jonathanf2

I'm currently running horizontal dropouts with mechanical disc brakes on a single speed gravel bike. The rear disc brake setup allows me to run wider tires in the back, but I find it a PITA with the horizontal dropouts to realign the disc rotor if I have to do a tire swap. My geared MTB with disc brakes, never has this issue with the fixed dropout position. I'm wondering if there's any tips on maintaining alignment with horizontal dropouts so I don't have to do constantly micro adjustments just to do a tire swap? It's such an annoyance that I'm considering running a V or wide caliper on the rear brakes and disc on the front. The front is a breeze to align, it's just with the rear that takes more time. Though I would need brakes that clear at least a 700 x 40c tire (the max width my bike can accommodate on the rear). Thanks for any advice!

mstateglfr 

What frame was made for disc brakes with horizontal dropouts?
That seems like a very obvious design flaw.

Since it has horizontal dropouts, do the dropouts have holes for adjuster screws? Setting those up properly will help ensure the wheel is aligned with the rotor.

jonathanf2

Unfortunately no adjuster screws. Sometimes if I'm lucky I can align it up perfectly and it'll take me 5 minutes. Other times, it just doesn't want to line up and I have to realign the brakes themselves, align the brake pad and tweak the barrel adjusters! It's super annoying. I'm seriously thinking of just taking off the rear disc brakes, but I'm not sure what caliper brakes I should get if I do switch them, maybe MTB brakes?

mstateglfr 

What frame is this on?

If you have a flat bar, then just use V brakes.
If you have drop bars, use Problem Solvers Travel Agents or one of the available knockoffs since Travel Agents are tough to source. These convert short pull road levers to long pull v brake arms.
https://www.ebay.com/itm/Litepro-V-B....c101071.m2460

Canker

Lots actually. On my Surly I just jammed the wheel all the way forward every time so it wasn't really an issue but mine wasn't a single speed setup, no chain tension to worry about. Would a set of tugnuts help? What mechanical disk brakes do you have? My BB5s and now TRP spryes are super easy to adjust for wheel swaps which I do on my road/gravel bike, takes like 30 seconds a wheel.

mstateglfr 

Interesting. I didnt take to disc until after thruaxles were well established, so I am clearly ignorant of how disc brakes design used to be.
Its surprising horixontal dropouts were usd since vertical had been well established for 2 decades before discs on drop bars really even began to be a thing.

Horizontal dropouts seem like a design flaw- having to get the wheel both centered and the proper distance for the disc caliper/rotor interface.

shelbyfv

My guess is that they were used as a compromise for frames that were advertised as able to accept a variety of configurations including single speed. QRs and discs are bad enough. Add a horizontal drop out.... If I had OP's bike I would consider a center pull brake for the rear if there was a way to mount it.

DrIsotope

Origin8, SE Snap-it, Tuggnuts or whichever chain tensioner tickles your fancy. I'm using the BOX One tensioners on my dirt-cheap Motobecane Fantom Cross SS frame-up build (nothing OEM survived the build save for the frame and fork) and setting the rear takes no more than a minute.

IME, so long as the rear wheel is in straight, the caliper is never an issue.

jonathanf2

I forgot to mention it's a Motobecane Fantom Cross Uno Pro. I use it mainly for urban riding, but I wanted something more versatile that a typical single speed/fixed gear bike with skinnier tires. I actually like the steel frame and fork the most on this bike. I might look into the chain tensioners. I don't really plan on spending much money on this bike. I just want to keep it simple and solid, even though I wouldn't mind upgrading everything from the crankset to the wheels!

mack_turtle

my Karate Monkey is singlespeed and has horizontal dropouts. it takes me ten seconds to line up the axle, tension the chain, and centering the rotor is never an issue. the axle is not slammed forward, but 4-5mm back from the forward-most position. I use a Surly chain tensioner on the drive side. install the wheel, snug down the tensioner until the chain is where you want it, then push the tire to center it in the frame just before cinching the bolt on the axle down. I have the caliper in just the right spot, so if the rotor is not centered in the rotor caliper, i just tweak the hub in the frame a tiny bit. easy as pie and takes a few seconds.

shoota 

That sounds awful. I have going through scenarios in my head for my SS El Mar. The alternator dropouts are pretty great, no alignment needed, but I still wouldn't want to switch it around very often.

mack_turtle

It's not. it takes exactly one extra brain cell to figure out and no noticeable additional amount of time. if I needed to remove my rear wheel often enough for it be a problem, I would be doing something very, very wrong. maybe it's because I rode BMX for 25 years that centering an axle in horizontal axle slots became second nature after doing it a few times. I mastered this technique when I was 12 years old. it's not hard but people act all helpless and butthurt when a bike doesn't just put itself together. the horizontal track end style dropouts and slotted caliper mounts are elegant and simple, no moving parts to swing, strip. come loose, bend, etc.

however, I spent a lot of time hunting down my current drop-bar gravel bike frame. I chose one with a PF30 BB so I could run an eccentric BB. that's also something that gives people such a huge headache for no reason and I don't get what the hangup is. it's nearly as dead-simple as track ends and works flawlessly if you have any mechanical aptitude and follow instructions.

jonathanf2

Thanks for all the help. I think chain tensioners will probably help ease alignment and minimize any issues.

mstateglfr 

You are a couple weeks late- Festivus and The Airing of Grievances happened on Dec 23rd.

jonathanf2

Yeah, looking at those alternator dropouts look much more easier to work with! The issue I find with horizontal/track style dropouts has more to do with the rear mechanical disc brake which only has a few millimeters of leeway.

mack_turtle

I celebrate Festivus year-round, but I savor my most profound Grievances with my family for December 23. consider yourselves honored that I shared this one with all of you.

shoota 

I can see that. It's probably why Salsa came up with their new system that slides the dropout, axle, and disc all at the same time.

jonathanf2

I'd be interested in seeing how your build turned out since i have the same model. There are couple things that annoyed me after getting the bike, like the 120mm rear hub and 26.0mm seat post. It somewhat limits available options. I'm not sure how much I want to spend on this bike though even though I could see several areas of improvement to make it a solid ride.

jonathanf2

I just wanted to follow-up. I added a chain tensioner to my bike and I feel it's a bit easier now to align the wheel to the disc brakes. Also because of the tensioner, I decided to add a smaller chainring for those times I'll be doing hill climbs. Right now I have to pull out the wrench to do the adjusting, so I'm trying to think a quick way to adjust the chain to the chainring when riding. Unfortunately my rear wheel doesn't come with a QR skewer, so my options are somewhat limited on bolt fastening. I was thinking of running some sort of derailleur setup, but I'm not sure I want to complicate things and keep my gearing straight forward.

shoota 

Sounds like you need gears at this point lol.

Rolla

I've got rear-facing track ends on my singlespeed klunker with hydro discs, and with a chain tensioner on the drive side, it's no trouble whatsoever. Yes, I have to swing the brake caliper up to pull the wheel out, but reinstallation takes all of 15 seconds. Shimano hydraulics are the easiest brakes in the world to deal with. Line up the rotor, squeeze the lever, tighten the bolts, ride.