Add a rear rack that can carry a lady weighting ~130 pounds

[venexiano]

As you noticed in my other thread, I just bought a Radrunner so I can carry my girlfriend when we go out. I presently have a Phantom XR (https://www.lifeelectricvehicles.com/products/phantom-xr) and I want to add a rack so that it can carry a girl. Why? Because We are very good friends with a couple who come over often, and we said we should go out for a double date riding 2 different bikes and each of us carrying the gf on the back. I will lend my Phantom bike to them (or I can give them the Radrunner). My friend's gf is more or less like my gf as for height/size, so I would say ~130 lbs. Any suggestion of a good rack? What I found in Amazon is:

1) West biking rack. Says 310lbs but some reviews say sticker says 110 lbs. Seems like there might be 2 models, 110 lbs and 310 lbs, its not clear... but most likely its a typo: https://smile.amazon.com/gp/product/B074Z8PVNV/ref=ox_sc_saved_title_1?smid=&psc=1

2) Comingfit Rack. It is rated for 180 lbs, but a comment says "This definitely cannot hold 180 lbs. I have been using it to carry a JBL Boombox (roughly 20lb speaker) and it has bent at about a 15 degree angle. Has it completely failed? No but the paint has chipped at the crease" https://smile.amazon.com/gp/product/B07MJFRZ27/ref=ox_sc_act_title_10?smid=A3PDM01FOMEFGT&psc=1

Any other option?

 

[chunk]

2 more bikes, for the ladies?

 

[Dave Rocks]

Wow I hope yer gettin' some.

 

[retiredNH]

No way your rear rim and tire are built to handle that much weight. Of course it will carry the weight for a time, until it won't. You want to be going fast when it fails, probably as a total wheel fail?

 

[Duc]

Somewhat related: you should look into foot peg options too. Trying to hold your legs up constantly is not comfortable. You don't want their foot to hit the derailleur while moving either.

I have the West biking rack and it worked fine for ~120lbs.

 

[Sparky731]

No way your rear rim and tire are built to handle that much weight. Of course it will carry the weight for a time, until it won't. You want to be going fast when it fails, probably as a total wheel fail?

The bike’s owners manual should identify the maximum weight it is designed to carry.

 

[indianajo]

My yuba bodaboda (2017) left has a welded rack on the back rated 200 lb. 80 lb behind the axle. There are foot rails, not just pegs, on both sides. You can see the front of one in the avatar behind the bag. I put a bit of aluminum angle (1/4") between the convenient 5 mm threaded holes in the front back of the foot rail, to hold the bag up. Would also work on adult feet,although I'd use 3/4" aluminum box stock for an adult to stand up. There are plenty of tapped 5 mm holes for cap screws on top of the rack to hold a wood shelf, wrapped with foam & vinyl sheet for a padded seat. Yuba sells a grab bar that attaches to the seat post for the hands.
Similar bikes you didn't buy are blix packa eurorau cargo model & yuba combi.

 

[ChezCheese:)]

Rent a couple of ebikes for your girlfriends. That will really put smiles on their faces. They probably don't need to be hauled around like cargo.

 

[m@Robertson]

There is no way a seatpost rack like that has a prayer of carrying 310 lbs or even 110 lbs - maybe it can do it once or thrice but long term, and hit a bump and then what?

Commercial bicycle racks cannot do what you want them to do, unfortunately. You would need some custom superstructure, and then you will run into your next problem: Frame stability. And then wheel strength. Even a full on cargo bike is not happy doing two full adults. The Rad Runner is expressly built to carry a passenger and you need something meant to do the job you want.

I have done this kind of weight on a cargo bike but the money involved with custom wheels etc. etc. is prohibitive. A rack alone making this happen is unfortunately a fantasy.

 

[retiredNH]

It's too easy, I think, for some people to think of an ebike to be like a scooter or motorcycle, either of which it's common to have a passenger behind the driver. But an ebike is built with a much lighter ( = weaker) frame and much lighter ( = weaker) wheels. Cargo bikes can be designed for weight, and they're in a different class, although most cargo bikes are designed more for bulky loads than heavy loads.

Years ago I had a decent bike with substandard wheels. I was constantly getting snake bite punctures on the rear, and regularly had broken spokes. Either will spoil a ride. I finally fixed the problem by building a new wheel set. I shudder to think of how impressed the girl friend will be on her first ride, waiting at the side of the road for a flat fix or worse...

 

[ActionJackson]

1) West biking rack. Says 310lbs but some reviews say sticker says 110 lbs. Seems like there might be 2 models, 110 lbs and 310 lbs, its not clear... but most likely its a typo: https://smile.amazon.com/gp/product/B074Z8PVNV/ref=ox_sc_saved_title_1?smid=&psc=1

I bought the exact same thing for my wife. However she doesn’t sit on it. I installed it on her 20 inch folding bike so I could push her around with her on the bike while she became accustomed to balancing it again. The tube bracing is aluminum. The screws are junk metal. Not suitable for your application at all.

 

[Hasaf]

I am going to go in a different direction here. My experience comes from living in Asia where various female friends would ride on the rear rack regularly. I also took my adult daughter (about 130 Lb) to work regularly.

The trouble is that most western women will not ride correctly. To be done, the passenger needs to ride side-saddle, leaning back a bot so that their centre of gravity is directly over the rack. The passenger also needs to dismount at stops, this helps avoid any side to side wiggle.

Done correctly, a passenger can ride on a normal book rack. Outside of the western world, this is commonly done. However, in the US I would also tell you to read up on bike laws. in the US the bicycle can only be ridden on seats designed and intended for passengers. Also, for some reason, riding side-saddle is not very popular in the US.

 

[ChezCheese:)]

I might point out that riding sidesaddle on the center bar is not comfortable for very long. Think about it: you're balancing on a pipe. Riding on the rear carrier is also not comfortable, whether sidesaddle or astride.

I have ridden sidesaddle plenty on the back of a motorcycle when I used to live in Pakistan, and it is just as comfortable as riding astride, but that is on the padded seat. Perhaps even more comfortable because the shocks from the road don't go directly into your spine.

Seriously, just rent ebikes for your girlfriend. She'll have much more fun actively participating than being hauled around like a sack of potatoes.

 

[BeltzerNYC]

I use the companion bike seat rated for up to 200 lbs and have carried my 5'7 gf, my 100lb daughter and a few other adults no problem. just doesn't look like they make them anymore. the key is the seat rests on steel pegs, I would buy those ebike pegs if u have a hub motor and see if someone can fabricate u a similar design. definitely doable.. https://www.thebikeseat.com/

 

[m@Robertson]

I use the companion bike seat rated for up to 200 lbs and have carried my 5'7 gf, my 100lb daughter and a few other adults no problem. just doesn't look like they make them anymore. the key is the seat rests on steel pegs, I would buy those ebike pegs if u have a hub motor and see if someone can fabricate u a similar design. definitely doable.. https://www.thebikeseat.com/

Its easy to make a metal rack capable of carrying that extra weight. Wheels and tires are a different story entirely. Can you get away with it? Maybe. Can you pretzel the wheel? Oh hell yeah., Hold my beer y'all and watch this!

The guys who sell these bike seats say as much :

Add a Companion Bike Seat to your bicycle and you can carry a passenger with you

Check out all the options we offer for our various bike seats

www.thebikeseat.com

Do the math on what they are saying regarding max capacity. And remember a bike's rated max capacity is assuming a rider sitting in the seat, spreading the weight onto both wheels. Not just one on the back.

Do a long tail cargo bike, then if that bike doesn't have a 36- or 40-spoke rear wheel, make yourself one with your local bike shop using something like an MTX39 rim or even a 65mm Weinmann. Get some proper Sapim E-Strong spokes, use brass nipples, hi volume tires and NOW you can carry a passenger without worrying about the dropouts shearing off or the wheel committing suicide when you hit a respectable bump.

 

[BeltzerNYC]

Its easy to make a metal rack capable of carrying that extra weight. Wheels and tires are a different story entirely. Can you get away with it? Maybe. Can you pretzel the wheel? Oh hell yeah., Hold my beer y'all and watch this!

The guys who sell these bike seats say as much :

Add a Companion Bike Seat to your bicycle and you can carry a passenger with you

Check out all the options we offer for our various bike seats

www.thebikeseat.com

Do the math on what they are saying regarding max capacity. And remember a bike's rated max capacity is assuming a rider sitting in the seat, spreading the weight onto both wheels. Not just one on the back.

I upgraded rear spokes to sapims and everything's been fine!

 

[m@Robertson]

I upgraded rear spokes to sapims and everything's been fine!

You need more than spokes. I mean... did you do enough to get away with it? Mayyybe.

Over the weekend I found out I popped a damn spoke on one of my cargo bikes. The wheel (MTX39) was so strong I never even noticed. Its still true. It was one of the two spokes surrounding the stem where a colored alloy nipple was used for aesthetics instead of a brass one. If I had just changed my spokes when I did the wheel build I bet I would have had a much different weekend. And if I had just done something as small as used longer brass nipples on those two adjacent spokes I bet I would still have an intact wheel. Doesn't take much.