calderp

x posted to SS/Fixie

I'm a dumbass and I cracked my rear Trek Matrix rim last night, now I need a new wheel but I'm thinking this might be a good chance to learn how to build one. I've got the Shimano Ultegra 600 hub from it and there's a dude on CL selling a new Velocity deep V for $60 (is it worth 60? I was going to try and talk him down a bit but I dunno what they cost). Only problem is, I don't have a truing stand or any experience building wheels. If I can get my hands on a stand, how hard would the build be using sheldon's article? I know the rear is harder than front but wouldn't a SS rear be easier than w/ cassette? Also, right now I have a ghetto-rigged freehub (the Shimano) w/ spacers and SS cog, how would this translate to my rebuild, would I need a new hub, cause I don't really have the cash. What about just dishing it the same as it is now? Basically, I don't know **** about wheels. Do you think the chances of me screwing up a $60 rim make it not worth trying, or would I just have to relace it if I did somehting wrong. Lastly, if I can't get the rim or want to be really cheap, I've got a Bontrager race lite front wheel that I dumpstered (it's even true!), what about taking the Trek Matrix rim off my front wheel, lacing it onto the rear freehub, and riding with the Bontrager in front so I was just throwing the hub onto the same type of rim, w/ the same spokes? Would keeping the same spokes and rims make this a lot simpler and would I be safe riding the **** out of a low spoke count front wheel (I work bike delivery so it'll get a lot of use on kind of ****ty streets)? If I just relaced the freehub on the same rim, think I could do it w/o a truing stand by just numbering each spoke or would it be impossible to get them all the right tension? Sorry for the long questions...
Thanks!

Air

Search is your fried...even just the front page

Short answer - the spokes are probably set from the original build and even if you could use them the distance between different hubs and rims vary so they probably wouldn't be the right length. Check out here for a primer.

calderp

Thanks, I got a bunch of info from searching and sheldon's site but it didn't answer all my questions. In terms of reusing the spokes, I have a set of Trek Matrix rims, one of which is cracked so I was thinking of taking apart the undamaged front wheel and using the hub and cassette off of the cracked rear wheel to rebuild them, meaning I would have the same brand/model of rim.

tellyho

You can definitely reuse the rim; you will probably (possibly?) need new spokes, as rear wheels sometimes take two different lengths. You'll want to check out a hub and rim database to find out. Spocalc was excellent, but might not have your hub and rims in the database.

calderp

But would I still need new spokes since I'm using the same rim? I would be taking the hub and spokes off the rear wheel, without removing the spokes from the hub, then taking apart the front wheel and putting the identical rim from the front wheel on the hub and spokes from the rear so that the only thing that would be different would be replacing the Trek Matrix rear rim with the front rim, which I assume is identical?

smurf hunter

You can get a new Velocity Deep V in any color, w/ or without machined brake track for just over $60 at many LBS.

Retro Grouch 

How on earth can you say that without seeing what condition the rim is in?

grolby

In fact, you can get the pair for $40 + shipping at the moment - just use the coupon code they supply on the front page when you check out. I just snagged myself a pair for about $46.50 shipped!

aaronspoker

I definitely recommend building your own wheels, if you have the time to learn, and the fairly modest budget necessary to get the right equipment.

If you want to learn to build your own wheels, I highly recommend you get Jobst Brandt's book on bicycle wheels. While it is just the bare basics and covers traditional wheel styles only, it is understanding that any wheelbuilder needs to have. Not everybody agrees with all of Jobst's recommendations, but the important part is to know why he recommends what he does. Without understanding how a wheel works, you are quite likely to make an error which would yield a very unsafe wheel.

You want to get new spokes, probably stainless steel double-butted unless you have a specific reason to get something else. (Don't forget brass nipples.) Two main reasons that I can think of:
-Spokes will eventually fail, and this is an excellent time to replace them.
-Spokes are not really designed to be reused; the threads may wear badly during the rebuilding process.

You absolutely need a stand of some sort in order to get the wheel true. It is possible to use the front fork of a bicycle for this, but it may be much harder to get the wheel true, particularly radial (up and down) true, which can't be done easily using the brake pads. You can be pretty much guaranteed, though, that equally tensioning up the spokes will not yield a perfectly true rim, particularly if you're reusing an old rim.

Just to get you going on this decision making process, here's a list of what you'll need:
-Hub, reusing old is probably fine
-Rim, undamaged
-New spokes and matching nipples (probably want a few extra)
-Rim Tape (you may be able to improvise this)

-Good instructions. Jobst's book is a good start. There are some good websites also.
-Truing stand (as above, bicycle fork will work)
-Dish gauge: a truing stand or bicycle fork won't be able to tell you precisely if you're dished. You may be able to improvise a dishing gauge, since they're fairly basic tools.
-Lubricant for spoke nipples (I use whatever grease. Others use various particular oils, WD-40, locktite, trademark products, etc)
-Spoke wrench of the right size (Do not try to use an adjustable crescent wrench or screwdriver.) A major fear in wheelbuilding is rounding off nipples, so getting the spoke wrench correct is important.

Recommended but unnecessary thing:
-Tensiometer: Even pros need to use these to ensure optimal tensioning, and it sure makes things easier as a beginner to be able to quantitatively analyze your spoke tension when something goes wrong.

Unfortunately, these things all cost money. If you don't have the budget to do it right, I would not recommend attempting a build, because there is a serious risk of having a bad experience or building an unsafe wheel.

Hope that helps.

calderp

Thanks for the tips! I borrowed a truing stand and have the parts so I guess all I would need is a dish stick and some spokes, I was thinking for the first time of just taking it a bike shop and getting them to check the tension when I was done, I'm assuming it would be easy for a mechanic to tell if I screwed it up? Also, sheldon brown says you can tell by pitch, would a guitar tuner work as a DIY tensionmeter? Thanks

aaronspoker

It is very difficult to tell the absolute tension by pitch, for a variety of reasons, but mainly due to interference where the spokes cross. You could try the tuner, but it may not register the tone very well.

However, you can tell relative pitch and a ballpark pitch fairly easily. When you're almost done building the wheel, pluck spokes near the rim, and the spoke tension should be somewhat close (not exact) from one spoke to the next. (If not, you need to balance them out to prevent a spoke from coming loose later.) Also, the pitch of the tone of the plucked tightened spokes should be at least as high as the old wheel.

smurf hunter

Gerd Shraener's book mentioned that a wheel built with a higher tension will hold up longer, but for practical reasons this is more complicated to build. I followed this for my first wheelset and so far it's held true.

For the higher tensioned wheel it really raised my confidence to validate my build with a tensionmeter. Is Shraener's view pretty widely accepted, or this is one of those debatable issues?

aaronspoker

Yes. The wheel should be as high tension as possible, up to the lowest of the limits of the spokes, nipples, or rim. If its a radially-spoked or otherwise fragile wheel, other considerations may apply. Which is the limit probably depends on spoke count. Jobst recommends a fairly unusual procedure for finding the tension limit by pushing the rim past the tension, then backing off--but somehow this seems questionable to me.

Incidentally, I recently bought Schraener's book (the English translation), and I thought it was pretty terrible. The translation itself was bad, but the content itself was also pretty questionable in my mind. He starts off the book disclaiming any real qualifications except artisan, then goes with filler, various long-dispelled myths, and some questionable information.

Well, at least I enjoyed the section he where he wrote about what he thinks of people who use twisted spoking patterns.

Air

How do you determine that tension based on the spokes, nipples, and rim? Do they come with limits?

calderp

Yep, tension is proving to be the hard part. I built it up last night, it took a while but turned otu to be pretty easy with the truing stand but I'm not confident that I tensioned it right and don't want to ride it without knowing so I'm going ot take it to a bike shop and just get them to check it for me. Thanks for all the tips guys.

aaronspoker

Air, if you're lucky, the manual or specification will say. All popular spoke types have specified tension limits. Some rims do not. With nipples, it will become apparent while tensioning the wheel that the nipples cannot be tightened further, although at what point this happens probably is not specified anywhere.

When all information is not available, its hard to say exactly what to do, so most people just wing it. Jobst's tension-discovery procedure is an option. Other people just make sure they're above 100 kg-f, which some evidence suggests is enough for a normal 36 spoke wheel. Sometimes you know which factor is likely to be the limiting factor, and use that. For example, for low spoke count wheels, the nipples will probably be the limiting factor, so its usually safe to tension up to the maximum you are able.

Air

Gotcha, thanks!