Rockshox RS-1

supersonic

I guess many of you will have seen this, but RS are releasing an USD fork. Details are sketchy though.

jimothy78

I know a few manufacturers have tried this, but I've never been sure of the advantages? Obviously no bridge would save a few grams, but presumably the axle has to be extra stiff to stop the two stanchions from being able to move independantly of each other.

What's the actual AIM of the USD design?

cooldad

Ideal to get even more crud than usual on the stanchions, nevermind easier to ding.

Dumb idea, and I'll stick to right way up forks.

lawman

Thing is I can't see how it makes sense in the mtb world. RS have the Sid which is mega light and has been the top of the range fork for donkeys years. I did see someone suggest it could be a CX fork, which kinda makes sense. The original RS1 changed mountain biking, and from the marketing bumpf from the images released this fork plans to do the a similar thing, except I'm not sure how this fork would "change" mtb, but it sure as hell would shake up the CX crowd, especially with the recently introduced CX1 groupset... the upper part of the fork sure looks kinda CX like rather than mtb like...

supersonic

Unsprung weight is reduced, which slightly increases bump response, seals get 'oiled' more, and possibly overall weight will drop, but it does require a massively stiff axle, dropouts and hub. Also can design a lower C2A.

The steerer and uppers are rumoured to be all carbon - I'm guessing they are going to try and undercut the SID considerably, maybe looking at around the 1-1.1kg mark.

rockmonkeysc

It should be very light if the uppers and steerer are a single carbon fabrication. It should be very stiff as well, carbon can be made much stiffer than aluminium/magnesium alloy used in normal fork lowers.
I don't see why the stanchions will get more crap on them. Most of the crap gets flicked off the top half of the tyre, this will be lower than that. Looking at my muddy forks from today, the lowers are about the cleanest part of the fork.

lawman

Well it definitely ain't a CX fork!! :oops:

russyh

Thought the uci didn't allow suspension in cyclocross, same as tyre size is restricted.

stubs

That brake mount looks a bit flimsy and exposed.

Kowalski675

jimothy78 wrote:

What's the actual AIM of the USD design?

They originated in motocross, where they provided more rigidity and less stiction than long RWU forks (as they have a long thick fork tube and short stanchion, rather than a long, thinner stanchion), but at the expense of more weight. Whether they have any useful application in MTB, I have no idea.

cooldad

Sh1t idea then.....

JMcP92

stubs wrote:

That brake mount looks a bit flimsy and exposed.

They make that kind of mount work perfectly well on motorbike everywhere, I'm sure it should be fine... probably, just don't make the mount of magnesium :P

adamfo

I hope they fit plastic sliders over the tubes. The lower tubes on my KTM enduro motorcycle would have been damaged in minutes without them.

The Northern Monkey

cooldad wrote:

Sh1t idea then.....

And yet that looks so much nicer and actually more up to date than the RS-1!

The RS-1 looks a bit like a dart.

nicklouse

The Northern Monkey wrote:

cooldad wrote:

Sh1t idea then.....

And yet that looks so much nicer and actually more up to date than the RS-1!

The RS-1 looks a bit like a dart.

And don't forget how long ago that was released.

supersonic

The RAC was a dog.

rockmonkeysc

Manitou Dorados are really nice and they are upside down. Not very reliable but I don't think thats anything to do with them being upside down.

bigmitch41

Radial brakes next...

rockmonkeysc

Rim mounted discs.

RevellRider

On of the lads at work went on SRAM training today. All carbon uppers, 29" wheel only and 28mm axle were the things he mentioned. £1400 RRP

gt-arrowhead

cooldad wrote:

Sh1t idea then.....

That looks really cool.

rockmonkeysc

28mm axle? Thats HUGE! Could mean a very light hub though.

Chunkers1980

RockmonkeySC wrote:

28mm axle? Thats HUGE! Could mean a very light hub though.

Surely it'd mean bigger flanges and inner circumference, so not really?

rockmonkeysc

Chunkers1980 wrote:

RockmonkeySC wrote:

28mm axle? Thats HUGE! Could mean a very light hub though.

Surely it'd mean bigger flanges and inner circumference, so not really?

Less metal needed in the hub because of the bigger inner circumference and a big hollow axle should mean less total metal. It won't necessarily need bigger flanges.

jimothy78

RockmonkeySC wrote:

Less metal needed in the hub because of the bigger inner circumference and a big hollow axle should mean less total metal. It won't necessarily need bigger flanges.

Would need big bearings to wrap around that axle, though - they're a significant part of the weight, surely, as they're steel, rather than alu. Reckon that's got to cancel out any weight saving from axle size itself, if not tip the scales the other way.

Dick Scruttock

No way does that have a 30mm maxle.

nicklouse

BigMitch41 wrote:

Radial brakes next...

Errr done.

RockmonkeySC wrote:

Rim mounted discs.

Done.

RevellRider

Rick Draper wrote:

No way does that have a 30mm maxle.

I didn't go on the training, but I can't see why my work colleague would make up such a random fact

supersonic

I'm guessing it has some none round axle with propriety bearings.

Dick Scruttock

RevellRider wrote:

Rick Draper wrote:

No way does that have a 30mm maxle.

I didn't go on the training, but I can't see why my work colleague would make up such a random fact

I think he misheard the facts on the axle IMHO.

RevellRider

I don't think so. The photos of the fork is shown with a hub, none of the other Rock Shox launch photos are shown with a hub. That leads me to believe there is a propriety hub with this fork (I didn't ask him about that), so there must be some new axle standard