny sidewalls though.

[gtinut]

Grail is way to go. I use them on my cross bike with Sector28 and CX tires.

[AdyM]

Maybe take a look at DCR wheels 24/25 disc rim. It's the same profile as the grail, 24 wide, 25 deep, 20mm internal, but is only 415g (30more than Iron Cross, 45 less than grail?) £60 per rim.

Here's what they say:
DCR 24/25 disc, 24/28h, black, £60/rim24 . 25 disc
As ever the idea with the DCR components is to meet the demands of serious cyclists, so here are some vital statistics:

24mm width
25mm depth
Welded joint
6066-t6 alloy
415g
Tubeless ready
Extra thick spoke beds
From my perspective, the spoke beds is a very important element, but will likely be glossed over by those reading the stats. They have actually been tested to withstand over 300kg, which is higher than any other rim I have seen results on. The 6066 alloy is naturally stronger than the 6061 more commonly used and the heat treatment is applied to the rims after they have been extruded, rolled and welded. That means you get the heat treatment on the weld as well, rather than essentially creating a weak point in the rim where it has been melted.

A welded joint means easy sealing with tubeless. The deep cavity in the centre of the rim means easy fitting of tyres. The 415g weight means if you paired this rim up in a 24/24 drilling (my preference would normally be 28/28) with Tune Prince/Princess hubs (to illustrate what is possible) you would have a set weight of around 1360g.


....This is the rim I'm building my next CX wheels onto.

[kingkongsfinger]

Don't.
You might get away with it....but probably not.
Go with the Grails....better all around rim. Stiffer, seats a tubeless cross tire better...and can handle road pressure

This ^

Been using Grails for over 18 months, with cross tyres and road tubleess with Hutchinson Fusion's inflated to 110 PSI, been superb built with Hope Pro 2's.

[robertshepherd]

FWIW, I've been running Crests with 28 mm Continental GP 4S with tubes on my commuter bike for 2.5 years.

Had the same fear about PSI, but the local Stan's rep confirmed that the PSI limitations are based on tubeless. Apparently there is sufficient tire/rim interaction for far higher pressures when running tubes.

Have been using my 28s at 80-100 PSI and haven't had a problem. Lots of road and gravel km's under them.

Best of luck!

[stephenjames]

Had the same confirmed to me directly by No Tubes. The limitations on pressure are only with tubeless. Running tubes you can go with high pressures and no concerns. I've been running Crests on a commuter bike for 2 years at 90psi.

[jcrr]

Since the discussion has centered around Grails and Crests, I decided to give Stan's a call specifically re: Iron Cross.

Their words: "You can run a tube and clincher tire, but are limited to 50psi for a 28mm tire."

If anybody has any real world experience at 80+psi specifically for Iron Cross, I'd love to hear about it and which tire you are using.

The cross-sections show the hook of the grail and iron cross rims to be very similar.

[mrlobber]

ZTR Grail - Challenge Almanzo 33mm with tube was blown off @ 55 PSI

[jcrr]

@mrlobber- sorry to hear, hope it wasn't mid-ride... Can you comment on how the tire fit? Was mounting easy? Hard? Did it seat properly as far as you could tell?

55psi on a 33mm is roughly the same as 115psi on a 23mm tire, so nothing crazy in terms of pressure... hmmhh...

Anybody else?