vman5

Hey forum, I'm building a wheelset and having read a number of forums and articles am trying to figure out if the build is reasonable for my use, or may run the risk of breaking spokes/tacoing the rim.

The facts:
1. I weigh about 125 lbs
2. The bike is a custom build lightweight steel frame road bike (~4.5 lb frameset) with a rear rack. I'm the second owner, and it's in great structural shape with no dents or dings, just paint damage
3. It's my only bike and I use it to commute, recreate on, do overnight tours on/buy groceries carrying up to 30 lbs.
4. The bike has disc brakes - Avid BB7s
5. The bike has 100mm front and 130mm rear hub spacing and currently has Velomax Sagitta rims with 28 double butted 1.7 mm spokes that have been reliable for the ~8 years I've had them with minimal truing needed.
6. I run 25mm Michelin Pro 4 endurance tires front and rear which have been flat free and good in the PNW winter wet.
7. The bike has a 10 speed Campy Chorus drivetrain which has also been reliable.

I'm looking to make a switch to 650b wheels to get some wider tires on the bike to get a bit more comfort within the confines of my frame, and add a dynamo since I commute a fair bit and would like to have hassle free lighting in the PNW winters. While making these changes, my overwhelming goals are to:
1. Maintain the bulletproof reliability I've enjoyed from the bike,
2. Increasing it's versatility to "do it all" as it's my only bike and I have limited space, and
3. Maintaining the "chuckable" feel the bike has while riding for fun or commuting and it's unloaded.

The wheelset I've just gotten all the parts for, but haven't started building includes:
1. Shutter Precision SL-9 dynamo disc front hub
2. Hope RS4 disc rear hub with Campy freehub (will require cold setting the frame to be 5mm wider)
3. Kinlin TL-23 rims with 24 holes
4. CN Aero 424 spokes
5. Approximately 38mm width tires - need to figure out which ones

The primary reason I haven't built the wheels up is that I'm nervous I'm courting trouble by going with such a low spoke wheelset, especially in the rear due to my propensity to occasionally carry 30+ lbs of weight on the rear rack. My logic when originally ordering these parts was that since I was:
1. going to a wider tire that would absorb more shock,
2. a smaller rim diameter, and
3. I think, a burlier rim,
each would offset the loss of stiffness and durability from losing 4 spokes compared to what I currently have. But I'm not 100% confident so turning to people here who may be able to help.

If you made it through my essay above and have some expertise/advice - thank you!.

fietsbob

I have 24 spoke wheels but on a 349/16" wheel _ My Bike Friday Tikit (rear hub a 36 hole (1 in 3 holes shipped) rim 24 hole..

32 spoke 650B would be better .. it's a bigger rim than a 26" ..

WizardOfBoz

I weigh 240 and my two most frequently ridden bikes (both 700c) use 24 and 20 spoke wheels. My prejudice is that anyone weighing only 125 has no business worrying about wheel strength! Sorry to not be more substantive, but I think that there is something to this argument.

Just to understand your situation, do i understand correctly that you are going from 700c to 650b? 633mm BSD to 584mm? I think you'll be fine, but others may have a better experience base (like fietsbob, above). So pay heed.

Koyote

Geez, you included a LOT of extraneous info. In the future, stick to the relevant info and you'll get more responses. (e.g., your groupset has no relevance to this Q.)

At your weight, even with 30 pounds of load, you will likely be fine as long as the wheels are built properly. If you are really worried, get a rear hub and rim that can are 28h.

Andrew R Stewart 

I won't vote because any wheel you decide on can suffer a single boo boo that ends that wheel's useful life. so "trying to figure out if the build is reasonable for my use, or may run the risk of breaking spokes/tacoing the rim" is very possible with any choice.

Having said that with disk brakes on my personal bikes I would not use so few spokes. Unless you are the type who considers wheels as a consumable (and those who know my posting here are free to find where we had that discussion). Andy

veganbikes

If rear spacing is 130 no disc brakes unless you have some custom hub which I wouldn't recommend. If the frame has disc brakes and is 130 that is an oddity for sure.

tFUnK

I routinely ride 20/24 wheels but with a disc brake setup I would go for 28 or 32. At your weight I don't have reservations about spoke count but running discs I would recommend more spokes.

canklecat

Your proposed body weight plus load is my riding around weight -- I vary from 147-155 lbs. For the past year I've ridden an old set of Bontrager Race Lite Aero wheels with 16 DT Swiss aero spokes per wheel as my daily riding around road bike on chipseal and bombed out pavement. No problems. Probably my only wheelset that has never needed truing, ever. Those semi-aero rims were stiff. (The original old style DT Swiss 240 hubs were another story. Some owners reported cracked flanges, although mine are fine. But overhauling the old style DT Swiss hubs wasn't as easy as the newer style.)

I've broken spokes on 32 and 36 spoke rims, but that was probably due to mediocre wheel build. A well built 24 spoke wheel should be fine at your weight with only occasional heavier loads.

cpach

It's not what I'd spec for your use, even given your pretty darn light weight, but if you have parts in hand it's likely to be fine. Make sure to get rear tension as high and as even as you can.