|Wheel Building Question||PT|
Dec 2, 2002 2:00 PM
|I'm building a front wheel: Venus rim, Ritchey hub, straight guage DT spokes. It is to be laced radially with 24 spokes. I've built a few wheels over the past 20 years, but have never been very pleased with any of them. I resolved to go slow on this wheel and build it round and true. I intend to use locktite on the threads after being told it was essentially the same as spoke prep. Furthermore, Sheldon Brown recommends using spoke prep/locktite on radiallylaced wheels.
Now that makes it a bit complicated as I imagined I would lace, tension and true the wheel over many a cold winter evening. So, if I'm using locktite it would presumably setup in the course of a few hours, let alone over a fortnight of careful truing. Should I just bite the bullet and go for it in a single afternoon, or can I dribble in some locktite through the spoke holes after it's all done?
|re: Wheel Building Question||curlybike|
Dec 2, 2002 2:23 PM
|After the wheel is complete, you can put a drop of Loctite 242, blue, at the nipple end that the wrench goes onto. After you do all of them, give the wheel a really fast spin and the loctite will migrate into the joint, do it again untill the gap between the spoke and nipple stays full after the spin. Remove wheel from truing stand and lay it horizontal for a day or so. This will allow a max cure on the Loctite. The nipples wil still move later when you adjust the spokes. You may need to hold the spoke with smooth jawed pliers to resist twisting, or use a twist resist tool.|
Dec 2, 2002 2:51 PM
|I've never been that comfortable using Loctite on nipples - the threads are so fine, and proper tension should prevent serious loosening.
That said, 24 spokes increases the loading of each spoke, as does radial-lacing.
I'd still shy away from Loctite, unless absolutely necessary. Grease the nipple seats and spoke threads (it doesn't matter that much what you use, as long as it's slippery. I prefer grease as it stays in place longer than oils, and allows easier truing later on).
I'd also consider using butted spokes. They stretch more than straight-gauge, and should be "easier" on the nipples. I'd think this could make a difference.
The real secret to wheel building is going slow, and using small increments of tension all around. Don't try to bring it up to full tension in one go. I lace the entire wheel, using 2-3 turns of the nipple to hold spokes in place. Then I turn each nipple until only one thread shows. If your spokes are the right length, this wheel won't have any tension at this point. Then I add tension in full turns, working my way around the wheel. When tension begins to approach the right range, I start worrying about radial and lateral true.
Also, remember to stress-relieve the spokes during and after tensioning. This helps everything settle in, and minimizes post-build untruing (and that annoying pinging sound).
So, patience is key, but you'll probably be done in one evening (radial is simple). Have fun.
Dec 2, 2002 4:42 PM
|Linsead Oil! |
It's been a standard in wheel building for years b/c it tends to dry out and gum up a bit, but not so much that you can't make adjustments in the future. How well does blue loctite work once you've done some truing at a later date and cracked the bond? I really don't know anyone professionaly that uses Loctite. DT (and others) now have a nipple out that actually has a little plastic washer inserted like on a nylock (i.e. aircraft nut) inside the nipple to prevent loosening. Probably expensive and hard to find.
Currently building up a wheel for a buddy - and it reminds me that I think one of the keys is spending enough time getting the wheel *radially* true first. This is where errors in spoke tension get addressed - lateral truing is child's play in comparison.
|good point about radial truing||dzrider|
Dec 3, 2002 8:33 AM
|I've found most rims start out real close to round and that keeping them round and keeping tension even amount to much the same thing. Getting a hop or a flat spot on a wheel usually means I've screwed up something that was ok at the start. It also seems to take way too many turns to fix the problem. Each time I go around the wheel tightening I check to see if it's still nice and round. If it's off at all I fix it before tightening any more.|
|re: Wheel Building Question||Jofa|
Dec 2, 2002 5:40 PM
|Your post implies that your previous wheels didn't stay true so well. I'd urge you not to try to combat this problem by putting glue in the spoke threads; it is an ad hoc practice that is unlikely to be reliable in the long term, and an inelegant solution to a problem that shouldn't exist. Focus your attention instead on your wheelbuilding technique (and, as someone else said, use DB spokes). There are crucial processes in this that are not obvious and will not be guessed by the lone experimenter, who continues to be disappointed by his wheels. Sheldon's page is a good summary - though I'd say his recommendation on this particular subject is a little dubious - but by far the best text to work from is 'The Bicycle Wheel' by Jobst Brandt; there is a link to it on Sheldon's site.
I've built radial wheels before, with oil in the spoke threads as usual, and they have not lost trueness. Two of them however failed at the hub, as they are prone to do unless you use specially designed hubs.
It is far more satisfying to build an ordinary wheel very well than an unusual one badly, in my judgment.
|Just do it||pmf1|
Dec 3, 2002 6:53 AM
|all in one sitting. I've used Spoke Prep on many wheels with good results. You need to apply this before you start. Dribbling it through the spoke holes is only going to make a mess.
Dip the threaded end of the spokes in the bottle of Spoke Prep. I typically do 6-8 at a time. Now whap the spokes in the middle against a tree so that the excess flys off the ends. Do this making sure the excess does not fly towards anything you care about (i.e., avoid getting blue flecks on your house or your car). Let the spokes dry and lace them. I always tried to make sure I applied even numbers of turns. To start, do 3 full turns to get each spoke laced. Now go around doing 2, then 1, then a half until the desired tension is achieved. If you do this slowely and carefully, there won't be much truing to do. You can easily build a wheel in 2 hours.
|Use low-strength thread-locker instead of the 242 Blue...||Quack|
Dec 3, 2002 7:01 AM
|I wouldn't recommend using the blue thread-locker to build wheels. Once it sets, it won't let go until your spoke has twisted nearly 360 degrees. I have had great luck using the low-strength locker (I forget the number) on all types of lacing patterns. It leaves just enough material in the threads to keep them from unscrewing during riding, but still allows for a fairly friendly truing. You will still have twist, but not to such a bad extent as with 242. As far as truing your wheels over a few nights time, I would urge you to set aside a few hours when you first apply the locker and get as far as you can in that time. If the rim and spokes are new, a few hours should be enough time to get the wheel nearly perfect even if you're really slow. It sounds like you've already built a few bad wheels and have done some reading so you should have good luck. Just remember to make small changes, match tones, and always take the twist out and you should do well.
|re: Wheel Building||Chen2|
Dec 3, 2002 7:33 AM
|I buy my spokes from my LBS and he will dip them in spoke prep if I ask for it, and at no charge.
|re: Wheel Building Question||litesp|
Dec 3, 2002 8:50 AM
|I've built hundreds of wheels in the last decade while wrenching for bike shops and for local teams. Here are a few key things that work for me for wheel durability. (1)Properly seat the spoke elbows at the hub before adding tension, (2)Add tension to the spokes only after the wheel is laterally and radially true, (3)Slowly alternate between adding tension and truing while maintaining balanced tension between neighboring spokes on the same side, (4)Release any spoke twist during tensioning, (5)Approach optimum spoke tension (depends on spokes and rims). Note: Add a drop of oil to the rim-nipple interface to ease tensioning, don't lube the spoke threads. For detailed build info. check out Jobst Brandt's excellent "The Bicycle Wheel" book.
As for thread compounds, I've used SpokePrep for years with satisfactory results. Then some Mavic guys at a local race recommended using loctite 242 (blue) for straight guage. 222 (purple) is better for butted spokes because it reduces spoke twist during re-truing. Simply apply a drop to the spoke-nipple interface then spin the wheel and let centrifugal force draw it in.
Both DT and Sapim spoke mfg co. sell a thread compound that is re-labled loctite.
|Thanks, good info. (nm)||Chen2|
Dec 3, 2002 9:23 AM
|Thanks & one more question...||PT|
Dec 3, 2002 9:54 AM
|Thanks for the suggestions. I laced the wheel last night and have started bringing it into true and am experiencing the same issues I have with my previous builds -- I'm good at dealing with wobble, but "hop" is my nemesis. Previous wheels have been satisfactorily strong, but not as round as a high-quality wheel should be. I've done my best to keep my spoke tightening equal, but the hop is still there. Before I get to the point of no return, any hints for dealing with hop?
One more thing, there was several pieces of black-rubbery-turdy material bouncing around inside the rim, some of which I had to remove with a forceps. As this was a new rim, I am somewhat at a loss as to what it is...any ideas?
|Start by loosening...||Quack|
Dec 3, 2002 12:24 PM
|I would start by setting your radial gauge so that it rubs the rim at a high spot. Then loosen the spokes 1/4 turn in Right/Left pairs in areas of the rim where the gauge doesn't touch. Continue around the wheel until the rim just touches the gauge all the way around. Then increase tension uniformly by doing 1/8-1/4 turns at each spoke around the rim starting at the valve hole. Once your spokes are up to tension, the wheel should have fairly uniform tension, be round, and be close to true. Slight tweaks may be necessary to get it perfect. And don't freak out too much about the rim joint...the spoke tension almost never matches the rest of the wheel perfectly in this area if the wheel is perfectly round. Usually, if you match the tone, the rim joint will either have a slight dip or a hop, but you will not likely feel it while riding.
|re: Wheel Building Question||brider|
Dec 4, 2002 1:13 PM
|Ditto grzy's suggestion of linseed oil. Heard it recommended all the time. |
My builds, however, were done rather unorhtodox -- I just used regular old 30-weight motor oil, and have had ZERO problems in over 8 years. Always, when adding tension to the wheel, do so a little at a time, check roundness, and only true it up AFTER it's round. Check the roundness after EACE ROUND of tension, then true it up again. A radial laced wheel is going to be a bit more sensitive to uneven tension causing out-of-round problems, but it's the same process nonetheless.
As for Loctite, I'd suggest not using it at all. But if you must, go for green Loctite that's made for adding AFTER the parts are threaded together. And I'd only add that after the first several rides when the spokes have unwound and you've corrected any true and round issues.