Disc brakes on road bikes...

[LugHugger]

Re:

I'm putting together a hideous monstrosity that will no doubt get me kicked out of this forum forever. Build essentials:

Steel hardtail frame
rigid steel fork
Avid BB7 cable discs
drop bars and Tektro levers
friction bar end shifter (rear only...)
46T up front with 11-32T at the back (shifter I got for free only has 8-9 speed range with MTB RD)
26" wheels with a variety of tyres to tackle all terrains

Surly Disc Trucker?

 

[King Boonen]

Re: Re:

I'm putting together a hideous monstrosity that will no doubt get me kicked out of this forum forever. Build essentials:

Steel hardtail frame
rigid steel fork
Avid BB7 cable discs
drop bars and Tektro levers
friction bar end shifter (rear only...)
46T up front with 11-32T at the back (shifter I got for free only has 8-9 speed range with MTB RD)
26" wheels with a variety of tyres to tackle all terrains

Surly Disc Trucker?

It's pretty similar, one of those "I wonder what happens when I throw these odd bits I've got lying around together." I've kept it 26" so I can run big MTB tyres, but 700c CX wheels would fit fine. Cable discs are because my real aim is to end up with a single bike that does everything I need, which would mean the group set off my road bike would move across. Plus hydro discs are mucho dinero!

The fork I have it pretty rubbish, so it'll be changed for something from Salsa/Surly when I've worked out what works, likely covered in rack mounts.

 

[King Boonen]

Opinions..?

 

[winkybiker]

Re:

Opinions..?

Pretty ugly. Hideous monstrosity? Yes. Looks like something Johnny Tomac might have ridden! What does it do that a hard-tail mountain bike can't? I don't mind that the road and MTB categories are overlapping, but for me, this would do nothing my MTB can't. I want to slot a bike in between my race bike and MTB, but it will be more road-focused than this.

(And bar-end shifters remain a sub-par option)

 

[King Boonen]

Re: Re:

Pretty ugly. Hideous monstrosity? Yes. Looks like something Johnny Tomac might have ridden! What does it do that a hard-tail mountain bike can't? I don't mind that the road and MTB categories are overlapping, but for me, this would do nothing my MTB can't. I want to slot a bike in between my race bike and MTB, but it will be more road-focused than this.

(And bar-end shifters remain a sub-par option)

A swap of the tyres and it lets me use it on club rides throughout the winter. Running semi-slicks also allows me to ride to the trails on the road, ride the trails and then ride home, without ruining expensive mtb tyres. A HT MTB isn't a good option for this where I live as I am a good 15-30 miles from the trails. This will still handle the trails but gives me more options. It'll also get used for some CX riding and longer dirt road trekking. The final aim is a more road focussed bike to replace this and my road bike, something like this:

http://www.shandcycles.com/bikes/stooshie/

I only really have space to store two bikes so my road bike goes to my parents over winter for occasional riding with my dad. This bike will be my winter bike for MTB/road/off-road/cx and club runs and my fixed wheel will be for commuting/club runs. In the summer I'll swap it with my road bike and then it'll be used to explore trails in North Wales and the Lakes/Peaks.

I actually enjoy the bar-end shifter. I'm running it as a friction shifter and it copes better with grit than the MTB indexed ones. Plus I can dump 8 gears in half a second without having to click through them.


Yes, it is hideous, but luckily I don't mind that

 

[Giuseppe Magnetico]

Awesome build King Boonen! The essence of a well executed Frankenbike!

But barcons are "sub-par", winkybiker? Apparently my rando-commuter for the last 16 years has been sub-par all along. Who knew. :lol:

 

[42x16ss]

Re:

Opinions..?

My first reaction was BLECCCH! mostly because of the paint job, but the more I look at it, it looks like a lot of fun.

One thing I'd consider, is putting 650b/27.5" wheels in rather than 26" if possible, just for that little extra speed on the roads and firetrails, but that's just me. If you want it to be more versatile as a hard tail it's looking good.

Have you had a look at gevenalle.com (formerly RetroShift)? They do a few different 2 in 1 friction shifter/brake lever combos that might be better on the trails than a bar end shifter.

 

[King Boonen]

Re:

Awesome build King Boonen! The essence of a well executed Frankenbike!

But barcons are "sub-par", winkybiker? Apparently my rando-commuter for the last 16 years has been sub-par all along. Who knew. :lol:

Cheers I'd ideally like a decent fork on it, that On One thing is horrible but I got it really cheap Other things like better cranks, clutch rear derailleur etc. will come in time if I decide to keep it like this. More below:

My first reaction was BLECCCH! mostly because of the paint job, but the more I look at it, it looks like a lot of fun.

One thing I'd consider, is putting 650b/27.5" wheels in rather than 26" if possible, just for that little extra speed on the roads and firetrails, but that's just me. If you want it to be more versatile as a hard tail it's looking good.

Have you had a look at gevenalle.com (formerly RetroShift)? They do a few different 2 in 1 friction shifter/brake lever combos that might be better on the trails than a bar end shifter.

I think when I get a decent, black carbon/steel fork on there it will improve the look of it massively. I'm looking at either the Salsa Chromoto, Firestarter, Enabler or Fargo in steel (need to decide if I want rack mounts or not) or the Surly Karate Monkey. The Chromoto Grande thru-axle is probably the best option if I don't want rack mounts. Carbon it would have to be something fairly cheap like On One, but I've contacted a local company who do a very similar build, albeit much better, to see if they are willing to sell a fork only. If Sram did black parts for the BB7s instead of red that would also help!!

The aim is really a do anything bike. I'd love to have something I can ride on club rides, long road rides, do on-road/off road touring and take to the MTB trails. I tested it this weekend at Glentress and it handled a mix of blue, red and black trails fine so I'm happy it can do that. The club rides and long road rides are going to be the biggest test. It's not going to be anywhere near as fast as my road bike, but as my general road riding averages between 25-30kph (on geared and fixed and most of my club riding is on fixed) I'm not looking for it to be massively quick anyway. I think it'll work, but we shall see

The wheels are what I had when it was a proper hardtail. I could fit 650b's in there but there would be limited clearance for proper MTB tyres and it would lift the BB. What is more likely is, if it works really well, I would consider having some 700c disc wheels built. I tested it with my road bike wheels and with 28mm tyres they are the same diameter as my 26" wheels with the 2.2-2.4" tyres on so I could easily run a set of disc wheels with either road or cx tyres for road/xc stuff and just stick the big wheels on for the MTB stuff. If I go that way then I may very well consider moving the road groupset on my road bike across to this (hence why I went with cable disc brakes) using a Wolf Tooth Components Tanpan to run an MTB derailleur with the STI shifters. I can also get a friction shifter that does have range for a 10 speed MTB RD, the current one is Dura-Ace and I can only get 9 gears out of it. Friction shifting wasn't too bad, will see how I get on with it. It's a long project but I think it's going to be a lot of fun and I could end up with a really fun bike out of it

 

[winkybiker]

Re:

Awesome build King Boonen! The essence of a well executed Frankenbike!

But barcons are "sub-par", winkybiker? Apparently my rando-commuter for the last 16 years has been sub-par all along. Who knew. :lol:

"sub-par" might not have been the best choice of words. Definitely not to my taste, though. Their use on touring bikes was explained to me as "they allow riders to shift while keeping both hands on the bars". You know, for stability with a fully loaded tourer. My Cannondale T2000 is the most stable bike I've ever ridden, especially when loaded, so I don't really understand that argument. Touring riders never seem to have their hands down on the drops anyway except when shifting. The down-tube seems just as convenient to me for friction shifters. Shorter cable runs may also make them more precise. I get the argument regarding reliability compared to STI-style for long-distance touring in remote locales (although STI shifters are insanely reliable in my experience). Down-tube shifters would seem less vulnerable than either in the case of a crash.

I know people love them, but I just don't get it.

 

[Giuseppe Magnetico]

Winky, barcons are more popular among the randonneuring-light touring crowd. And yeah, we spend more time in the drops than loaded tourist traditionally do. At least I do anyway on certain stretches of road where I need to get my chest out of the wind. All personal preference.

 

[42x16ss]

Re:

I didn't see any photos but here's the bike:

That's my kind of bike. Speaking of which, Colnago have started doing the Arabesque again!!

http://www.colnago.com/arabesque/

MMMMMMM... Arabesque... aaaaggggh

Just slap on a Record groupset and a CF seatpost. I'd still race it!

 

[King Boonen]

Re: Re:

Awesome build King Boonen! The essence of a well executed Frankenbike!

But barcons are "sub-par", winkybiker? Apparently my rando-commuter for the last 16 years has been sub-par all along. Who knew. :lol:

"sub-par" might not have been the best choice of words. Definitely not to my taste, though. Their use on touring bikes was explained to me as "they allow riders to shift while keeping both hands on the bars". You know, for stability with a fully loaded tourer. My Cannondale T2000 is the most stable bike I've ever ridden, especially when loaded, so I don't really understand that argument. Touring riders never seem to have their hands down on the drops anyway except when shifting. The down-tube seems just as convenient to me for friction shifters. Shorter cable runs may also make them more precise. I get the argument regarding reliability compared to STI-style for long-distance touring in remote locales (although STI shifters are insanely reliable in my experience). Down-tube shifters would seem less vulnerable than either in the case of a crash.

I know people love them, but I just don't get it.

There's a few reasons I went bar-end. Firstly, I got it for free It doesn't cover the full cassette but it gives me enough for the moment. Microshift do some bar-ends that do have enough range for an MTB RD, I don't know if you can get downtube shifters that do.

The bike doesn't have mounts for down-tube shifters and it also has a very large downtube. It would mean sorting out some band-on ones and as it's going to be used as a mountain bike (I took it round some pretty serious trails at the weekend, these are probably the hardest bits: https://www.youtube.com/watch?v=p9HlLWqq6dc It's an old video and they have changed a little, the very first steps have gone and have been replaced with a steep chute, the trails are a bit rougher due to wear and the final chute is now much steeper but dirt only) I would be a little worried about the vulnerability of downtube shifters in a crash. Even if they didn't break any slipping would mean faffing about with tools to get shifting sorted. I also have the option of very easily running full outers if I want (the top tube has an extra set of bosses for a dropper post hose) with bar ends and I don't think I could do that with downtube shifters.

I agree with you about shifting, I don't think bar-end is any easier than downtube (although on trails it might be better to keep both hands on the bars) and I also probably would have run an STI lever if I knew about the Tanpan from WolfTooth and had the money to buy both, this is a likely change in the future if I decide bar-end isn't right. My worry about STI is crashing and breaking it, but now Shimano are doing aero Tiagra levers the cost of replacements will be much less.


All in all it's very much a "work in progress", "test what works and what doesn't" kind of build which will slowly evolve as I work out what's good an what isn't. The bar-end was ok on trails I'm pretty familiar with (although it's about a year since I last rode any of them) and the ability to dump 8 gears from the drops in half a second was great, but I do think that if I'm out in the unknown an STI set-up will work better.

 

[winkybiker]

Re:

I didn't see any photos but here's the bike:

That's my kind of bike. Speaking of which, Colnago have started doing the Arabesque again!!

http://www.colnago.com/arabesque/

This is from 1976. It is hanging on my living room wall.

 

[42x16ss]

Re: Re:

I didn't see any photos but here's the bike:

That's my kind of bike. Speaking of which, Colnago have started doing the Arabesque again!!

http://www.colnago.com/arabesque/

This is from 1976. It is hanging on my living room wall.

I couldn't do that, the temptation to show it off would be too great

 

[42x16ss]

https://cyclingtips.com/2016/12/opinion-poll-reveals-that-pro-riders-still-dont-want-disc-brakes-so-why-are-we-forcing-the-issue/

Ouch! According to a CPA survey 40% of pros questioned don't want discs, and another 44% only under specific terms, leaving a whopping 16% in favour...

 

[Giuseppe Magnetico]

https://cyclingtips.com/2016/12/opinion-poll-reveals-that-pro-riders-still-dont-want-disc-brakes-so-why-are-we-forcing-the-issue/

Ouch! According to a CPA survey 40% of pros questioned don't want discs, and another 44% only under specific terms, leaving a whopping 16% in favour...

When disc brakes were allowed in CX seven years ago that first season saw maybe 3-5 riders between WorldCup, Superpestige, and Bpost. The rest absolutely did not want anything to do with it, much like what's happening in road today. This is the second season of CX where disc brakes are 100% saturation.

All it takes is one rider to win something big. The next generations of pro roadies are going to laugh at the old codgers who used to brake on their rims. Seriously.

 

[winkybiker]

https://cyclingtips.com/2016/12/opinion-poll-reveals-that-pro-riders-still-dont-want-disc-brakes-so-why-are-we-forcing-the-issue/

Ouch! According to a CPA survey 40% of pros questioned don't want discs, and another 44% only under specific terms, leaving a whopping 16% in favour...

When disc brakes were allowed in CX seven years ago that first season saw maybe 3-5 riders between WorldCup, Superpestige, and Bpost. The rest absolutely did not want anything to do with it, much like what's happening in road today. This is the second season of CX where disc brakes are 100% saturation.

All it takes is one rider to win something big. The next generations of pro roadies are going to laugh at the old codgers who used to brake on their rims. Seriously.

I think you're 100% right.

 

[Bustedknuckle]

https://cyclingtips.com/2016/12/opinion-poll-reveals-that-pro-riders-still-dont-want-disc-brakes-so-why-are-we-forcing-the-issue/

Ouch! According to a CPA survey 40% of pros questioned don't want discs, and another 44% only under specific terms, leaving a whopping 16% in favour...

When disc brakes were allowed in CX seven years ago that first season saw maybe 3-5 riders between WorldCup, Superpestige, and Bpost. The rest absolutely did not want anything to do with it, much like what's happening in road today. This is the second season of CX where disc brakes are 100% saturation.

All it takes is one rider to win something big. The next generations of pro roadies are going to laugh at the old codgers who used to brake on their rims. Seriously.

More about money than anything in CX or road racing
. Bike makers will throw huge $ at these guys to ride a heavier, more complicated 'system' on their bikes. Plus they have a legion of mechanics and van full of spares. BUT neutral wheel support is going to be comedy central, even with some sort of hub/rotor/calipermount/axle 'standard'.

Discs in cross vs on predominently dry roads not 'quite' the same and even todays CX champs mention, 'Discs are for stopping, I don't want to stop'.

 

[Giuseppe Magnetico]

https://cyclingtips.com/2016/12/opinion-poll-reveals-that-pro-riders-still-dont-want-disc-brakes-so-why-are-we-forcing-the-issue/

Ouch! According to a CPA survey 40% of pros questioned don't want discs, and another 44% only under specific terms, leaving a whopping 16% in favour...

When disc brakes were allowed in CX seven years ago that first season saw maybe 3-5 riders between WorldCup, Superpestige, and Bpost. The rest absolutely did not want anything to do with it, much like what's happening in road today. This is the second season of CX where disc brakes are 100% saturation.

All it takes is one rider to win something big. The next generations of pro roadies are going to laugh at the old codgers who used to brake on their rims. Seriously.

More about money than anything in CX or road racing
. Bike makers will throw huge $ at these guys to ride a heavier, more complicated 'system' on their bikes. Plus they have a legion of mechanics and van full of spares. BUT neutral wheel support is going to be comedy central, even with some sort of hub/rotor/calipermount/axle 'standard'.

Discs in cross vs on predominently dry roads not 'quite' the same and even todays CX champs mention, 'Discs are for stopping, I don't want to stop'.

Who said that exactly? The European CX pros were given the choice what brake system they prefer since 2010. 2016-17 looks pretty clear to me that cantis in the pro ranks are long gone buddy. Suppose the last straw came when Nys made the switch to this "heavier,more complicated" system and the old guy was still giving the youngsters fits before bowing out. From the young generation I'll give you van Aert as a last hold out, but even he finally tossed his cantis in the garbage at the end of last season.

If disc brakes are so heavy how is it possible that anyone can go buy one of a half dozen disc road bikes off a showroom floor that are at or below the UCI weight limit? Have you ridden any relatively current disc road bikes lately to somehow back up your arguments? So by what metric do you measure that disc brakes make no difference on dry roads and are too "complicated" if you "don't use 'em, don't work on 'em, and never will"?

Look Mr. Grumpyknuckles, all it's going to take is for Sagan or any of the other pros in favor to win something big that can without a shadow of a doubt be attributed to having better brakes. It's already happened in Mtb, CX, and then road once the old traditionalists are out of the way that are a hinderance to progress. History has a strange way of repeating itself.

 

[Bustedknuckle]

https://cyclingtips.com/2016/12/opinion-poll-reveals-that-pro-riders-still-dont-want-disc-brakes-so-why-are-we-forcing-the-issue/

Ouch! According to a CPA survey 40% of pros questioned don't want discs, and another 44% only under specific terms, leaving a whopping 16% in favour...

When disc brakes were allowed in CX seven years ago that first season saw maybe 3-5 riders between WorldCup, Superpestige, and Bpost. The rest absolutely did not want anything to do with it, much like what's happening in road today. This is the second season of CX where disc brakes are 100% saturation.

All it takes is one rider to win something big. The next generations of pro roadies are going to laugh at the old codgers who used to brake on their rims. Seriously.

More about money than anything in CX or road racing
. Bike makers will throw huge $ at these guys to ride a heavier, more complicated 'system' on their bikes. Plus they have a legion of mechanics and van full of spares. BUT neutral wheel support is going to be comedy central, even with some sort of hub/rotor/calipermount/axle 'standard'.

Discs in cross vs on predominently dry roads not 'quite' the same and even todays CX champs mention, 'Discs are for stopping, I don't want to stop'.

The European CX pros were given the choice what brake system they prefer since 2010. The choice has been made, cantis are long gone buddy. Suppose the last straw was when Nys made the switch to this "heavier,more complicated" system and the old guy was still giving the youngsters fits. From the young generation I'll give you van Aert as a last hold out, but even he finally tossed his cantis in the garbage at the end of last season.

If disc brakes are so heavy how is it possible that anyone can go buy one of a half dozen road bikes off a showroom floor that are at or below the UCI weight limit? Have you ridden anything newer than your decades old Merckx lately? Have you pegged any of those killer descents in your backyard at 50+mph on carbon tubulars with rim brakes? Of course not because disc brake armchair critic #1 still thinks that there's no benefit, even on dry roads.

You must have some sort of skin in this game. Are discs more powerful? Do 'some' offer great modulation? You bet but saying that 'implies' canti brakes are 'lacking' somehow and they just aren't in 90% of the road racing scenarios. But you can call me all the names you want but I guarantee I'll continue to point out the shortcomings of disc brakes on road bikes. Like expense, weight, complication...yes, yes, you the uber mechanic can go from in the box discs to smiling as fast as some hack like me when installing cantis..my, my, good for you.


and who GAS...

 

[Giuseppe Magnetico]

https://cyclingtips.com/2016/12/opinion-poll-reveals-that-pro-riders-still-dont-want-disc-brakes-so-why-are-we-forcing-the-issue/

Ouch! According to a CPA survey 40% of pros questioned don't want discs, and another 44% only under specific terms, leaving a whopping 16% in favour...

When disc brakes were allowed in CX seven years ago that first season saw maybe 3-5 riders between WorldCup, Superpestige, and Bpost. The rest absolutely did not want anything to do with it, much like what's happening in road today. This is the second season of CX where disc brakes are 100% saturation.

All it takes is one rider to win something big. The next generations of pro roadies are going to laugh at the old codgers who used to brake on their rims. Seriously.

More about money than anything in CX or road racing
. Bike makers will throw huge $ at these guys to ride a heavier, more complicated 'system' on their bikes. Plus they have a legion of mechanics and van full of spares. BUT neutral wheel support is going to be comedy central, even with some sort of hub/rotor/calipermount/axle 'standard'.

Discs in cross vs on predominently dry roads not 'quite' the same and even todays CX champs mention, 'Discs are for stopping, I don't want to stop'.

The European CX pros were given the choice what brake system they prefer since 2010. The choice has been made, cantis are long gone buddy. Suppose the last straw was when Nys made the switch to this "heavier,more complicated" system and the old guy was still giving the youngsters fits. From the young generation I'll give you van Aert as a last hold out, but even he finally tossed his cantis in the garbage at the end of last season.

If disc brakes are so heavy how is it possible that anyone can go buy one of a half dozen road bikes off a showroom floor that are at or below the UCI weight limit? Have you ridden anything newer than your decades old Merckx lately? Have you pegged any of those killer descents in your backyard at 50+mph on carbon tubulars with rim brakes? Of course not because disc brake armchair critic #1 still thinks that there's no benefit, even on dry roads.

You must have some sort of skin in this game. Are discs more powerful? Do 'some' offer great modulation? You bet but saying that 'implies' canti brakes are 'lacking' somehow and they just aren't in 90% of the road racing scenarios. But you can call me all the names you want but I guarantee I'll continue to point out the shortcomings of disc brakes on road bikes. Like expense, weight, complication...yes, yes, you the uber mechanic can go from in the box discs to smiling as fast as some hack like me when installing cantis..my, my, good for you.

Expense- If something out performs another thing, it's usually more expensive...Usually. Shimano 9100 rim brake caliper set $450. TRP HY/RD w/rotors $300. Oh well.

Weight- Absolutely, when comparing just the parts alone a disc system is heavier. Does this mean that race weight and below bikes aren't achievable? Absolutely not.

Complication- How do you really know after declaring repeatedly;

"don't use 'em, don't work on 'em, and never will"

So by your logic I should use the accountant at tax time that doesn't like math, won't work with it, and never will. Ok, got it. Suspended mtb's are more complicated to take care of than full rigid, but people actually ride them and figured out how to maintain them. Do you really have this little faith in humans that we can't figure out a brake system on a bicycle because it has drop bars? Weird.

Skin in the game? What exactly are you implying here, that I'm paid to argue with a retired shop owner on a forum that nobody comes to anymore except for politics? Sure, go ahead, I'm making millions!! :lol:

 

[blaxland]

The difference in use between cross and road isnt comparable.there are no wheel changes in cross racing(only bikes)whereas road racing has lots.so until there is a faster way of wheel changes/and compatability(between brands) there will not be a revolution in dics.I have been riding bikes for over 35years and have never had a issue with rim brakes..

 

[Giuseppe Magnetico]

Re:

The difference in use between cross and road isnt comparable.there are no wheel changes in cross racing(only bikes)whereas road racing has lots.so until there is a faster way of wheel changes/and compatability(between brands) there will not be a revolution in dics.I have been riding bikes for over 35years and have never had a issue with rim brakes..

The comparison is a case study of what direction disc road is headed, nothing to do with format vs format. Regarding wheel changes; aside from a rotor standard to be agreed upon (140 f&r is my guess), the only thing left to figure out is variance of caliper position as it relates to taking a spare from neutral, rotors aren't going to always line up. Like a 'reset pad position' button that the mechanic can flip when they swap a wheel. I can tell you that when pros take a neutral wheel sometimes they're leaving the calipers in the open position because not every service course has the same concept of spoke tension or dish. I've been riding, racing, and wheel building for 30 years and had many issues with rim brakes. Different strokes.

 

[Bustedknuckle]

[
Skin in the game? What exactly are you implying here, that I'm paid to argue with a retired shop owner on a forum that nobody comes to anymore except for politics? Sure, go ahead, I'm making millions!! :lol:

""Have you ridden anything newer than your decades old Merckx lately? Have you pegged any of those killer descents in your backyard at 50+mph on carbon tubulars with rim brakes? Of course not because disc brake armchair critic #1 still thinks that there's no benefit, even on dry roads."

Forgot it was you with a new name..you haven't changed have ya?

out

 

[berend]

Re: Re:

The difference in use between cross and road isnt comparable.there are no wheel changes in cross racing(only bikes)whereas road racing has lots.so until there is a faster way of wheel changes/and compatability(between brands) there will not be a revolution in dics.I have been riding bikes for over 35years and have never had a issue with rim brakes..

The comparison is a case study of what direction disc road is headed, nothing to do with format vs format. Regarding wheel changes; aside from a rotor standard to be agreed upon (140 f&r is my guess), the only thing left to figure out is variance of caliper position as it relates to taking a spare from neutral, rotors aren't going to always line up. Like a 'reset pad position' button that the mechanic can flip when they swap a wheel. I can tell you that when pros take a neutral wheel sometimes they're leaving the calipers in the open position because not every service course has the same concept of spoke tension or dish. I've been riding, racing, and wheel building for 30 years and had many issues with rim brakes. Different strokes.

Leaving the caliper in the open position happens often. It's easy on rim brakes, and it points to one of two answers:
* no pro cares about brakes
* they still work "well enough" in suboptimal operation (ie. rim brakes are already better than necessary)

Remember that the pros also want the lawyer tabs removed for faster wheel changes. Lawyer tabs are a problem for the pros, but possibly good for consumers who don't check their skewers before every ride. Or at least, they're good for the lawyers.

I've had a wheel swap with a misplaced rotor. It's not difficult to fix, but it'll cost you a race.

In road racing it feels a bit like road tubeless tyres (and yes, I also have a set of those): good, proven tech that doesn't work in a new application.