Direct Mount Crankset for Fixed Gear?

[brewsmith]

I like the look and ease of chainring swaps on direct mount cranksets and was wondering if anyone has had luck using them on a fixed gear or single speed. My only concern is that it looks like the only 1x chainrings for these are narrow wide etc. so not sure how that would play with a 1/8"chain. Anyone have any experience?

[p nut]

Originally Posted by brewsmith

I like the look and ease of chainring swaps on direct mount cranksets and was wondering if anyone has had luck using them on a fixed gear or single speed. My only concern is that it looks like the only 1x chainrings for these are narrow wide etc. so not sure how that would play with a 1/8"chain. Anyone have any experience?

I run a Rival crankset on my fixed gear. It’s got direct mount chainring option.

All chains are essentially “narrow wide.” No issues running 1/8” chains. I like 8-9 speed SRAM or KMC, personally.

[Mark McM]

Originally Posted by brewsmith

I like the look and ease of chainring swaps on direct mount cranksets and was wondering if anyone has had luck using them on a fixed gear or single speed. My only concern is that it looks like the only 1x chainrings for these are narrow wide etc. so not sure how that would play with a 1/8"chain. Anyone have any experience?

I wouldn't count "ease of chainring swaps" as a plus for direct mount cranksets. For most direct mount cranksets, you have to remove the cranks to replace a chainring (in addition to multiple more bolts to remove the chainring). With a spider mounted chainring, you just have to remove the chainring bolts and can leave the crank on the bike.

[AngryScientist]

as long as your frame and rear end configuration allow you to get the correct chainline, there is no issues with using a narrow-wide ring on a single speed or fixed set-up.

[ColonelJLloyd]

Chain line would be my concern.

And personally, I'd prefer to have an 1/8" chain ring if I'm going to use an 1/8" chain.

[p nut]

Originally Posted by ColonelJLloyd

Chain line would be my concern.

And personally, I'd prefer to have an 1/8" chain ring if I'm going to use an 1/8" chain.

Forgot to mention I am running Rival on 130mm spacing. But the rear hub is a Paul, which I believe is typical 120mm/42mm chainline but with added spacers. So the difference is 1-2mm with the Rival cranks. I haven’t had issues yet but it is on the back of my mind.

Regarding the 1/8” chain. I wonder with the slight difference in chainline, if this would be of benefit to have a slightly wider chain (assuming they’re 3/32” chainring/cog).

[thirdgenbird]

Originally Posted by p nut

Forgot to mention I am running Rival on 130mm spacing. But the rear hub is a Paul, which I believe is typical 120mm/42mm chainline but with added spacers. So the difference is 1-2mm with the Rival cranks. I haven’t had issues yet but it is on the back of my mind.

Regarding the 1/8” chain. I wonder with the slight difference in chainline, if this would be of benefit to have a slightly wider chain (assuming they’re 3/32” chainring/cog).

I’m guessing running a standard chain that has more lateral flex would be better.

I seem to recall a lot of 11spd chains used by pros that were going after the hour record.

[seanile]

i had a direct mount rival 1x front crankset and i could feel the minor back-and-forth movement of the ring's splines against the crank's splines because it's not a perfectly flush fit. bothered me too much and i went back to a classic gxp crankset.

[ColonelJLloyd]

I agree that if there is some variance in chain line of the chain ring and rear cog that a multi-speed 3/32" chain would be a better choice.

I'm using a Miche Pistard 2.0 because I wanted a setup with outboard bearings and larger spindle. Unfortunately, there are not a lot of choices out there.

[brewsmith]

Originally Posted by ColonelJLloyd

I agree that if there is some variance in chain line of the chain ring and rear cog that a multi-speed 3/32" chain would be a better choice.

I'm using a Miche Pistard 2.0 because I wanted a setup with outboard bearings and larger spindle. Unfortunately, there are not a lot of choices out there.

Thanks for the input all, I have no issue going with a multi speed chain, my power output and braking ability leave plenty to be desired, so I don't think I would have durability problems there

How do you like the Pistard 2.0? That has a 30mm spindle? What BB are you running?

I guess I should note the bike in question is an All City Big Block, so 120mm rear spacing, clearance for up to a 60t(!) chainring according to their specs

[joevers]

I would definitely not if you're running fixed without brakes. I had a friend using Rival 1 cranks and the spider ended up coming loose. There's not really anything you can do about that. It's also less stiff than running track cranks and very likely less round. They don't need to be that round when you're running a derailleur. And they use a different chainline- 42mm for track, 49mm for 1x road/cross.

What you're getting out of nicer track cranks is that they're very round and they're very stiff- both great things regardless of the level of the rider. You can run something around a 45t chainring with 144bcd which should hopefully get you a low enough gear if that's your concern. People have used the Easton EC90SL cranks with direct mount ~50t rings for fixed crit racing, but for every day use I'd pass for a couple of reasons.

Originally Posted by p nut

Forgot to mention I am running Rival on 130mm spacing. But the rear hub is a Paul, which I believe is typical 120mm/42mm chainline but with added spacers. So the difference is 1-2mm with the Rival cranks. I haven’t had issues yet but it is on the back of my mind.

Regarding the 1/8” chain. I wonder with the slight difference in chainline, if this would be of benefit to have a slightly wider chain (assuming they’re 3/32” chainring/cog).

I think your chainline is off closer to 7mm if your hub is for 42mm chainline. If you're running an off chainline it's better to go with 3/32". It's not going to give you issues really, but it will be louder and it will wear out quicker and less evenly.

[AngryScientist]

for info i'm running a 7800 130BCD crank on my mootsie with a profile racing rear hub. perfect chainline. 130 rear spacing on this one.

[p nut]

Originally Posted by joevers

I would definitely not if you're running fixed without brakes. I had a friend using Rival 1 cranks and the spider ended up coming loose. There's not really anything you can do about that. It's also less stiff than running track cranks and very likely less round. They don't need to be that round when you're running a derailleur. And they use a different chainline- 42mm for track, 49mm for 1x road/cross.

What you're getting out of nicer track cranks is that they're very round and they're very stiff- both great things regardless of the level of the rider. You can run something around a 45t chainring with 144bcd which should hopefully get you a low enough gear if that's your concern. People have used the Easton EC90SL cranks with direct mount ~50t rings for fixed crit racing, but for every day use I'd pass for a couple of reasons.



I think your chainline is off closer to 7mm if your hub is for 42mm chainline. If you're running an off chainline it's better to go with 3/32". It's not going to give you issues really, but it will be louder and it will wear out quicker and less evenly.

I thought I remembered the Rival at 44mm chainline, but it looks like it’s 45.5mm.
I also looked up Paul’s specs and it’s 44mm chainline on the fixed side. Sorry for the fake news up there.
1.5mm isn’t bad. I don’t think it’ll be an issue (hasn’t been).

Regarding the direct mount. I use it on my fixed gear and MTB (xx1 cranks), as well as on my fat bike (WI cranks). I’ve never had one come loose. I have had chainring bolts come loose though. I much prefer direct mount when going SS or 1x, personally.

[jasonification]

Originally Posted by AngryScientist

for info i'm running a 7800 130BCD crank on my mootsie with a profile racing rear hub. perfect chainline. 130 rear spacing on this one.

This just makes me want to build a single speed..I do happen to have a 7800 crank kicking around the parts bin.hmmm

[ColonelJLloyd]

Originally Posted by brewsmith

Thanks for the input all, I have no issue going with a multi speed chain, my power output and braking ability leave plenty to be desired, so I don't think I would have durability problems there

How do you like the Pistard 2.0? That has a 30mm spindle? What BB are you running?

I guess I should note the bike in question is an All City Big Block, so 120mm rear spacing, clearance for up to a 60t(!) chainring according to their specs

The Pistard 2.0 has a 24mm spindle. I'm using a Hollowtech II. The crank feels great. My whole setup is super smooth and quiet. But, I was scratching my head installing the crank. It took serious torque to install and deformed NDS arm slightly. There is no bearing play adjustment so I honestly don't know how/why it works but it's been good so far. Only a few hundred miles on it.

It's on a Gunnar Street Dog FWIW. 120mm spacing. Gran Compe fixed/fixed hub so 42mm chain line.