Wheel building for heavy riders

[Kinst]

Who can give me some ideas on building a wheel for a big guy that wants to ride but keeps thrashing wheels, he's riding city streets, not racing or slamming down hills or over rocks, potholes, bumps, or curbs, he just needs something that will stand up to his hefty size until he can ride the pounds off.
He's on a budget but obviously it's cheaper to put a little money into a good wheel than it is to have it rebuilt over and over again.

[Daisetsu]

I've used straight 14 and 15 ga DT spokes built with MA40's (Record hi flange, 36h, 3X, brass) for 10s of thousands of miles, no cracks either. I guess they were the only good pair of MA40's out there. :-)

I used 14ga in the rear and 15 in the front. I always bought straight gauge due to lower price.

I did have to replace 9 drive side spokes due to chucking the chain in the gap. And replaced a couple bent ones from a stick in the spokes.

[Pink]

Is a fatigue failure in a rim the spoke pulling through the eyelit? If that's the case, then the drive side, rear spokes need the butted and the others wouldn't matter. Why does a 14/15/14 do better than a straight 15 ga.?

You've mentioned using spokes for tens of thousands of miles. Have you experienced fatigue failures in straight guage or butted spokes?

[bourne]

mmartin-<< Who can give me some ideas on building a wheel for a big guy that wants to ride but keeps thrashing wheels, he's riding city streets, not racing or slamming down hills or over rocks, potholes, bumps, or curbs, he just needs something that will stand up to his hefty size until he can ride the pounds off.
He's on a budget but obviously it's cheaper to put a little money into a good wheel than it is to have it rebuilt over and over again.

36 hole, Mavic T520 or Velocity Deep V, 14/15 spokes laced three cross, brass nipps, build well, of course.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302 (303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

[Kinst]

So far he's just had wheels go out of true for no reason we can figure out, he doesn't make a point of avoiding every little bump in the road but he's fairly cautious about them and avoids riding through potholes or off curbs. So far he hasn't had any rim, spoke, or hub failures, just had to have his rear wheel re-trued more often than he should, like twice in 20 miles... though for the last 20 miles it's held up fine. (We'll see how long it goes before he needs it again, this last truing might have corrected the problem).

I wonder if there wasn't some spoke twist that came out when he rode the bike after that first truing?

[ejok]

Also, remember that the amount of dish in a rear wheel plays a big role in its potential reliability. If you are willing to use a 7spd freehub body, you "gain" about 5mm in the relative positions of the flanges to the center of the axle, which is significant. You can still have an 8-speed setup by doing the "8 of 9 on 7" setup as described in Sheldon's article about
Shimano cassettes (http://sheldonbrown.com/k7.html).

[Pink]

Makes sense and also explains why spokes are double butted rather than single butted. I just haven't seen spokes that fatigued out by breaking off at the threads. They break at the heads.

Loose spokes on the non drive side and having the chain visit the spokes seem to be the most common failure modes. Of course physical accidents as well.

I own, have read, and have studies your book several times. This forum and what is in The Book is likely all I know. I still believe that the value of butted spokes is overestimated.

[Pink]

I don't know how big is big. A rim that is 15 mm between bead seats instead of the more common 13 with double eyelits and 36 hole and laced with butted spokes can carry lots of weight. A 300+ tandem does fine with this sort of wheel. All assumes the wheel is built to high tension.

I have a 40 Hole Shimano HF-07 hub and a T519 rim, which is 19mm between bead seats and can build it to 130 spacing for a road bike.
It is a 400 lb wheel and would cost ~$150 shipped.

[Night Stalker]

Ouch! That .1 ton hurt! Luckily I'm only 105 kilo's myself.

I have the similar problems - broken spokes, spokes loosening themselves (after 40 miles???). I'm currently waiting on a set from a custom builder.
I was on 32 spoke Ultegra hubs & Mavic OpenPro rims; the builder has suggested
36 butted spokes, CXP33 rims with DT Swiss Onyx hubs.

I'll let you know

-Kalukis

[taygoo]

I weigh in at 220 and can put a lot into a rear wheel. I build my own wheels and firmly believe that a good rim ( I like the Velocity Aerehead OC or
Mavic CXP-33) with a good hub and 32 spokes (double butted) properly tensioned and stress relieved will perform very well. Of the wheels I have built like this I have never broke a spoke and have only done minor truing.
You can go with 36 spokes for some added strength, but if the wheel is really built properly, I don't think you need the extra 4 spokes. On my tandem wheels I run 40 spokes front and rear with the same build as above, and with a loaded weight at right around 400#'s have never had a problem. If the guy is really strong then I would go with the Mavic rim due to the fact that the spoke holes have eyelets and should be a little less likely to have a spoke pull through the rim.