Before we get into this week’s main subject – paceline safety responsibility – I want to share a couple of helpful comments that came in about last week’s column on diagnosing chains that fall of the chainrings. Readers Chuck and Frank added that front derailleur adjustment issues can cause chains to fall off, including a bent derailleur cage and improper limit screw adjustment that lets the derailleur throw the chain one way or the other. Let’s look at these issues:
Bent front derailleur cages
It’s relatively easy to bend a derailleur cage if you get something like your pants or a shoelace snagged on it while pedaling. Try to avoid this and if something snags, check if the cage is now crooked. If it is, first make sure that the derailleur is tightly attached to the frame. If it was even a little loose, it might have only moved out of position, not gotten bent. If so, simply move it back and tighten it. If it turns out that it was bent, gently bend the cage back where it belongs (an imaginary line bisecting the cage should run parallel with the chainrings).
Tip: Whether it clamps on the frame tube, is bolted onto a mount brazed to the frame or to a mount that’s screwed onto the frame, if the front derailleur loosens, it can throw the chain and/or move and possibly get damaged when it’s shifted. For these reasons, I recommend checking the bolt(s) that hold the front derailleur in position at least twice a year. Some carbon and aluminum frames have bolt-on front derailleur mounts with small hidden allen bolts. Don’t forget to also check them if you have them.
Limit screws another possible culprit
While derailleur limit screws don’t normally change adjustment, if they were adjusted even slightly off, as the drivetrain breaks in, that slight maladjustment can lead to issues. If the chain is thrown to the inside, you need to turn the inside screw clockwise. And for chains thrown to the outside, do the same with the outside screw.
Checking chainline on triple drivetrains
Another reader, Gregory, also asked how to check your chainline when you have a triple crankset.
Oops, that was an oversight on my part. I meant to explain that last week and forgot.
To check chainline on a triple, you ballpark it by putting the straightedge between the small/medium chainrings, followed by between the medium/large chainrings. In each straightedge position, you note where the straightedge rests on the cassette and find the middle point.
That middle point should be on the middle point of the cassette if you have a perfect chainline. Checking this way is not as easy as with a double since you have to eyeball it, but it’s still pretty easy to see if your chainline is off, and by how much.
Maybe a better way to check chainline?
Final thought on chainline checking: I haven’t tried this, but there might be a way to check bicycle chainlines by first marking the bike’s centerline with a laser level. If that was possible, you would only need to measure from the center of the chainring and the center of the cassette to the laser-marked chainline and compare the measurements to check your chainline very precisely. Maybe someone who knows laser tools can tell us? (Comment below the Newsletter version of this article, if so.)
Post paceline-crash thoughts and questions for you
While it may not seem like a technical topic, riding in pacelines is highly technical and not understood well by most riders – regardless of how experienced, fit or skilled they are otherwise. We’ve provided lots of expert guidance over the years. Here are 3 good pieces we’ve done on paceline rules:
- https://www.roadbikerider.com/paceline-rules-to-remember-d1/
- https://www.roadbikerider.com/riding-in-advanced-pacelines-part-1-d3/
- https://www.roadbikerider.com/riding-in-advanced-pacelines-part-2-d3/
Paceline are on my mind because of a crash I was in last Saturday. Don’t worry, apart from bruises and very minor road rash, no one was hurt. But I and my friend in front of me hit the deck at about 25mph. The fall taco’d both of his wheels, so we landed hard.
The primary cause of the crash was a squirrel that caused my friend to brake and slow suddenly and rapidly. As you know there are no brake lights on bicycles (at least none that work instantly in a situation like this). Also, no one yelled or pointed out the hazard. And I never saw the critter. So I had no warning at all.
I realized I was about to rear-end my buddy just in time to throw my weight left to try not to hit him straight-on. And, though, I ended up flat on my back on the pavement, I think I smashed into him first, which knocked him down, and may have been what destroyed his wheels.
Whose fault, or whose responsibility, is it?
My first adrenaline-fueled angry thought just moments after crashing was, “Who the heck hits the brakes in a paceline?!” Learning pacelining with the Putney Bicycle Club back in Vermont in the ’70s, we were coached to never, ever hit the brakes in a paceline unless you were at the very back of the line. The reason is that everyone behind you is relying on you, and you can cause a big pile-up through your actions.
If a dog darts out from a yard (or a furry-tailed rodent) you don’t want to hit the dog and crash, but you know that even more important is letting the riders behind know about the dog. So you shout or point out Fido and take whatever evasive action you can, but without endangering the folks behind.
I didn’t bring all this up to the other crashee because as I started calming down from the jolt of the crash, it dawned on me that he had actually seen the squirrel while I hadn’t seen anything. It turned out that two other guys had seen it, too. So, obviously, I was not paying as close attention as they were. So, I feel like it was my fault that I crashed, too.
However, I still believe that as a rider in a paceline, you should never brake hard enough to risk crashing those behind. And I would also say that it’s everybody’s responsibility when riding in a paceline to shout and/or point out hazards. And to never assume the others see them and don’t need a warning.
Hopefully, these simple safety tips will keep the shiny side up for you on your group rides.
It would be interesting to get your take on whose responsibility it is to keep everyone safe in a paceline? Maybe we can all learn something? Please Comment below the Newsletter version of this article. We’ll report back on your feedback.
As for the blame in your particular crash, I don’t hold you responsible at all. From your description, you were 4th or 5th wheel, or farther back. That makes it really hard for you to see anything in the road at or near the front of the line. I can’t blame you for not seeing the squirrel.
I would, however, fault the 3 guys who did see it – and said nothing. If any of those 3 had yelled out a warning, you may have at least had a chance to expect something in front of you was about to happen.
Finally, I know squirrels running across the road are an unpredictable hazard, but usually swerving or – even better – holding your line and letting the squirrel be “squirrelly” and dart back off the road, out of the way, would be preferred to braking hard and endangering anyone behind you in the process.
That’s my take. Will be interested to see what others say.
Re: dropped chains. Jim, any thoughts … when I drop a chain it seems to be only under a specific set of circumstances. The dropped chain occurs from big ring to small ring and when the chain is on the 4th largest cog on the rear. Running Di2 so there is built in initial overshift. Seems like it might be overshifting too much?
IMO squirrels and bicycles are like cars and deer – a fact of life. While there is some risk of going down if you hit a squirrel, the overall risk is far greater if you hit the brakes or swerve wildly in a pace line. Just run over that bushy tailed rat!
I view one of my key responsibilities in a pace line is to keep things smooth. That means that when the person in front of me jumps the speed, I slowly close the gap rather than jumping along with them. And when things are slowing down, I move slightly to the side and catch the wind rather than hitting the brakes. Each of these (and many other) tactics make it easier on those behind me to keep things steady. If everyone in the line takes the same approach things will be a LOT smoother and therefore more enjoyable for all.
Jim,
Regarding chain drop, 99% of the time I find it’s a simple adjustment of the inner and/or outer throw limit screws on the front derailleur as you point out, However, I recently bought a bike with Campy EPS (electric shift) and don’t see any limit screws on the front derailleur. In reading the Campy technical manual it appears all front derailleur limit adjustments are done by adjustments to the EPS brain by a qualified Campy EPS mechanic. There appears to be an outer limit adjustment screw on the rear derailleur.
This may explain why the previous owner opted to use Campy’s chain drop cage on the front derailleur.
With regard to chainline, Park Tools made the CLG-1 and CLG-2 chainline gauges. They are both now discontinued, but there’s still a nice article on the Park website describing how to use the CLG-2 here: http://www.parktool.com/blog/repair-help/chainline-concepts
The laser level idea sounds interesting and I’ll give it a try at some point, but I think I’d prefer that Park bring back a re-designed model of the CLG. Who doesn’t want a reason to buy a new tool!!
Kamikaze squirrels can be tough on cyclists! About three years ago a lady triathlete was training for the national championship on the Pinellas Trail on the west coast of Florida when a squirrel darted into her path. She braked, swerved, lost control and crashed. She was seriously
injured and missed the championship.
With that incident in mind, squirrels dart in front of me at their peril
First glad to hear no one was seriously hurt. Second I don’t pace line anymore. I gave it up after seeing too many crashes from people that didn’t know how to do it properly. Anyway all I do know is ride our recumbent tandem with my wife (the ultimate pace line) or my single while bike commuting (nobody to pace line with) so it’s not an issue for me. And when we are on tour a recumbent tandem doesn’t pace line decently with anything other than perhaps another recumbent tandem so no worries there either!
Before I latch on to a pace line of unknown riders, I stay back a while to observe the group; if after that I don’t think the group knows what they are doing I stay where I am. One of the things I “look” for is if the group is being vocal, pointing out road hazards, biker and walkers to be passed, etc. Recently, in Oregon, a buddy and I decided not to join a line that we thought looked squirrelly – good thing, since when we caught up to them a few miles up the road they were on the ground.
Everyone needs to take responsibility in the group, regardless of their position of their position in the paceline. While the front rider is the leader, even they can’t always see everything as there is so much constantly going on such cars, sizeable rocks in the road, turns, etc.
I’ve (unfortunately or fortunately) ran over a few squirrels over the years because I do know better than to disrupt my line, but I had to “train” myself to react that way because I don’t think it is necessarily instinctual.
If all the riders in a paceline stay as aware as they can of their surroundings rather than rely solely on the leader, everyone will be much safer. But nothing is a guarantee…pacelining will always have it’s risks!
I likewise no longer ride in a paceline after having crashed myself breaking my collar bone upon catching the rear wheel of the rider in front of me as he suddenly stood up and stopped pedaling to stretch his back with no warning. It is not just braking, as this illustrates, but any sudden slowing down in effect makes the rider go backward relative to those behind. Too many riders forget that in a paceline you can no longer ride as you would if riding alone and that makes them dangerous. “Quoth the Raven, Never More.”
I say ignore them. If someone calls out a squirrel, what are the following riders to do? The squirrel is an obstacle that moves too fast and too unpredictably for a rider to avoid. If you swerve, you are no more likely to miss the squirrel than if you hold your line.
A friend of mine went down in a pace line and broke his arm when a squirrel tried to cross the road through his spokes. There’s no avoiding that.
Finally, it’s worth noting that George Costanza said we don’t have a deal with the squirrels:
https://www.youtube.com/watch?v=xPCZtrac-Ss
On my bikes, 3 of 4 being triples, I check chainline with a metric ruler to measure from the centerline of the seat tube to the the teeth of the middle chain ring. My ideal for the triples is 45mm, as recommended by the late, great Sheldon Brown (http://sheldonbrown.com/chainline.html). It’s pretty easy to estimate the centerline of the seat tube accurately enough (within a millimeter or so). Or if that seems too difficult to determine, measure from the teeth to the surface of the seat tube, then add half the diameter of the seat tube.
A worn chain ring can cause the chain to unship when backpedaling. I had one that did that even though the teeth weren’t hooked enough to cause skipping. The teeth were worn to a point, however, and that seemed to be the cause of the unshipping–especially when the chain line wasn’t square. This might occur when pedaling as well but I have an inside chain retainer so it never did so for me.
Hi Rick, I would check the setscrew deep inside the Di2 front derailleur that rests against the frame plate to brace the derailleur and hold it in place. I have found that sometimes that screw is not set right and/or the plate on the frame is not set right. If that screw or plate is not doing the job they are supposed to, the derailleur can overshift and throw the chain. If it’s not that, it’s the cage alignment or the inside limit screw being a touch too loose.
If someone I knew pulled a stunt like that, (braking for a squirrel) causing a crash, I’d never ride right behind him again. He, himself, would move into the class of “squirrel”………Never let a “squirrel” slide in, in front of you.
Running over the “bushy tailed rat” isn’t exactly safe either. I heard of a guy running one over, and it then got stuck on the wheel as it was turning, got wedged in between the fork and wheel, locked up the wheel, causing him to go flying over the bars with some pretty serious injuries!
My problem with chain drop is that if I adjust the limit screw so that the chain NEVER drops, in the outside cassette gears the chain rubs on the derailleur cage. Happens both with the large cog/small chainring and small cog/large chainring. If I adjust it 1/4 turn in/out so it doesn’t rub, I will occasionally drop the chain, especially if I shift the front when the rear is already in the last couple cogs on that side of the cassette.
Sorry Jim: I know you probably feel that riding in a close Madeline improves riding efficiency, but I suggest you leave a bike-length of space between riders. There will always be a squirrel or dog or pothole or simply a poorly instructed braking rider amongst your riding friends and if you keep a safe distance from the wheel in front of you, you’ll avoid crashes like the one you suffered.
“Never” is absolute, and, as the tale reveals, sometimes ya’ just gotta brake. Yell about the hazard, but brake to avoid it if it’s really necessary.