Sep 12, 2003 1:03 PM
|I'm building a set of wheels with Chorus hubs, Mavic Open Pro rims and DT spokes (15/16 in front, 14/15 in back, brass nipples - as advised on this forum, mainly by Mr Grumpy - thanks, Grumps). Wheels are for daily use, I'm about 150lb, spinner, covering mountains and flats on reasonable roads.
Questions - any advice on what tensions I should use? BTW, anyone know how much spoke-tension you can put on Open Pro rims? Their website isn't helpful, and the Park website only seems to list recommended tensions for complete wheelsets (Ksyrium etc).
Appreciate the advice, past and future.
|If you have a spoke tension device, it'll be in the .....||MR_GRUMPY|
Sep 12, 2003 1:29 PM
|instructions ($50-$90). If not, play it by ear. After building and truing, pluck a spoke, and compare it to a good wheel. If fact, compare it to a few wheels. Your friens will wonder, what the hell you are doing, when you start to play with their wheels.
If you get them too tight, the drive side spokes will start to break after some time. If they are too loose, the non-drive side spokes will begin to break.
|here's what I do||DougSloan|
Sep 12, 2003 1:37 PM
|I don't know the absolute tension, really, as that involves using the tensionometer and converting from some table based upon the material and diameter of the spokes.
So, if you have a known good wheel with similar parts, measure that tension and then shoot for similar tension in the wheel you are building. Give it a reality check by plucking the spokes and comparing the feel and sound. Also, when it's starting to get tensioned right, it becomes harder to turn the nipples, and it just "feels" right, particularly if you have trued a lot of wheels over the years (but only if the threads and nipples are lubricated and not stuck).
What's more important, I've read, than absolute tension is the relative tension among the spokes on the wheel. They should be within 10% of the same tension, all on the front, and for each side separately on the rear. When measuring relative tension, you need not convert, as whatever reading you get applies equally to all measurements.
Nonetheless, I have seen published recommended absolute tensions. I just can't recall where.
These books are helpful to me, particular the first one:
The Art of Wheelbuilding: A Bench Reference for Neophytes, Pros & Wheelaholics, by Gerd Schraner
The Bicycle Wheel, by Jobst Bradt
Zinn also has some wheel building information in the Art of Road Bike Maintenance, too.
|re: Spoke tension?||torquecal|
Sep 12, 2003 3:51 PM
|I don't know the max tension the open pros can take but I've read that the perfect tension is somewhere between 200-225 lbs (The Art Of Wheelbuilding by Gerd Schraner).
However, this book and Brandt's agree that the perfect method is to keep tightening until, when you stress relief the spokes and then put the wheel back in the stand, it has a two wave lateral untrue condition that wasn't there before you did that last stress relief. Then back off spoke tension to get the wheel back to true. This takes the whole wheel just slightly beyond the optimum tension but then backs off in the final truing process.
It works, and when done right it results in a wheel that won't have to be retrued after a couple of rides out on the road. Once you get it make a note (if you have a tensiometer) of what the final average spoke tension is. Also make a note of the rim type, spoke gages and size used, as well las lacing pattern. If you have to build another one the notes might save you a little time.
|re: Spoke tension?||divve|
Sep 13, 2003 1:20 AM
|For OP rims Mavic recommends 90-110 kgf for the front and drive side in the rear.|
|re: Spoke tension?||Mink|
Sep 13, 2003 8:36 AM
|Thanks, all.|| |