Maximum weight

[MrNice]

What is the tsw of a sam2 6.9 290 XL ?

I can't find any info on their website and have no idea if I'm too heavy at 100kg.

I don't even fully understand what it is lol but read something somewhere and now looking into it but can't find the maximum weight for these bikes

 

[Zimmerframe]

I think the limit is 120kg for rider and bike. I seem to remember reading that was just based on it conforming to a particular standard though.

Just found this one :

First ride review: 2021 FOCUS SAM² 6.9 – An eMTB bike for one purpose: riding downhill!

The 2021 FOCUS SAM² 6.9 comes with a Bosch motor and lots of travel. Read our first ride review to find out how the bike performed both on challenging DH tracks and flowy trails.

ebike-mtb.com

Recently purchased a Jam2 6.9 and have to say I'm really pleased with it. Makes my Kenevo feel like a pile of junk.

 

[MrNice]

Thanks. I did read that somewhere myself aswell. But how reliable is that source is the question.
I mean, its a big burly bike in an XL that would only really suit the larger guys. So it would be a bit weak to only allow someone who's roughly 85-90kg . I cant seem to find a reliable source that provides the info

 

[Zimmerframe]

The frame is pretty stoutly built. The headstock is 50% larger than the Kenevo for instance.

For the sake of 5kg's, personally I wouldn't worry about it if it's the bike you want.

 

[steve_sordy]

This has been discussed on here before.

Good afternoon, anyone know the maximum rider weight for a Focus E-mtb

good afternoon a short question, what is the maximum allowed weight for a Focus Ebike? My weight is 98 kg ex backpack is total 105 can I choose for a Focus? do not know for sure but according to me 120 kg is the max?

www.emtbforums.com

 

[MrNice]

This has been discussed on here before.

Good afternoon, anyone know the maximum rider weight for a Focus E-mtb

good afternoon a short question, what is the maximum allowed weight for a Focus Ebike? My weight is 98 kg ex backpack is total 105 can I choose for a Focus? do not know for sure but according to me 120 kg is the max?

www.emtbforums.com

And the answer wasn't made clear then either. There's contradicting advice given and nothing is clear, even the labelling on the bike from the CE sticker.
The website says bike and rider plus gear and all the sticker on the frame actually says is " max permissible weight ".

So which one is right ? The website or the actual warnings given on their bikes ?

 

[steve_sordy]

And the answer wasn't made clear then either. There's contradicting advice given and nothing is clear, even the labelling on the bike from the CE sticker.
The website says bike and rider plus gear and all the sticker on the frame actually says is " max permissible weight ".

So which one is right ? The website or the actual warnings given on their bikes ?

View attachment 65479

I must be missing something. What is the difference between "max permissible total weight" (off the pic above) and "bike and rider plus gear" (Focus website)?
What would be useful would be an actual figure stuck on the frame.

 

[MrNice]

I must be missing something. What is the difference between "max permissible total weight" (off the pic above) and "bike and rider plus gear" (Focus website)?
What would be useful would be an actual figure stuck on the frame.

In hindsight, anybody who doesn't know anything about mtb would look at that sticker and think that they can't be over 120kg in weight. Otherwise its a bit like saying your car can only carry 100kg of luggage because you have to take into account the weight of the car. It makes no sense

 

[Zimmerframe]

 

[Zimmerframe]

The thing is built like a tank. I wouldn't worry about a cow riding it.

 

[steve_sordy]

In hindsight, anybody who doesn't know anything about mtb would look at that sticker and think that they can't be over 120kg in weight. Otherwise its a bit like saying your car can only carry 100kg of luggage because you have to take into account the weight of the car. It makes no sense

I still don't understand the point you are trying to make. What else can "max permissible total weight" mean? The bike makers have to use total weight (bike, rider, kit), due to the massive range of rider weights. Especially when even the lightest rider is likely to be at least twice as heavy as the bike alone. In my riding kit, I'm 4.5 times heavier than my bike. So rider weight (inc kit) is a key design criterion to the bike designer.
But my car is quite happy with just me in it OR me plus 4 passengers, a boot full of luggage and a tow bar rack with two bikes. My weight is a triviality to the car designer.

 

[steve_sordy]

View attachment 65481

That's more like it! I don't remember seeing that on my bike!

I'm not saying it wasn't there, just that I don't remember!

 

[MrNice]

If you asked Joe bloggs off the streetvto read the label and then answer the question of... what is the maximum weight for the bike they will tell you 120kg.
They would even think about adding the weight of the bike into the mix so why are people saying you have to take this into account when the labelling doesn't state this

 

[Zimmerframe]

Focus stopped selling bikes in America just because no one was under 120kg's ... (not really) .. I guess it was too expensive/complicated logistically.

 

[Billybopsbasher]

Ignore the weight limits... 170kg here on a 2019 jam2 and no issues. Just don't expect amazing battery life unless you spin the gears and use low tread tyres

 

[St4nley]

Not a Jam owner but I would say that the 120kg limit mentioned is probably more about the carrying weight of the Wheels as these are normally built to max Kg carrying weights and do not include there own weight in this total as it’s nominal . As already mentioned the “Frame” alone will probably carry a Cow, but as also mentioned if you are a total 170kgs then your wheels probably won’t last as long as someone who’s a total 120kgs

 

[Billybopsbasher]

Not a Jam owner but I would say that the 120kg limit mentioned is probably more about the carrying weight of the Wheels as these are normally built to max Kg carrying weights and do not include there own weight in this total as it’s nominal . As already mentioned the “Frame” alone will probably carry a Cow, but as also mentioned if you are a total 170kgs then your wheels probably won’t last as long as someone who’s a total 120kgs

Disagree... You will outdo the limits of the rear shock waaay before you reach the limits of the wheels. Obviously is frame (and leverage ratio) dependant though.
Correctly built wheels can take a hell of a lot of weight (providing you don't ride like a ham-fisted rhino)

 

[St4nley]

Disagree... You will outdo the limits of the rear shock waaay before you reach the limits of the wheels. Obviously is frame (and leverage ratio) dependant though.
Correctly built wheels can take a hell of a lot of weight (providing you don't ride like a ham-fisted rhino)

Do rear air shocks come with a maximum weight limit?? I don't know.

DT Swiss and other wheel manufacturers clearly state maximum limits thats why they build different types of wheelsets, range from 120 kg to 150kg for Hybrids & Ebikes.

 

[steve_sordy]

Do rear air shocks come with a maximum weight limit?? I don't know.
.......

No, but they do specify a max pressure to inflate to.
They will of course have allowed for the pressure increase as a consequence of compression.

 

[Jimbo Vills]

No, but they do specify a max pressure to inflate to.
They will of course have allowed for the pressure increase as a consequence of compression.

But on the rockshox that max pressure if based on a weight - As there's a chart showing weight and pressures. So if the max pressure is recommended for the max weight on that chart its a fair assumption that the shock isn't going to be rated for someone heavier...

 

[Coolcmsc]

But on the rockshox that max pressure if based on a weight - As there's a chart showing weight and pressures. So if the max pressure is recommended for the max weight on that chart its a fair assumption that the shock isn't going to be rated for someone heavier...

That’s exactly what I thought @steve_sordy was saying — sorry Steve if I’m butting in ?

 

[Billybopsbasher]

It's based on the leverage ratio of the bike really.
Broadly speaking, there is a certain average ratio of about 2:6-1 whereby at max pressure on a rockshox (350psi) I cannot sit on a bike without it blowing through 50-60% of its travel... Therefore rendering that bike unuseable for me.
Now, if I sat on a bike that had a low lev ratio ie 2:2-1 or so I can actually not just sit on the bike and be fine.. I can actually ride it hard with no shock pressure issues.
I could use the same wheels on both bikes and they wouldn't be a problem.
I've used dt swiss wheels in the past with no issues... Killing wheels comes down to technique more than weight... It just happens to be that most heavier people also tend to be a bit less refined ?

 

[MrNice]

I find it strange that an average sized person like myself (6'2" and 100kg) is apparently not suitable for a bike that weighs 26kg and built like a brick sh** house lol.
I know I'm a few lb's overweight but not exactly huge. I understand that they have to cover their backs with warranties but at the end of the day they could be losing out on future potential sales by having such low maximum weights.
Anybody can break any bike if the crash is serious enough and with enough speed and force.
So unless your very slim and tall then riding an XL bike would be a bit silly. I mean, even muscle weighs more than fat lol.
Anyway, yes the components can fail if they exceed the recommended weight but again... so can anything.
With all my riding gear and water etc it would come to around 130-135kg and they recommend a max of 120kg.
I'm also wondering if I'd be better off sticking with the 35mm diameter raceface bars or would I be OK going with 31.8mm renthal fat bars.
I mean, how often do people look at specifications when changing bars, stems, pedals, cranks etc etc

 

[St4nley]

So what is the defining component that dictates the maximum weight limit of an Ebike ?

 

[steve_sordy]

But on the rockshox that max pressure if based on a weight - As there's a chart showing weight and pressures. So if the max pressure is recommended for the max weight on that chart its a fair assumption that the shock isn't going to be rated for someone heavier...

I agree with that statement.
My answer was based upon a question about rear shocks not front forks. I have never seen a fork with a max pressure on the side. I'm not saying there aren't any, just that I have never seen one. However, I have seen several shocks with a max pressure listed. But I fail to see why only shocks should have such a limitation, unless it is because the pressures are higher for shocks than forks. Whatever the reason, both fork and shock will have a maximum pressure that they can withstand and that will have nothing to do with the weight of the rider. However, a heavier rider will exert more pressure on the suspension than a lighter one will at full compression simply because the starting point (the sag point) requires a higher pressure. A heavier rider will take then shock pressure closer and maybe above the design limit for shocks. It could be that the design limit for forks is not directed by a max pressure, but more one of stiffness. It may be that the max pressure the fork can withstand that results is many times beyond what the heaviest rider could exert and that's why they don't indicate a max pressure, just a max weight.

The weight/pressure chart is the advisory for a recommended sag.

 

[steve_sordy]

I find it strange that an average sized person like myself (6'2" and 100kg) is apparently not suitable for a bike that weighs 26kg and built like a brick sh** house lol.
I know I'm a few lb's overweight but not exactly huge. I understand that they have to cover their backs with warranties but at the end of the day they could be losing out on future potential sales by having such low maximum weights.
Anybody can break any bike if the crash is serious enough and with enough speed and force.
So unless your very slim and tall then riding an XL bike would be a bit silly. I mean, even muscle weighs more than fat lol.
Anyway, yes the components can fail if they exceed the recommended weight but again... so can anything.
With all my riding gear and water etc it would come to around 130-135kg and they recommend a max of 120kg.
I'm also wondering if I'd be better off sticking with the 35mm diameter raceface bars or would I be OK going with 31.8mm renthal fat bars.
I mean, how often do people look at specifications when changing bars, stems, pedals, cranks etc etc

I would expect that even a really heavy rider would be safe on a 120kg rated bike, as long as they are not doing big jumps! A suddenly applied load causes twice as much stress on the components as a steadily applied load (laws of physics). The designers have a tough job to do. The bike has to be cheap, light and strong. Those three are impossible to achieve. Generally you can only manage two of them. Designers have to compromise. What sort of rider, how heavy is the rider, what sort of trail, what price bike?

If I was a heavy rider and or an aggressive rider, I would not be chasing lightness by swapping out components for lighter ones unless I was certain that they were at least as strong. Most people do not have to look at strength and stiffness specs because they are well inside the "normal" range for weight and riding behaviour.

By the way 6'2" and 100kg (15st 10lbs) is not average.
According to Google:
The average adult male (over 20 yrs) in England is 5'9" 13st 2lbs
The average adult male in USA (over 20 yrs) is 5'9" and 14st 2lbs

 

[MrNice]

I would expect that even a really heavy rider would be safe on a 120kg rated bike, as long as they are not doing big jumps! A suddenly applied load causes twice as much stress on the components as a steadily applied load (laws of physics). The designers have a tough job to do. The bike has to be cheap, light and strong. Those three are impossible to achieve. Generally you can only manage two of them. Designers have to compromise. What sort of rider, how heavy is the rider, what sort of trail, what price bike?

If I was a heavy rider and or an aggressive rider, I would not be chasing lightness by swapping out components for lighter ones unless I was certain that they were at least as strong. Most people do not have to look at strength and stiffness specs because they are well inside the "normal" range for weight and riding behaviour.

By the way 6'2" and 100kg (15st 10lbs) is not average.
According to Google:
The average adult male (over 20 yrs) in England is 5'9" 13st 2lbs
The average adult male in USA (over 20 yrs) is 5'9" and 14st 2lbs

Thanks for the input on this. When I was referring to an average sized weight rider I was referring to an average weight for my height. Google probably says a different weight for my height but they must be keeping these people in a dark small room somewhere lol.

 

[Coolcmsc]

It may be that the max pressure the fork can withstand that results is many times beyond what the heaviest rider could exert and that's why they don't indicate a max pressure, just a max weight.
The weight/pressure chart is the advisory for a recommended sag.

Not that I have any idea what the actual answers are here, but there is something not mentioned yet that‘s relevant and differentiates forks from shocks.

So far, the discussion has been about forces directed into the fork/shock directly in line with the axis of the piston(s) — through the long axis of the pistons. This is by far the most important factor concerning the forces exerted on a shock, although that is a little dependent on how the same shock articulates slightly differently in its bearings in different frames

But forks are subject to other forces as well. The first tends to bend forks lengthways into a curved shape (?) and there are two others as well. Here are the three additional forces and all are obviously affected by total weight and speed.

For the first force, have a good look — and a laugh — at this hilarious PinkBike ‘huck-to-flat’ test of cheap bikes. The emphasis is on the shocks and frames, but the best bits are at the front watching what happens to the forks
Also, but to a lesser extent, forks tend to twist around their long axis in fast turns, especially with a weighted front for traction — Fox’s new axle fixing system is in part designed to address this. Then there’s the unilateral load imparted through the calliper mount by the power of the brake/disc-size combination which tends to twist the left leg backwards at the bottom by tying to rip the bottom mount off.

When building a fork, the design will consider all these loads. When considering what’s a safe working envelope, published or not, all these factors apply to a fork.

And really only one of them applies to a shock:— the long axis compression through the piston.

So peak pressure is important for shocks and forks. And there are are several further factors that are important for forks alone.

Combined total weight and speed (momentum) will affect all of them, sometimes when dropping off onto things and sometimes riding forwards into things and most importantly when both happen essentially at the same time.

 

[steve_sordy]

Not that I have any idea what the actual answers are here, but there is something not mentioned yet that‘s relevant and differentiates forks from shocks.

So far, the discussion has been about forces directed into the fork/shock directly in line with the axis of the piston(s) — through the long axis of the pistons. This is by far the most important factor concerning the forces exerted on a shock, although that is a little dependent on how the same shock articulates slightly differently in its bearings in different frames

But forks are subject to other forces as well that potently tend to bend them lengthways into a curved shape (?).

Have a good look — and a laugh — at this hilarious PinkBike ‘huck-to-flat’ test of cheap bikes. The emphasis is on the shocks and frames, but the best bits are at the front watching what happens to the forks
Also, but to a lesser extent, they tend to twist around their long axis in fast turns, especially with a weighted front for traction. Then there’s the unilateral load imparted through the calliper mount by the power of the brake/disc-size combination which tends to twist the left leg backwards at the bottom by tying to rip the mount off.

When building a fork, the design will consider all these loads. When considering what’s a safe working envelope, published or not, all these factors apply to a fork.

And really only one of them applies to a shock the long axis compression through the piston.

So peak pressure is important for shocks and forks. And there are are several further factors that are important for forks alone.

Combined total weight and speed (momentum) will affect all of them.

I agree with your post. Which is why in a the previous (No #25) I said " It could be that the design limit for forks is not directed by a max pressure, but more one of stiffness. It may be that the max pressure the fork can withstand that results is many times beyond what the heaviest rider could exert and that's why they don't indicate a max pressure, just a max weight."

 

[Jimbo Vills]

That’s exactly what I thought @steve_sordy was saying — sorry Steve if I’m butting in ?

I agree with that statement.
My answer was based upon a question about rear shocks not front forks. I have never seen a fork with a max pressure on the side. I'm not saying there aren't any, just that I have never seen one. However, I have seen several shocks with a max pressure listed. But I fail to see why only shocks should have such a limitation, unless it is because the pressures are higher for shocks than forks. Whatever the reason, both fork and shock will have a maximum pressure that they can withstand and that will have nothing to do with the weight of the rider. However, a heavier rider will exert more pressure on the suspension than a lighter one will at full compression simply because the starting point (the sag point) requires a higher pressure. A heavier rider will take then shock pressure closer and maybe above the design limit for shocks. It could be that the design limit for forks is not directed by a max pressure, but more one of stiffness. It may be that the max pressure the fork can withstand that results is many times beyond what the heaviest rider could exert and that's why they don't indicate a max pressure, just a max weight.

The weight/pressure chart is the advisory for a recommended sag.

my response was also shock related ??