prendrefeu

Hello,

I thought I'd start a thread to gather any opinions on the design of the new SRAM RED Cassette (pictured below)... It's composed of steel, which is great... but what may be a concern is that there are very few teeth set to engage with the freehub - and what there is, is only on the 'ends' of the cassette...

So what do you think? Will this simply destroy freehub bodies frequently, thereby negating the 'lifespan' that steel would provide, considering most freehub bodies are aluminum? Or is it just fine, and I'm ignorant about bicycle mechanics...

Or... ?

Discuss. Thank you.

HillRider

Actually, most Shimano (SRAM is Shimano compatible) freehub bodies are either steel or Ti. The only Aluminum Shimano freehub body is the Dura Ace 10-speed and even that is being replaced by Ti for 2008.

The SRAM design is a way to reduce weight without going to Ti cogs and their accompanying poor durability and cost. It's too new to tell how practical it will be.

prendrefeu

I'm bumping this thread because SRAM Red has been out for a while now, and perhaps a few people on here have seen (or not seen) the results on a freehub body when using these types of cassettes...

Anyone?

CdCf

I'd love to build up a bike with the SRAM Red group!

Bob Dopolina 

Interesting. All this buzz about RED but who has bought a group? A post like this would be up to 30-40 replies if it had been about Rival shifters or Force cranks.

prendrefeu

Well, RED is being supplied as the stock drivetrain on several new models... and they have been in use by a few teams now, so I'm thinking/hoping that someone on this forum has seen the damage, or lack there of, of the cassette on the freewheel after a few thousand miles.

Perhaps I'll need to bump this thread again in another month or so?

CdCf

Why would there be any damage to the body? I've used a steel sprocket for my singlespeed conversion for about a year now, and when I removed that wheel two weeks ago (the rim was worn out), I checked the body, and there was no damage at all. Well, the paint was a bit worn, but the splines were undamaged.

frozin

I've installed a few Red cassettes and it's hard to say. The plate where the cassette makes contact is a little thicker than it looks in the photo, but right now it's too early to say if it would cause damage to an aluminum freehub. I've seen it happen multiple times with Bontrager freehubs with Dura-Ace cassettes though. I'm curious to see what happens, but only time will tell. Steel freehubs will be fine I'm sure of that.

HillRider

If the body is steel, there should be absolutely no damage. It it's Ti the notching should be minor. If it's Al I'd expect problems. This is a more demanding situation than a singlespeed/fixie because the largest cog is on a cassette usually much larger than the single cog and the torque on the body splines can be much greater.

CdCf

Fair enough. The body was steel and I run a 48x14 gearing.

prendrefeu

Most freehub bodies on the higher-end wheels (700c) tend to either be alum. or titanium, for weight considerations. There aren't too many high-end hubs out there with steel cassette bodies, as far as I'm aware of.

frozin

True, however Mavic features steel freehubs on the entire product line. I'd consider that to be a lot of wheels out there then...

CdCf

Having now held a SRAM Red cassette in my hands today, I can tell you that the backplate (the red part with the "teeth"), as well as the toothed part that engages the splines at the lockring end, are both made of aluminium. So, no possibility of damage to alu splines!

The alu backplate is pressed into the steel part.

The entire Red group is just ridiculous to handle. The rear derailer is so light you'd think it's made out of cardboard! Looks great too!

And the rep told me that the SRAM guys are working on an all-carbon crank, but they weren't quite there yet.

Doggus

I had the exact same question as the OP. Bought a new Trek and asked if I could switch the 12x25 for an 11x23. All they had was an SRAM Red cassette. Told me it was fully compatible but I got a little 'fraidy-kat when I saw the teeth were limited to the inner 'cog'. After seeing what my Powertap hub looks like with a Dura-Ace cassette, I'm a wee'lil concerned.

HillRider

The only Al Shimano freehub is the 10-speed only 7800 series Dura Ace and it isn't compatible with SRAM cassettes. Campy's high end freehubs (Record and Chorus) have Al freehub bodies but, again, won't accept SRAM cassettes.

ScrubJ

Several Red gruppos installed locally. One has a recurring shift problem but the others seem to work fine. The only cassette I've held was all steel.

CdCf

That doesn't make sense... The one I've handled was a mix of steel and aluminium.

HillRider

I assume it was meant that the cogs were all steel. Only the backing plate is Al.

bellweatherman

I don't like how SRAM decided that all the cogs on the cassete were going to be one single unit. Might as well bring back the freewheel. It's lighter than the cassette hub and cogs anyways.

HillRider

The gimmick with the Red cassette is that it's hollow and all of the cog teeth are machined as the outside of a single conical shell. It weighs the same or less as the Dura Ace or Record cassettes with Ti cogs but has the durability of all steel cogs. It has to be one piece since there are no full plate cogs or spiders among the top 9 cogs.

CdCf

I personally think the Red cassette is great in its concept and design. The next step is probably to put slots or holes between the "sprocket ridges" and drill holes into the alu backplate to lighten it further, although they probably have to seal the holes with some light-weight plastic material to prevent accumulation of water and dirt inside. Still, a piece of plastic weighs very little compared to a chunk of steel of the same size.

prschaa

I have about 2K on my red group. Cassette is holding up, got rid of the SRAM chain after 1K miles, replaced w/KMC and haad better shifting performance. It's harder to keep shifting smoothly compared to the force group on my other ride, requires tweaking more then I'm accustomed to on other groups, particularly when changing wheelsets.
YMMV