Cargo Bikes

So if I have a smaller wheel (reduced trail) but a straight fork (increased trail) then it should be ok? Just basing it on Wikipedia's explanations of rake/trail... Ideally I would like to have a seat-shaped front rack cargo area that extends beyond the wheel. It seemed to make sense in my head, but maybe I have not thought it through? This is a mockup (the smaller 24" wheel is just the black circle with the centre at the end of the straight "fork" end that is drawn in as a black line). The fuchsia area is where the cargo area would be (obviously have to be well attached/distributed to the frame):

Not sure that logic would work, because by putting a smaller wheel on you are also steeping the head tube angle.

This website is super helpful for figuring out trail http://yojimg.net/bike/web_tools/trailcalc.php

Also, i would cut the headtube out and put a longer one in the extends past the downtube, that way you can mount your load lower and it will be more stable.

Old set of 1" bmx forks and a 20" wheel worked quite nicely for me. I just slid a 1.125" steerer over top of the bmx forks and welded it up.

Not sure that logic would work, because by putting a smaller wheel on you are also steeping the head tube angle.

That's only true if you don't extend the fork/headtube further down, though right? in my mock-up (admittedly very poor!) I haven't changed the angle of the head tube angle.

This website is super helpful for figuring out trail yojimg.net/bike/web_tools/trailca­lc.php

Thanks - that is really helpful... however, I am having difficulty knowing what is a good range to aim for in the numbers it outputs. Should I try to get the trail between 40 and 100 roughly? Higher number for trail creates "better steering" is that right?

Thanks!

Yes, if you keep the headtube unchanged and put a smaller wheel on, you will steepen the headtube angle.

I suppose if you added on the difference between the height of the two wheels to the headtube, the HT angle would stay the same.

As far as trail goes, as i said you want it to be in the low 40s. A bike with 40mm trail and a bike with 100mm of trail will handle completely differently.

as I said you want it to be in the low 40s.

Ah,right sorry I missed that earlier... I wasn't sure quite what you were referring to in that post.

HHSCB?
looks insane

Should I try to get the trail between 40 and 100 roughly? Higher number for trail creates "better steering" is that right?

No, the higher the trail, the more stable the bike. Sounds good, but too stable and you find steering unresponsive. A low trail randonneur bike would have trail of 38 or below - perhaps as low as 30, so perhaps aim for 40 as the higher end of the range you're aiming for. Cargo bikes might go even lower trail - I tried out a Babboe City bakfiets at the weekend and it was super twitchy when carrying my baby. I had a look afterwards and found that the rake resulted in pretty much 0 trail. I'm sure that's super when you have 100kg of kids and shopping loaded, but it was far too responsive with just the nipper.

You better get good quick at making stoppies with that weight balance...

yeah, I will have pannier rack and a crate or something on the back to balance loads, but also looking at this as an excuse to try out a front disc brake, for more stopping power... if I can just find some cheap 26" IS mount ones with a long 1" steerer (PM if anyone has anything going).

Current plan is actually to butcher a second bike and weld its head tube upside down to the bottom of current frame's head tube. This should allow the TT and DT of the butchered bike (light green) to support the rest of the rack really solidly, along with some other supports which will run from the DT shifter bosses (light blue). The cargo area will not extend quite as far forward ending at the yellow, which should also help to balance things.

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Very distinctive cargo child transporter bike stolen:

https://twitter.com/MamaMoose_Be/status/653146065445724160

Keep an eye out.

So I'm looking at plans for a cargo-ish bike for my photography kit. Basically I'm sick of carrying up to 15kg on my back in a rucksack. Only problem is that when I had a cetma rack (which mounts to front hub axle and handlebars), the vibrations from the road killed my kit, and it was a fairly expensive repair to get some of my lenses fixed.

So, I'm thinking I have a small/med front rack about A3 size, that mounts to my frame. Pic below. If I was to get fat tires - say 1.75 - and some front suspension forks, do you think this would work?

@M_A_X you mentioned up thread about weight/rake for steering, how much do you think this would be affected? I'll be carrying average 10kg most of the time, though sometimes 15kg.

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Wouldn't panniers be a better solution as the material would allow for a degree of dampening of the vibrations?

Front rack is more on trend for a hip fashionista like Ben.
Or are panniers back in for 2016?

Could some clever anti-vibration elastomers be built into the rack mounts to further smooth things out?
http://www.novibration.co.uk/?gclid=Cj0KEQjwtO2wBRCu0d2dkvjVi5cBEiQAMEIVGYtPlELPn5ZKFwogaG1HV0z74ydxvaHwV6rHATy1AigaAsXC8P8HAQ

And line the base of the rack with plastazote foam sheet? We use it in various thicknesses at work to reduce vibrations to pretty good effect.

How about something custom. A rack frame with a Omniumesque tube weave ala:

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Hadn't thought of rear rack, but my reasoning that some air suspension forks will give greater dampening at the front.

@edmundro didn't know of anti-vibration elastomers existence, will look into them now, see if they can be integrated. I didn't mention it, but anti-vibration foam was already part of the plan, have it mounted to the rack.

@JesperXT I've seen a courier with that rig, which is cool, those a bit excessive for the load I need, which is a large rucksack.

I just thought of something sized like a regular front rack - 30 by 40 cm'ish - without supports/rods/tubes in the middle, but a tube weave instead. Just large enough for a backpack.

I just got one of these for a bike I'm building up. I ride with front pannier lots it's not an issue so long as you are in the saddle, up out the saddle the bike goes a bit wild(with panniers). Unsure how this will change with the new rack as it won't turn when I steer so the weight should stay in the middle.

http://www.decathlon.co.uk/500-bclip-front-bike-rack-id_8328048.html

Just buy an old butchers pashley and line with hay...

Or get Ted on it to build you what you need.

What bike is it? your trusty Panasonic?

Only problem is that when I had a cetma rack (which mounts to front hub axle and handlebars).

If you're getting rid of it, I have first dibs.

But like other said, elastomers or similar would be better.

That's excellent. Who made it?

It's an Omnium Cargo, which is basically a cheap Bilenky

Omnium Mini singlespeed;

I reckon it make the perfect work bike for your work.

Looks interesting. Thanks.