# Maximum Weight on a Tourer



## HormyAJP (13 Jul 2009)

Hi all,

I have a Ridgeback Horizon (tourer) with rear panniers and tyres that can run up to 110psi. I did a weeks cycling last year with two full panniers and a ruck sack but never actually thought about the max weight the bike can take (both the tyres and the rear of the frame). 

I'm due to go away again soon for 4 weeks and was planning to take roughly the same amount of stuff. It had never really occured to me to check that I wasn't over loading (mainly because I thought there would be no harm in filling a pannier bag up full else they wouldn't design them that size).

Anyone any idea of what sort of upper weight limit is sensible for this sort of bike?

Thanks,
Andy


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## Bigtwin (13 Jul 2009)

Likely that the wheel will give out before the frame by a way. Or more likely still, if they are decent, that you will be done trying to get it up anything of a hill.

That said of course, the more weight, the more hitting a pot hole etc is likely to do damage. That's the usual cause of problems, not the thing just folding under the sheer weight of luggage, so it's rather hard to say.


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## Brains (14 Jul 2009)

The maximum weight is what you can lift up a flight of stairs.

Some years ago 6 of us were doing a fully loaded tour of southern France, so had 3 tents, 3 stoves, sleeping bags, food, water etc. 

We then bought 4 cases of wine (48 bottles) we were then forced to drink a bottle each as there was simply nowhere to put them all, the maximum capacity of a fully loaded touring bike being 7 bottles of wine each.

This was fine until we got to the station to go home. We found we simply could not lift the bikes, the extra 8KG of wine and glass per bike made them impossible to lift up and down the stairs between the platforms (OK so the bottle of wine being shipped internally may have had someting to do with it) but you get the idea.


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## Ben M (14 Jul 2009)

Brains said:


> we were then forced to drink a bottle each as there was simply nowhere to put them all



The terrible hardships that we face!


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## pinkkaz (14 Jul 2009)

Brains said:


> the maximum capacity of a fully loaded touring bike being 7 bottles of wine each.



LOL!

Is this an official statistic?



Brains said:


> This was fine until we got to the station to go home. We found we simply could not lift the bikes, the extra 8KG of wine and glass per bike made them impossible to lift up and down the stairs between the platforms (OK so the bottle of wine being shipped internally may have had someting to do with it) but you get the idea.



Next time make sure you choose stations with lifts.


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## Bigtwin (14 Jul 2009)

Poor planning.

Any decent rack will take 3 wine boxes each side, and you can substitute the inner of one for your Camelbak bladder.


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## srw (14 Jul 2009)

HormyAJP said:


> Anyone any idea of what sort of upper weight limit is sensible for this sort of bike?



How much do you weigh yourself? If this isn't the sort of thing you've considered before, the chances are good that you yourself are considerably lighter than some touring bike riders, and that whatever you can stuff in your paniers won't come close to making up the difference.


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## Chonker (14 Jul 2009)

Don't forget the inner tubes, if they're air tight they should be able to hold other fluids too


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## Bigtwin (14 Jul 2009)

Chonker said:


> Don't forget the inner tubes, if they're air tight they should be able to hold other fluids too



What - as well as the frame? You're hardcore there!


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## HormyAJP (15 Jul 2009)

Haha, so basically as long as I take bucket loads of wine I'll be fine!

Anyway, after much research I've realised that given I'm 80kg and my total pack weighs less than 20kg I think I'll be fine. 

That said, I spent a long time the other night trying to find out any details on how much weight a bike, frame, tyre, wheel can take and got almost nowhere. It's amazing, you'd have thought this would be a fairly key stat if you're selling bikes, and equip, for touring. Oh well!


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## srw (15 Jul 2009)

HormyAJP said:


> Anyway, after much research I've realised that given I'm 80kg and my total pack weighs less than 20kg I think I'll be fine.



Lightweight!


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## JackE (15 Jul 2009)

I'm fairly sure that the Horizon was advertised as an Audax/light tourer. I remember reading (on the CTC forum) that the maximum weight advisable on an Audax bike was around 10kg. I used to have a Dawes Audax and even with 700x28 Marathons, I wouldn't have wanted to go above this weight. The Panorama is the Ridgeback "weight carrier".


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## Brains (15 Jul 2009)

10KG !! - What sort of as tourer is that ?

A full case of wine comes weighs in at over 10KG, that is before the less critical items such as sleeping bag, stove and tent, sandles, beard trimmer, pipe, tankard and the CAMRA guide. 

You need a proper tourer


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## andrew_s (16 Jul 2009)

Many racks have a published weight limit, generally in the 20-30kg range for a rear.

The bike frame should stand up to lots, if you look at some of the very large people who ride.For weight as luggage, the practical limit is probably the point at which frame flex makes the handling go squiffy, though you can get used to a fair bit.

Tyres will need to be pumped harder. This is probably best judged by inflating so that the width of the weighted section at the bottom of the tyre remains similar when you compare you with you + luggage. A measuring assistant would be required.

Wheels will depend on the build. The weight on a wheel should be less than the spoke tension. You can go over, but it's asking for fatigue and spoke failure if you carry too much too long. Allocate your weight 1/3 front, 2/3 rear, then add the luggage. Spoke tension should be somewhere in the 70-120kgf range. You really need access to a tensiometer to find out.


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## snorri (16 Jul 2009)

I've just come home from a tour and have been doing some weighing on the bathroom scales. 
My weight 79kg.
Bike weight (Dawes Galaxy) 16Kg.
Luggage weight, including water 26kg.


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## Bigtwin (16 Jul 2009)

JackE said:


> that the maximum weight advisable on an Audax bike was around 10kg. I used to have a Dawes Audax and even with 700x28 Marathons, I wouldn't have wanted to go above this weight.



My clip-on seat post rack is rated at 8Kg!


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## ch3 (20 Jul 2009)

On a similar topic, is there any chance at all that a carbon fork may fail because of heavy load, let's say while going downhill and hitting a hole or something? Anyone had a bad experience with carbon parts breaking?

I notice there was a warning on the inside of my fork saying not designed for off road use. I am not planning to ride it off road, but I am planning to go touring with loads of stuff on it and I can't help my self thinking about this video every time I hit a bump going downhill.


View: http://www.youtube.com/watch?v=JLRDRzMWIsg

I know he was pushing the limits, but I bet this bike was probable 10 times more expensive than mine, plus I doubt it had a carbon fork.


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## chris667 (20 Jul 2009)

I'm 115kg, and my Dawes Galaxy carried all sorts of inadvisable loads, sometimes off road.
I once rode from Reading Farmer's market to my boat with a 50kg sack of potatoes on the rack. Half of which is offroad.


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## TheDoctor (20 Jul 2009)

I can vouch that a mountain bike will take 6 cases of French lager, and 6 bottles of cotes du rhone.
It makes the cornering very strange though...


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## byegad (22 Jul 2009)

Given I'm 95kg and routinely carry 10kg of stuff you have nothing to worry about except generating the power to climb hills.


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## dellzeqq (23 Jul 2009)

A Brompton will carry 50 cans of beer on the back rack. And teenagers will consume said cans in three hours.

In all seriousness I'd ask Madison. Frames do fail, although they are more likely to fail as a result of leaving too little seat post in the frame, splitting the seat tube.


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## bike_the_planet (27 Jul 2009)

ch3 said:


> On a similar topic, is there any chance at all that a carbon fork may fail because of heavy load, let's say while going downhill and hitting a hole or something?



Yes.

Carbon has a very high UTS (Ultimate Tensile Strength). But that's measured in tension (ie pulling).

However, unlike steel or aluminium, carbon's strength is not isotropic (ie the same in all directions).

In compression, carbon is pretty weak. Essentially, it is the epoxy that takes most of the compression force.

If you hit a bump at excessive speed then the rear face of the fork blades get heavily compressed and this is the common point of failure. Personally, I've never understood why manufacturers don't really beef up the blades at this point.

In addition, carbon's failure mode is essentially catastrophic. Simply meaning that its yield point (point at which it deforms) is similar to its failure point (point at which it snaps). Steel, for example, will bend well before it snaps.

Carbon forks work great on a lightweight road bike and a smooth road. But I would avoid putting them on a loaded tourer, and then riding through bumps and potholes if I were you.

Cheers,


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## asterix (27 Jul 2009)

This is a proper 531 steel tourer with about 23kg of load including tent but not counting food and fluids. The bike weighs c.12.5kg.




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It's ten years old and has had several modifications and a new top-tube after I foolishly dropped it against a sheffield stand and dented it. Unfortunately the damage was just before a 2 week tour and I didn't have time to get it fixed, but it was fine. The tyres are 26x1.75 slicks and carry such loads admirably; the descent down the west side of the col was one of the best I have had on any bike. (It rides best with all the stuff on the back although I do have front panniers)


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## Tim Bennet. (27 Jul 2009)

> In compression, carbon is pretty weak. Essentially, it is the epoxy that takes most of the compression force.


I think you're getting it confused with kevlar, (see table below).



> Essentially, it is the epoxy that takes most of the compression force.


Simply not true.



> If you hit a bump at excessive speed then the rear face of the fork blades get heavily compressed and this is *the common point* of failure.


There is no common point of failure. Carbon fibre forks are extremely reliable. So much so that they are commonly used on bikes! If manufacturers had any worries about their reliability they would not choose to use carbon fibre for this, the most highly loaded part of a bike. All forks of any material can and do fail. Where is the evidence that carbon forks are less reliable or suffer 'common failures' ?

Carbon fibre forks are not used for touring bikes because the weight saving is not an issue on a loaded touring bike and the inherent conservatism of touring cyclists. But if there was a demand, engineering a touring fork in carbon would be no problem.


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## Bigtwin (27 Jul 2009)

Tim Bennet. said:


> There is no common point of failure. Carbon fibre forks are extremely reliable.



Two different things. Carbon forks don't fail all that often if used and maintained correctly (which they often aren't). But by far the most common point of failure is the blade/steerer interface area.


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## Tim Bennet. (27 Jul 2009)

> But by far the most common point of failure is the blade/steerer interface area.


How common? Do you have a percentage figure of all carbon forks made? How does this compare to steel fork failures?


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## andym (27 Jul 2009)

I'm not sure about the 'how much you can carry up stairs' rule as you can always take the panniers off and do the lift in two stages (or alternatively, et/drink the contents of the panniers). But 'how much you can drag up hill' would be a good rule of thumb. Unless you are really really heavy or your bike is really really weedy (OK hands up who isn't an engineer) then you're it's much more likely that you'll give in long before your frame does.


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## Bigtwin (27 Jul 2009)

Tim Bennet. said:


> How common? Do you have a percentage figure of all carbon forks made? How does this compare to steel fork failures?



This is concentrated stress area, and for Al steerer forks, the point of joint stress too. For full carbons, there are failures at the top of the tube, generally due to excessive stack height/poor clamp adjustment/poor internal shimming/parts (wrong nut) etc.

Can't imagine how anyone could collect figures for all carbon forks ever made.

Don't know anything about steel fork failure. Personally, I've never seen one fail.


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## bike_the_planet (29 Jul 2009)

Tim Bennet. said:


> I think you're getting it confused with kevlar, (see table below).
> 
> 
> Simply not true.



Carbon fibre is based on a weave of carbon filament threads of around 0.5 microns in diameter. Tensile strengths are up around 5GPa _in the axis of the thread._ However, they are relatively soft and brittle.

The figures you have given are for the fabric weave itself, not the composite carbon structure.

Ever seen it? My local frame repairer has a reel of the stuff. In tension it is incredibly strong. But you can but a piece between two fingernails and squash it. How can a weave based on string fibres be strong in compression? It's the resin body that gives the tube structure its strength

What gives the material tensile strength in particular directions is the weave orientation. That's why the material is non-isotropic in strength. And that's what makes it so useful in structures in industries such as aerospace. You can engineer the strength in whatever direction you want. In impact compression, it is not particularly strong and it's simply not used in that way.

Why are so many carbon parts labelled with maximum torque settings???



Tim Bennet. said:


> There is no common point of failure. Carbon fibre forks are extremely reliable. So much so that they are commonly used on bikes! If manufacturers had any worries about their reliability they would not choose to use carbon fibre for this, the most highly loaded part of a bike. All forks of any material can and do fail. Where is the evidence that carbon forks are less reliable or suffer 'common failures' ?



I don't believe I said that they were less reliable, did I??? What I did say was that they don't bend when they are overloaded. They snap. Steel and aluminium are very forgiving in that their yield point is well below their failure point. You get warning.

My local frame repairer has written several reports and submitted them to manufacturers with regard to carbon forks damaged in impacts with road debris/potholes. In every one, they snapped at the back of the fork where there was the greatest compression. This is an area where manufacturers could improve. Instead of making the fork blades of uniform thickness, they could be beefed up at the back. This might cause the fork to fold rather than snap, a bit more like steel or aluminium.



Tim Bennet. said:


> ICarbon fibre forks are not used for touring bikes because the weight saving is not an issue on a loaded touring bike and the inherent conservatism of touring cyclists. But if there was a demand, engineering a touring fork in carbon would be no problem.



For someone who wants the lightest bike, and is willing to look after it and regularly visually inspect it, carbon fibre is the best choice.

But the average tourist doesn't want to do that. They want a bike they can load up. That might get knocked, bashed, chipped, abused by baggage handlers etc etc. Carbon is not a resilient material when it comes to impact strength.

My local frame builder has given up building frames - instead he makes a handsome living repairing carbon fibre bikes damaged due to either a) accidents or  compression failures where over-zealous mechanics have over tightened seat clamps, headsets etc etc.


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## Tim Bennet. (29 Jul 2009)

> How can a weave based on string fibres be strong in compression?


Chapter 1 in any Composites handbook will tell you all you need to know.


> Carbon is not a resilient material when it comes to impact strength.


Really? So the crash cell in a Formula One car isn't made of carbon fibre because it can stand the repeated impacts of flying through the air and tumbling along the track into the armco barrier at nearly 200mph. 

Or look at this Youtube clip. 
View: http://www.youtube.com/watch?v=__PBiSqFBVY

Seems the carbonfibre passenger cell was pretty resilient to impact damage. The driver walked away.

Repeating popular misconceptions about carbonfibre will never make them fact. Carbonfibre components may fail and their mechanism of failure may not appeal to everyone, but please apportion blame where blame lays. The design, manufacture, installation and maintenance of bike components have at times, all been found wanting, but carbon fibre is just the material. And it's a fantastic material with properties that make it superior to everything else. When we've had as much experience of using and developing CF as we have with steel bike tubing (100 years plus), I'm sure its implementation will be as reliable.


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## bike_the_planet (29 Jul 2009)

Tim Bennet. said:


> Repeating popular misconceptions about carbonfibre will never make them fact. Carbonfibre components may fail and their mechanism of failure may not appeal to everyone, but please apportion blame where blame lays.



Please explain exactly what misconceptions I have propagated.

One again, my local framebuilder is currently inundated with carbon fibre composite bikes awaiting repair. None of the cases involve spontaneous failure. They are damaged cycles, mostly through accident/collision. Several of the cases are due to overtightening of components reulting in cracks in the composite resin.

Please state clearly if you are accusing me of lying.

Please also explain where I have apportioned blame on either the material or the manufacturer, I don't remember doing so.



Tim Bennet. said:


> The design, manufacture, installation and maintenance of bike components have at times, all been found wanting, but carbon fibre is just the material. And it's a fantastic material with properties that make it superior to everything else. When we've had as much experience of using and developing CF as we have with steel bike tubing (100 years plus), I'm sure its implementation will be as reliable.



I too think it's a material with a big future. I don't think that I have said anywhere that it isn't. Please explain where I have siad this.

And you keep inferring that I have implied that the material isn't reliable. Once again, please explain where I have questioned its reliability.

Seems that you have alot of exlaining to do, huh?


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## willem (29 Jul 2009)

To return to the original question: this bike is an audax style bike and 20 kg really is rather a lot for that kind of bike. It gets marginally easier with the widest possible tyres. but that is about it. The best you can do is reduce the load. Take some inspriration from the ultralight hikers: they go well below 10 kilo´s. Realistically, you can go down to 15 kilo without investing in fancy gear. With luck, this will allow you to leave that horrible rucksack at home.
Willem


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## ch3 (29 Jul 2009)

hmmm mixed opinions about the carbon fiber fork. Apart from the scientific side of things, has anybody heard/seen a fork snapping while touring or during everyday cycling?
I am sure it will be fine if I look after it. I just need to be prepared for a mega faceplant if that does happen!
=
By the way, what is the fork blade? Is it when the wheel attaches with the fork?


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## Bigtwin (30 Jul 2009)

ch3 said:


> hmmm mixed opinions about the carbon fiber fork. Apart from the scientific side of things, has anybody heard/seen a fork snapping while touring or during everyday cycling?
> I am sure it will be fine if I look after it. I just need to be prepared for a mega faceplant if that does happen!
> =
> By the way, what is the fork blade? Is it when the wheel attaches with the fork?



The blades are the actual forks below the headset. The steerer is the bit inside and poking out the top of the headset.

Info here: http://www.bikeradar.com/gear/article/buyers-guide-to-carbon-forks-11419

A few seconds on google will give you hours of photies and stuff about carbon fork failure.

Starter for 10: http://cozybeehive.blogspot.com/2008/12/bontrager-carbon-fiber-fork-failure.html

http://www.articlesbase.com/law-articles/safety-concerns-over-carbon-forks-on-bicycles-1042147.html

http://forums.roadbikereview.com/showthread.php?t=16546

*Fork Failure*
With carbon fiber, failures can be even more insidious. I have handled several cases involving fork failures, which can be deadly. In one case the forks on a high-priced carbon fiber frame broke when the rider was doing nothing more than leaving his driveway at a very slow speed. He was thrown to the ground and hit his head. At the time he thought he suffered no more than a headache but 3 days later, he went into a seizure due to a subdural hematoma. After several months in hospital he was released and attempted to lead a normal life but shortly after his case settled, he suffered another seizure, hit his head and died. He was wearing a helmet when he fell but even at low speed impacts, helmet manufacturers warn that a helmet cannot prevent serious injuries.

Since that case I have had several other fork failure cases, from broken necks to minor scrapes and bruises. 

The problem with the fork failures is that there is no way to detect them before they occur. The failure generally stems from inadequate construction techniques which will lead to micro-cracking. These types of cracks expand during the life of the bicycle use until it ultimately fails. They can occur at any speed and over any type of surface.


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## adrianlondon (30 Jul 2009)

How about if most of the bike is made of carbon? Maybe some safer part will break before the fork does and throws me head first into the ground. Luckily, as I don't wear a helmet, I'll probably survive 

http://www.focus-bikes.com/bike_detail.asp?active=1&lang=english&rub=fit&pr=90000189&do=det


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## asterix (31 Jul 2009)

What exactly is the point of using CF forks for a tourer?


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## ch3 (31 Jul 2009)

Well in my case, I bought the bike before I even thought about touring. Now I've already spend a few hundreds pounds for gear and stuff and ideally I'd like to avoid buying a completely new bike or even changing the current fork.


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