Rear Hub Spacing Standards on New Frames

[Sam Song]

In the past not too long ago, rear hub spacing on frames were quite simple with 26 inch frames being 135mm and 20 inch frames being 116mm. 

There was a brief period of manufacturers introducing "modstock" spacing with 116mm rear spacing for 26 inch frames but they did not end up sticking around. 

Nowadays, Clean has their proprietary 120mm rear through-axle. Jitsie is running 116mm rear spacing. And Inspired is running the usual 135mm through-axle. 

Were these different standards really necessary? It makes switching parts between frames very hard nowadays.

I would personally love to see bike companies going back to 135mm spacing with a choice between bolt-on and through axle. 

Meanwhile, the rest of the other single speed DJ frames in the MTB are happy sticking with the usual 135mm/142mm spacing. 

 

 

 

[craigjames]

I don't think there is any logical need for the 120mm spacing used by Clean and Comas unless it's a chain line thing? My cynical mind tells me that they've probably done it to sell their proprietary hubs. Crewkerz use 135mm on their 20" bikes, as does my MK6 Echo 20". I run a hope Pro5 SS hub. So they've proven that a 135mm hub can play nicely with the chain line on a 20" bike.

It's a bit like Jitsie and their 1-1 1/4" tapered headtubes, there's just no need!

I don't see the need to move to 142mm on 26" bikes, I don't think it will bring any real world benefits to trials.

 

[La Bourde]

5 hours ago, craigjames said:

I don't think there is any logical need for the 120mm spacing used by Clean and Comas unless it's a chain line thing? My cynical mind tells me that they've probably done it to sell their proprietary hubs. Crewkerz use 135mm on their 20" bikes, as does my MK6 Echo 20". I run a hope Pro5 SS hub. So they've proven that a 135mm hub can play nicely with the chain line on a 20" bike.

It's a bit like Jitsie and their 1-1 1/4" tapered headtubes, there's just no need!

I don't see the need to move to 142mm on 26" bikes, I don't think it will bring any real world benefits to trials.

 

Agree.

I think it would be much better for all brands to stick on some standards.

Just for the sake of completeness, the 142mm standard is the same as 135 regarding chain line or disc placement. They only add 3.5mm on each side to lead the hub within the frame rear ends (which is a nice feature, it makes installing the wheel easier, but far from necessary)

Not sure a wider hub will increase a lot the stiffness of the wheel.

I guess the current rims lack stiffness.

 

[craigjames]

Rear rims have followed a fairly similar design for quite a while now. So unless something crazy and new comes along, I don't see that changing.

Stick to 135mm it works for all different sized wheels, one size is cheaper for bike and component manufacturers, it also opens up the choice in aftermarket hubs. I think from a design and materials point of view, that we've reached peak trials bike, it will just be incremental improvements.

Maybe more parts produced by additive manufacturing using exotic materials?

[Ali C]

10 hours ago, craigjames said:

 I think from a design and materials point of view, that we've reached peak trials bike, it will just be incremental improvements.

 

I disagree, I think there’s still some big changes that could happen…I can imagine carbon frames designed with some built in vertical flex that acts like a spring. I currently see trials as pole vaulting with a completely stiff pole, imagine how high you could jump if the bike could be slightly preloaded and then unleashed, like a more specifically designed tyre preload.

 

i do agree that all brands using 135mm hubs would be nice though!

[craigjames]

10 hours ago, Ali C said:

I disagree, I think there’s still some big changes that could happen…I can imagine carbon frames designed with some built in vertical flex that acts like a spring. I currently see trials as pole vaulting with a completely stiff pole, imagine how high you could jump if the bike could be slightly preloaded and then unleashed, like a more specifically designed tyre preload.

 

i do agree that all brands using 135mm hubs would be nice though!

I did think about this, my only issue is you don't see many pole vaulters landing with their poles. What I mean is you'd need to be able to dampen that springy energy whenever you landed a move to rear wheel to stop you getting bucked off. It might be possible, but does make things more complicated.

[Ali C]

I think people would get used to it pretty quickly