This post was written by
Kecia on July 6, 2010
Posted Under:
Reviews 
I’m going to break the entire 
Britax Marathon 70 review into smaller bite-sized pieces. Partially because I don’t have a lot of time today, partially because it’s 100 degrees outside right now and partially because I know everyone is anxiously awaiting more info and I don’t want to keep you waiting longer than necessary.
The Britax Marathon 70 is a convertible child restraint rated for children 5-40 lbs in the rear-facing position and up to 70 lbs in the forward-facing position. It has a listed height limit of 49″ tall but since all children are proportioned differently, it’s possible that it may be outgrown before that listed height limit is reached. Since many of our readers are familiar with the original Britax Marathon model, many of my comments will be comparative.
The new Marathon 70 has a deeper seat pan so it will provide more leg room/thigh support than the original. The outer crotch strap position measures 8″ so it offers considerably more room in that area than the original model did. The side walls are deeper and wider too so that’s a nice improvement as well. I promise exact measurements and more pics in part II of the review, which is now posted HERE.
Forward-facing installation with LATCH in the captain’s chair of my minivan was a breeze. 15 seconds flat and the seat was installed rock-solid with the lower anchors and top tether. Honestly, it just doesn’t get any easier that that. It was too hot to try any other installs at that moment but I promise more installation comments in a few days.
Next, I tried my just-turned-6-year-old in the seat. He is currently 50 lbs and 47″ tall. Unfortunately, I think he has slightly (maybe a half inch?) less room height-wise than he has in his old Decathlon which has the same shell as the original Marathon and Roundabout 50 models. Considering that most 6 year olds don’t ride in convertible seats I really don’t see this as a major problem. The new Marathon 70 should still get most average-sized kids to the age where they can safely transition to a belt positioning booster seat. Off-the-chart and long-torso children will always be the exception.
Here are the pics of DS2 in the Decathlon:
Marathon 70 installed in the upright position:
Check out Part II of the blog review
HERE and stay tuned to CarseatBlog.com for more
Marathon 70 updates over the next few days!
I’m going to break the entire 
Reader Comments
Has sort of a Recaro side profile, doesn’t it? Except for, you know, actual leg support.
It seems more upright FF – I like that. And I was hoping that would help give it a little more torso room – doesn’t look like it though. Can’t wait to see more!
I’m a sucker for new design–I like the new look. I also like the little bit more seat depth for leggy kids and more room in the crotch area. And how can you not like a seat that installs in 15 seconds? I’ve installed more Britax seats using LATCH in that timeframe than any other seat. They’ve got that part down for sure.
I’m liking that leg support! Bummer it’s a little shorter for torso height. Can’t wait to hear more.
It sounds like they improved almost everything. Had they only increased the height limits even by a half inch or something, it would have been amazing. Even so, if the crash test performance is as good as it is supposed to be, it should be an exceptionally safe seat. I’m anxious to see the infant insert in action, too. Thanks, Kecia!
I am very happy to see the increased seat depth as this is one of the major complaints I see with the current models. I wish they had increased the height limits
but its great to hear that the seat is still a breeze to install, I think that is one of the biggest factors when I recommend Britax. A correctly installed seat is the best seat, and the easier this is on parents the better.
Oh and thanks Kecia for braving the heat to give us all a bit more info
thanks, kecia for this update!! i would love to hear any thoughts about install in a smallish sedan with a seatbelt, if possible. i love how it looks!
its 90+ degrees here in Maine right now too! cheers for a/c!
The Decathlon has always been a smidge taller in the harness slots than the Marathon. The RA50 and FPSVD are also a little taller than the Marathon, since they use the Decathlon shell. So it sounds like the slots on the MA70 are the same as the original MA. Too bad, they could have easily raised them a bit, and a lower bottom setting would be great too.
from what I have read the bottom slot is 8in compared to the 10in of the older model and if you add the new infant insert then I believe the new seats will fit most average to heavy newborns
or maybe it was 9 t0 11 . . . I would have to look it up again to be certain
I’m curious whether the lock-offs are still optional or have they become mandatory like on the TrueFit? It looks like Britax went with more TF-like lock-offs, which in my vehicles were worse than the original MA lock-offs.
where can I buy it?
CMESS – It’s not available yet but should be shipping to retailers in the next few weeks. Many retailers are taking pre-orders.
You can find some photos of the infant insert in this thread: http://www.car-seat.org/showthread.php?t=135236
Hi ev1,
I am a new grandma & would appreciate any advice.
My daughter just had twins, a boy & a girl. They will be 9 mths old sept 3rd.
She was wondering if there is a major difference other than price between the Britax Marathon 70 & the Britax Blvd 70?
Thanking you in advance
Ilene
Hi Ilene. The only difference between the Marathon 70 and the Boulevard 70 is in the headwings. The BV has larger headwings.