Bicycle Mechanics - reliable 28 spoke rear wheel?

I've been having problems with a 28 spoke rear wheel, spokes loosen and occasionaly break. The rim is a Weinmann TR18, laced to a Joytech hub . I'm 235lbs, ride mostly smooth roads with occasional areas of patched pavment, never hop curbs, take up bumps with my arms and legs. This is my everyday ride, not a touring bike. Your opinions on whether this wheel is too light or just needs more attention being tuned.

it's not a particularly light rim.
I would guess that the spokes are all under-tensioned and fatigued

Nothing short of a full rebuilding of the wheel by a competent wheel builder with new spokes will solve this problem.

for 200lbs and up, I would recommend a minimum of 32h with 36h rear wheel preferred.

I have heard plenty of stories of big riders and 28 and fewer spoke wheels who ride many miles with no problems. I also hear many stories of big riders with 32 and 36 spoke wheels who have spokes popping like popcorn. WHile I agree that you should ideally have 32 spokes or more, 28 properly tensioned and stress relieved spokes shoudl be fine. Have your wheel rebuilt with new spokes and make sure you have an experienced builder who understands that bigger riders need higher spoke tension.

What AEO said...

1. Rebuild with new spokes...
2. Have a pro do it...
3. Proper tension from the outset is the key - 110 to 115 kgf on drive side is a good start.

If in the future if you do an upgrade that is wheel oriented - 32h/36h double-wall double-eyelet with better hubs would be nice. Save up!

=8-)

+1. You are really getting no benefit I can see from having 28 vs 32 or even 36 spokes - although if you are concerned about lighter rims 32 is probably easier. At 250+lbs with bike it would take quite a bit for even rotating weight to make any significant impact.

Thanks for the input. I just had the wheel rebuilt with DT's; after 30 miles, 4 spokes loosened. I trued the rim and checked tension on all the spokes. I'm going to keep an eye on the wheel the next few days. I've been thinking about a 32 spoke rear, perhaps for piece of mind that might be best.

What AEO said...

1. Rebuild with new spokes...
2. Have a pro do it...
3. Proper tension from the outset is the key - 110 to 115 kgf on drive side is a good start.

If in the future if you do an upgrade that is wheel oriented - 32h/36h double-wall double-eyelet with better hubs would be nice. Save up!

=8-)

The cost of re-lacing this wheel is going to be $60.00 - $70.00 as you need to pay the builder for their time and buy new spokes... better idea is to put this money toward a better wheel.

For $150.00 you could get a pretty bombproof wheel built with decent parts.

Thanks for the input. I just had the wheel rebuilt with DT's; after 30 miles, 4 spokes loosened. I trued the rim and checked tension on all the spokes. I'm going to keep an eye on the wheel the next few days. I've been thinking about a 32 spoke rear, perhaps for piece of mind that might be best.

Find another wheel builder.

The cost of re-lacing this wheel is going to be $60.00 - $70.00 as you need to pay the builder for their time and buy new spokes... better idea is to put this money toward a better wheel.

For $150.00 you could get a pretty bombproof wheel built with decent parts.

The rebuild was taken care of via a warranty since the bike was new and assembled at a LBS. If the problem persists, I'm going to look into upgrading the wheel.

28 spokes and 235lbs don't mix very well. Go get one of these: http://www.coloradocyclist.com/product/kit/SSFCEU32

We cannot underscore the competency of the wheel builder enough. Relacing, if he did that is not enough. Proper (high enough) and balanced (10% variance in tension for same side spokes) is VERY important. If you are already having trouble with his recent work, I highly suspect one or more of these factors are not present. FWIW, I ride a set of 32 hole Mavic Open Pro rims(not known to be the strongest rims) laced to Ultegra hubs. I weigh 230 and have over 5000 mile on these wheels so far. I have had absolutely no issues but I know the wheel guy (me) and he is a stickler for quality.

My recommendation is that if you upgrade, and since many wheels are machine built, you still should find a local wheel man with a good reputation and have him properly tension the wheels. This will cost you more but give you far better results.

Find another wheel builder.

Yeah.

28 spokes and 235lbs don't mix very well. Go get one of these: http://www.coloradocyclist.com/product/kit/SSFCEU32

+1.

Absolutely bombproof build, especially if you go with the 36-hole wheel. Although I prefer the CXP33 instead of the Open Pro.

I do notice the weight, especially when trying to accelerate hard. But noticing a bit extra weight is a lot better then noticing your spokes popping.

I would agree that competent wheelbuilding is a must, but I have noticed that narrow, deep section rims like the TR18 seem to be slightly more prone to spoke loosening, all other things equal.

At your weight 36 double butted spokes are the way to go. They should be tensioned to at least 100kg on the drive side. This is a good set. A friend has a set and he is over 250 and carried over 50 lbs on a short tour.
WE635 Premium 8-/9-/10-speed Shimano D-LX T660/Mavic 36
http://sheldonbrown.com/harris/wheels/622.html

http://go.bikeforums.net/?id=42X129555&xs=1&url=http%3A%2F%2Fwww.coloradocyclist.com%2Fproduct%2Fkit%2FSSFCEU32&sref=http%3A%2F%2Fwww.bikeforums.net%2Fshowthread.php%3Fp%3D10914239%23post10914239

Looks like a decent enough deal but would pay the extra 3 bucks and change for brass nipples... I will build wheels with alloy nipples if people are really insistent, and it will be a good wheel, but will only guarantee wheels built with brass nipples.

Thanks for all the info. Went for a 20 mile ride this evening on smooth pavement, the relaced rim ran fine so far. What I did notice was a tighter wheel under acceleration, it was obvious.



I would guess that the spokes are all under-tensioned and fatigued

Nothing short of a full rebuilding of the wheel by a competent wheel builder with new spokes will solve this problem.


I believe AEO was correct, the original wheel was under tensioned from the factory which created the problem. The rebuild is working so far, I'll ride with a spoke wrench and keep an eye on the wheel while a put some $ away for an upgrade. Thanks for the links and recomendations!

[QUOTE][Find another wheel builder. /QUOTE]

Don't think I want to throw my LBS under the bus Sixty Fiver, He relaced both rims at no charge, has a good reputation for the work he puts out. The problem may ultimately be the rim. I'd rather give him the benifit of the doubt until proven otherwise.

Thanks again for all the adivice and info, we really have a great community here!

http://go.bikeforums.net/?id=42X129555&xs=1&url=http%3A%2F%2Fwww.coloradocyclist.com%2Fproduct%2Fkit%2FSSFCEU32&sref=http%3A%2F%2Fwww.bikeforums.net%2Fshowthread.php%3Fp%3D10914239%23post10914239

Looks like a decent enough deal but would pay the extra 3 bucks and change for brass nipples... I will build wheels with alloy nipples if people are really insistent, and it will be a good wheel, but will only guarantee wheels built with brass nipples.

It appears brass nipples are standard and only black brass are more. Absolutely no reason to go for aluminum nipples in your case - and I think it's completely silly anyway. If you want to save 40 grams, or better yet let's use 80 grams to account for "rotational weight," just take 3 ounces less water with you on your rides. The pretty colors are the only reason I can see to choose aluminum spokes, and you have to accept the possible downsides.