Bontragers site makes no mention of a Gum-Bi ACX, neither in normal or TLR versions
Other tyres such as Mud X's and Earls do have that they're Gum-bi mentioned
I've an old set (bought August '08)of normal folding ACX's with no Gum-Bi labelling and in use feel as if they're pretty hard, the only gripe I really had with them, mostly when cornering

I've seen a picture of an ACX with GumBi on the side of it, which ones are Gum-Bi. The TLR ones? I'm assuming they'd be the same as Mud X's, ie 55/62a which sounds just about right, like a decent volumed Mud X

Pretty sure my ACXs are a dual compound, and 55/60 rings a bell. I bought them because they looked ideal for muddier stuff and they seem to have proven me right.

They're the tubeless ready ones, dunno if thats what TLR stands for?

I have some that came on a bike and have a blue logo on the side. They are folding but not tubeless ready or dual compound. The tubeless ready ones i have specifically say Gumbi on the side, have the durometers written on a la mud x and most importantly, have red logos that match my bike.

They are very similar to mud-x (same compounds according to the label) but are a little quicker rolling and more plump. I like em as I dont have to bother changing tyres around all the time, i just put the muds on in autumn when it gets wet, and change them sometime around april/ may when the trails are a little less sticky.

hope that helps
edit – TLR is tubeless ready.

I think it does help yes thanks, just odd that Bontrager has failed to say anything on their site about the Tubeless Ready ones being dual compound

I think it does help yes thanks, just odd that Bontrager has failed to say anything on their site about the Tubeless Ready ones being dual compound

I'm surprised it says anything about ACXs at all as they're not a current product (sadly)

are you sure? They are still shown on there, along with the newer XR4 which looks like a tarted up version.

Shame, I like these tyres 🙁

matthewlhome – Member

are you sure? They are still shown on there, along with the newer XR4 which looks like a tarted up version.

Pretty sure. Trek UK are no longer listing them.

Shame, I like these tyres

Me too.