nuclear_biker

I got a 1992/3 Trek 720 hybrid. Its got a 7 speed rear cassette. I have been overhauling it as it hasn't seen use in quite awhile. Got it working pretty good thanks to you guys here in the Mechanics subforum. To make a long story short, it looks like the rims only have limited life in them, and I want to start thinking about my options now. The wheel is a 700c (at least, I think it is), with original hubs and tires (700x35c). I am kinda new at working on bikes, but have really enjoyed myself so far. Try to bear with me if I screw up the bike wheel/tire sizing, its pretty confusing. I should also point out that this is mostly a commuting bike, with some pleasure rides on the weekends/evenings.

I have three options as I see it (please let let me know if there are more), and I want to figure it out now so that I can plan finances, parts, etc. I think I will stick with the same tire size, 700x35c seems to be sort of a happy medium, and works well so far.

Option 1: buy totally new wheels (easiest, but potentially more expensive).

Option 2: Buy new rims and spokes, reuse old hubs. The hubs look to be in pretty good shape, the bearings feel good, no wobble. Is lacing a tire something I could do? I watched a few videos online, and it looked doable but time consuming (which is fine). I have access to a truing stand. (probably cheapest option)

Option 3: Buy new rims, spokes, and hubs. (Might be a bit more expensive than option 2, but potentially cheaper than option 1, and I may get a better hub than i have now).

I'm currently leaning toward option 3, as with option 2 I'm worried that future problems could arise with the old hubs and then I'd have to relace the wheels again. If lacing is difficult to get right, then maybe it's best to go with option 1. Thanks in advance!

FastJake

If you are so inclined, wheel building is a fun and rewarding process with lots of benefits versus prebuilt wheels. I would go with option 2 assuming the hubs are in good shape and are genuine Shimano hubs and not some off brand. Have you cracked them open and re-greased? Once you do that you will have a better idea of what kind of shape they're in. You should really do this anyway since it probably hasn't been done in 20 years.

My one recommendation is to get butted, stainless steel spokes and brass nipples. I get mine at Yellow Jersey in WI for $30/wheel which is the best price I've ever seen.

AnkleWork

Begin there. Why do you think the rims have "limited life in them"?

Of the options mentioned, #1 is probably best and usually cheapest.


But you said they are in good shape. Maybe worry less and ride more. The wheels are probably fine as-is.

If the hubs and rims were perfectly new, they'd still have "limited life" and "future problems" could arise anyway..

SkyDog75

What specifically leads you to believe that your wheels need replacing?

If you do need to replace them, it's often cheaper to buy pre-built wheels than to buy parts to build your own. Buying complete wheels also prevents things like buying the wrong length spokes, or the need for a truing stand, not to mention the time/effort/ability to build wheels.

If you choose to buy something, regardless of what it is, you'll want to know what size/type parts you're replacing. We know you've got a 700c rim and that you run 35's, so we've got the info we need for the rim. A Trek 720 probably has 135 mm rear dropout spacing, but you'll want to confirm that by measuring. You've got 7 cogs on the rear, but are you sure it's a cassette? There's a good possibility it's a freewheel.

Retro Grouch 

Hubs are actually pretty reliable and generally will outlive several rims. I would encourage any average home mechanic to attempt to lace up a wheel for himself. It's not a particularly difficult job provided you think through each step as you go. I wouldn't expect to save a ton of money but you might save a little.

nuclear_biker

They're getting pretty concave, and the rear one has damage to it that couldn't be completely removed by the LBS and a spoke wrench. I will post a picture of this area later. I'm not sure how to tell how much life they've got left, but I could take some calipers to them later and try and get some idea. Any good way to gauge life remaining? My limited research indicates if they're concave and smooth, replace them.



I thought I remember the LBS guy mentioning it was cassette but I could be misremembering or he might have misspoken. Is there an easy way to tell? I will post a picture of it when I get home. I will also measure the dropouts.

Here are some pictures of the hubs. Rear: https://i.imgur.com/mY1DdAr.jpg front: https://i.imgur.com/kVb0fgW.jpg. At first I thought they might be rusty but it seems to just be 20 year old dirt/dry grease coating them. I can't tell what make they are. I can pull the wheels out of the dropouts and take a closer look later.

Interesting. Generally (not even bikes specifically, but very generally) you save money by building yourself. I will try and price it out tonight.

Sure, problems can always arise, but because the maintenance history is somewhat of a mystery (it was my dads bike, and he doesn't really remember much) and because they're 23ish years old, I'm more nervous about using them. But, it shoulds like they should be fine.

philbob57

Truing a newly built wheel is very frustrating. If you choose the DIY route, prepare for the frustration. OTOH, my tolerance is pretty low, and I'm still riding the wheel I built in 1981. (I'd be riding 2 of my wheels, except I crashed and pretzeled the front one in '84.) The frustration was overwhelming as I went through it, but it was temporary. It just didn't feel temporary during the build. :-)

If you DIY, I recommend having a pro tweak it after you think you've got it right. Just don't tell 'em that you built the wheel, because, if you do, they'll probably tell you they have to rebuild it from scratch....

hueyhoolihan

if it hasn't already been mentioned, first thing off the bat is to find the spacing of your rear dropouts. they may be 126mm or 130, or possibly even 135mm. this will determine much of what is possible WRT economy. if 126mm, new pre-built wheels and even new hubs may not be so easy to find. not that they aren't available. so if 130mm or 135mm you shouldn't have any trouble finding pre-built wheels anywhere from 150 on up. or you could build them yourself from readily available parts you can find online along with a little guidance from youtube videos and websites.

have fun.

AnkleWork

So take out the mystery. Clean and inspect the bearings, hub, axle then assemble, lube, adjust. Mystery solved.

FastJake

Sounds like your rims are indeed due to be replaced. Find out if you have a cassette or freewheel here: Freewheel or Cassette?

They should say "Shimano" on them somewhere unless the stickers are missing. If the front hub is some off brand that's fine but I don't bother re-using off-brand rear hubs since quality Shimano ones can be had so cheaply. If you buy used they can be had even cheaper.

If you shop smart you can save money building your own wheels. Or you can spend way more than you would on a prebuilt set. But if you want to learn IMO the experience is worthwhile.

Funny, I build my own wheels to prevent things like broken spokes, or the need for constant truing due to poor build quality, not to mention the freedom to build whatever I want. Like an old Campy record hub laced to a Velocity clincher rim for my fixed gear commuter. Try finding that pre-built. Or my cyclocross race wheels with Shimano cassette hubs laced to old tubular rims (GEL280, Fiamme Ergal, etc.)

nuclear_biker

I will probably do this at the same time as a rebuild. If it looks bad I'll replace it.

Pulled the wheel off, and the rear one is a Shimano FH-HG20. It looks to be in pretty good shape, so I don't see why I can't repack the bearings and use it. The front hub is a Shimano Exage HB-RM50. Looks fine as well. Dropouts measured to be 135mm from the inside surfaces. Both look to be 36 spoke hubs.

I will price out rims, spokes and nipples tonight. What sites are good for rim parts?

The cassette itself doesn't look too good. I will have to check what is compatible with this hub before rebuilding.

SkyDog75

I'm not disagreeing with you; there are absolutely benefits to building wheels, especially if you need or want something that's not readily available off the shelf. To add one more to your list of examples, I just built a set of wheels for my daughter's road bike because I wasn't likely to find a set of 650c rims laced to a 126 mm hub.

But talking strictly from a price standpoint, pre-built wheels in common sizes can often be found for lower prices than the parts you'd need to build those same wheels yourself. You can go to Niagara or Nashbar or VeloMine and find serviceable brand new wheelsets for under $100. (We don't need lightweight high end race wheels for a 23-year-old Trek 720 hybrid.)

That is sometimes the case, but not always. To name just one example, compare the price of a new car to the price of all the parts you'd need to build your own. The assembled car will cost you A LOT less.

FastJake

Wow, that's really cheap. Fair enough. But to play devil's advocate... OP already has (assumingly serviceable) Shimano cassette hubs. High quality, double butted, stainless steel spokes can be had from Yellow Jersey bike shop for $60 plus whatever they charge for shipping. I found some Sun Rims CR18 rims online that can be had for $64 shipped. So for around $140 the OP could have a hand-built wheelset that I'm assuming will have much higher quality parts than a $100 Niagara wheelset.

https://www.ebay.com/itm/Sun-CR-18-70...item2c952cbd2b

Al1943

Here is what Bikepedia has for the 93 Trek 720:

1993 Trek 720 - BikePedia

Originally it came with 700 z 35c tires. If it was mine I'd put on 28 or 32 mm tires, depending on the road surface.
I doubt that the wheels need re-building but that depends on the condition of the rims, and hubs. I'm sure the hubs need cleaning and greasing, and probably the same for the headset, bottom bracket, and pedals.

nuclear_biker

Fair point.

Sun Alloy Rim 700c CR18 Silver 36 Hole PV is this not the same rim for a bit less? Here is what appears to be the exact same item (at least the specs are all the same) but a slightly different name, and costs a little bit more: Sun CR-18 700c 36 hole Silver rim. One is PV and the other is not, but I can't for the life of me find out what the difference is. I thought it meant Presta valve but they both seem to have that. I'm sure somebody will point it out and I will feel dumb. I did some research on the rim and it seems to be pretty well liked, especially for the tire sizes I plan on running.

Thanks this link is pretty helpful. Based on what this says mine is a 1992 as it has all Shimano 200GS hardware. Also, I'm not too worried about tires yet, though I'm still leaning toward staying with 35's. I like the versatility and I do drive on gravel on my commute. Why would you pick a 28 or 32 over a 35?

hueyhoolihan

could be Polished Version as opposed to Satin Silver. they come in both finishes i think.

nuclear_biker

For more rage, here is a 3rd one, that seems to be the polished version: Sun CR18 700c 36 Hole Polished Road Rim ABT(Advanced Brake Track)

FastJake

PV is presta valve, probably. Keep in mind it's possible to run a presta valve in a Schraeder hole, and the stock photos of these rims may not match the actual product.

The CR18 was just an example, and I didn't realize how heavy it was! For me personally I'd look for a lighter rim. But if you don't care about weight it's certainly a fine choice.

nuclear_biker

I have no idea what a good weight would be. I'm by no means worried about weight, and they seemed a bit lighter than some of the other budget offerings. This is the rim I think I have Araya PX-45 Rim | Chain Reaction Cycles (500g). The quoted weight of that rim is actually less (460g or 480g depending on what site you belive). Sun CR18 700c 36 Hole Polished Road Rim ABT(Advanced Brake Track) or https://www.bikeman.com/RM8491.html

Al1943

I was thinking a smaller tire for lighter weight and smaller contact patch for better performance on paved roads. Depending on your gravel road I might prefer 32's for lighter weight, but you are the better judge of what will work best for you.

nuclear_biker

So, weird thing. I was looking at my SO's tires and they looked a tiny bit thicker than mine, but they were also marked as 700 x 35. I took some calipers to my tires and they are actually 32mm, but they say 35 on them... Anyway, I like what I have so I will be sticking with that. Is it common for sizes to be... wrong?

FastJake

Yes. Tires usually measure narrower than they say. Sometimes the same size. Almost never wider. It depends a little bit on your rim width.