Hi all, just joined the forum as I have some questions relating to a frame I’m looking to have custom built in the near future.
The bike is to carry my dog in a basket up front, at the moment I use a Surly Straggler but I’d like something with wider tyres and drop bars.
My question is around the ideal geometry for a fork that will be carrying up to 12kg in a basket. My thoughts are that a higher fork offset would allow the basket to be installed further behind the front axle and therefore effect the steering less.
I have read that cargo bikes usually aim for a low trail so once loaded the bike will handle better. I will be riding this bike loaded and unloaded regularly as my dog either runs alongside or rides in the basket, so I dont want to compromise handling if the front is unloaded.
There are a lot of articles online covering low trail geo so I won’t jump into that. I will say that I think 12kg is the upper limit of what I would comfortably want to carry above a fork. Especially a dog which will be sensitive to side-to-side movements.
I owned a 58cm Surly Straggler with a Crust Clydesdale fork for a couple years. Geo of that bike below measured as built. The 40mm of trail would be considered low and it rode fine unloaded. The handling is quicker but I could adjust. The smaller wheel also allows for a lower COM. It was a fun bike to ride but the steering was sketchy with larger loads. I don’t miss it and it wouldn’t be my first choice for a dog.
What I replaced it with is an Omnium Mini-Max. This was around the same time I got a dog, 23kg fully grown. The Omnium is also low trail design (30mm, geo below) but has linkage steering and a longer platform that is fixed to the frame via an extended downtube. They clear a 2.1" tyre front and rear and people have set them up with drop bars. I’ve toured on mine with the dog, 100+ km per day with the dog running about 30km, and it was perfect for that. Full disclosure, I run Omnium distribution in Australia, but I would 100% own one even If I didn’t, they’re great bikes.
That being said, given your dog is only 12kg you may not need the extra capacity of a linkage type cargo design. The Omnium Mini (50mm trail) is the more compact version, with a fixed deck and 20" front wheel still. The Bombtrack Munroe Cargo (40mm trail) and Frances Platypus (can’t find geo/trail numbers) are other bikes I can think of that might be similar to what you’re looking for in a bike. I’m sure there are plenty more, including some built by members of this forum.
Thanks Bushtrucker, that’s really helpful. I agree that 12kg is at the top end, particularly since I’m hoping to get this on a 29er so it’s about as high up as it will be. The dog at the moment is 10kg, and hopefully has stopped growing (she’s 14 months old now). Plus the weight of the rack and box brings me to about 12kg. I manage with her fine on the Surly Straggler with a cargo rack bolted on. My plan is for a custom rack that won’t rely on M5 bolts and in general will be sturdier.
My thinking behind drop bars was that because the bars sweep forward and the brake hoods are forward of the stem, I could mount the box between them and steer from further forward in relation to the weight of the dog, rather than from behind as I do now with the swept back bars on my Straggler. I’m not sure if this necessarily makes sense though?
What’s the reasoning behind wanting the large front wheel? Yes 29" rubber will roll better over rough terrain but exactly where I wouldn’t wanna ride a heavily front loaded bike. In that case maybe a mid-tail is better with the dog on the back?
I don’t think you’ll have any issues building a sturdy enough rack, even one mounted with M5 bolts. I’ve owned a couple Pass & Stow racks which are about as well built as you can get. Despite the racks being much stronger, Matt has a suggested weight limit of 25lbs (11.3 kg) because ~ as you add more weight to the rack, the steering becomes less responsive, so the weight limit is set to find a balance between safety and function.
Bar choice is a very personal decision. A lot of people love drops but personally I only chose them if I want/need a super aerodynamic position. In all other instances (town, trail and touring) I’ve found flat/alt bars to perform far better.
The rides I do with my dog are mostly offroad with her running alongside or behind, often this is on singletrack where I prefer to ride a 29er. When we end up on the road and she is in the basket I find the bigger wheels roll better as well. I prefer having the dog on the front because I can see her and what she’s up to, partly means it’s more safe because I know if she’s going to try launch herself at a squirrel (training is helping with this of course) and partly because it’s just more fun.
40ish mm trail is the magic sweet spot for me where you get the low trail benefits with a load and it handles well unloaded. I switch back and forth between bikes with 40mm trail and 80+mm trail pretty often and find it to be natural.
I enjoy low trail and steep STA bikes on trails, but there is no question that they are less capable than slack STA high trail bikes. A green trail feels like a blue on a steeper STA low trail bike because roots and rocks will knock you off your line.
I don’t know that I can suggest a single bike that will do what you want. I do agree with others that a smaller front wheel is going to handle better with the load. A fixed (frame attached) rack on a higher trail bike is one good option but you’ll have to deal with bar sweep and will still have a lot of wheel flop.
Have you thought about making a cycle truck style frame with the rack attached to the frame? I’m currently making one with a 20" wheel for my girlfriend to carry our dog. (I’ve been meaning to update my post with current pictures of the build)
With a small dog like yours you could build it around a larger front wheel. It’s really nice not having the weight in your front rack pulling your handlebars back and forth and could probably help you get away with a bit higher trail
Either way, if you’re wanting to keep the trail number a bit higher for better singletrack riding you could slacken the head tube to get the front wheel further forward and under the basket
Welcome @Nedsynoo! I think @bushtrucker pretty much nailed it, they have much more experience than I do with cargo bikes and dogs.
I agree with Ben on this one; I think the key to a lot of cargo bike designs is the smaller wheel to lower the center of gravity. Having the weight 40mm lower will have a much bigger impact than 40 vs 80mm of trail.
That being said, I think it depends on how you look at this bike: is its a fun bike that carries a dog, or dog carrying bike that is fun to ride?
Sounds like I need to forget the 29er wheel, I’ve been playing around with the geometry for a 27.5 bike and it is easier to get the trail down without getting toe overlap or having too steep a head tube angle. I could aim for around 65mm of trail which would still seem acceptable for an offroad bike that doesn’t have a dog on the front but should assist a bit with steering once she’s in the basket. It would be an improvement from my Surly Straggler (79mm trail) too.
Since I got my dog I haven’t been cycling without her, so it’s safe to say she’ll be along for the ride, question is how much time she will spend in the basket and how much she will spend running alongside. I’d like to do more touring with her so I should expect some longer sections where she’s in the basket.
Thanks everyone for your help
Cheers @Daniel_Y. I’m by no means an expert on dogs or bikes but the crossover it’s defo a recent interest area for me haha. I think big takeaway is every bike is a compromise so it’s just choosing what you want to prioritise.
@Nedsynoo it seems like ya leaning towards the former with a fork mounted rack/basket setup. Might be worth looking at MTB’s with higher offset forks. The first that comes to mind is the 44 Bikes Ti Ute by Kris Henry. It features a 70mm offset 490 A-C fork that’s opimised around front loading. A similar bike is the 44 Bikes Ute John Watson used to have, with a 70mm offset fork at 468 A-C. Both bikes are designed around 27.5 wheels.
Personally I think that’s a really awkward way to load a bike for off-road riding. You will lose a lot of responsiveness with the front wheel which makes it hard to pick clean lines. I much prefer small rear panniers. However with the dog you don’t have as many options so it’s a setup worth exploring.
I know Stooge bikes also experimented with higher offset forks on their early production MTB’s, getting as wild as 80mm offset with a 66 HTA on their Mk4 run of frames (86 mm trail) but they’ve since settled on 57mm of offset across their range. These are rigid MTB’s that aren’t necessarily designed around front loading.
The only other off-road bike I can think of with similar front end geo is the Tanglefoot Bull Thistle. Hell it’s even designed around drop bars which you mentioned initially.
I’d still vote for a cycle-truck style design as mentioned by @olivia_violet. I could see one with a 24" front wheel—for which there are some great tyre options—being a super fun bike to ride loaded or not! It would also be a fun experiment which is part of reason to go custom anyway.
I think you’re right, thanks for pointing out the 44 bikes ute and the Tanglefoot, I wasn’t aware of those. I’m also looking at the Surly Grappler geometry but with a higher offset fork and some tweaks to fit me a little better. I agree it’s not a great way to load a bike for riding off-road, but anything more technical than a gravel track and the dog won’t be in the basket anyway, so the only load will be a couple of water bottles and the rack. I’m hoping that by getting a frame custom made I can maximise the space for a frame bag to make up for the space lost where I would usually run a barbag.
I think the latest Stooge the Dirt Tracker has 101mm of trail from a 65mm offset fork and 66deg head tube angle, not designed for much weight on the front though. I’ve usually ridden a Jones 29er with 55mm fork offset but the truss fork prevents me from fitting a rack and loading the dog to see how it handled.
I think for me it would be too much of a compromise if I’m riding trails, particularly if the front wheel is concealed by the rack. If I was road/gravel touring I think I’d be fine with it.
Well at least you know what you want. If ya happy with the Jones maybe you could start with getting a rigid fork made that allows for a rack to see how that goes. If it works out you could always have a frame built later too. It damn pisses me off that Jones don’t even do geo sheets for their bikes. From what I can find online they use around 75mm of offset. And I’d assume the AC is around 440-460 for 29+. They should be easy enough numbers to hit.
You could get extra funky and try an integrated truss fork/rack kinda thing. I’ve seen both Moustache and Drust do something like that. Does add a fair bit complexity though.
Also speaking of Analog Cycles I’ve always found their views on trail to be interesting. Although I think some of the issues they raise can also be solved by simply swapping from drop bars to flat bars. But I’m also a bit of a drop bar hater haha.
I did actually try to get a fork made by Marino in Peru, I specified 135mm OLD with front disc spacing so I could use the wheels from my Jones, they botched it and put rear disc spacing on it, so its mostly useless. Also they managed to make it weigh 3kg, proper boat anchor! I gave up after that and I’m leaning towards a frame and fork with some modern standards like boost thru axles etc…
I have considered exactly that, I like the way the truss fork rides and had one made for a different bike in the past. Not sure if having the truss and a front rack would mean the weight is set too far forward, in my mind the best spot for handling is close to the headtube but perhaps it should be centered over the axle, I think thats how one of the 44Bikes Ute was setup.
