# bike to weight ratio



## Fuse6F (Jul 5, 2017)

100lb rider on a 31lb bike. 19 remedy 8

she rides okay but just cant stay up at a decent speed for long
ends up bonking nearly every ride

we have tried better nutrition and on ride nutrition

but was thinking that a motorized bike might help

problem is she is tiny woman. 

how much bike weight is too much bike weight

motorized bike would be 50% of body weight

everyone says they get the same workout on their ebike, that they do on their regular bike!

well thats not going to work. 

we need her to be able to go 3 to 4 times her normal distance without getting excessively tired.

i just question how thats possible w a heavy 50lb motorized bike.

what body weight % do you feel is too much?

we like the extra capability that the remedy bike offers. it bails her out without much stress.

but selling it and getting a 25lb xc bike would drop the capabilty but make a big diff on her power to weight ratio. 33% to 25%

if i swapped wheels and tires and took 600gm away, whats the real benefit to her. $2000 for that alone.


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## plummet (Jul 8, 2005)

Sounds like fitness is the issue not size or bike. Get out there and ride 3 times per week and the fitness will come.

If you want to add an engine don't worry about bike weight. The engine counter acts that.

As far as bike spec for lighter ride you can spec light weight gear. A lighter bike will make it easier. But it wont fix lack of fitness.


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## RBoardman (Dec 27, 2014)

Arguably the fastest enduro racer women in the world is 5'0" and just over 100lbs. So if your saying the "problem is she is tiny", you might want to come up with a different excuse. Also don't blame the bike, because that's never a valid excuse for lack of fitness. Get an ebike for her because they are fun and allow people to ride further.


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## NoCanSurf (Feb 19, 2021)

I don't mean to come down on you. We have very little data to go on, and we frankly need her side of there story. 

A heavier bike isn't going to solve this, its going to make the downhill section more difficult and dangerous for her. That's a lot more mass she's going to need to deal with. Yeah, sure she'll blast up the uphills, but the problem now has moved to the downhill sections. Try taking long brakes in between rides. Just sit and eat, relax. Give her a chance to refuel. She might be cool, having a picnic, while you make a few more runs. 

It would be easier to make suggestion if we knew what she thought.


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## Crayefish (Apr 4, 2021)

Get a new riding partner at your level, and find a friend for her at her level 😁

This is why when I go skiing with my gfriend... we ski separately 🤣


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## LMN (Sep 8, 2007)

Honestly size isn't the issue. There is just a fitness difference between you. Yes, with lots of work and training on her part, or increased beer consumption on your part, that gap might close. But an E-bike is a way of closing it immediately.

When my wife was pregnant we got her a Levo-SL., instantly the gap between us closed. I would recommend that if you are going to go the e-bike route go with one of the lighter ones, Orbea Rise or Specialized Levo-SL. Both of those bike handle like a conventional bike. Also a full power e-bike is just too powerful to ride with regular bikes.


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## RBoardman (Dec 27, 2014)

NoCanSurf said:


> A heavier bike isn't going to solve this, its going to make the downhill section more difficult and dangerous for her. That's a lot more mass she's going to need to deal with. Yeah, sure she'll blast up the uphills, but the problem now has moved to the downhill sections. Try taking long brakes in between rides. Just sit and eat, relax. Give her a chance to refuel. She might be cool, having a picnic, while you make a few more runs.
> 
> It would be easier to make suggestion if we knew what she thought.


Not necessarily. As someone who rides both moto and mtb nearly every weekend, there are plenty of people who can shred on a moto and are super sketchy m and/or slow on a mtb. Weight doesn't make a bike harder to ride downhill if you have a decent skillset.


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## rangeriderdave (Aug 29, 2008)

Talking about power to weight ,if you compare a moto's power to weight you will find that they are very powerful to the weight. Then add a rider ,still true. When you do the same with mb , the difference isn't as big ,where the difference comes from is the rider and that can be huge. So either she gets fitter (and maybe never gets to your fitness), you learn to slow down and enjoy the kind of riding she can do or she gets a e bike to even things out power wise. I wouldn't be overly concerned with the weight ,plenty of smaller people riding moto's and not having many problems.


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## slapheadmofo (Jun 9, 2006)

Fuse6F said:


> we need her to be able to go 3 to 4 times her normal distance without getting excessively tired.


Why?

Maybe you should try riding 1/3 your normal distance without getting excessively bitchy and give her a chance to build fitness while having fun.

?


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## Suns_PSD (Dec 13, 2013)

I have a novice lightweight wife I've ridden with a good bit.

People this size simply don't need the robustness in their components that larger stronger people do. In fact they don't even need the same traction larger people do, not even close.

Not sure what your friend is riding but assuming it's a good pedaling bike and the sag is set correctly (set while seated please!) just put her on some very fast lightweight XC tires. That alone will give her 25-50% more range if she is currently on Minions or something.

The best solution is an uber lightweight bike with components sized for her including:27.5" XC wheels, small brakes, 32-34mm fork, very light tires, not much travel, save weight wherever you can.


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## MSU Alum (Aug 8, 2009)

I'm guessing the issue is that she runs out of energy on the climbs, right? Not the descents.
In that case, a lighter bike, with faster rolling tires would help some.
An ebike would help more, probably.
When I first rode with my youngest son (when he was about 6), we'd go out half a mile on a flat trail, he'd stop, eat a snack, have some water, and we'd return.
It really never occurred to me that he had to go farther or ride faster. Now when I ride with him, I don't even get to stop to puke. When I ride with my wife, a trail that takes me an hour, takes her 2. As far as I'm concerned, that's an extra hour of fun. Just go out and ride slow, stop and enjoy the outdoors, keep her heart rate low enough so that she can continue.


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## plummet (Jul 8, 2005)

MSU Alum said:


> I'm guessing the issue is that she runs out of energy on the climbs, right? Not the descents.
> In that case, a lighter bike, with faster rolling tires would help some.
> An ebike would help more, probably.
> When I first rode with my youngest son (when he was about 6), we'd go out half a mile on a flat trail, he'd stop, eat a snack, have some water, and we'd return.
> It really never occurred to me that he had to go farther or ride faster. Now when I ride with him, I don't even get to stop to puke. When I ride with my wife, a trail that takes me an hour, takes her 2. As far as I'm concerned, that's an extra hour of fun. Just go out and ride slow, stop and enjoy the outdoors, keep her heart rate low enough so that she can continue.


Yep. If you are a hardcore biker and the other half rides occasionally then there always will be a gap. Do chilled rides with the missis and hard out rides with your mates.

Side note.

My Boy now 13 has surpassed my wife for speed and crazy level. Riding with him is starting to get interesting. We can hit some fun stuff that my wife wont or my 17 year old daughter who rides at about the same level as my wife.

PS They are all short arses.... 5"1 is the tallest and 50kg weight. 13 year old boy is the fastest out of them and hes shorter and lighter maybe 4"6 and 40 kg. But he's punching jumps and drops and steeps and quite difficult stair sections. Good times.

Size is not the limiting factor! Fitness, skill, and mental attitude.


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## Fuse6F (Jul 5, 2017)

like i said...

what does riding a machine 50% of your weight do from a mtb perspective vs riding one 25% of your weight but sans engine.

realistic examples

if your 165lbs are you happier on a 40.5lb xc or a 81lb ebike

if your 220lbs then 55lb xc or a 110lb ebike

im 255lbs so that means for me im out there on a 63lb xc machine or a 127.5lb ebike

doesnt seem fair to say go get more fit when my bike would be 81lbs at 33% body weight which is what she is on at the moment


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## slapheadmofo (Jun 9, 2006)

Fuse6F said:


> like i said...
> 
> what does riding a machine 50% of your weight do from a mtb perspective vs riding one 25% of your weight but sans engine.
> 
> ...


If you lost 40 pounds, do you think you would be faster or slower?


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## MSU Alum (Aug 8, 2009)

Are you only wondering whether or not bike weight, as a % of muscle mass, or body weight is an issue?
I would say, yes, it's an issue, or at least it makes some difference.

Is this more of a "what should she do" question?
If so, I'd say go lighter on the bike (though that may not be enough) or suggest she demo or get an ebike.

The people who say they get as good a work out on an ebike are probably exceptionally good riders who REALLY hammer it. Someone like me would not get as much of a workout on an ebike. For me, that's a feature, not a flaw and I expect she would be in the same category. I suppose it's also likely that the greater mass of an ebike, on a complex downhill would have its own challenges, but it doesn't sound like that applies to her either.


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## Suns_PSD (Dec 13, 2013)

Fuse6F said:


> like i said...
> 
> what does riding a machine 50% of your weight do from a mtb perspective vs riding one 25% of your weight but sans engine.
> 
> ...


It seems like it should work like that, but it doesn't. Either that or my kid is an insect cause she was pedaling around 50% of her body weight, quite effortlessly.

No doubt that body weight vs. bike weight matters, I just don't think in the real world it's the 1:1 relationship we make it out to be. For example, a 200# person will in fact not go 2x as fast/ long/ your preferred metric as say a 100# person on the exact same bike assuming they have the same level of bike fitness and both fit the bike well. Sure they will likely be significantly stronger overall on the bike, but not 2x as strong.


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## Nick_M (Jan 16, 2015)

take example from kids, you start small with short distance with multiple brakes in btw and bag of m&m's (whatever food source rider prefer)
you carry all on their water, and yes you will be bored to ride at the beginning, with time and consistence practice -> magic happened;

so as example my:
2 year old weights 12 kg and rides 3 kg bike (does not mean that he can ride longer then other two, mile or two)
5 year old weights 15 kg and rides 8 kg bike ( motivated to ride 10's of miles )
6 year old weights 20 kg and rides 10 kg bike (able to ride 10's of miles, however not motivated much)

I would not focus on the bike itself, focus on rider and his motivation


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## slapheadmofo (Jun 9, 2006)

Suns_PSD said:


> It seems like it should work like that, but it doesn't. Either that or my kid is an insect cause she was pedaling around 50% of her body weight, quite effortlessly.


This.

I regularly see people in the Kids and Families subforum making the same sort of comparison as the OP as if it's gospel, but in the real world, it just doesn't work that way. If it did, all we'd have to do to get faster would be to pack on a bunch of weight and XC champs would weight 400lbs.


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## LMN (Sep 8, 2007)

Fuse6F said:


> like i said...
> 
> what does riding a machine 50% of your weight do from a mtb perspective vs riding one 25% of your weight but sans engine.
> 
> ...


Think about it this way. Generally the upper level for sustainable power for human beings is around 450 watts. So for you this is around 4 watts/kg. It is unlikely that you are sustaining 450 watts, 300-350 is probably where your at. Lets say 2.8 watts/kg.

A sustainable power output of 3-4 watts/kg is very reasonable for most women to achieve, particularly if they are 100lbs. In other words if she was to train properly for 6 months you would be one talking about getting an e-bike to keep up!


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## RBoardman (Dec 27, 2014)

Fuse6F said:


> like i said...
> 
> what does riding a machine 50% of your weight do from a mtb perspective vs riding one 25% of your weight but sans engine.
> 
> ...


You're right, we're wrong. It's all on the bike and how much it weighs. Nothing to do with rider fitness. Other kids and small adults who are capable of riding circles around your 255lb body must be defying your laws of physics and understanding.


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## Whiterabbitt (May 16, 2020)

Fuse6F said:


> everyone says they get the same workout on their ebike, that they do on their regular bike!
> 
> well thats not going to work.
> 
> ...


I ride e-bike and regular bike and swap frequently. It is NOT the same workout. The LEGS get the same workout (for me), but the lungs do not. HR still goes elevated, but I am sure medically/biologically it's not the same workout for the heart.

So find out how she is bonking. Is it the core, or the legs? If legs, e-bike's not gonna help. If it is not legs, eBike can help.

I don't think weight ratios matter, but if so, my ebike is 57 lb and I am 145. That's the same ratio as an Orbea Rise on a 100lb person.


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## Whiterabbitt (May 16, 2020)

Crayefish said:


> Get a new riding partner at your level, and find a friend for her at her level 😁
> 
> This is why when I go skiing with my gfriend... we ski separately 🤣


I swear when I first read this it said "That's why I go skiing with my gfriend...." and then I was anticipating the second part of the sentence '...instead of with my wife 🤣'


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## MSU Alum (Aug 8, 2009)

Come to think on it, I remember back when my other son was about 10 or so and maybe 80 pounds on a fairly heavy hard tail. I was slowly falling back behind him as we were climbing and I came up on a couple of guys standing around. One of them chuckled as I got there and said, "we were just commenting on how your son has a real 'climber's build'". It was pretty funny and I'd forgotten about that. So, yeah, the bike/body weight ratio by itself may not be that predictive.


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## LMN (Sep 8, 2007)

slapheadmofo said:


> This.
> 
> I regularly see people in the Kids and Families subforum making the same sort of comparison as the OP as if it's gospel, but in the real world, it just doesn't work that way. If it did, all we'd have to do to get faster would be to pack on a bunch of weight and XC champs would weight 400lbs.


Given that Olympic men's and women's champs have a combined weight of less than the OPs I think it is safe to say that light weight riders can manage to overcome their bike weight.


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## Le Duke (Mar 23, 2009)

A 50kg woman with 15% body fat, on a high carb diet, would have approximately 1500 calories of glycogen available for lower body exercise. 

If she’s pushing 150w and she has middle of the road biological efficiency, she’d burn ~560 calories per hour. That’s 2 hours and 40 minutes, with no refueling, before she’d exhaust her muscle cell stores of glycogen. 

Are you trying to tell me a) she’s bonking b) eating won’t fix it and c) you want her to do 4,500-6,000 calorie rides? That you want her to ride 8-10+ hours with you?

Something doesn’t make sense here. 


Sent from my iPhone using Tapatalk


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## Grinchy8 (Jul 6, 2021)

I had a 60 lb fat tire eBike. It wasn’t very much fun to live with, but it was fun to use.
Eventually it became more hassle than it was worth. The mass isn’t such a big deal while riding, but it is a big deal at all other times.
if you get on eBike, get the lightest one you can afford.


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## Fuse6F (Jul 5, 2017)

so i appreciate the comments.









Cycling Wattage Calculator


If you're curious what power you produce while cycling, and how it depends on your position, speed, or even tire type, give this cycling wattage calculator a try! 🚴




www.omnicalculator.com





here with all things being equal you can see the effect of bike and gear on performance.

it works out to a 10w drop in effort on a 10% grade. making it 4.85% harder to do on her current bike by mass alone. at 10km/hr

as you know riding near your limit is okay, but going over just a little bit will make you blow up and your done. gotta back it off.

i think im satisfied w the calculators result. 4.85% more effort w current bike vs the xc bike weight. probably another 5% more efficient pedal platform vs a remedy 150mm rear travel.

so round it up and say 10% diff. then that means 20w of power. that could be a game changer for her average speed. perhaps an xc racer could verify.

now riding up a hill w a 250w motor means she would have to put zero power into the effort. just have to work harder coming down and during the physical aspects of control. so i guess the ebike wins hands down.

this is backed up by commercial trends imo.

still it has to be fun to ride. will have to look into a test ride somewhere somehow.


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## Fuse6F (Jul 5, 2017)

Le Duke said:


> A 50kg woman with 15% body fat, on a high carb diet, would have approximately 1500 calories of glycogen available for lower body exercise.
> 
> If she's pushing 150w and she has middle of the road biological efficiency, she'd burn ~560 calories per hour. That's 2 hours and 40 minutes, with no refueling, before she'd exhaust her muscle cell stores of glycogen.
> 
> ...


im trying to understand the effects of bike weight vs performance when at the low weight end of the spectrum.

i admit she isnt ridding much because its not her favorite thing. so her cardio is low and we have to ride at her pace.

we are trying to understand diet and what needs to be done to keep her system running both before hand and while on the trail. that can be another forum topic.

recently ive tried getting her to eat at the trail head and then during rest stops. just so she feels more energy and can enjoy the ride better.

any tips you have would be welcome.

stats
48, 45.5kg, barely 5'4", eats low carbs, has a very low body fat %, 3100ft asl

whats an average w/kg for a tiny female weekend rider?
whats an average w/kg necessary to successfully trail ride single track trails?
is is possible that at the lower weight end of the spectrum that it becomes harder than for that body type, due to the higher percentage of bike weight vs body weight.
what would the impact be on your riding to bring your bike weight up to 33% of your body weight?


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## Fuse6F (Jul 5, 2017)

LMN said:


> Given that Olympic men's and women's champs have a combined weight of less than the OPs I think it is safe to say that light weight riders can manage to overcome their bike weight.


so yolanda neff is 5'6" and 117lbs and the best in the world. as in not the normal athletic female. her supercaliber weighs probably 20lbs. that is 17% of her body weight.

what happens to her performance on a 38lb bike?

is she still olympic champ?


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## MSU Alum (Aug 8, 2009)

My wife is 68 years old. She likes to eat a "tide pod" (lemon Gu Gel without caffeine) at the trail head. She seems to think that helps. She's 125 pounds on a 27 pound 27.5 and a typical good ride for her is about 12 miles, 2000 feet of climbing on the Wasatch Back at a pace that is sustainable for her, avoiding anything close to max HR, with short stops every 15 to 20 minutes that last 1 to 2 minutes.


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## 33red (Jan 5, 2016)

Fuse6F said:


> 100lb rider on a 31lb bike. 19 remedy 8
> 
> she rides okay but just cant stay up at a decent speed for long
> ends up bonking nearly every ride
> ...


For 7 years my girlfriend was 92 pounds.
The way you present it you see her as the problem.
Maybe you are the problem.
One option is you get to the parking lot and you split in 2 groups.
She could get a 21 pounds bike.
You make it sound like a 10 year old must ride with 15 years old.
My solution was to enjoy doing activities together but i accepted her
limits, i never blamed her.
Pushing her limits too much she is more likely to get injured.
Maybe an Ebike will help but since you seems to be the problem
maybe you can get a 600$ HT and the solution will be to stop
blaming her.
Would you push your 75 years old dad and blame him?

Make sure the transmission is geared for her that helps.


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## Jayem (Jul 16, 2005)

Le Duke said:


> A 50kg woman with 15% body fat, on a high carb diet, would have approximately 1500 calories of glycogen available for lower body exercise.
> 
> If she's pushing 150w and she has middle of the road biological efficiency, she'd burn ~560 calories per hour. That's 2 hours and 40 minutes, with no refueling, before she'd exhaust her muscle cell stores of glycogen.
> 
> ...


Yeah, if anything, weighing 100lbs she has an advantage over most people. If she trains and eats well, she should be killing everyone on climbs in no time.


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## LMN (Sep 8, 2007)

Fuse6F said:


> so yolanda neff is 5'6" and 117lbs and the best in the world. as in not the normal athletic female. her supercaliber weighs probably 20lbs. that is 17% of her body weight.
> 
> what happens to her performance on a 38lb bike?
> 
> is she still olympic champ?


my comment was snarky. I apologize for that.

Here is simple a simple equation for effect of bike weight on climbing performance.

Time =. (Change in weight)(Change in altitude)(9.8)/(Power output). (All SI units)

As you can see rider weight isn't a variable. The rider controlled variable is power output. If you do a bit of math you will find that the lower the average power output is the greater effect a change in weight has.

Power output put is loosely correlated to rider size. But a rider like Neff has a sustained power output equal or greater than most riders twice her weight.

But getting side tracked on your question.
-Where are you based? Does she need a 31lb trail bike? There is a big difference between the effort recovered to ride a trail bike and a light trail bike. My wife has zero problems climbing on a 31lb bike but she prefers 24lb light trail bike.

-If you do go e-bike, go light weight ones. I have a friend who lost his leg a couple of years ago. He has a Kenevo, if I am going full gas on my Levo SL I am still getting dropped.


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## Le Duke (Mar 23, 2009)

Fuse6F said:


> im trying to understand the effects of bike weight vs performance when at the low weight end of the spectrum.
> 
> i admit she isnt ridding much because its not her favorite thing. so her cardio is low and we have to ride at her pace.
> 
> ...


If she has a lower body fat percentage, her biologically available glycogen goes UP relative to someone who has more body fat at the same weight. So, she has an advantage there. That said, I'm still not sure that we are fully grasping the problem here.

Like I said in my previous post, unless she's doing these rides at near the power and amount of time stated, she shouldn't be bonking (running out of glycogen in leg muscles). If it's a general fatigue thing, that might be a medical issue that needs to be addressed by a health care provider, as that's not really normal. A healthy adult should be able to go for a short ride without crushing fatigue. In terms of w/kg, even with a relatively heavy bike for her size at 31lbs, if she can do 150w for any significant length of time she should be riding away from you. Even at 2w/kg, using the total system weight of ~60kg (and thus 120w), she'd likely be riding away from you.

To me, though, the biggest thing is the fatigue you bring up. Sucking wind is normal when pushing yourself but being overly tired after a short effort doesn't make much sense to me, which is why I suggested perhaps seeing a doctor.


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## slapheadmofo (Jun 9, 2006)

Fuse6F said:


> she isnt ridding much because its not her favorite thing. so her cardio is low and we have to ride at her pace.


Issue solved.


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## Suns_PSD (Dec 13, 2013)

I'll also say that a low carb diet made be personally really weak on the bicycle. 

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