paulbi

I got myself a New Diamondback STI-8 just 3 months ago. I got it on eBay though (saving 200 hundred dollars) so I have no warranty. When I took it to my local bike shop he said the spoke design was poor and I was going to be breaking spokes regularly (i'm 300 pounds and he said the spoke design could maybe hold 200 pounds).

I asked if he could redesign the spoke pattern, but he said I couldn't. I asked if there was such a thing as stronger spokes and he said no.

The hub is "(F) 32h Alloy QR (R) 32h Shimano Nexus internal 8-spd"

Diamondbacks page for the bike is here: https://www.diamondback.com/2012-insight-sti-8

Part of me worries that this guy is doing something to get a customer every 2-3 months with the excuse that it's bad design from the bike causing it. The other part of me says that he's telling me the truth and since I'm a big guy I just need to get another bike.

Thanks in advance.

cny-bikeman

The only thing that cannot be changed is the 32 holes. (Yes, technically one could transfer the guts to a 36 hole hub shell and then lace on a new rim. If it does not have DT or similar, high quality double-butted spokes could help. But given 32 holes, which is marginal at your weight, the best predictor of longevity is proper initial tensioning of the wheel. The front should not be a problem at all - it's the rear about which you need to be concerned.

jimc101

A spoke is a spoke, there are very few variances in basic design, straight pull or regular which yours has, unless you are looking at propiatary spokes, the only additional differences will be in the butting, single, double, triple or bladed, and the spec of steel they are made from, galvanized or stainless.

Unlikely that with a 32h 3 x pattern you will have any issues, but if you did, that would most likely be due to poor build quality, pretty hard to judge with out seeing it.

For getting stronger spokes, Sapim make these https://www.sapim.be/spokes/butted/strong so may be time to fine a new LBS who know what products are available, even if they don't sell them.

fietsbob

Aka, a Pyrrhic bargain.. now you put the savings back out, in getting it repaired.

[ from the Pyrrhic victory of 280 BC https://en.wikipedia.org/wiki/Pyrrhic_victory]

Diamond Back name was sold,* spoke problem is likely they built the wheels,
with the low bid spokes. it's Economics, not Design.

* it's now offered through non bike shops. [ like amazon & Ebay]

Schwinn is having 2 lines made one sold thru their long standing shops, the other through Big-Box stores.

rebuild with better name-brand spokes, Sapim , DT, Wheelsmith, etc.

you got a bike in the condition most Bike Shops start with,
then they, take the wheels off tension and true them and see to the adjustments in the whole,
are up to the standards of the Shop.

nymtber

Sounds like an LBS that has no clue how to tension and true a wheel properly.

Find a new LBS. One that builds wheels. 32h might be marginal for your weight, but 32h 3x laced should be fine if properly tensioned, stress relieved and trued, if you ride it gentle (no potholes and curb jumping! )

My mountain bike has 32h 3x wheels and has for 11 years (same set). I have weighed between 200 and 235 during that time, and they were NOT properly tensioned till about 3 years ago. I beat on them, jumped, rode rough anything a young 20's guy on a mountain bike can do. Sure I had to true them every so often using the brake pad to get them "close" but they have and continue to hold up. CR-18 rims (known to be strong) laced to Shimano LX hubs. Machine laced, $150 wheelset. I got them, tossed tires on them, and away I went.

furballi

The few new DB bikes that I've come across last year had acceptable spoke tension, although I don't believe that the spokes were properly stress relieved. Look for a knowledgeable wheel builder in your area to see if it would be wise to stress relieve and increase the spoke tension to compensate for the additional weight. Do this ASAP to minimize future problem with the wheel.

There is not much more that you can do at this time. If the wheel does not last, then upgrade to a stronger rim, like the 32 H Velocity Chukker. Use 2.0/1.8/2.0 butted spokes. The wider contact patch between the ground and tire will result in a better handling bike.

https://www.velocityusa.com/default.asp?contentID=700

bigfred 

You've got a fairly standard wheel with normal elbowed stainless spokes.

There can be a difference in the quality of spokes between the major manufacturers (DT Swiss, Wheelsmith, Sapim) and generic equivalents. But, initial build quality, stress relieving, follow up retentsioning and ultimate spoke tension probably have far more to do with spoke longevity.

Unless you've already suffered spoke breakage, there's a very good chance that some proactive tensioning of the rear spokes could provide them with the best chance of providing you with reasonable survice life.

There have, from time to time, been batches of generic spokes that were known to be defective. If you're wheel does suffer from such an issue, there is no reason why you couldn't relace the wheel with new spokes. Expect about .50c per spoke plus labour.

cycle_maven

The 32-spoke wheel might be a little weak for 300 pounds, but there are some things you can do-

1) Get the rear wheel tensioned, stress-relieved and trued. A good wheelbuilder can do this for some $50. Factory wheels often have uneven tension and may not be stress-relieved at all, and that will cause the spokes to fail earlier than they should.
2) Ride "light"-- don't jump curbs, take the weight off the saddle when going over bumps, etc. This will keep the max stress lower on the wheel- it's repetitions of max stress that cause wheel failure.
3) When the wheel starts breaking spokes (after your third broken spoke) (which if you do 1 and 2 may be never), trash it and get a 40-48 spoke hand-built wheel with DT Alpine spokes and an eyeletted rim built on a good Shimano freehub. That's what the tandem folks do. Mountain bike right?- so maybe a 36-spoke wheel would be OK if not used really harshly.

Carbonfiberboy 

There is a misapprehension that proper spoke tension might be in some way related to rider weight or bike use. It is not. Every rim manufacturer publishes or can give you the proper spoke tension for their rims. Rear rims' tension specs will be different from front rims because of the different spoke angles between drive side and non drive side. These spoke tensions will be the same for any use of a particular rim, no matter how many spokes it has.

You will do fine with the 32H rims. As others have pointed out, a reputable mechanic or wheelbuilder will need to check and possibly retension your wheels. Or they may be fine. I ride a tandem with a 450 pound all-up touring weight, running 36H rims and 14-15 DB spokes with never a problem. My rims are not eyeletted. I use DT Competition spokes.

fietsbob

An IGH, by having a wider flange spacing, can make a decent wheel ,but
you cannot ignore it and expect it to stay fine indefinately.

at 300# dropping by the shop and having the wheel tension and truing checked , more often
it will be more reliable. if the shop does a hand rebuild,
have them keep an eye on the maintainence , thereafter,
they should include that service after the work done.

ksisler

OP PaulBi; Before you jump fully into being a victim and rant on blaming the LBS for trying to rip you off... You frankly have probably found a good LBS with personnel not afraid to tell you the facts; You have the wrong wheel and more that likely the wrong bike also. Nothing he can do to fix or rebuild you current hub/rim/spoke combo to do the job you need done...

What the LBS failed in is to not explain wheels to you and then to quote you a set of wheels that fit your total riding weight and type of riding you plan to do.

Another poster suggested a tandem wheel and that is the extreme end point of wheel strength, but an expensive item to pony up to. A decent rear tandem wheel on ebay is $300 today just for the 40 spoke version and those are there today (26" and 700C in liquidation sales at the cost of parts only). A 48 spoke one is more, when they are for sale there. Building a new one is in the $450-460 for rear and about $1,000 for both in a matching wheelset.

But there are a lot of strong wheels you could do with the appropriate tires for a good bit less cash. As a conservative builder and rider, that is my view on your quandary. Until you get the right rolling stock under you, you are going to keep breaking thing and likely suffer an injury.

Hope it helps. /K

bigfred 

??? Perception? Conception?

Manufacturers specs for a given rim are usually expressed as a range. Adhearance to the top or bottom of that range will in fact be determined by, rider weight, use, spoke type and location. In the case of heavy riders, greatest wheel longevity or durability can usually be achieved by using or even exceeding the top end of the recommended tension range. For instance, in order to maintain a durable rear wheel for my 115kg self, my drive side tension is approximately 110% of the manufacturers recommended max. Any less and I experience sufficient lateral flex to allow non-drive side nipples to back off.

Sorry but, optimum tension for a given rim does vary depending upon rider weight, use, spoke pattern, etc.

bigfred 

It's a reasonable hybrid with a 32 hole shimano Nexxus hub, double wall aluminum rims and generic 14ga stainless spokes. There's nothing wrong with that. And it should be capable of holding a 300lb'er.

What hasn't been answered, is whether he took the bike in for an already broken spoke. If that was the case, chances are that all the spokes will have fatigued and fail in subsequent order. But, there's absolutley no reason why that hub and/or rim wouldn't provide adequate service with some brand name spokes laced in and tensioned to the maxiumum allowable tension for the rim.

I quite successfully ride 32 and 36 hole wheels with both 14ga straight and 14/15ga double butted spokes from 300-250lbs.

Bill Kapaun

I notice a lot of the posters are giving you advice, thinking you have a conventional "cassette hub", instead of the IG hub you have.

Hopefully mrrabbit or FBinNY will be by shortly to give you some "SOUND" advice.

I'm new enough at wheel building to be dangerous, but it seems I've heard that the IG hubs with their large flanges might require a 2 cross instead of 3**********

I would still think your existing wheel could be greatly improved with the use of double butted spokes and PROPER tensioning.

Al1943

Good advice!

IthaDan 

It is a 2-cross (2x) spoked wheel, so it's a little out of the ordinary, and it sounds like it's a lot out of his expertise. Like many have already said, there's nothing inherently flawed in the 2x pattern, I guess it might be marginally weaker, but the biggest impact is the build of the wheel itself. I guess you could buy beefier spokes, but I have a feeling a spoke replacement followed by proper retensioning should resolve this.



It'd be close to lace this 3x, but can anyone see why that would be impossible?

FBinNY 

A few things to consider, but first a question.

Are you alrady having wheel alignment and spoke problems, or is this just something the shop person said?

In any case, consider that the overall design standard for bikes is based on riders who weight less than 200#s, and building heavy duty enough for heavier riders would make the entire bike heavier than necessary for the typical rider. That doesn't mean you automatically have problems, but you will have more than average.

It's analogous to buying a 1-ton pickup truck, and using it to haul 1.5 tons of equipment daily.

Also consider that production wheels original to bikes, are rarely as well built as those built by hand in the after market. So if/when your wheels start giving you problems, you should be able to find a decent local builder (or order from a specialty builder) who can use your hubs and build a wheel more ideally suited to your weight. Ironically, this wheel can even end up being lighter than what you have now, so it's win/win (except for the dough).

Meanwhile, there are things you can do for yourself.

1- adopt a smoother riding style, turning the pedals at a higher cadence (using a lower gear) as this lowers the peak torque on the wheel.
2- stay alert to pavement conditions, steering around bumps and potholes hen possible, or standing with your knees flexed to let the bike float over them without having to lift your weight (you are the suspension system).
3- avoid rocking the bike when standing or climbing steep hills. The wheels are much stronger for the normal radial (vertical) loads than they are for the side loads that rocking imparts.
4- be attentive to loose spokes, or mis-alignment, and deal with it sooner rather than later. In wheel care, a stitch in time..... really makes a difference.

fietsbob

in a 32 hole, hub , lacing 3 cross , the 1st cross, is the nearest spoke headed to the opposite side of the wheel-rim.

same with 4 cross 36 hole, and 5 cross 48 hole.


Rohloff is another 32 hole IGH, the Manufacturer specifies 2 cross ,[ they can be built 3 cross , if you get the 1st, key spoke, right]
( unless its a smaller rim then 1 cross is their reccomentation.)

A 3 cross build with a 32 hole hub. particularlty a Big Flange like that will
make the spoke pulling out the metal of the hub flange even less Likely,
becuse the tangent line has more metal between the hole and the edge.

Bill Kapaun

He posted last night saying he had 1 broken spoke which turned out to be 3.
Wonder if he made it home?

https://www.bikeforums.net/showthread...t-home-tonight

Post 12

Carbonfiberboy 

[h=3]mis·ap·pre·hen·sion[/h]/ˌmisˌapriˈhenSHən/

A mistaken belief about or interpretation of something.
Synonyms
misunderstanding - misconception - mistake - error

Manufacturers commonly give a 10 KGF spoke tension range for their rims. That's as close as I can consistently read for every spoke on my TM-1. If you can't keep a wheel from flexing within the manufacturer's limits, you might try different wheel parts or different design. They limit spoke tension because their engineers feel that's the limit of their spoke bed, with of course some factor of safety. You exceed it at your own risk.

The OP's hub probably has ~25mm driveside flange spacing, which is very good compared to the usual ~16mm driveside road spacing for 130mm. IOW, this oughta work.

bigfred 

It would have been helpful if the OP had included some of the details from that thread in this one.

If three spokes have already broken chances are reasonably good that the others are equally fatigued. Its sounding like either a full spoke replacement may be in order, or, if the rim has suffered a complete rim and spoke replacement.

paulbi

Yeah, sorry, maybe should have included post about last night. I felt a big wobble in the back wheel and noticed that it wasn't true. I did the best I could trueing it while I was at work. That was when I noticed one spoke just dangling. Then I looked closer and saw 2 more that were still in there, but were about to pop off.

Or at least I guessed they were because the little flange? the circle? that is wider then the spoke that holds the spoke onto the hub was gone on two of them. They were still in the hub, but i'm sure were waiting for one good pothole to pop out. I got a ride home to be safe when I realized it was one spoke gone, two ready to go.

Shop has fixed it now, but as mentioned by you all I'm worried the others may have been stressed and they'll start braking too.

Is the consensus that I could go to a 3 cross instead of the 2? Or does that seem like a no go? Someone did post a picture and that is what it is. Thanks again.

Andrew R Stewart 

I'd maintain a 2x pattern when you replace the spokes and rim. (note I suggest both). Get a wide box section (double wall) rim for most strength/stiffness nd use a wide a tire as will reasonably clear the frame/fender. Why stay with 2x? because the hub now has the spoke holes "worn in" by the original spokes. I like to have replacement spokes fall into the same spoke hole wear indents so to limit the hub's further wear also with a touch more contact between the spokes and flange there's a bit less focusing of the stresses on the spoke's elbow. The evenness of the new spokes' tensions and the rim will be a bigger effect then 2x or 3x.

Remember that whatever you do with this bike that it carries your load will place more stresses on it, all of it's parts are working harder. As mentioned your riding style can greatly impact (bad almost pun) the longevity of the bike. One pot hole or lack of proper air pressure will negate all this wheel investment. Andy.

furballi

OP,

If you already had several broken spokes on that wheel, then per my previous post, it's time to upgrade to a stronger/wider rim, like the 32 H Velocity Chukker. Use 2.0/1.8/2.0 DT butted spokes. The wider contact patch between the ground and tire will result in a better handling bike. Be sure to seek out a good wheelsmith to build that wheel. Specify 12 mm hexagonal brass nipples for a higher spoke tension on that Chukker rim. Chuckker can easily handle an extra 50% increase in spoke tension as compared to a traditional double-wall boxed rim.

You could replace all the old spokes and re-use the old rim, but you'll still have to pay about $50 for labor, and there is no guarantee that the rim will hold up to the extra load.

https://www.velocityusa.com/default.asp?contentID=700

https://www.sapim.be/nipples/brass/hexagonal

https://www.dtswiss.com/Components/Ni...exagonal-brass

mrrabbit 

Get a rebuild.

If you can afford a better and stronger rim - double-wall with very thick center line, or eyelets or double eyelets. Velocity, DT Swiss, Mavic, plenty of choices out there...

Double butted spokes would be nice. Brass nipples...continue with 2X lacing.

Whether you have it done with cheap spokes or quality spokes, it is very important that the wheel build includes stress relieving which is easily accomplished by a very strong pair of hands with gloves squeezing parallel pairs of spokes on both sides for two rotations of the wheel.

After a final true, dish AND stress relief cycle - and the wheel holds true - it's ready.

Since this is likely a symmetrical IGH rear - try to get the tension up in the 95-107 range which is what I typically aim for.

Most important thing to remember most of all is the following:

IGH hubs tend to FAR outlive the other components. FB and others here can probably tell you stories about IGH hubs that have outlived their OWNERS!!! You will wear out rim sidewalls, you may even break a bunch of spokes again 100,000 thousands miles later...

It's not a reason to be down on yourself, it a reason to be proud of yourself for getting a good return on your investment - and then do it again with another rebuild.

=8-)