2 kids on deck with their feet in the bags and a stadium blanket. They’re kind of wusses.
People who see us around San Francisco may have already noticed that we have added a new cargo bike to our stable. Around when school started, we got an EdgeRunner. It’s fantastic.
I realize that we are in a fortunate position in being able to buy a second cargo bike outright. When we sold our minivan in 2012, we got enough money from it to buy two assisted cargo bikes. So we used about half of that money to buy the Bullitt, and we saved the rest for some vague future transportation need. At the time we weren’t sure whether we’d want to replace our car eventually, and figured the money we saved could be a nice down payment if it came to that. Two years later, we’ve found that we are just fine with renting cars for our very occasional driving trips, and have no desire to own one.
However we were feeling that it would be very helpful to have a second 2-kid capable cargo bike. The construction work in our garage smashed up the mamachari (RIP, mamachari), so we were suddenly down a bike. With two kids going to the same school for the first time this year, we were in the new position of wanting each parent to be able to pick up and drop off the kids together—before, we could split up because each of them was going to a different place at a different time. That was way more complicated, but it also meant that riding around on one-kid-hauling bikes wasn’t a big deal. Moreover, our son had become a strong enough rider that he was ready to go to school sometimes on his own bike. The problem with that was that the kids take a bus to their after-school program, and there are no bikes allowed on the bus. So if he was going to ride, we needed a way to get his bike from the drop-off at school to the pickup at after-school.
One option was to assist the Kona MinUte—because both kids are too heavy to haul around unassisted now—but it was a tight fit for two kids even when they were smaller, and left the question of how to haul our son’s bike unresolved. If you’re in the bike-on-bike-hauling business, your best bike is a longtail. We had taken enough test rides over the years to know that our favorite longtail, by a long shot, was the EdgeRunner. So around the time school started, we headed to The New Wheel to buy a BionX EdgeRunner. They were our bike shop of choice because they know so much about assists—anyone can take care of an unassisted bike, but having an electric assist-focused shop to maintain our bikes is an enormous luxury and it would be crazy not to take advantage of it. Also they are very nice. Even though we have to cross town and haul up serious hills to get there, which is not fun with kids when an assist is on the fritz, it is worth the effort.
This is Davey Oil’s stoked EdgeRunner with the same massive front rack.
Because I’ve gotten particular about certain things over the last couple of years, we put some unusual accessories on the bike as well. I credit G&O Family Cyclery for these particular specs, which I tried and loved on one of the EdgeRunners I rode while visiting Seattle to compare the BionX to the Stokemonkey. Specifically, we added a frame-mounted front rack and Rolling Jackass (very regrettable name) center stand from Haulin’ Colin in Seattle. The front rack was a huge pain to install, given that no one in San Francisco had done it before, and almost made me wish I’d flown my bike to Seattle instead of having the rack put on locally. But the payoff was a massive front basket (I have a Wald Giant basket zip-tied to the rack) that is independent of the steering and absolutely rock-solid, and that has easily swallowed loads like: my work tote, both kids’ backpacks, a clarinet, and a bag of groceries, with room for more. Finally, the EdgeRunner’s tiny rear wheel meant that I was getting a much bigger boost from the assist, which in my still-weakened state, meant that this was going to be my primary ride for a while.
The transition to riding the EdgeRunner with both kids was not without its issues. Our son doesn’t ride his own bike every single day, because he tends to go at a maximum speed of 7mph, making even my normal pace look like road racing. When we leave home on the later end of normal, we have to stick him on the trailer-bike to make it to school on time, and that means I’ll end up carrying both kids home in the afternoon. Although both kids easily fit on the EdgeRunner’s deck, for the first two weeks sharing the deck they fought so relentlessly that I actually found myself yelling, “I can stop this bike right here!” I am happy to report that this was a short-term problem—they eventually settled down, and now they usually have pleasant conversations sitting face-to-face during the times that they share the deck. The only remaining annoyance is that our long-legged son will drag his feet on the ground sometimes, which acts as an unwelcome extra brake and does his shoes no favors. He’s getting better about this.
Loading up my son’s bike for the tow.
There are compensations. The biggest is that when he does ride, it is laughably easy for me to tow his bike to work in the morning, and to his after school program in the afternoon before riding home. It has definitely reduced our load and is improving his stamina (and although he doesn’t like to admit it yet, he’s in a much better mood when he rides to school and back home). The bike can also haul unusual loads that were formerly pretty tricky. When I had to pick him up from school a couple of weeks ago because he’d gotten sick, I had no trouble towing the bike while he was nodding off on the deck. That kind of doubling-up has historically been the Bullitt’s weakness.
Our daughter is our primary deck-rider, though. The EdgeRunner deck has a bit more space for a kid than the Bullitt, but it is also uncovered. This has led to some complaints about having to experience weather, and some excitement. We have a Hooptie around the deck, and given our daughter’s personality, that was a smart move. She treats the deck as a combination small room and performance space, and kind of does what she feels like doing back there. Sometimes that’s lying down flat to take a nap. Sometimes that’s standing on the deck on one tiptoe while holding onto my shoulders. Sometimes that’s leaning waaaaaaaaay over to one side to check out something on the ground (at which point I once again feel a sense of gratitude for that low deck, because I can feel her doing it but it doesn’t dump the bike). The EdgeRunner is our mullet bike: business in front, party in the back. Our daughter has been a frequent flyer in the hospital emergency department since she was less than a year old, thanks to her try-everything attitude , which means that we have more experience assessing what constitutes a serious physical risk to her than we ever wanted. I’ve learned not to worry about her shenanigans, because her balance is excellent, she’s corralled by the Hooptie, our route consists of quiet streets and protected lanes, and I’m usually riding at (much) less than 10mph behind my son. However I definitely get a lot of drive-by parenting. I mean that literally. People in cars pull up next to us and tell me to tie her down, sometimes pointing to their own kids strapped in 5-point restraints in car seats as examples. I am already so over this. And I have begun to wonder, from a philosophical perspective, what it says about us as a society that our kids spend so much time literally tied down.
I digress.
Seriously, these bikes are all over San Francisco now. These are the racks at my office.
Riding an EdgeRunner is also fun because it makes me to feel like I joined a club. Although it gets a lot of attention from people who don’t ride bikes, it is definitely the bike of choice among San Francisco parents (along with the Yuba Mundo). As one might expect, most of them are BionXed up as well. There are two EdgeRunners on the Panhandle riding to school most mornings, and I see a blue one just like mine almost every day, coming the opposite way on Post Street after I’ve dropped off the kids. There sometimes yet another EdgeRunner, with a Yepp seat, parked at the racks at my office. After a couple of years riding the Bullitt, which raises eyebrows wherever it goes and has tourists snapping photos, the relative obscurity of riding an EdgeRunner is a nice change of pace.
Most importantly, it does what we need it to do. The addition of the EdgeRunner means that Matt and I can each ride a cargo bike that can haul both kids, and/or their bikes, wherever we’re going. Even though the BionX is not the most powerful assist you can put on a bike, we have used it to get up the hills of Bernal Heights with both kids on the deck. That’s steeper than we ever hope to go on a daily basis. And with the regenerative braking it has crazy-range–I sometimes feel as though I’ve returned home with the same charge I had when I left.
We came late to having two big cargo bikes, but it’s been working well for us. Having two kids in the same school has allowed our schedules to ease enormously, and having two big bikes to haul them and their bikes around as needed makes it easier still. Our son may be slow when riding his own bike, but we’re still beating our old car commute times. I’ve heard a lot of people say that having a box-bike and a longtail is the perfect two-cargo bike situation. Based on our experience so far, I’d have to agree.
Hum of the city 
Yay for Edgerunners! We also have the blue one. Our 3yo has been in the Yepp seat so far. I plan to add the Hooptie (so we can carry friends) and the U-tubes in the spring. We’ve been very happy with Xtracycle’s KickBack center stand. Curious why you went with the Jackass over that . . . .
Even with just one kid, we find ourselves wishing for a second longtail (or even just the addition of a midtail), but I’m currently leaning toward a Bike Friday tandem — our son should be able to ride stoker soon.
Let us know if you figure out a good weather solution for the Edgerunner. I’ve seen people rig rain covers for the Yepp seats, but we’ll be switching to the Hooptie soon enough.
Thus far for weather protection we’re having the kids put their legs in the X2 bags, and then wrapping them up in a stadium blanket (fleece on one side, waterproof/wind-blocking fabric on the other). Admittedly it doesn’t get very cold here but so far their only complaint has been that their faces get cold–eventually we’ll get the balaclavas out and I hope that will be enough.
Thanks for the great write up! When you are towing you son’s bike, how do you attach it to the Edgerunner? Also, why do you find the front frame and basket valuable compared with the cargo bags that the bike comes with?
(1) To tow our son’s bike, we put the front wheel in one of the X2 bags, and use the straps attached to the bag to hold frame to the EdgeRunner (the straps’ receivers are attached to the deck). We have removed the velcro rain covers from the X2 bags and keep them open all the time, by the way. Because this is San Francisco and bike theft is a constant concern, I also use his lock to attach his frame to the Hooptie. When I tow, his bike rolls on its rear wheel. The whole setup is extremely solid.
(2) I find the frame-mounted front basket valuable for a few reasons. First, because it is very handy to have a front basket of any kind while riding–I can take off a jacket or take out my phone (I do this all the time in order to photograph double-parked cars, it’s like a hobby) without having to dismount from the bike or put down the center stand. Second, when both kids are on deck they like to put their legs in the bags, for both comfort and protection from the wind, and that is hard with other stuff in them. So in that circumstance the “stuff” goes in front and they typically get the whole back deck and both bags. Third, like pretty much everyone with a cargo bike, I tend to overload the bike on occasion, and having a front basket that will hold several bags along with the two X2 bags, which will hold even more, means that I never have to worry about how I’m going to get everything home. Those are the main reasons. A front basket is also better for fragile items–I can keep bananas from bruising up front, but rarely in back.
After using this bike for 6 months, we can totally see the utility of a big front basket. Even with our son’s feet not in the bags (he’s still in a Yepp seat), the bags (we also have the X2s) just don’t hold all that much.
I’m still in the market for a cargo bike – still considering a mamachari, but with weather issues (it rains a LOT in Ireland) I’m now looking at saving up for a Bullitt. Could you do a compare/contrast on the pros and cos of both? I have one small 3-year-old (15kg) and no plans for any more any time soon!
Did you get The New Wheel to do the front rack install, or do it yourselves?
Oh, The New Wheel totally did it, we know our limitations.
Ha – I’ve been feeling the ‘drive by parenting’ love as of late too — someone drove slowly in front of me and my daughter on our boda boda, while simultaneously videotaping us and reminding me of the danger I am placing myself and my daughter in while riding in the lane (on a side street with a max 25 MPH and with no side to the road)…
I prefer to remember the couple times people have shouted “you’re the coolest dad ever!”
What a helpful post! I’ve been researching Edgerunners, especially in comparison to the Boda Boda, and the amount of detail you have here is great. Thanks!
Do you think the X2 bags are a worthwhile upgrade from the X1 bags? The velcro rain covers won’t be useful to me for a while since my littlest will be in a child seat for at least another year and a half.
It depends (doesn’t it always?) The difference that sold us on the X2 bags was that the front and back on the X1 bags are so low that people we know reported having their stuff fall out of the back while riding. The X2 bags are more like totes–the edges of the bags are equally high all the way around, so everything you throw in stays put. If you haven’t had a problem with stuff falling out, then it may not be worth upgrading. The X2 bags also have a set of internal straps that make towing a bike easier, which again was important for us, but isn’t for everyone–I met one person who thought it was overly complicated, but he admitted he doesn’t tow bikes either. And the X2 bags themselves are waterproof, which matters more in some places than others. My kids like sticking their legs in the bags, because the waterproofing also blocks the wind.
Thanks, that was very helpful. I’m planning to buy an Edgerunner in the new year (after months and months of obsessive and likely excessive research) and was back and forth about the bags. I think you’ve sold me on the X2s. Being able to tow a bike would be great, and I’m in Vancouver so waterproof is good.
Rochelle, we figured out a way to kind-of attach the rain covers while using a single Yepp child seat. It was actually tricky even getting the seat into place with the bags, though, never mind the rain covers. We have the seat in the front position, and we kind of had to scrunch the bags back. I’m looking forward to ditching the child seat for the hooptie (which I wish we’d ordered in the beginning).
Just brought home my Edgerunner this weekend. I’m both excited and nervous that I won’t use it enough to make it worthwhile. I have never spent so much money on something for myself before! This was all very useful information in deciding to finally it – my husband is still skeptical but we’ll see how it goes!
yup like you said – Best Longtail Ever .
I LOVE LOVE Freaking LOVE my new Edgerunner ! After suppressing many years of Xtracycle envy, I just got and started riding a 24D to taxi our 3 y.o. around and get to & from work and errands and whatever else comes up. Xtracycle LOVE ! I bike commuted pretty consistently before our son’s arrival and our move to a home further away from my work and for whatever other totally lameass reason I made up like new parent sleep deprivation it has taken this long to get back out of the car and onto a bike. Our boy loves it so far, he is riding in a Yepp seat inside the Hooptie. When I picked him up today we got to stop next to the construction site and thoroughly inspect all the cranes, the same ones we usually fly past in the car every weekday.
Christened the Great Pumpkin because it joined us at Halloween and is orange and black, it’s maiden voyage was 6.5 miles of Tucson Cyclovia fun a couple days ago. Cyclovia has always been one of my favorite alternate reality days.
I was originally planning on electrifying right away, but after a couple days riding, I found this bike is super smooth and easy to ride without e-assist. I am going to wait a bit on the e-assist and see what happens. We are mostly flat ground riders here in our city, but I would like to have some kind of e-assist to extend my range eventually.
I tried some other cargo bikes before deciding on this one ( keep asking myself why I waited so long to take the plunge , duh ), but this one felt best to me and the clincher is the 20″ wheel in the back (lowers the cargo in back, more stable) and the overall quality of the build is great. It’s a big gulp to throw down a couple grand for a bike, but I really see this as a good investment on many levels.
More Edgerunners are quickly popping up around town here also in the past few months. Nice to see these in addition to all the badass free radical builds that have been around Tucson for so long.
@humofthecity re: front basket – looks like the picture of the front cargo basket is on a 20″ wheel , how does that feel vs. the 26″ wheel?
Yes, the new rack on our bike replaces the 26″ front wheel with a 20″ front wheel. The change leaves more space for a deep basket. It felt a bit odd at first. The pro of a smaller front wheel is that the bike corners much more tightly with it (handy when turning around), the con is that the ride is slightly more bumpy. It seemed like a good tradeoff.
We have a similar set up (orange), but it goes by “El Camino” which was bestowed by a baffled co-worker (as in “what kind of bike is that? it looks like the bike version of an El Camino”). I’m happy to hear you’re enjoying riding around Tucson, we’re going to be there for a week and love our bike so much we decided to rent an Edgerunner to get around while we were visiting.
It gets colder here than SF, I assume- but when my son was a passenger last winter he often complained about the wind tearing up his eyes (the clava kept him warm, but the eyes uncovered, obviously). Kid ski goggles solved that- relatively cheap, easy to find, and he loved them!
Can you please tell my why you choose the bionx wheel instead of the XxtraCycle Electric version that has a electric offering built into the product that they sell? For example the 27D or 24D ?
Thank you
Sorry, I see that the XtraCycle does use the Bionx. Never mind.
Hey I told you you’d get used to the wide loaders in the back. Takes miles.
We bought our Edgerunner in June and love it for doing our kindergarten and work commute. After our son was born I never figured out how to make the bike commute happen again. We’ve got a very wiggly, 70 lb, 4 ft tall 5 year old and the Edgerunner+BionX means I can take him to school (which is naturally at the top of a very steep hill) and then ride to the opposite side of town to get to work. We bought it from Barb and Joel at Splendid Cycles in Portland, and opted to get the primo, road bike gearing because my long-time biking spouse wanted it to go faster on the flats. It’s literally changed our life and I can’t believe I waffled about buying one.
One thing that has been frustrating is that once my work clothes bag and work bag, his lunch, the locks, the spare everything kit into the X2 bags with their rain flaps (we leave in the PacNW, it’s always wet in the winter) there isn’t a lot of space left on the running boards for his feet to rest and we struggle with him clipping my heels sometimes, usually when I am trying to start after being stopped at a busy street. I’m intrigued by the idea of having him put his feet inside the bags, but not sure how it would work with rain boots! The idea of a front rack is intriguing.
So far we’ve just done a windblocking fleece under the rain overalls and raincoat from Polarn O Pyret and cheap poly fleece gloves. It’s worked fine for 40 F mornings, we’ll see when it gets colder. I’ve ordered some wool under helmet caps for all of us and merino aviator hat for him from Randi Jo Fabrications after seeing them on Shane MacRhode’s kids at a birthday party.
Would be curious to hear about the differences in the kickstands…
There are two main differences in the center stands.
The first is that the RJ, unlike the Xtracycle stand, has a hand release lever (a small BMX lever on the handlebars). So the kickstand drops down to the ground using the hand release, and it can then be pushed into place without having to feel around with your foot. That makes it easier to park the bike when fully loaded.
The second difference is that the RJ has two large plates on the end of the stand’s tips, so when the stand is down the bike can only be rocked a bit front to back, like a seesaw. It is virtually impossible to tip it sideways, even when, say, two kids climb on board from the same side of the deck.
The RJ is not a necessary upgrade or anything–Xtracycle’s stand is very nice, although I did find it a bit of a hassle to get down sometimes–but I like having the extra stability.
Thanks, that is good to file away for future reference. I do sometimes have trouble pushing the Xtracycle stand into place, especially when it and my foot are muddy and wet and the kid plus stuff is on the bike. Not a deal breaker but enough that it could be better.
yes, a bit hard to get the kickback down with utubes installed. only almost tipping over so far has been on uneven grass.
I put bar ends on my Kickback stand. Makes a big dif.
@jim, do you ever have issues with the bar ends making it so the Kickback stand pops down when it’s not supposed to? Because of the weight I guess…otherwise, it’s a great idea. I am not fond of having to fish for it under the running boards and the bar ends are a great work around.
leftcoaster, no the additional weight is nominal so it doesn’t pop down. What can cause it to drop is not cinching your bag straps tight when heavily-loaded and/or the tension of the return spring is too lax. You can move the spring’s attachment point back a bit; once it maxes out you either have to get a new spring or cut the old one, uncoil it a bit and adjust to desired tension.
You can easily run your running boards with enough of the bar end sticking out to big toe it. Highly recommended cheap mod.
leftcoaster, (cont.) the bar ends also serve to widen the stand’s stance, stabilizing top-heavy loads.
I know this is a tricky one to answer, but I wonder if you have a feel for how much difference the lower deck on the Edgerunner makes to stability with two kids on board?
I currently ride a Kona Ute (with Hooptie attached) which carries the deck higher than even the normal Xtracycle and I feel like any movement or messing about from the kids has a horrible effect on the handling (it’s actually a previously e-assisted Electric Ute which has the deck an inch or two higher even than the normal one).
Kids are 3 and 5 so I am really hoping for another couple of years hauling them around, but I don’t think I will manage it safely or enjoyably with the Ute so I am serious considering an Edgerunner. From reviews I have seen elsewhere and the posts on your blog I am guessing it would be a lot easier, but there is no way I can take a test ride so I am trying to get a view as to how much difference it makes.
thanks!
The only relevant comparison that I can make is between the MinUte and the EdgeRunner because I haven’t ridden the Ute. There is a noticeable difference in favor of Xtracycle between the MinUte and the EdgeRunner in terms of stability, despite the MinUte’s inherent advantage in having a much shorter deck–and the shorter deck would make it less tippy than the Ute.
The biggest advantage is when we are slowing or stopping. I can keep any bike much more stable when we’re moving at a constant speed or accelerating. Unless the kids get so bouncy that they start actually whacking me in the back, nothing they do back there really affects the EdgeRunner’s handling while we’re moving. They do sometimes lunge from side to side when I am slowing down for a light and I definitely notice that, but I have yet to dump the bike. We dumped both the Big Dummy and the Mundo on test rides, so I am a serial offender and very grateful for those evidently critical few inches of difference.
The other place I really notice the difference is when cornering at the bottom of the hill. On the MinUte, I could feel the weight on the top of the deck pulling the bike like it wanted to roll over. This never happens with the EdgeRunner.
I heard from a friend who is over 6 feet tall that he noticed a significant difference between his old Ute and his new Xtracycle FreeRadicaled bike, and even that is still higher than the EdgeRunner deck, so I’m guessing the difference for you would be substantial. FYI, the 2015 EdgeRunner is supposed to come with a frame-mounted front rack option, so it’s probably worth the wait.
Thanks – that is really helpful! I’ve never really felt the effect of the weight pulling the bike on corners, but I suspect it may be because I am a fairly substantial counterweight?!
However, in a straight line when the kids mess about I really feel it, and trying to push the bike when dismounted is really difficult – on a couple of times it has got away from me and I haven’t actually been able to keep it uprighting… resulting in a slow but inexorable fall over. The Hooptie helps with this actually as it acts as a really solid handle towards the back of the bike to hold onto.
Currently my sort list is the EdgeRunner and the WorkCycles FR8, but I suspect the weight and gearing of the latter will rule it out. I have a friend who rides one so I am going to try it out on a few regular routes.
Thanks very much for the feedback!
Curiously, have you found a chain guard that works on the Edgerunner? I’ve already ruined one pair of boots, from the chain grease; I’d love any ideas to protect my future wearables. 😉
Alas, I have not.
I *just* left the New Wheel from purchasing my new, white Edgerunner (thanks, Brett!). I get to pick to up Friday–wheee! We did a new crankset, to one that will have a chain guard.
which crankset and chainguard? thx
Alivio with chain guard (all one set)
Maybe you addressed this elsewhere, but how do you and your husband find the sizing of the Edgerunner? Which size did you end up getting? My wife is about 5’7″, and I’m 6’0″. We would like to get one that we can both ride relatively comfortably. I have no way of trying one without driving all day to swing my leg over one, so it would be very helpful to know since we will likely order it without getting a chance to test ride one.
I am 5’7″ (170cm) and Matt is 5’9″ and we have the medium frame. I would call a family bike shop or EdgeRunner directly to ask how you might suit a medium at 6’0″.
Hi Andrew, not sure if this will help, but I’m 5’9″ and my husband is 6’2″, and we are happy on the large-size frame. He needed an extra-long seat post, and it took awhile to find a handle-bar style and position that we were both happy with. Have you contacted Xtracycle to ask?
I am pretty sure the frame size stays the same, but the length of the seatpost changes for medium vs large ( 16″ vs 19″ – took me forever to figure this out when shopping ). The Xtracycle website used to have the specs listed, but i can’t see them right now on their website, they have changed the available product pages. I believe it used to say that the medium could fit riders up to 6′ and the large would fit riders up to 6’4″ . Best to check with them or a local dealer.
You could get a quick release for the seatpost to accommodate two riders. Mine didn’t come with a quick release. I am 6′ , and ended up choosing the Large – 19″, in part knowing that my sweetee ( 5’8″) would probably never ride it.
And after riding for a couple months, I decided to switch out the handlebar stem for a Satori TURN-UP. I am SO much happier with the riding position this gives me, I have been able to dial it back to be closer to an upright riding position vs. the slightly more MTB/aggressive position on the stock stem. — SO MUCH EASIER on my neck and shoulders ! The Turnup has lots of possible riding positions, the only drawback so far is a little bit of “creakiness” from the handlebars. I may have to adjust the tightness of the fasteners. There are 3 or 4 other adjustable stems out there for MTB setups.
check out this page for some specs:
http://mikesbikes.com/product/xtracycle-edgerunner-27d-x2-9874.htm
“EdgeRunner’s upright riding position and unique geometry enables moms and dads to ride the same cargo bike comfortably. Available in two sizes, the medium size sports a 16.5” seat tube that will fit riders 5’0” – 5’10”. Our large size features a 19” seat tube and will fit riders 5’8” – 6’4”. ”
seat tube vs. seat post = same thing?
We ended up getting an Edgerunner in large and it has fit both of us nicely, once I added a quick-release to the seat post. We also electrified it with a Cycle Stoker kit from ebikes.ca.
I wanted to ask whether you still have the Cycletruck rack on the front and how well it has been working. We bought a cheaper Wald rack that attached to handlebars and fork braze-ons, so we can’t really put much in it without affecting the steering quite a bit. I would like to be able to carry more, but alas our Edgy does not have the braze-ons for a Yuba Breadbasket or the new Porter rack that Xtracycle makes. So now I’m considering the Cycletruck.
We have still have the Cycletruck and it’s great. The installation was a pain, however.
Also, you may plan on changing the seat itself, it is basic and is adequate but was less than friendly for my own butt.
Last thing I will say at this point is that I have ended up with a bunch of flat tires even with thorn resistant tubes. Keep your air pressure above 40PSI , otherwise your tubes will slip inside the tires and fail at the valve stem.