| Author | Message | ||
     Acgwolfe |
After a crash the front wheel on supermoto is now warped. I checked it tonight and it seems to be about 1/4 inch out. Can I repair this by tightning the spokes or do I have to get a new rim and have it relaced. | ||
| Sifo |
IMO, based on mountain bike experience, once the rim is bent you will either have a wheel that has one or more of the following... A) Out of true. B) Out of round. C) Uneven spoke tension. How much of any of these is acceptable is up to the owner. | ||
| Preybird1 |
It can be straightened sometimes... but only if you know what you are doing. I had an old 1979 honda xl250s enduro and you could not get parts for it and i had a wheel trued up and it worked just fine for many years. | ||
| Natexlh1000 |
I would suggest loosening them all up til it's floppy to see how bad the hoop actually is before trying to MAKE it good with force. Perhaps it's worse than it looks is all I'm saying. | ||
| Sifo |
The only problem with loosening up the spokes is it makes it hard to measure the rim. You could completely unlace it and lay it on a flat surface to measure run out, but you would have a very hard time measuring out of round. I would say true it up and see where your at. You can get a good idea of how even the spoke tension is by whacking the spokes and listening to the tone. Building spoke wheels is part art and part science. It's hard to put a tolerance spec. on that sort of thing. The hard part is figuring out if you only need to tighten spokes that have been stretched, or if you need to loosen the opposing spokes too. Keeping it round can be the hard part. I would probably say that if you can get it close to straight, close to round, and all spokes with a similar tone when struck the wheel is probably going to be usable. It will never be perfect again. If in doubt of your work, check it after every ride for the next few thousand miles gradually going longer between checks as you gain confidence that the wheel is staying true. It's unlikely to just catastrophically fail without showing serious signs of spokes flopping around lose. | ||
| Britchri10 |
I dunno if this will work but template it. Mark center on a large sheet of paper, wood, flat garage floor etc' draw a large circle to coincide with the circumference of the wheel. lay wheel on it & you should get an idea of "roundness". Provided the surface you work on is flat you can estimate "trueness" also. (yeah, I know it's not an actual word!) If it's only a little "out of round" you should be able to correct it via spoke tightening etc'. I don't know a "shade tree" way of correcting it if the wheel is out of "true". (Brass Hammer?) Good luck! Chris C | ||
| Sifo |
The problem with laying it on a flat surface is that you need a hole big enough to accept the hub, unless you have a very narrow hub or wide wheel. It's much simpler to just spin the wheel on a stand. You can make the fork work in a pinch. Rig a pointer that can be adjusted right next to the rim so you can closely watch the run out. This makes it easy to spot high/low spots and you can just run the rim forward/backward to locate the center of the fault. Making small adjustments is key! | ||
| Britchri10 |
Sifo: You're right. It's been 30+ years since I did anything like this. Since '81 all my bikes have had cast wheels! My father is a tool maker by trade & he did most of the "trueing" for us. The board (with the hole for the hub, which I had forgotten) was his solution to the problem. Chris C | ||
| Patrick2cents |
I would take it to a wheel builder/someone who knows what they are doing with spoked wheels and have them true it. Truing it can be tricky if you haven't done it before. | ||
| Sifo |
Haha, My dad had a tool & die shop near Detroit! It's funny the stuff you learn but forget over the years. It comes back fast when the memory is jogged though. I hate to think how few of the next generation will have seen the ingenuity of a tool & die maker. | ||
| Britchri10 |
Mechanically my father can still run rings around me. He's 77 now & has just finished rebuilding an '84 car engine & gearbox. My son is 12 & has trouble operating a wrench or screwdriver (He's a whizz at video games though!) I gave him an old ceiling fan to take apart last week. He did it & did it well, but he just has no interest in anything like that. Chris C | ||
| Just_ziptab |
With zero experience,I've re-laced 4 rims....but it's been years ago. I clamped the axle/wheel with wood pads in a vice,set up a "pointer" and had at it. Seems most of them were very untrue with just the spokes laced in at finger tight. Tedious but fun. All of them trued up to nearly perfect. The hard part was using a 4 inch crescent wrench to turn the nipples. Now I have a nipple wrench(shad up pervs) | ||
| Thumper74 |
There are TONS of wheel building sites for bicycles. Google Sheldon Brown. He has a great website on bicycle repairs, with a comprehensive section on wheel building and truing. The rules all apply to you bike as well. It DOES require patience, proper(ish) tools, antiseize and more patience. | ||
| Acgwolfe |
Ok, I spun it on the axle with a guide and noticed it is warped side to side roughly 3/16. The impact of the crash was on the side of the rim. It didn't look to be out of round. But I probably need to check a little closer. Thanks for the help. | ||
| Sifo |
Sounds like it's time to twist some nipples! I would start at the center of the bump. loosen a 1/4 turn on one side while tightening a 1/4 turn on the other then check where you're at and repeat. Take your time and stop to think about which way you are turning the nipples. It's easy to confuse yourself as you turn the wheel and look at the nipples from one side then the other. A bit of penetrating oil at the joint of the nipple and rim might help the nipples turn without stripping the nut area. Hitting the threads probably wouldn't hurt either. Depending on the design of the rim the innertube might put pressure on the backside of the nipples, so it doesn't hurt to let the air out it the tire is still on. One last thing I would check before you start. Check the rim with a guide on the other side to make sure the rim isn't just squeezed from the impact. | ||
| Fast1075 |
If the rim is flat spotted (bent), no amount of spoke adjusting will fix it. Call Buchanan Spokes and talk to them...they may be able to straighten the rim...or lacking that, can drill you a new rim...if none of the nipples are rusted to the spokes, it is a fairly simple matter to unlace the old rim and lace up a new one....but the force must be with you...it takes a certain degree of finesse and some of the tweaks are counter-intuative... Or you could package it up and send it to Buchanan...I very highly recommend their parts and service...I had a bike that ran mid 8's on a spoked wheel with their heavy duty stainless spokes. | ||
| 86129squids |
"You can tune a piano, but you can't tuna fish!" 'Tis worth studying a bit- it is both an art and a science. | ||
| Akbuell |
Back in the early '70's I worked on bikes for a living, and got to lace up 2-3 wheels. Not my favorite job. Also 'tuned' several, including my own. Plan A- Ride the bike. If no vibration or handling issues, ignore it. At least until the end of the riding season, then try B or C. Plan B- Take the tire off, and mount the wheel in a stand, or back on the bike, and set up a pointer to see what the wheel is doing. Use the tire bead seat as your reference, and check both sides. You may have a cosmetic flaw, and need do nothing. Only one side of the rim may be bent, so Plan A may be better. Take your time, tighten and loosen as needed, check runout frequently. FWIW, my '69 Sportster service manual lists a tolerance of 1/32in, both radially and laterally. A spoke wrench makes the job much easier. When done, don't forget to check the spoke nipples on the inside for protruding spokes. You may have to do some minor grinding. Plan C- Put the wheel in a box and ship it to Buchannan's. They do good work, they have been in the business for a long time, and I have used them with good results. You also may be able to find someone in your area that you trust to do the job. Hope this helps, Dave (Message edited by Akbuell on September 04, 2011) | ||
| Acgwolfe |
I didn't think about it being squeezed. I'll check that before I do anything. It does not seem to be out of round. So that could be the problem. | ||
| Kyrocket |
Craig where do you ride? I'd like to get back into it but don't have anyone to ride with. When I was living in Richmond in the early 90's I absolutely trashed a rear rim and took it to a bike shop on the by-pass IIRC it was somewhere close to where Hooters is now. They put on a new rim and it was good as new until someone stole my bike a few weeks later.  | ||
| Natexlh1000 |
Well of course they stole your bike. With a fancy new ROUND wheel, it was just asking for it! | ||
| Acgwolfe |
Kyrocket, I ride the supermoto on the roads around my house, in Redlick, through Irvine, Mckee. I have got some great supermoto roads if you like tight twisties and gravel roads. Ill pm you my #, maybe we can get together. I rode the bike down the road tonight before I touched anything and it didnt seem to handle any different. But you can look at the tire and can tell it is off. I believe it can be repaired by someone who has the knowledge, not me, with little effort. I just dont know of anyone close who can help. I guess I will change back to the dirt setup and send the wheel off. Unless you know anyone around here Kyrocket. |
