BIG_BIKE

Greetings Bike Forum’s members:
Our goal is to design and build a better bike for larger "Clydesdale" individuals(Upwards of 300 lb. of normal height). We are a group of 3 undergraduate students at the University of Colorado Boulder working with Prof. Rodger Kram(This is a school project, not a commercial venture.) We call ourselves the “BIG BIKE” project. We have engineering backup and are working with an established frame builder. We need all the help we can get from real life people who have experienced the hassles of riding a bike unintended for obese riders. Here are some of the issues we need your opinions, complaints, and experiences to create the best bicycle possible:

1) Strength of the bicycle (all aspects)
2) Seat comfort
3) Gearing
4) Brakes
5) Tires/Wheels
6) Aches/Discomfort/Pain associated with riding

FYI, I am an avid bicyclist and hope to go into the profession of Physical Therapy post graduation. Any contributions or opinions about these issues are greatly appreciated.
Sincerely,
Gabe Kowalsky (gabriel.kowalsky@colorado.edu)

To better help: why not take a survey?
How much do you weigh? would you prefer a diamond frame (DF) or a step- through (ST) frame provided the step through can be made adequately strong and light? Also any suggestions or opinions on the components listed above.Thank you for your time- BIG BIKE

StephenH

First off, I'd suggest defining your target audience. I fit into the "Clydesdale" category as I weigh over 200 lbs. But, not a bunch more, and I'm reasonably tall, so for me, all it means is I may need a little beefier wheels than the average rider.

To be honest, I don't think there's a lot of design that needs to be done, the parts are there (with numerous options), it's just a matter of figuring out what works for each individual. And that's going to vary a bunch, too, depending on weight and fitness.

Aches/Discomfort/Pain- why yes, I have had those. Did a 1200k a couple of years ago, and that did lead to some soreness and numbness in the contact points, but those had little to do with weight.

If you're not familiar with it, check out this firm's offerings:
https://lightfootcycles.com/big-and-tall/
Also check out:
https://www.zizebikes.com/
I've not dealt with either firm (although I do have a Worksman bike, which is one of the brands sold by Zize).

skilsaw

Designing and Building new bikes from scratch and selling them to a niche market and breaking even is very challenging. Making a profit is even more difficult.

Get a job in a bike shop. Learn on the job everything there is to know about bikes and running a small business. Fit obese people on suitable bikes from the current world of bikes.

You will go broke designing and building BIG BIKES.
If you still want to try it when you have 3 to 5 years of bike retail experience, go for it then.

aggst1

Out of curiosity, what course is this project for? Marketing or business, or materials science engineering or something like that?

bigfred 

Gabe,

You might need to better define your intended market. Specifically the "obesity" range that you're interested in serving.

Techincally by BMI terms I am "obese" at 195cm and 115kg. I ride a traditional race geometry alloy frame with 39/53 X 12-25 gearing, use a medium width Selle Italia Turbomatic saddle and only make concession to my size by using 32 or 36 spoke wheels carrying 25-28mm tires.

However, this forum has lots of members who have had to solve numerous individual issues in order to ride.

We've got trike riders, flat footed/pedal forward riders, pedal extension users and folks on tandem wheels, as well as lots of discussions around saddles and what works for various folks and what does not.

I'll sum up what is frequently offered here to new, would be, super clyde cyclists the best I can.

If you're shopping for a used bike and have limited resources, look on Craigslist for a '90s mtb with a nonsuspension fork. Hopefully this bike will have at least 32 or preferably 36 spoke wheels which should suffice in all but extreme cases. You may want to change the saddle and stem to achieve personal comfort. But, be aware that wide and soft saddles are not neccessarily more comfortable, despite what many first imagine. They tend to spread the pressure over inappropriate soft tissues and prevent you from being able to move those pressure points. The correct fitting saddle will be determined by the shape of your sit bones, which is independent of how much weight you may be carrying.

If you can affford a new bike look for fitness or recreational models like the Trek FX range or Cannondale Adventure or Quick lines.

If you are uncomfortable with those options, there are trikes and flat footed models available from a number of companies.

Fangowolf

My OPINOINS

1) Strength of the bicycle (all aspects)
Steel frame. we put pressure on points and aluminun snaps, steel bends
2) Seat comfort
Highly personal and different ideas. I'd rather not have a squishy seat
3) Gearing
Low Gear Inches Crank 22,32,44 26,36,46 Cog 11-34
4) Brakes
Disc brakes first V brakes if not
5) Tires/Wheels
Extra strong rims (Velocity Chukkers etc) 36-40 spokes 14G DT swiss
6) Aches/Discomfort/Pain associated with riding
Crank arm length helps knee issues (170 or 165 on shorter frame bikes

vesteroid

You are going to quickly find out that everyone one here is an expert in every subject.

i personally am convinced there is a market for your idea. I believe there is a real business opportunity in catering to obese riders.

there of course are challenges, and business issues to be worked out, but that exist whith any "new" idea.

my suggestion is that you research the cottage industry that grew up around lightweight backpacking. Not too many years ago several small groups of avid backpackers saw a market that was being untapped by the current regime. They started making totally new products in their garages and many of them did very well. They saw an opportunity and made a business out of it.

check out people like Henry shires at tarptent.com, or joe at zpacks.com, or Ron at sixmoondesigns.com, or glen at mountainlaureldesigns.com. Or ula-equipment.com

all of these guys grew a small business from their garages.

even if it never goes anyplace, it will be a great learning experience. Follow your dreams and don't listen to the noise.

if you ever want to kick around an idea or ask a question from someone who has successfully owned and operated a metal manufacturing business for almost 26 years, shoot me a pm....always happy to help people get started.

TrojanHorse

You can peruse the list of threads of people who are >350 (pick a number) and a common theme is "I don't have a lot of money to spend on a bike" so keep that in mind.

BIG_BIKE

Thank you so much for your input. This is exactly what I'm looking for.

BIG_BIKE

We are an Independent Study. Although we are Integrative Physiology majors geared toward Biomechanics.

BIG_BIKE

We are going to use all pre-made parts from various manufacturers, except for the frame. We are planning to build a custom steel frame (step through style). As a metal manufacturer do you have any advise? Thanks- Gabe

BIG_BIKE

That would be great. Could you guide me through this process? I am new to the forum thing. Thanks-Gabe

BIG_BIKE

Thank you for your contribution. Your advise helps a lot. I reworded my opening sentence to hopefully better accommodate my audience. Also you posted some great info- Gabe

adrien

Hi guys --

Interesting project.

An idea on targeting -- why not market strength and toughness, rather than targeting "obese"?

As for me, following the format you like:

Strength
- steel, triple-butted, high quality (Reynolds, Dedacciai, Columbus), preferebly oversized on DT
- lugged for strength
- King headset (amazing durability)

Seat comfort
- VERY personal. I like almost no padding, flatish profile. I've settled on a charge knife.
- stop calling it a seat. You're into biomechanics -- it's a saddle. It should be a perch, not a seat

Gearing
- road, Pro-compact crank (52/36) and a tight cassette (12-25). Much closer gear ratios


Brakes
- long reach ultegra do fine for me

Tires / wheels
- tires -- contis, either GP4000s or GP 4000 all-seasons. 700X25 for a little cushion
- v-style rims, 28-36 spokes. I have Velocity deep-vs on ultegra hubs, DT Swiss RR585s on King hubs, and Ambrosio FCS28s on Dura-Ace track hubs.

Pains
- none

I should point out that I dropped from 250 to 205. My BMI is now right around 25. No idea if I'm the target demographic or not.

Oh, and I would not ride a step-through frame. Unless I couldn't ride a standard frame.

StephenH

That just eliminated about 90% of your target market, I think.

But here's a frame idea that's not so common:
https://www.biria.com/bicycle/easy-boarding/cruiser
I don't know that the sloped seatpost would be a good idea in terms of handling a lot of weight. But that comes back to the issue of defining your target market. People that weigh 220 lbs don't need a custom frame, people that weigh 500+ lbs are probably very seldom on 2-wheel bikes.

vesteroid

I had a long reply written out, and deleted the entire thing. here is my best advice. Get your masters in PT, and practice. You will have a job for life, and one that is in very high demand. Work in the cycling field with your PT if thats what you want. Manufacturing is not what you want to put your efforts into.

My Wife is an OT and she comes home each day bubbling about how she helped this patient or that patient...you can see it in her face she loves her job. Lets just say I dont come home that way

jimblairo

Co-Motion cycles in Oregon makes a flat bar bike for people up to 450 lbs. You might check them out.

jimblairo

Check out the web site of Supersized Cycles.

TrojanHorse

Well, just look at the thread topics and go from page to page... there are always "new super clyde" or "new big rider" or the like threads to peruse. It would probably benefit you to see what they say they're looking for.

cyccommute 

Aluminum is a soft material not a brittle material. Soft materials don't "snap". Aluminum "tears". Steel is a brittle material and it does "snap" when it fails. It can bend but when it does fail, it snaps.

Nor is aluminum a bad choice for a heavy rider. I'm a big guy and I've been riding aluminum exclusively since 2003 when I ditched my touring bike. But I've been riding aluminum mountain bikes in punishing off-road conditions for many, many years before that. Yes, I have broken frames but I've broken 2 steel frames...they went "snap" and were broken...and I've broken 2 aluminum frames. The aluminum frames cracked, creaked and never completely cracked through. One of the steel frames broke in 3 separate places (and were repaired) before I finally gave up on the frame.

5) Tires/Wheels
Extra strong rims (Velocity Chukkers etc) 36-40 spokes 14G DT swiss

A classic mistake. The rims provide little in terms of wheel strength. Again, going back to my mountain biking roots, I ride...and jump and abuse...light weight aluminum rims off-road...my favorites are Mavic XC-717 which is a very light rim. Rim breakage is seldom a problem. The spokes do all of the heavy lifting when it comes to the strength of the wheel. A better choice for heavy loads are spokes that have 2.3mm heads like the DT Alpine III, Sapim Strong or Wheelsmith DH-13. These are more durable, stronger and fit the hub better than spokes with thinner heads.

You can build a bike for a heavy rider or heavy loads without having to make it into a tank.

corwin1968

I think everyone here mentioned 700c wheels but it seems that 26" wheels might be a better choice. I've always read and been told that the real weak point in a bike ridden by a very heavy person is the wheels. If a person is just doing normal riding on pavement or hard packed dirt, modern production frames are plenty strong enough. I ride a 1995 Trek hybrid and I weigh 400 lbs. I have no issues whatsoever with the strength of my frame.

Also, check out Peter White's website and the Tout model bicycles he carries. Even though they are only rated to 300 pounds (I think that's very conservative but I'm sure it's a result of lawyer's input) that's what I think of when I think about a bike for very heavy people.

Here is a link to the bike I'm talking about:

https://www.peterwhitecycles.com/tout-terrain.asp

Yo Spiff

I think that $$ issue is going to be the biggest problem to having a successful product. Someone who is just starting to ride isn't usually ready to invest a more than a few hundred in a bike.

squirtdad

As mentioned before a clearer definition of the target will help. Obese is not well defined.... over 300 lbs over 400 ??? and there is the skil set of the rider...new rider, returning after 30 years.....etc

and it might help if posters put there height/weight there.

and recognize it is an opinionated group. An example is the the step through frame. Many people who are experenced cyclist don't see the need, but a new cyclist at 450 lbs might consider this a godsend.

I am 6" and 270. I ride steel frame road bikes (drop bar and priest/postino style bars....not flat bards) with 32 spoke rims and have no problems with breakage.


if it were me I would build a city bike style

Step throught or mixte frame (maybe be off setting to some, but would be unisex, and has benefits for those with limited mobiliyt or concern about being able to put foot down and not hit frame)

nortth road styel bars (think english 3 speed )

700 cc wheels, 36 spoke able to take at least a 35mm tire

Brakes to cleare above.

thinks about simple gear setup.... single up front, many on rear (sram has a new mountain 1 x 11 setup)

make sure frame has eylets etc

avoid overpadded saddles

tpy2010

I have read the above and agree with some of the points made. I would re-define clydesdales to BMI. There are many people greater than 200 pounds that are not carrying excess body fat. Easy on frames are a great asset for those who have BMI's >35. If this is a dream of yours to get into bicycle manufacturing, pursue it. I just watched Paulo's video on the catrike website and he tells of his dream to build bicycles in America. He was a mechanical engineer living in Brazil at that time. Look at him now.
I am a 340 pound guy with a BMI > 40. I have never purchased a special frame because of my size. My trek 5500 is carbon fiber and I rode several RAGBRAI's on it without any special wheels or any frame problems. Now I have a recumbent - catrike and exceed the weight recommendation by 65 # and load the bike with 20-25pounds of gear and do long distance rides. I did ride 4500 miles between May 2012 and 12/2012. I gave up the DF bike because of pressure on my perineum and subsequent numbness. This is not a problem with my trike. I think a crank forward design has merit, but remember that a very obese person may have difficulty getting going with a 2 wheel recumbent. Have fun, don't re-invent the wheel if you don't have to.

Myosmith

Lots of good advice already, here's my two cents worth:

Even very large Clydes don't need radically redesigned frames, just a good sturdy frameset. A more relaxed geometry may be beneficial for comfort and stability. I like double butted high quality steel in a touring geometry. Lugged is an option but not an absolute. For extremely heavy riders and off road use you might want to include some gussets in high stress areas. Like Cyccomute said, it doesn't have to be a tank to be strong. I personally prefer steel as I find it comfortable at a reasonable cost, but AL and CF have also been used successfully for Clyde bikes. Step through designs have inherently weaker geometry and may require additional reinforcement. They will also appeal to a very narrow market. The frame must accommodate wider tires than some main stream road bikes. 32mm width would be the least I would accept on a road bike for a Clyde, 40+ on a trail or commuter bike. Not that everyone will use tires that wide, but they should have the option. Depending on the intended use, you will also have to look at mounting points for fenders, racks and accessories. Maybe even disk brakes.

Saddle comfort has way more to do with frame geometry and proper rider fit than it does with the saddle itself. The big point I want to make here is, it's a bike, not a barstool. An excessively upright seated "barstool" position on a wide cushy saddle is inefficient to pedal, more difficult to balance, and uncomfortable for anything other than occassional short cruises. Remember that saddle width is based on the width of the ischial tuberosities, not the size of the person's butt cheeks.

Gearing will depend on the intended use of the bike. If you are looking at general road riding, touring or offroad/trail riding, I'm a fan of a triple chainring with a fairly wide range cassette, something like a 12-28 in a 9-speed. Look at durable drivetrain components like Shimano Deore, LX, or XT (personal preference for my touring and trail bikes, there are other options). The triple chainring is an advantage over a compact double for Clydes as it gives you a low bailout ring for climbing.

Disc brakes would be a nice addition but any good solid double-pivot calipers or cantilevers would work just fine. Again, I picked Deore and LX for my most ridden bikes. I've got older double-pivot RX100s with Tektro levers on my roadie. Ultegra brake pads all around but again some people like Kool Stop or other brands/models.

You don't need battle cruiser wheels but quality and proper design/build are extremely important. My personal preference is 36 butted spokes on Deore LX hubs with double-wall eyeletted rims. The rims I chose were Salsa Delgado which are slightly wider than most road rims and are designed for touring or cyclocross. They take a wider tire nicely. I suggest you stick with either 26" or 700c/29er wheels for maximum tire availability and selection. As far as tires, that again will vary with rider weight and desired riding style. I'd stay away from anything under 28mm wide for morbidly obese riders. 28s are still just fine as a road or light touring tire. 32mm-38mm make good touring or commuter tires, trail and offroad will get beefier yet. I'm a fan of Specialized All Condition Armadillo Elites for road and touring and Schwalbe Smart Sams for trail riding and mixed surface touring. My local wheelbuilder also sold me on building 36 or more spoke wheels in a 4X pattern for both strength and comfort. For extremely heavy riders you might want to consider a 40-spoke + rear wheel on a tandem hub. The front wheel carries less weight and doesn't deal with drive train stresses, so 36-spokes on a touring or MTB hub should be strong enough.

As far as aches, pains, discomforts, you need to look at adaptability to fit the riders' needs. Some might need extensions to move the pedals slightly wider, different stem lengths and angles, setback seat posts, etc. Bike fit is very individualized and your design will have to be adaptable.

One part of your original post that concerns me is that you are planning to build "a" better bike for obese individuals. The problem there is that there is no one type of obese rider. You will need a range of bikes to suit various purposes and preferences. I know morbidly obese riders who are roadies, others who are endurance riders or tourists, utility/commuters, fitness riders, recreational cruisers, off road trail and MTBers.

Take a look at the offerings from Workman, Surly, and several other companies that have become the mainstays of bikes for obese riders. You might find that you are reinventing the wheel, so to speak. Of course, if nobody ever reinvented the wheel we'd all be driving around on wooden rims.

Contact your local bike shops and try to get in touch with a cross section of obese riders. Find out what they are riding and do a survey of what they do and don't like. Don't base your designs on what skinny or athletic people think that obese people need, go ask the big guys (and gals). Is anyone in your project group and avid cyclist? Are any of you obese cyclists? What experience does your group have in bicycle building and design in general?