Author Topic: Should I stop loading up my aluminum frame bike?  (Read 5447 times)

GreenPen

  • Stubble
  • **
  • Posts: 107
Should I stop loading up my aluminum frame bike?
« on: March 31, 2015, 06:22:05 PM »
I live a life of luxury, owning two road bikes.

The first is a steel-framed road bike from the 80s. The second has an aluminum frame and carbon fork, and was built in 2000. The steel-framed bike used to be my work horse, since I didn't want to load up the bike with the aluminum frame. But since the latter bike is nicer, I've been loading it up more and more frequently (e.g. on grocery runs, which puts up to 40 pounds on the back of the bike).

I have read that stress can be a real issue with aluminum frames, and I'm also not sure if I should be worried about the carbon fork under this weight (even though the weight is on the back of the bike). Am I crazy to carry 40 pounds on a bike with an aluminum frame and carbon fork? How much weight would you feel comfortable carrying on this bike?

kpd905

  • Handlebar Stache
  • *****
  • Posts: 1734
Re: Should I stop loading up my aluminum frame bike?
« Reply #1 on: March 31, 2015, 06:29:25 PM »
How much do you weigh?

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #2 on: March 31, 2015, 06:32:23 PM »
The "how much do you weigh" is the question that matters. I've broken an aluminum-framed bike before and it was with my own body weight. The frame broke where the down-tube attaches to the steerer tube. It's the point of maximum stress imparted to the frame by the forks. The welds tend to go at that point because it's a "pull" on the weld, not a "shear".

If you are loading your bike with front or rear panniers, you're doing pretty well and as long as you weigh 220 or less, you should be OK.

GreenPen

  • Stubble
  • **
  • Posts: 107
Re: Should I stop loading up my aluminum frame bike?
« Reply #3 on: March 31, 2015, 06:41:59 PM »
Thanks for these quick responses. I weight ~160lbs, and load up with rear panniers on either bike.

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #4 on: March 31, 2015, 07:02:18 PM »
Thanks for these quick responses. I weight ~160lbs, and load up with rear panniers on either bike.

IMHO, you are in excellent weight territory. Especially with the panniers on the wheels. I guess I'd just keep an eye on spokes.


BlackIronStubble

  • 5 O'Clock Shadow
  • *
  • Posts: 41
  • Location: Mid-sized Southern City
Re: Should I stop loading up my aluminum frame bike?
« Reply #5 on: April 01, 2015, 05:40:17 AM »
I weigh 230 and bomb around on my aluminum hybrid with my work gear and the occasional sack of groceries.  No problems yet, but maybe a road bike is not as strong.  Or maybe I'm in for a rude awakening!


Sent from my iPhone using Tapatalk

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #6 on: April 01, 2015, 08:54:13 AM »
I weigh 230 and bomb around on my aluminum hybrid with my work gear and the occasional sack of groceries.  No problems yet, but maybe a road bike is not as strong.  Or maybe I'm in for a rude awakening!

Hey BIS: if you have front suspension forks (most hybrids nowadays do), you should be OK. The hybrid frame I broke had a solid front fork, which I chose on purpose to try to keep weight down. What I learned from that experience is that anyone weighing more than, say, 250, should get a bike with front forks not just for a more cushy ride but to protect the frame from impact stresses too.

I have a Specialized Sport Expedition that I converted to an ebike. At one point, before I lost weight, with me, battery, motor and cargo, all-up, it was about 380 lbs. I was constantly having to nurse the spokes on the rear wheel, but the rest of the bike handled it A-OK.

Nowadays, all-up, I'm about 100 lbs less than that, or 280 lbs. That's much easier on the spokes, but I'm still looking to lose 20 lbs or more to get me into more gross weight for a bicycle.

BlackIronStubble

  • 5 O'Clock Shadow
  • *
  • Posts: 41
  • Location: Mid-sized Southern City
Re: Should I stop loading up my aluminum frame bike?
« Reply #7 on: April 01, 2015, 10:02:19 AM »
Mefla, scary!  I've been riding this solid fork one since 2008, but weighed 190 until two years ago.  I'll definitely pay attention to any signs of stress.

Congrats on the weight loss!  If you keep having spoke issues, you might want to build a more badass rear wheel for your ride.  My other bike is a Yuba Mundo, which has a stated 440lb limit, which I've surpassed several times with no issues.  I run Schwalbe Big Apples, which have a 500lb each limit on a rear wheel with 48 spokes built around a 14 mm bmx hub.  Absolutely big boy bomb proof.   You wouldn't necessarily need something that extreme—they sell a standard 10 mm wheel for about $70—but I like the safety margin.

How do you like the ebike?


Sent from my iPhone using Tapatalk

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #8 on: April 01, 2015, 10:17:12 AM »
...
Congrats on the weight loss!  If you keep having spoke issues, you might want to build a more badass rear wheel for your ride.  My other bike is a Yuba Mundo, which has a stated 440lb limit, which I've surpassed several times with no issues.  I run Schwalbe Big Apples, which have a 500lb each limit on a rear wheel with 48 spokes built around a 14 mm bmx hub.  Absolutely big boy bomb proof.   You wouldn't necessarily need something that extreme—they sell a standard 10 mm wheel for about $70—but I like the safety margin.

Thanks for the good word, much appreciated. I believe you are right about building a more badass rear wheel. I've been pondering that and might take a stab at it this weekend. I have some used downhill rims that are simply way better than the stock rim I keep nursing.

SO...you have a Yuba Mundo! IMHO, the Cadillac of cargo bikes! A local REI had one of those that had been returned, took all my willpower to leave without buying it (I have 4 bikes already, so I gotta use what I have...no impulse buying for me...)

I run Schwalbe Marathons on my ebike and they "changed my life". Schwalbe makes amazing tires - worth every penny if you are riding hard, long distance, or every day.

Quote
How do you like the ebike?

The ebike has been KILLER! I have a fairly long commute - 32 miles each way. I'm aware of how bad that is from what I've learned about mustachianism, and I agree car commutes are crazy. Building and using the ebike changed all that, however. I'm very nearly being able to commute the distance using the ebike in the SAME TIME it takes to do it in the car, because traffic moves slow and I can pass everyone on the ebike.  Ebikes and ebike components aren't "cheap", but if you ride every day, you make that money back pretty quick.

Now, one important thing: I didn't build an ebike to get an electric scooter. Pedaling is important to me and if I didn't want to pedal, I'd just have converted a motorcycle. So I'm not telling you this because I've turned my back on bicycling - the battery and motor are only a range extender for what I already do with my other non-electric bikes.

Just to ruin your life, :-) here's the link to my "build thread":
http://endless-sphere.com/forums/viewtopic.php?f=6&t=45993
« Last Edit: April 01, 2015, 11:35:14 AM by mefla »

GreenPen

  • Stubble
  • **
  • Posts: 107
Re: Should I stop loading up my aluminum frame bike?
« Reply #9 on: April 01, 2015, 11:18:50 AM »
Just to ruin your life, :-) here's the link to my "build thread":
http://endless-sphere.com/forums/viewtopic.php?f=6&t=45993

Wow, so much on that thread... thanks for posting the link!

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #10 on: April 01, 2015, 11:47:20 AM »
Just to ruin your life, :-) here's the link to my "build thread":
http://endless-sphere.com/forums/viewtopic.php?f=6&t=45993

Wow, so much on that thread... thanks for posting the link!

Sho' nuff! And what I mean by "ruining your life" is that the sheer volume of information on that forum site (just like MMM forums) will keep you up till the wee hours and deprive you of sleep while you excitedly digest as much as you can!

Although I often ride for fitness, I've been mostly a transportation biker all my life. Sports cyclists will call electric drive "cheating", which is a bizarre thought to me. I'm not competing with anyone, I'm trying to get somewhere. The motor drive expands what I can do with the bicycle and makes it go a little faster. But if it's not charged up or I am riding for exercise, I'll take the non-electric bike. Sometimes simple and manual matters more than speed and distance.

Ebikes are more regulated in Europe than they are in the US, yet they have really caught on there. The Bosch mid-drive system is very popular despite being limited to only 250 watts. In Europe, Ebikes are considered a serious alternative to the auto.
« Last Edit: April 01, 2015, 11:54:04 AM by mefla »

BlackIronStubble

  • 5 O'Clock Shadow
  • *
  • Posts: 41
  • Location: Mid-sized Southern City
Re: Should I stop loading up my aluminum frame bike?
« Reply #11 on: April 01, 2015, 12:33:48 PM »
Wow!


Sent from my iPhone using Tapatalk

BlackIronStubble

  • 5 O'Clock Shadow
  • *
  • Posts: 41
  • Location: Mid-sized Southern City
Re: Should I stop loading up my aluminum frame bike?
« Reply #12 on: April 01, 2015, 12:59:21 PM »
And the Yuba is amazing. But also reasonable, as it allows me to bike with 100 lbs of kids or do date night with the wife without a car.  I've also used it to haul a couple of bushels of apples, plenty of groceries, and a Christmas tree.

I think I figured I needed around 3,000 miles to have it pay for itself in reduced car usage.  I may not be there now, but I will be by the time the youngest can keep up on her own bike.


Sent from my iPhone using Tapatalk

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #13 on: April 01, 2015, 01:34:01 PM »
And the Yuba is amazing. But also reasonable, as it allows me to bike with 100 lbs of kids or do date night with the wife without a car.  I've also used it to haul a couple of bushels of apples, plenty of groceries, and a Christmas tree.

I think I figured I needed around 3,000 miles to have it pay for itself in reduced car usage.  I may not be there now, but I will be by the time the youngest can keep up on her own bike.

I'll bet you the Yuba has paid for itself in less than 3000 miles. when I started the ebike, I only used gasoline to figure payback. Then I had a rash of car bills for my 2000 Honda Insight and realized gas wasn't even the half of it. I had to figure:

Gasoline
Maintenance (labor: I do as much as I can but some things I don't have tools for)
Maintenance parts (oil, filters, tires. Recently, catalytic converter = $1000)
Insurance
Taxes

Years when I have to put a new set of tires on my little car, that will push annual maintenance cost between $600-$800. If I'm lucky and get 2 years (miniumum) out of the catalytic converter I'm replacing, it will still have cost me $500/year.

I've considered converting a wrecked motorcycle to electric, so I'll have a low-cost electric vehicle. But I'm considering, instead, a cargo bike with electric drive.

BlackIronStubble

  • 5 O'Clock Shadow
  • *
  • Posts: 41
  • Location: Mid-sized Southern City
Re: Should I stop loading up my aluminum frame bike?
« Reply #14 on: April 01, 2015, 03:30:56 PM »
Quote
I've considered converting a wrecked motorcycle to electric, so I'll have a low-cost electric vehicle. But I'm considering, instead, a cargo bike with electric drive.

So, I had a chance to ride an ElMundo with the BionX kit.  It. Was. Sweet.  You tell it how much help you want, and it gives you a boost with your pedal strokes.  There's still a normal throttle if you need it, but mostly it just makes you feel like the incredible hulk. 

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #15 on: April 01, 2015, 04:16:28 PM »
Quote
I've considered converting a wrecked motorcycle to electric, so I'll have a low-cost electric vehicle. But I'm considering, instead, a cargo bike with electric drive.

So, I had a chance to ride an ElMundo with the BionX kit.  It. Was. Sweet.  You tell it how much help you want, and it gives you a boost with your pedal strokes.  There's still a normal throttle if you need it, but mostly it just makes you feel like the incredible hulk.

That's "PAS", or Pedal Assist System. Europe calls it "Pedelec", and it's the only way they are allowed to have it (no throttle allowed). I guess the euro governments want to make sure their bicycle riders don't get fat like Americans? :-)

Joking aside, people who ride with PAS eventually prefer it over a throttle, because you actually have to THINK about a throttle in addition to pedaling, where PAS requires less thought. I know on long trips, my thumb throttle causes my hand to go numb so it's definitely got that disadvantage.

I'm about to convert another ebike using a different motor drive that has a PAS system built in. I've ridden that system before and it's kinda nice - not as fancy and smooth as the Bosch systems, but still not bad.

kpd905

  • Handlebar Stache
  • *****
  • Posts: 1734
Re: Should I stop loading up my aluminum frame bike?
« Reply #16 on: April 01, 2015, 06:34:11 PM »

Gasoline
Maintenance (labor: I do as much as I can but some things I don't have tools for)
Maintenance parts (oil, filters, tires. Recently, catalytic converter = $1000)
Insurance
Taxes


Aren't you still paying insurance and taxes even while using the e-bike?

Faraday

  • Handlebar Stache
  • *****
  • Posts: 1192
  • Age: 57
  • Location: NC
  • Solar Powered Slice
Re: Should I stop loading up my aluminum frame bike?
« Reply #17 on: April 02, 2015, 08:10:02 AM »
Gasoline
Maintenance (labor: I do as much as I can but some things I don't have tools for)
Maintenance parts (oil, filters, tires. Recently, catalytic converter = $1000)
Insurance
Taxes
Aren't you still paying insurance and taxes even while using the e-bike?
That is an excellent question and deserves an answer. But the answer is embarrassing. I'll keep it short, I don't want to hijack the thread:

Before the ebike I was paying insurance and taxes on four old vehicles.  I've been getting rid the vehicles as I use the ebike more and more. It's a long story. Please just know, I didn't TRY to have four vehicles. I had to learn....just because someone gives you an old vehicle doesn't mean it's FREE.

I realized I'd rather use a $1000-$1500 ebike to get to work instead of a free car. No gas, no taxes, no insurance, easy to fix and cheap to maintain. It's the most awesome thing to bike 32 miles to work for almost the same time as a car, costing maybe 8 cents worth electricity. (My battery has less than 1kwh of capacity.)

Oh, and I left out tolls. I can avoid tolls with the ebike also.