Supercross, the disc and … something else!

April 2018

Supercross, the disc and … something else!

April 2018

Not prone to sitting on his laurels, Bill Ryan over at Supercross BMX is looking at the Disc Brake, as we’re sure most of you noticed on their social media feeds. And not just a bracket adapter but a modification to the already stunning RS7 … if you’re going to do it, do it right! But don’t hold your breath, if Supercross are going to do this, and we believe they will, it’s going to have to tick all of the stringent Supercross boxes.

We know that Supercross and the disc is not really unpredictable but the next bit of news is, well to us anyway … that RS7 prototype frame is also build to test something else that everyone missed … OS20 is now under evaluation over at Supercross HQ too! More on that in a bit … first let’s get back to what we’re really excited about … the disc, here’s what Bill Ryan told us …

“I have been a proponent of the DISC brake movement in BMX. I have seen the disc brake movement come and go. This goes back to the mid 90’s when you were first starting to see Disc on MTB’s and people wanted to adapt them to their BMX, surprise, it didn’t work, so the movement stopped, fast forward to the early 2000’s we used to share a building with Atomlab and they were gung-ho and doing Disc brake conversions on any and every BMX they could find….. Guess what, it didn’t’ work … Now fast forward another 15 years and we are seeing disc make another resurgence in the MOVEMENT, and so far, again, it is not working …

But, and it is a big BUT, we are playing around with a few prototypes. As the Road market moves more to disc and MTB is moving to an all DISC situation, we know a day will come where BMX will be all disc. Not because we need it, but because we will have had to adapt and learn to live with the problems of the disc brake.”

Supercross RS7 Disc

“I have seen what other companies are doing and how the adapter and conversion companies are doing it, and so far, I don’t see anyone solving the biggest problem in the disk brake market … which is the ease of customer use.

A lot of people have sited that the disc is dangerous, which it is, it’s a Stainless-Steel blade spinning at high speed next to lose fingers in an accident, we have all seen what the spokes and the chain can do. Guess what, the disc can do worse, but that is not my biggest concern. Next if you are in a race and someone crashes into the disc in a turn down a straight … and your disc gets bent, guess what, race over.  If your rim bends, the V-brakes may grab, but it will still spin. On the disc, if it bends, the tolerance is so tight on the pads, that it will not clear the caliper. So, the race is done. 

People have also sited that the disc set up is heavier than the V- brake which is true, but you can make a lighter rim if needed with a disc as you don’t need the brake track on the rim. So that washes out. WHEN the disc specific rims are made.

People also say that the hydraulic brakes are a pain to bleed etc … Truth. No question about it, but most BMXers will want to find a high-quality cable activated set up as the cable activated ones are lighter at the lever assembly and easier to set up.

But the biggest issue I have seen is watching people change a tire with a disc brake BMX bike.

On the MTB it is simple drop the wheel down, change the tire and Click the wheel back up into the fixed position. The derailleur takes up the chain slack and tension, the biggest thing I have seen, is professional mechanics trying to get the wheel back on in the same spot after a quick wheel change.

The BMX dropout is a sliding axle, it is adjustable to take up chain slack, and if your chain stretches and you need to pull the wheel back, your disc is not lined up properly. Or if the wheel is slightly off centre, the disc binds and drags. Wheel pulls forward a little bit, then the disc drags and binds.

It isn’t user friendly.

The only one I saw that properly addressed this was the Meybo fixed rear axle. That was awesome. But now you have a fixed rear axle length, which is a common thing on a road bike or MTB, but BMXers, we are a disagreeable bunch and trying to agree on the proper C/S length, is it 15” is it 15.25” is it 14.75”, you try to get them to agree. I like my wheel forward, I like my wheel slammed. 

But aside from the detriment of a fixed axle, you now have an Idler Pulley / Chain Tensioner, which creates more drag. And in BMX we are looking for the least amount of drag, the least amount of resistance. So that is a second issue that takes away from that idea.

And there are a few ways around this, but then you end up with an over complicated, over engineered, heavy rear triangle…

And why … so you can run a disc.

Don’t get me wrong, I want discs on my car, I want discs on my motorcycle, I have disc on my MTB, and I am even building a new road with disc, but for BMX we still like the V-brake …

BUT as mentioned above, we are not close minded and we did build a few prototypes. So, we are going to play around with it a bit and see if they have progressed as much as we think.”


So, that’s Supercross and the disc … we’re still confident that we’re going to see these available for BMX consumers … the real question is when? Sooner rather than later we hope, but with the list of Elite riders that are disc equipped growing by the day it can’t be that far away …

Supercross RS7 Disc Detail
Supercross RS7 Disc Detail
Supercross RS7 Disc Detail

Now, back to the small matter of the OS20 … to be honest we had thought that this was dead. It’s been tested by some of the worlds best but hasn’t found its way on to the gate at the highest level. It is UCI legal so we are wondering, if in-fact there is an advantage, why hasn’t it gained traction. The answer may well be found in brands and teams sponsorship restrictions. Supercross, for instance, have been locked out of the OS20 because of contracts with Maxxis and VEE rubber, and as you know, the OS20 only exists in the Tioga world. Things have changed though as Bill Ryan told us, “… with no tire sponsor we are free to try whatever” and after some OS20 requests from their UK distributor Supercross decided… “2 birds, 1 stone …”

But will we see OS20 in the Supercross stable … hummm, we’re not so sure …

Bill Ryan … “we already have the 20” (406) wheel size, the 451 for the little kids, the 507 cruiser, the 520 mini cruiser, do we really need a 451 OS20 for the adults? It means new frames, new rims, (luckily forks fit) new gear ratios, ugh…. Mikey Day tested it, wasn’t a fan, Sam tested it, wasn’t a fan … or so it seems. 

I don’t know, it is almost 1/2 way between class and cruiser. But cruiser died, no one rides cruisers.

22” is keeping the Older trail guys going, would OS20 keep the older BMX racers around? I don’t think so …  Is it faster, we will see.”

Follow Supercross BMX: Website | Instagram | Facebook | Twitter

Photos: Supercross BMX