Most Important part of bike when it comes to weight?
 

Hi all. I'm new here. I'm wondering what is the most important thing when it comes to cycles handling overweight riders. I weigh around 102 kg. I bought a 26 Fat Tyre bike. The frame is made of alloy. The guy at the shop said it will hold up to 110 kg. I have my doubts, I have gone a few rounds on it. So far no prob seems to be there but for knowledge sake I need to know does bigger tire size or frame of the cycle matter the most when it comes to riding for heavy people. Thanks for your time in advance.

Spokes. Any less than a 32 spoke rear wheel will likely not go the distance.

The wheels. (And tires too of course). This is where vintage bikes have a big advantage over the new stuff. BITD 36h wheels were the standard. If you weighed 250 or 300lb. you had no worries on a set of those.

Yes, a robust rear (especially the rear) wheel. The wheels as-made from the factory often don't have the spoke tensions set properly. So, find someone or DIY & set the spokes to an even, good-n-tight tension.

I'll agree with the others, it's the rear wheel. If yours are 26" MTB wheels with 32 or 36 spokes, they'll be fine.

If you are really worried, have the shop double-check the spoke tension on both wheels.

Frames are pretty strong, so I wouldn't worry about that.

Is your fatty rigid, hard tail or ?

like all have said, more spokes. I weight 190 lbs. and prefer 36 spokes

102kg is only 225#. Thats hardly anything to really worry over when it comes to a new fatbike. A modern alloy fatbike frame is overbuilt(ive seen some examples of inner tube overbuilds by manufacturers, its interesting and clear as day) and it has 3+" tires to reduce stresses created from rider weight.
As pretty much everyone has said- wheels are what you need to care about. I will disagree that you need a crazy high number of spokes, though it certainly doesnt hurt. A properly tensioned wheel is way more important. 32 spokes on a 26" wheel is effectively equal to or 'better than' 36 spokes on a larger 700c wheel, when it comes to 'strength'. Quotes because those are common perception words but not really too accurate in describing what is actually happening.

You could get a wider tire if you want and that will reduce the 'stress' of the bike overall, but if your current wheels are properly build there is no need.

Also, I am shocked that an aluminum fat bike can only officially handle 110kg of weight. Thats super low for such a bike in general.

I guess it was bound to happen. Road bikes never used to mention rider weight until we all followed the anorexic racers into stupid-light frames so they could climb Mt. Everest (or the Italian/French equivalent). Mountain bikes were rugged when they were invented, then suspension came along to soak up the shocks, and tube weight went down to try to keep the overall frame weight from soaring. Fat bikes were like the original MTBs 8-10 years ago, so now it's time to see if they can't be lightened until larger riders might break them.

But machine built wheels are still the achilles heel for heavier cyclists.

Not just spokes but the proper spokes. There is a huge advantage in going from a 2.0mm straight spoke to a 2.0/1.8/2.0mm butted spoke and an even larger advantage with going to a 2.3/1.8/2.0 butted spoke...aka a triple butted spoke. There's about a 30% increase in strength when going from the straight spoke to the triple butted spoke. Eric Hjertberg says it's like adding 10 spokes to the wheel. I'm not sure I would go that far but it does significantly reduce broken spokes on bikes that carry heavy loads.

As a rider who weighs more than ryder101 does and puts more weight on the bike to tour, I can attest to the strength of triple butted spokes. I broke spoke regularly up until 2005 when I moved to all triple butted spokes. I haven't broken spokes since then. I tour both on- and off-road. Off-road puts much greater demand on the spokes especially when loaded. Broken spokes have just stopped being an issue.

good info. I guess when you buy the wheels, look for triple butted in the description? Are these common wheels and do they come on any new bikes or are they special order? thanks

I have never seen a prebuilt triple butted spoke wheelset for sale. If they exist, its relatively rare.
Quality wheelsets with butted spokes are common, they just are not triple butted.

Special order. You usually have to build them yourself or have someone build them for you. Quality Bicycle Products (QBP) will build wheels with black DT Alpine III. Most every shop in the US has a QBP account.

I am convinced that my current 28h front 32h rear gravel wheelset is exponentially stronger/more reliable than any 36h wheelset I have from 'BITD'. Wheelsets with double walls, butted spokes, and basically anything besides the common box section shape = stronger and more reliable.

You are correct. However, if more people ask for them, they build demand and the spokes will get more use.

I'm bigger than the OP. I would ride the stock wheel until you have a problem. I have never broke a spoke but after a year or so (3,000-5,000) I will start to see where the nipple is pulling and cracking the rim. At that point I buy a better wheel.

Fyi I just got a wheelset from Hunt Wheels last month. triple butted, disc, but only 28 spokes. Hopefully they last longer than the stock 28 spoke wheels that come on $1,500 bikes.

Actually my comment about # of spokes applies to road bikes.

It's kind of hard to imagine getting very high stresses with a 4" tire, particularly as I rarely see them going fast.

It's a multi-variable situation with the wheels. Generally, more spokes = more strength, smaller diameter = more strength, wider rims = more strength, dual wall rims = more strength. So, going by this, if you had a 16" wheel folding bike with dual wall 3" rims and 45 spokes in each wheel, you could be pushing 600 lbs with no worries.

I weigh in at 105 kg buck naked and must use well built wheels with at least 32 spokes. Anything less and they are used up within a year. As for the bicycle frame, any material will be just fine. I have had carbon, aluminum, titanium and steel. They all have held up just fine. Only ride steel now. As for rims, double walled and eyelets are my preference. Mavic rims have served me well. Velocity as also served me well. I build my own wheels and always modify the axles to 135mm to encourage even spoke tension between drive and non drive sides. Spokes are DT Swiss 2.0 or 2.0-1.8 DB. Only use brass nipples. Aluminum nips break on me.

As for fat bikes, I have yet to see any come into the shop with problems in the wheels other than cheap hubs falling apart. The rims and spokes seem to be fine.

I used to weigh as much as 220 lbs (down to like 190 now), and had a bike with the dreaded Bontrager "Paired Spoke Technology" wheels with a low spoke count. I rode them for thousands of miles, and never had an issue. I never even had to true a wheel.

Another friend of mine is about 250 lbs (guessing based on appearance), and he has been busting spokes like crazy on 28 spoke wheels. There clearly seems to be a weight in the 200's that causes problems with spokes, and it must truly depend on the exact products you are using.

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The guys @ my LBS described the "volcanoing" phenomenon with some very early CF fatbike wheels.
(Whisky rims have been bomber for me for 5+ years).
I've been curious about Hunt wheelsets...they sure seem like a great bang for the buck...can you provide (please) a report/review after 6+ months of use?