We tested the Britax Marathon model G4.1, which first became available in Oct 2014 when it replaced the G4. The Marathon has since been retired.
The Britax Marathon
This chart provides a comparison of the overall scores for all of the convertible seats we tested in this review. The Britax Marathon is shown in blue.
The sections below provide detailed information on how the Marathon performed during testing for each metric. The metric scores were used to determine the overall score with an emphasis on crash test results and ease of installation.
The Marathon is one of only 2 seats in the review to use EPP foam instead of EPS for energy absorption during a crash. EPP is more environmentally friendly and it does not off gas like EPS.
The Britax Marathon earned the highest overall crash test score in the review. While it did not have the lowest recorded G-force data for either the chest or head sensor taken from the crash test dummy, it did have the lowest scores across the two. This seat, like all others in this review and for sale in the United States, meet or exceed the Federal safety guidelines outlined in FMVSS 213.
Therefore, each seat is considered to be safe. Our testing is designed to the same specifications as those used by the National Highway Traffic Safety Administration (NHTSA), so we could provide a true side-by-side comparison for each seat. Some seats, including the Marathon, have test results that indicate an additional margin of protection with G-force recordings that are significantly lower than the maximum allowable amount, and lower than much of the competition.
The charts included here show the data collected during testing from the sensors in the test dummy for the Marathon (shown in black). Also, the charts include the crash test data results for the seats that have the lowest recorded amount of G-forces during testing for comparison purposes (shown in green).
This chart show the head sensor data from the Marathon compared to the data for the Evenflo, the seat with the lowest recorded G forces in the head sensor
This chart shows the chest sensor data of the marathon compared to that of the Clek, which had the least amount of recorded G forces in the chest for this review
The Evenflo Tribute LX sensor recorded the lowest amount of G-forces in the head sensor during crash testing than any of the other products in this review. The Clek Foonf has the lowest level of G-forces recorded for the chest sensor in our review. The Marathon has the second lowest head G-forces and the third lowest chest G-forces for the group.
The Britax Marathon earned one of the highest scores in the review for installation using the LATCH system
Ease of Install - LATCH
The Marathon earned a 9 of 10 for ease of installation using the LATCH system. The Marathon tied with the Roundabout with essentially the identical LATCH system, and the Chicco NextFit that sports what the manufacturer calls "SuperCinch".
The Clek Foonf
, Britax Boulevard ClickTight ARB
, and the Britax Advocate ClickTight
impressively earned the highest score, coming in with a perfect 10.
Installing this seat using LATCH is a simple procedure and easier than using the vehicle belt. The LATCH anchors are positioned fairly well for easy connection to the vehicle anchors, but the seat base is close to the anchors, so depending on your car you might need to jostle it around a bit to get them connected. The seat feels stable when installed using LATCH, especially in the forward facing position and we liked that it feels like it's part of the car once attached. Loosening the strap is a little more difficult, but it isn't as hard as some and won't leave you crying or asking for assistance from a helper. Luckily, if you are like most families, you won't need to loosen the seat very often because it will likely stay in your car and only move occasionally.
The recline adjustment handle on the Marathon is under the seat where you will be unable to reach it after it is installed rear facing
The recline adjustment handle is located on the base near the foot of the seat. This makes it difficult or impossible to adjust once the seat is installed securely. You will need to set the recline before
you attach the LATCH anchors or before you tighten them.
The open frame design on the Marathon makes the belt pathway easy to start
Ease of Install - Belt
Installation using the vehicle belt is a little more complicated, but it still managed an overall score of 8 of 10 for this metric. This ties with the Britax Roundabout, Chicco NextFit, and Peg Perego Primo Viaggio Convertible.
The high score for the metric is 10 earned by the Britax Boulevard ClickTight and the Britax Advocate Clicktight with the ClickTight installation system that makes installing the seat with the vehicle belt almost foolproof and super easy.
The photos above show the belt path for forward-facing, including the portion of the path behind the seat with the lock off (right).
The photos above show the belt path for the rear-facing installation, including the portion that travels under the seat and through the lock-off (right). Notice the seat cover and padding needs to be pulled away to thread the belt (left).
Installation with the vehicle belt is easy enough to get tight, but finding the belt path is a bit convoluted and requires somewhat of a disassembly of the seat cushions. Even then it is hard to see, and some testers felt it wasn't the best for larger hands. Adding to the problem is that the lock-off won't close if the vehicle belt is too tight and if it isn't tight enough the seat will not be secure. It is a bit like Goldilocks and the three bears for finding just the right level of tightness. At one point we had to use a screwdriver to get the belt lock off open. This might have been a result of the belt being too tight, but given that some other seats had lock-offs that are easier to use it is a bummer.
The recline angle for the Marathon can be checked for proper installation by using the line on the side of the seat
The indicator for proper angle adjustment for proper installation is a line on the side of the seat that must be parallel to the ground when the seat is installed.
The Marathon buckle and chest clip aren't the easiest to use, but it does sport what the manufacturer calls an impact absorbing harness that has rubber attachments on both shoulder straps
Ease of Use
The Marathon earned the second to the highest score for ease of use with a 7 of 10, which tied with Evenflo Tribute LX and the Peg Perego Primo Viaggio Convertible. The high score is once again earned by the Marathon's big Bros, the Britax Boulevard ClickTight and the Britax Advocate ClickTight.
Ease of use is an important metric in our mind because it reflects the daily experience that impacts how much you will like or loathe a seat.
The hook and loop narness attachment points on the Marathon cover do not work very well. The straps do not stay attached when placing baby in the seat, assuming you get them to meet up and attach in the first place
The Marathon buckle isn't the best or the worst we saw in this review. It is an identical buckle to the one found on all the Britax options, and they fell somewhere in the middle of the group with several other buckles. It is on the stiff side, but it won't require two hands like the Diono Radian
. The chest clip is also the same as the one found on the Britax Roundabout
and we liked that you can release the clip without putting your hand underneath it. The seat cover has hook and loop attachments to the sides that are supposed to hold the harness straps open and out of the way, but they do not work well as the strap barely reaches the connection point and doesn't stay attached when the baby is placed in the seat.
The Marathon harness height adjustment is the easiest one in the group to operate
The Marathon has the easiest to use non-rethreading harness height adjustment in the entire lineup of products (equal to the Britax Boulevard ClickTight and the Britax Advocate Clicktight). The size and shape of the handle that you squeeze to release the mechanism are perfect for most hands and squeezing it and moving the apparatus up or down to the desired position is smooth and potentially a one-handed operation. We like the non-rethread adjustment because it allows parents to make harness corrections quickly and easily the moment that you notice a need. These changes can be done with baby in the seat and take almost no time to master. The rethread options, on the other hand, are best done with baby out of the seat and often with the seat out of the car. The Marathon harness has ten different shoulder height options and two crotch strap positions for forward-facing and one for rear-facing.
To loosen the harness, there is a button located on the foot of the seat under the fabric (left). It is easy to use and not too hard to find. The tightening strap is located right below it, and while easy to pull, it is tricky in the rear-facing position because it is tucked up against the vehicle seat (left).
The LATCH anchors on the Marathon click into the base when not in use. You can also see the red honeycomb impact absorbing portions of the base in this photo
The LATCH anchors on the Marathon clip onto the back of the seat as does the tether strap clip. The extra strap for the tether is stored in a fabric pocket located at the top of the seat on the back of the seat cover. This storage system doesn't really keep the straps out of the way, and we preferred the seats that had dedicated pockets or hidden storage.
The users manual for the Marathon is located behind the cover but in front of the belt lock off on the seat back. We don't think this is the best location compared to some of the competition that provided a pocket
The fabric cover is fairly easy to remove with only a minor hiccup in the process with the headrest mechanism. The fabric can be hand washed and laid flat to dry. The user manual is located under the seat padding against the seat back. It isn't the best place because it could get damaged and is somewhat in the way.
The Marathon would have scored higher for quality and comfort had the cover been more form fitting and less like a slip cover
The Marathon earned a score of 7 of 10 for comfort and quality. The high is 9 earned by the Chicco NexFit and the Britax Boulevard CLickTight and the Britax Advocate CLickTight.
The Marathon fabric is nicer than that on the Britax Roundabout and is one of the features that sets these very similar seats apart. It is a smooth fabric that is friendly to bare skin, and there is a softer more velvety fabric in the head region that would be especially gentle to the face. It appears easy to wipe clean and wasn't very absorbent in our tests. The padding on the seat is excellent all the way around, while some only offer padding in the seat bottom or minimal padding throughout, the Marathon offers a little bit nicer padding over the majority of the inside of the shell so children can be extra cozy. The infant insert adds more cushion, but it isn't something you can use for the duration of the seating life.
The back of the Marathon is open and shows the harness height adjustment. We think the seats with covered backs would be easier to clean
The shell on the Marathon is not contained, and the back is entirely open with straps and bars exposed. This includes the non-rethread adjustment mechanism that has a lot of nooks and crannies where dirt and crud could build up and potentially impede the motion of the mechanism. We prefer the seat backs that are smooth and covered both in looks and practicality of use that keeps them clean and obstruction free, like the one found on the Britax Boulevard ClickTight
The seat is made using Expanded Polypropylene (EPP) for its energy-absorbing foam inside the shell. This type of foam is less common than the Expanded Polystyrene (EPS) found in most seats and bicycle helmets. We prefer the EPP foam because it is less brittle and a little more forgiving should it be dropped or bent. Also, it is more environmentally friendly and doesn't off-gas like EPS, which is a big win in our book for little ones. Only the Britax products in this review use the EPP foam.
The Marathon has a rubber feeling edge that helps it avoid sliding too much. The bottom itself is not entirely smooth, but it also doesn't have parts that might damage a vehicle seat
The overall fit and finish of this Britax product are nice compared to much of the competition. Everything on the seat stays in place, and it has a nice contained look about it with no parts hanging off or protruding where they shouldn't. The fabric fits the shell and frame snuggly without looking too much like a slipcover. It isn't as sleek and polished looking as the Chicco NextFit or the ClekFoonf, but it is still better than most. The bottom of the seat is not totally smooth. Although, there are no concerns with sharp corners or edges that might damage the vehicle seat if it rubs for a long time.
The Marathon weighs about 18 pounds, putting it about in the middle of the group for weight
The Marathon is on the heavy side for the seats in this review with a weight of about 18 pounds. This doesn't compare to the hefty options in the review like the Clek that is closer to 35 pounds, but it is twice as much as the Evenflo that is just over 9 pounds and the lightest product we tested.
While weight isn't as important in this style of seat as it is in the infant car seats, because parents aren't likely to move the seat very often, it might still be of interest to parents who travel or frequent taxis or Uber. Eighteen pounds is probably more than you want to lug very far, but in the top 5 seats only the Roundabout is lighter with a weight of 16 pounds. On the bright side, the Marathon is narrower than all but 3 products in the review with a width of 18.5 inches. The smallest width is 17 inches shared by the Clek and Evenflo, which makes the Evenflo the lightest and smallest in the group.
Other Versions and Accessories
The Britax Marathon ClickTight convertible style seat
The Britax ClickTight installation method uses the vehicle belt across one of two pathways depending on the direction of installation. Installation has 3 steps: 1. Turn the ClickTight Key on the foot of the seat to lift the seat bottom up 2. Thread the vehicle belt through the pathway and connect it tot he car buckle 3. Click the seat Closed
In addition to the Britax reviewed here, there is also something called the Britax Marathon ClickTight
. Britax claims the "ClickTight" version is even easier to install and it only uses your vehicle belt with a 3 step process, and given our experience with the Britax Boulevard ClickTight
and the Britax Advocate ClickTight
we tend to agree. If the Marathon is your seat of choice (we did give it an Editors' Choice award), you might want to consider the ClickTight version or take a peek at our Britax Boulevard ClickTight ARB review. We believe this seat is a great choice because being able to correctly install your car seat impacts the seat's overall safety. Many injuries from car accidents are related to seats or harnesses that were not used correctly. Whatever increases the chances of a correct installation is worth a look in our book.
Britax sells several accessories for use with the Marathon. These include the following:
- Britax travel bag — This bag is a good way to ensure your car seat is protected from possible damage or loss of parts that can happen during travel. Checking your car seat for air travel? This bag is almost a must have that also makes carrying the car seat easier.
- Britax kick mat — As baby gets bigger and switches to a forward-facing configuration they may be able to kick the seat in front of them. This kick mat hangs off of the back of the front seat to protect the seat back from dirty little feet and potential damage that comes with constant kicking from kid passengers. This mat also has storage pockets for toys and necessities that help keep your baby supplies organized and in one place.
- Britax vehicle seat protector — This handy rubber mat fits under the installed car seat and protects your vehicle seat from any wear and tear that may occur over the life of the car seat years. This mat has a channel groove for spills and prevents food and other liquids from making contact with the car. Protecting your long-term vehicle investment is important and can not be overstated.
- EZ buckle belly pad — This cool pad offers more than just additional comfort for baby. The construction of the pad holds the buckle forward for easier onboarding of baby by keeping the buckle up and out of the way. No more searching under baby bums to find the buckle and the pad has been crash-tested and is compatible with all Britax brand car seats.
- Seat saver waterproof pad — If you are worried about keeping your car seat clean and don't want to hassle with removing the entire cover this is the product for you. This waterproof pad sits into the bottom of the car seat and catches all the spills and diaper accidents so your car seat stays clean. The fabric is wicking and helps keep baby drier until you can get home and wash the pad and baby.
The Cozy Greens back seat mirror
Another accessory available for purchase is the Cozy Greens Back Seat Mirror
from Cozy Greens. The mirror can be quickly attached to the headrest with a flat base that fits against the front of the headrest and stays in place by two adjustable straps. The convex shape of the mirror allows for a wider field of view, and it has a crash-tested shatterproof surface. Once the mirror is adjusted, you can tighten the pivot point so that the mirror can't be bumped out of position accidentally. This mirror does require an adjustable headrest to attach properly, and Amazon users seem to love it.