ClarkinHawaii

Needing to retrue and retension a set of wheels with 32-spoke (3x rear/2x front) Ultegra 6800 hubs, HED Belgium rims, and 2mm straight gauge spokes. Rider weighs 160 lbs.

From some guy's blog I found HED Belgium rim max acceptable spoke tension of 163Kgf. Seems kinda high--especially compared to the Mavic Open Pro I grappled with a couple of days ago--

anybody agree or disagree with 163 for RDS?? Maybe 110 for the front? Thanks

FBinNY 

There's no benefit from more tension than needed regardless of the max that the rim can take. I'd go higher when there are fewer spokes, but for 32h, I'd build them with something close to 100kgf in front, and 60kgf left rear, letting the right end up where it does. If you want to go a bit higher, do so, but don't go for the max.

AnkleWork

Search "define maximum."

ClarkinHawaii

Music to my ears--Thanks.

chriskmurray

Just because you can, does not mean you should. You see this often with China carbon rim manufacturers, it almost seems like they use max tension as a bragging point on how "strong" their rim is when in reality there is much more to a durable rim than simply max tensions.

I will second FB's comment about not focusing on the max tension possible but rather build to a more "normal" tension range like he mentioned.

ClarkinHawaii

+1

ClarkinHawaii

Well, turns out the front wheel has got a teensy little problem--the owner was in an accident and the front wheel has some abrasions that I can sparingly file/emery board off. So far so good.

BUT the only way the wheel will true up is with spoke tensions varying between 60-120 Kgf.

My understanding is that this is not unsafe, per se; but uneven tension like this will definitely result in wheel/spoke problems down the line. If it is inherently unsafe to ride, please let me know!

Does anybody know where I can get a good deal on a new (or used in good condition) HED Belgium+ rim? Shipped to Hawaii? (I mean better than what's advertised on the Net) The owner has got a bad case of road rash and deserves a break! Thank you.

chriskmurray

I would not call it unsafe but it is certainly very far from ideal and will present problems down the road.

You can get it better with a little massaging, also not ideal but if you can't afford a new rim it will make it much closer to acceptable. There are a couple ways of getting the rim straighter one much quicker/less accurate than the other. The quick one is to loosen spoke tensions until there is just a slight amount of tension on the spokes, find the spot that is badly bent and with inflated tire installed on the rim smack the high spot on the ground until it is as close to round as you can get it and retension/true. I have saved many wheels like this for people who simply could not afford a new wheel/rim.

The other option is to unlace the rim and find the high spot, clamp the good section down to the table with the bad hanging off the edge and a piece of wood over the length of the bad section and hit it with a mallet until the rim is as straight as you can get it. At this point though, if you can afford a new rim just buying a new rim makes much more sense since you already have things apart. You could also probably find a way to not have to unlace the rim with this but it is easier to see how flat you have the rim with everything apart.

For finding a new rim, any shop who is set up with a QBP account, which is nearly all of them, can order HED Belgium rims.

Curtis Odom 

Have you checked with HED?

ClarkinHawaii

Hey, Chris--Great tips! Thank you.

Kimmo

If you get the rim off, hold it against a window to check how straight it is.

And put it in a corner on the floor and roll it in place against the wall while watching the top of the rim to see how round it is.

Some well-judged brute force can get it straight again, and you can even have some success making it round, if you can find a wooden post in the ground to pull out flat spots against.

FBinNY 

OK, I thought this was a carbon rim, but it's aluminum.

So here's my way of horsing bent rims back to shape. Use a yardstick on a secant spanning the rim in sections and eyeballing radially until you locate the bent areas. Then when you have an idea of where and how it's bent, loosen the spokes in the affected area so you're not fighting them. Then sit in a comfortable chair, place the crest of the bend on one knee, and pull the base of the bend toward yourself.

Bending this way gives you some degree of control, and the straight edge will tell you when you're close enough. When the rim seems decent, slacken see if you can bring it back. The first time, you might find it easier to slacken everything, then align as you would a newly built wheel, but with some practice you can use the quicker method.

Looigi

I do the opposite. I set the DS tension as desired and let the NDS fall where it may. Building rear wheels I tension and radial true the wheel using only the DS spokes leaving the NDS spokes totally slack. Then tension, dish and laterally true using only the NDS spokes.