iheartbacon

When I have my Burley Nomad loaded with groceries my Giant Escape will sometimes shift on it's own. When I took it into the bike shop the derailleur hanger was slightly bent. Am I exceeding the towing ability of my bike? I'd say the trailer, when loaded, weighs somewhere between 50 to 65 pounds. It doesn't do this empty, I towed home a load of groceries this week and there's a grinding noise coming from the drivetrain. Since I'm car free this is the only way I have of going grocery shopping. Just to add the bike weighs ~38lbs and I weigh 317lbs.

doublegg66

hhmmm-dont have an accurate answer,but I weigh in at 195 the puppy is now 50lbs and the trailer is 20lbs,and its pulled by an old univega-no issues at this time.

Rowan

The hitch for the trailer doesn't go to the derailleur side, does it?

Assuming it doesn't, the bent derailleur hanger is a result of something else. I'd suggested that the grinding noise also is a result of something else.

I can't really imagine you being able to do any damage to the rear triangle of the bike even with the load you have. The only real issue might arise if you jack-knife while braking or laying the bike over on the ground and binding up the hitch.

You may be getting some bottom bracket deflection that may lead to ghost gear changes, but I would think the out-of-line hanger would be the culprit there.

iheartbacon

The hitch is on the left side of the bike, it is somewhat crammed in there with the carrier and fender mounts competing for space. I'm going to have the bike looked at on Monday. Hopefully I didn't screw up the bike too bad. There's pictures of bikes on this site towing really heavy loads, it's just a weird coincidence that when I tow sometimes it shifts on its own. It doesn't do it all the time either and the bike has never done it unloaded. What else do you think could be causing this issue? What made my hanger go out of line in the first place?

prathmann

Ghost shifting sometimes happens when you push particularly hard on the pedals and cause the bike frame to flex some - particularly if the derailleur is already a bit out of adjustment (which a bent hanger could cause). I agree with Rowan that a heavy load either on the bike or trailer wouldn't cause a bent hanger - usually that's the result of laying the bike down on that side, leaning it against something when parking, or from a stick or other object knocked against it while riding.

Tim199

Some pictures might help some of the experienced people here figure it out. You aren't by chance cross gearing when you get the grinding noise are you? Far left gears on the front and far right gears on the back or vice versa can cause that. But yeah other people report towing as much as 500 pounds so the towing is unlikely to be the problem. It's possible though with your weight the extra weight from towing is just enough the flex the frame to get the effect you're seeing. Does seem odd though since the tongue weight on the trailer shouldn't be too high. I regularly pull 85-90 pounds with the trailer weight and don't get either of those issues, so I can't say what else it might be.

iheartbacon

I can do pictures, here are some. I almost exclusively use the middle ring on the front cog and gears 1 to 4 on the back. I don't get much past 5 even empty, I'm not in great shape.

erig007

Impressive. Miam miam i'm hungry i would eat that in a week

turbo1889

A whole lot depends on the bike and how it is set-up. The very best two wheels only dedicated cargo bikes can handle about a quarter ton of weight (500 pounds) in the hauling arena on the lower end of the spectrum that includes the weight of the rider on the upper end that is in addition to the weight of the rider and can tow as much or more. They have heavy duty (usually 48 or 64 spoke) wheels with heavy duty wheel bearings and quality steel instead of aluminum alloy free-hub body with steel cassetes with large cogs for strong low gear ratios.

They are not your average bike but dedicated heavy haulers. Dedicated purpose built cargo Trikes and Quads can take even more punishment. That said, your average bike especially if its wheel and drivetrain components are ligher duty are going to start being pushed beyond their design factor once you get over 250 to 300 pounds including the weight of the rider.

The best cargo hauler I have ever seen was a home-built trike that the guy used 20" BMX trick jumping bike wheels to build with an all steel derailer mid-transmission driving the two rear wheels from a stub-axle with double single speed chains. You couldn't physically get enough weight on that thing to hurt it. Saw him haul 10 bags of concrete mix each weighing 80 pounds on it once and the bike didn't even break a sweat (Although he most certainly did !!!)

ka0use

Saw him haul 10 bags of concrete mix each weighing 80 pounds on it once and the bike didn't even break a sweat (Although he most certainly did !!!)


i just bet he did, snort! i'm liking to die just thinking about it. you could pop an aneurysm easy.

turbo1889

He had some really low gears on it. If memory serves me correctly, he had a mountain triple chain ring crank in front that ran back to a a 7-speed "maga-range" free-wheel on a short stub axle that has the big bail-out gear first gear cog and then a small, low tooth count, fixed output cog on that stub-axle with a second chain loop run going back to a second 7-speed "mag-range" free-wheel on the second stub-axle with its output going down to the two rear wheels with the two single speed chains. Long story short with his front chain-wheel shifter in the #1 granny position and both of the rear right side 7-speed shifters in the #1 position the gear down ratio to the rear wheels was like 5-to-1 so you had to make the pedals go around five times for each turn of the 20" rear wheels. So you could haul or pull a lot with it just a lot of pedaling and not going very fast in the low gears. but with the three front chainwheels and two rear 7-speed free-wheel spools he had enough gear range to go almost just as fast as a regular bike in the top end of the gears (without a heavy load of course).

fietsbob

given: the trailer fits on the other side of the hub from the derailleur,
the bent hanger is unrelated to the load , towed.

that it was out of alignment, is why there was the auto shift.

more likely the bike fell over right side down, in the past, history
demonstrates that is the most common cause of bent derailleur hangers

once you load up a trailer, the getting it to stop becomes an issue..

100# load... a set of drum brake hubs and some surge braking linkage at the hitch
becomes a reasonable Idea.

turbo1889

Absolutely agreed, once you reach a certain point as far as trailer weight you really need to start thinking about trailer brakes. Especially if you aren't carrying at least some of the cargo on the towing bike. Adding weight to the bike as well doesn't help with stoping any quicker but does help keep the trailer from pushing you around and jacknifing you from behind in a hard stop.

The same set-up with an in-tongue surge brake linkage can also be done with mechanical disk brakes as well (done it). Might even be possible with hydrolic disk brakes but I'm not very familar with them (above my price point) so I wouldn't know how to rig it up with them.

ka0use

ohhhhh, boy. here's a thought-

years ago i saw a fella on the teeee-veeee (if i't on tv, it must be real) pull a semi tractor-trailer from a dead
stop with his teeth.

now, if'n a dude could do that, couldn't a bicycle?

probably have to use the same dude (which is NOT me).....

kevbo

That would give 147 gear combinations. Wonder what the total range was?

turbo1889

I don't know for sure since he don't live around here anymore and he took that bike with him when he moved and I'm relying on memory. I do know it was a triple in the front and two 7-speed spools in series for the rear. It had a set of regular grip shifters on it plus an extra thumb friction shifter for the extra 7-speed spool in the rear and you mainly used the grip shifters through their range and used the friction shifter only to make big adjustments in where you where in the range of gears available.

It was a pretty cool bike for a hauling rig, wouldn't mind building one like it myself some time but I never seem to have enough time or money to do all the projects I'd like to do. And I don't think there were a total of 147 different gear ratios. A lot of those 147 combinations were probably duplicate ratios. I just remember that the low end of the gear range was really, really low and the top end was about the same as a regular bike in its top end of the gear ratio so the extra 7-speed spool was set up to add to the bottom end of the range which obviously you can go a lot lower on a trike then you can on a two wheeled bike since you can only go so slow without having balancing troubles especially with a heavy cargo load on a two wheeled bike.

Dux_Helm

THe weight is dependent on the bike and the setup.

If you have a commuter bike with a basket or paniers, I would put no morethan 5kg in the basket, 20kg in the paniers (10kg per side)...You could push that number higher with Xtracycle or if you have something like Kona Ute or Yuba Mundo or something...


My bike is officially rated for 180kg of cargo (LarryvsHarry Bullitt).
Realistically I put no more than 50kg in the cargo area, I had 80kg of tools and stuff in it too, but that was with E-assist.

I had a friend with a trike, she used it to cart her 4 kids around and it worked great (so roughly 100kg in 'kid load' )...WOrked great until her husband decided to hitch a ride with them on the rear rack one day and the rear wheel collapsed!

I think there is a reasonable balance between what the bike CAN carry and what it SHOULD carry.

You have to think about the longevity of components, braking power, terrain etc.


Here's my bike with my daughter
We used to go for 4-5 hour rides around Vancouver where I live. SHe would nap in it as we rode. Good good times....

Dux_Helm

One thing I discovered is that coupled with E-assist with regen cargo bikes perform exceptionally well.
My favourite setup is front hub motor. That gives me 2WD, distributes the weight evenly and helps to get over any curbs or steps in my way (If I can spin the front wheel).

It's a good solution for hauling quite heavy loads.
Regen works like an engine brake on a diesel and helps to save my brake pads.

Speaking of brakes, anything loaded over 20-30 kg really should be equipped with disc brakes in my opinion.


P.s. Sorry, I went off on a tangent and did not address the original post

THere are a few things you can do:

1.Make sure you shift down lower than you usually do. Keep your cadence at 85-95rpm. That will put less stress on your drivetrain (and your knees).
That alone should be enough to solve the problem, unless you have some major hills in your commute and are already shifting dowh to the lowest gear ratios.

2.Get E-assist (pricey solution, but man, is it ever luxurious)
3.Keep a couple of spare hangers handy and treat them as consumables, like brake pads or tubes. THey are not expensive, if you get several you should get a discount.

turbo1889

The Yuba Mundo is officially rated for 400lb. of cargo in addition to a driver weight of up to 200lb. in the stock configuration with the extra thick solid 14mm rear axle on the stock heavy duty hub with 48-spoke rear wheel. Just thought since I knew that one that I should throw it out. Although I can assure you that you have got to be darn good at balancing and put the load down low and equally balanced on the two rear cargo decks on either side of the rear wheel to actually pull that off.

Dux_Helm

Agreed. with no E-assist that much weight even if balanced perfectly can only be moved safely on a flat road.
Any kind of uphill and you're stuck, any kind of down hill and you may not have enough braking power..Though I think the new Yubas are disc equipped now? I'm not sure.

Sixty Fiver

I have hauled as much as 300 pounds on a trailer, 200 plus pounds on my extra cycle (not counting myself)... sometimes it is not how much you can carry but how far you carry it.

I found my vintage Singer machine and when I told the people I was picking it up by bike they thought I was a little off... that and that a dude was coming to buy himself a sewing machine he would have to carry 10km.

Dux_Helm

good job, nice!
That is a serious trailer.
You have to watch the weight distribution a little, as the axle is so far back, but besides that it's about as practical as it can get.
I have seen those equipped with E-assist as well.

turbo1889

LOL!!! ~ I Sooooo know exactly what you are talking about. I've gotten so much sh*t from people for the fact that as a guy I have a dedicated sewing room with two different machines. Although they do back off a little when they figure out the vast majority of what I sew and the fabrics I use are "manly" stuff like heavy canvas, wool, flannel, and even leather with my old heavy-duty straight stitch only rotary bobbin machine with the right needles.

Dux_Helm

In my family, my father and my brother sew the most lol
This whole 'men jobs, lady jobs' is soo 1900's

Not to mention that some of the most well known tailors are men, same goes for chefs.

Turbo231

Yeah...I'm pretty good on the power side of hauling, but the brakes on my bike are meh enough with my butt and my little 23 lb girl on board...adding the extra bikes would make coming to an emergency stop harder then I care for...that being said, it's super convenient and knowing brakes aren't the best, you plan your stops better.

I have since upgraded to brake pads that aren't 20 years old, that helped a great deal. As said, its not how much you can pull, its how much you can stop.