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Relative merits in practice - direct mount rings

March 11, 2016, 7:55 p.m.
Posts: 0
Joined: Nov. 20, 2002

So, I've traded off my old Diabolus crankest and i'd been running it single ring with a 32 and a Blackspire bashring. It has come time to do something new, and maybe lighter.
So i got interested in the whole direct mount concept before it was "a thing" but the crank options at the time were all kinda not my cuppa, Middleburn was only ISIS (remember that?) there was the early DMR but it was pretty heavy, you know the drill.

I really dig some of the new cranks, but I'm wondering, aside from the different aftermarket rings available if anyone has any comparison of the different fitments? One of the early stated advantages was that there's a potential for better concentricity, which matters to me since i'm looking at this for a singlespeed rather than a 1x setup.

They've got the guns but we've got the numbers! Gonna win ya we're takin over.

March 11, 2016, 10:05 p.m.
Posts: 207
Joined: July 22, 2014

It doesn't make any diff.
Direct mount is fine, but requires removal of part of crank to remove.
So there is no real advantage if you ask me.
But it looks very form fitting, if you are into the sleek look.

Spider is easier to change chainrings for depending on whether you need to remove the whole crank or not for your crank mfg.
But DM looks very form fitting, if you are into the sleek look.

Next thing you have to worry about is if you are going DM oval or round.
That will be an endless debate unless you are already somewhat eccentric.

:)

March 12, 2016, 5:04 p.m.
Posts: 0
Joined: Nov. 20, 2002

I'm definitely already somewhat eccentric, but that's neither here nor there.

What i'm really wondering is if one direct mount spline is equivalent to the next, in practice, in terms of developing play or anything else that might separate them in use.

For instance i know that the Hope cranks come with the tool, the Cannondale tool is expensive and so far only available from c-dale, the SRAM uses just three small screws so seems easier to replace a ring at home.

Newer BMX cranks also have a sort of direct mount if you will, with both varieties that fit onto the spindle splines or the 9-sided Socket Drive which is a pressfit idea interface on the crankarm.

They've got the guns but we've got the numbers! Gonna win ya we're takin over.

March 12, 2016, 5:29 p.m.
Posts: 2121
Joined: Nov. 6, 2005

Your wording is confusing… but if I understand the gist of your question then that all the spline interfaces (Hope, SRAM, RF) are rock solid in general use, and shouldn't develop play if properly installed. The best option is the one that gives you the most chainring choices. Go for it, you can also run spiders on most DM cranksets if that tickles your fancy.

March 12, 2016, 8:44 p.m.
Posts: 1885
Joined: Oct. 16, 2005

… which matters to me since i'm looking at this for a singlespeed rather than a 1x setup.

Firstly, how tall are you? Over 5'8" or 5'9" if you are using the singlespeed for mountain biking (trail riding or racing) every singlespeeder I know prefers the extra torque from 180mm crankarms.

The only readily available, modern, 180mm cranksets are Shimano XT or XTR both of which use, depending on the generation, some form of 4-bolt set-up.

Even if you are shorter, or are using the cranks for a street/dirt application, one of the benefits of singlespeeding is the perfectly straight chainline and rings/cogs that aren't designed to shift that, combined with proper chain tension, remove any chance of a dropped chain.

With few (any?) exceptions those direct mount rings are all some kind of narrow/wide model. Narrow/wide rings are more expensive, wear faster (due to shaping), and limit your chain choices to widths that are compatible with the N/W profile.

i.e. BMX/Track chains do not interface nicely with N/W rings.

Go for it, you can also run spiders on most DM cranksets if that tickles your fancy.

This. I also haven't heard of any issues with the direct mount interfaces (SRAM, Raceface, etc) with a ring or a spider attached.

Cheers,

Mean People SUCK! Nice People SHOVEL!

Trails For All; Trails For Weather

March 15, 2016, 10:42 p.m.
Posts: 0
Joined: Nov. 20, 2002

Thanks a lot. Good to know.
I'm not huge on the long arms myself, and the intent was to machine up a SS specific ring, I didn't want to go through the effort and expense only to have committed to a flawed interface.
Bike might see some trails, more the jumps kind not a lot of tech epics. Not a huge fan of long cranks either. So all that's less of a factor.

I'd been thinking of the DMR since it's got hollow arms, which is neat, and the SRAM mount doesn't require a special tool. But i'm tending more towards the Race Face options now, a bit for nostalgia's sake, as i had originally built the bike up with Race Face cranks, but also because the 'special' tool is just a pretty standard cartridge bb tool, and maybe i can get away with carbon arms this time around?

They've got the guns but we've got the numbers! Gonna win ya we're takin over.

March 18, 2016, 11:08 a.m.
Posts: 0
Joined: Feb. 2, 2004

Narrow/wide rings are more expensive, wear faster (due to shaping),
Cheers,

We haven't changed the profile of our teeth from the old days. Still ASME/ANSI B29.1M sprocket tooth profile for sprockets with roller chains. Straight out of Machinery's Handbook.

You should come up for some riding in a couple months when the snow's gone. Some not the park riding.

www.northshorebillet.com

March 18, 2016, 2:26 p.m.
Posts: 1885
Joined: Oct. 16, 2005

We haven't changed the profile of our teeth from the old days. Still ASME/ANSI B29.1M sprocket tooth profile for sprockets with roller chains. Straight out of Machinery's Handbook.

You should come up for some riding in a couple months when the snow's gone. Some not the park riding.

Damn. I actually mentioned NSB as an exception in my post and edited it out as I wasn't sure… so your tooth profile plays happy with a 1/8" chain?

I definitely will come up this year! Have not ridden Whistler trails since my girl was born.

Mean People SUCK! Nice People SHOVEL!

Trails For All; Trails For Weather

March 18, 2016, 7:22 p.m.
Posts: 5731
Joined: June 24, 2003

Damn. I actually mentioned NSB as an exception in my post and edited it out as I wasn't sure… so your tooth profile plays happy with a 1/8" chain?

I definitely will come up this year! Have not ridden Whistler trails since my girl was born.

Yeah. I'm retiring in May and you'll have a place to stay. I'll have rockin' chairs on the deck and I'll loan you some beige chest pants. We can holler at kids and rant.

Debate? Bikes are made for riding not pushing.

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