Forward exiting vs rear exiting horizontal drop outs

I’m considering the surly ogre and surly straggler frame to build up from with a rear mounted 12t motor. I like the way the straggler looks more than the ogre but it has forward exiting horizontal rear drop outs (straggler) and I’m not sure if there’s any advantages to the rear exiting ones on the ogre.

Kemosabe70 said:

I’m considering the surly ogre and surly straggler frame to build up from with a rear mounted 12t motor. I like the way the straggler looks more than the ogre but it has forward exiting horizontal rear drop outs (straggler) and I’m not sure if there’s any advantages to the rear exiting ones on the ogre.

Click to expand...

Rear opening dropouts are only an advantage if you want the option to use fat tires, or to a lesser extent a single speed drive chain. They're a characteristic Surly quirk. They make installing and removing the rear wheel a bit more of a procedure.

Balmorhea said:

Kemosabe70 said:

I’m considering the surly ogre and surly straggler frame to build up from with a rear mounted 12t motor. I like the way the straggler looks more than the ogre but it has forward exiting horizontal rear drop outs (straggler) and I’m not sure if there’s any advantages to the rear exiting ones on the ogre.

Click to expand...

Rear opening dropouts are only an advantage if you want the option to use fat tires, or to a lesser extent a single speed drive chain. They're a characteristic Surly quirk. They make installing and removing the rear wheel a bit more of a procedure.

Click to expand...

I am actually looking to use a single speed drivetrain.


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Kemosabe70 said:

Balmorhea said:

Rear opening dropouts are only an advantage if you want the option to use fat tires, or to a lesser extent a single speed drive chain. They're a characteristic Surly quirk. They make installing and removing the rear wheel a bit more of a procedure.

Click to expand...

I am actually looking to use a single speed drivetrain.

Click to expand...

Either one will work fine for that. There's probably a little bit more range of chain tensioning and chainstay length variation in the rear opening kind. Straggler is easier to get the wheel in and out of.

To me, for a hub build the kind of dropouts that a frame has, is absolutely irrelevant. That is because a good hub build requires custom dropouts anyway. You have to make them in 1/4 thick steel, each side, and bolt them to the actual dropouts of the frame. Only then you know that your dropouts will never fail, no matter the future upgrades or various motors that your bike will ride in its lifetime.

MadRhino said:

You have to make them in 1/4 thick steel, each side, and bolt them to the actual dropouts of the frame.

Click to expand...

For what it’s worth, Surly dropouts are a little thicker than that, investment cast steel. They are open slots, so not trustworthy to resist being pried open by the axle reaction torque. But they're definitely more than adequate when paired with an external torque arm. We’re talking about a MAC motor, not some motorcycle thing.

While it's really a non-issue, as both dropouts are fine, the Straggler's dropouts are going to be slightly stronger against motor axle twist than the Ogre.
Of course, you need to use torque arms with either, so the slight advantage is moot.

The rear opening dropout would make it easier to run a single speed drivetrain without a chain tensioner. It would also be easier to modify if you ever wanted to weld on a pinch style torque arm.