zjrog

Let me state, I am a cheap guy. I don't mind spending money where I must. But I'm cheap.

A few months ago I bought a DT Swiss R1800 wheelset Giant Edition... Thinking, for $75, it was tough to go wrong...

Well. After having them tried, and putting less than 50 miles on them, the rear is catching the brake pads. Not tearing the pad up. Yet.


Driveside.


Non driveside.

As a heavier rider, 245 and shrinking, I no longer feel safe on this wheel. I'm guessing this wheel is going to fail, soon. So it is off the bike.

Choices. Rebuild with a new rim. Or. New wheelset. I'm untrusting of carbon fiber wheels in general, and are outside my price range anyway.

davidad

Get a rear with at least 36 double butted spokes for your weight. Something like this: https://www.harriscyclery.net/itemdetails.cfm?ID=3247

Wilfred Laurier

That looks like the joint where the rim is pinned together. Sometimes this seam is not smooth and you can feel a pulsing when you brake.

The good news is: this is not a safety issue at all and is not an indication of damage or a failure to come.

You can possibly improve this by sanding the edge smooth or by removing the tire and bending the side of the rim with an adjustable wrench so the seam is smoother.

dsbrantjr

Yes, there is no worry about the seam coming apart, it is under compression by the spokes and air pressure in the tire.

zjrog

If I still had access to a machine shop, I could turn that seam smooth... I may try sanding, and run this wheel on my trainer for the winter...

zjrog

Ow. I've been happily riding 32 spoke road wheels for some time. I do have 28 spoke wheels on my 29er that I'm quite confident on.

I am headed for 200 pounds, and if I was much heavier, yes, I would look at 36 spoke wheels...

cyclist2000

Excellent time to use a dremel tool

Andrew R Stewart 

What I don't like seeing in the second photo is the brake track machining lines don't align. As though there has been an "incident" that has misaligned them. Generally the brake track machining will produce those "lines" as continuous all the way around the rim. Like the machining texture left after turning on a lathe does. But that second photo shows these lines as disrupted at the seam. Like an earthquake will cut through a road. The road still is there but where the fault line is will have a "jog" to the road's flow.

This is actually pretty common when a rim has had an impact near the seam. Or when the rim has suffered a twisting (taco like) and the seam shifts a bit.

In this case given the "V" like fit of the sea, on the second photo I would speculate an impact caused a flat spot corresponding with the seam.

How wide a tire are you running? The photos are not real good at discerning this detail but look like a narrow tire is mounted.

As far as impending doom goes- rim failure is generally a slow death unless the incident is way too much for the wheel's structure to handle a side load (and we cycle back to tacos). Mere vertical usually don't cause instant failure, unless the resulting dent causes a spoke to bow out and catch the der or allow the tire to unseat and the tube to herniate. Andy

Moe Zhoost

A small flat file will be more accurate and do the job quicker.

If you want precision and control, use a non-powered hand tool working slowly and methodically. This minimizes the possibility of error. If you are not concerned about screw ups, by all means use a hand held rotary tool, your screw up will be quicker and more pronounced.

Andrew R Stewart 

I missed the OP's reference to actually using a lathe to face down the seam. My reference to a lathe was about the surface texture that a medium/coarse feed gets you. Given the amount of lateral out of true that a wheel has (even when "perfectly true") is so much larger then the run out a lathe chuck has I think actual turning down a rim side wall would risk thinning some spots too much. The vids I've seen of rim manufacturing have the un laced rim places of a faceplate/turntable and secured flat against it with a clamping approach.

I've dressed seams a bunch of times with varying success WRT brake pad grab. Always with a hand held method Andy

davidad

You do realize that the manufacturers went to fewer spokes to save money, not because the materials were better.

zjrog

The guy I got the wheels from hadn't used them, he had picked them up from a thrift shop. He decided against building the older bike he had with this wider rear hub (7 speed freewheel bike). I had my shop true the wheels, and he mentioned the seam might catch. But it has gotten a bit louder and I think I will take a fine tooth file to it. No, no power tools for this project. Since I don't have a machine shop to use. I have no idea what the history of these wheels is.

Been a long time since I had a wheel come apart on me, but that was a couple spokes pulled through the rim...

I run 700x25 on my road bikes.

Andrew R Stewart 

Really? I hadn't heard that before. At the wheel manufacturing level (not wheel building as this is a production item, not a one off) the added cost of more spoke (and the labor to touch them) isn't more then a few dollars. This margins out to maybe $20 at retail more. But the marketing "value added" of a fancy low spoke wheel's appeal is worth far more.

zjrog- At 240ish lbs I would suggest wider tires as well as wider rim and more spokes for a reliable non event wheel. If you've got a sponsor then who cares what you ride, as long as they have a good supply for you. Andy

zjrog

Thanks Andy! No, no sponsor. Well, bank of Me, Myself and I... As I mentioned, I ride a 700x25. I can't fit 28s on my CAAD8, and only the rear of my old KHS. Shoot, I might fit 32s on the rear of the KHS. But 25s are as big as I can fit in it's Nishiki fork... No racing for me. I like to push in a group,or be pushed, but I have my limits...

I bought 2 other sets of wheels last spring, one set is 32 spoke Rigida rims with Shimano 105 5600 series hubs, the other was a set of Shimano WH-561 wheels/hubs, 16 spoke radial laced front 20 spoke rear. No, I know better than to ride that set!!! I picked up a bike about that time with a set of Alexrims with Formula hubs. This set is 2 spoke the front is radial laced.

I'm not the speed demon or climb monster of my youth. After breaking my back a few years ago, I'm quite cautious turning and such, no standing on the pedals to climb or sprint.

Took a coarse, then fine file to both sides of the rim, I can't catch my fingernails on either side.. I'll try it on the CAAD8 tomorrow after I get back from my ride.. These DT Swiss wheels were bought for this 2006 CAAD8...

Andrew R Stewart 

You and a lot of others are beginning to understand the true cost of following the fashions that the bike companies dish out. back when bikes with such little tire clearances ran sew ups, which are better at handling impacts the clinchers are (of the same width). We have seen a lot of riders who are choosing bikes with greater clearances and enjoying the greater traction and smoother ride of the wider tires that fit their non racing bodies. Andy

GamblerGORD53

What's with the S crack in the second pic??
That rim has definitely hit a pot hole. Garbage it totally. It's Second hand used yet? pffft

02Giant 

That's what I thought.

zjrog

"S" crack is the sticker didn't split straight... Filing the seam was a great exercise for something I may have no choice but to fix.

I'll see if it still catches on the brake pad, but giving tons of thought to this being on my trainer only, since I ordered a trainer specific tire.

After perusing velomine.com, No sense using a questionable wheel. I've no vanity or ego to stroke or bruise if the "right" wheelset is used or not...

Another use for this wheelset might be as Christmas wreaths... I've done that in the past.

02Giant 

I should clarify. I would use it on a trainer. I wouldn't use it on the bike because, there has been movement in the joint and it may get worse and, be a nuisance.

Do I think it will assplode if you continue to ride it, No...it's aluminum.

WizardOfBoz

I'd suggest that this is too small. I'm about 245 myself. I ride 26 on my fancy CF and semi-vintage 853 (a '99 LeMond Zurich) bikes, and 1-1/4s on my vintage Schwinns. The bigger tires ride nicer.

Miele Man

I'm glad you decided not to ride it on the road. That rim looks like it twisted at the joint a bit. Also, when you filed the seam fairly smooth again did that compromise the integrity of the brake track? Being miles from home and having a rim side fold on you is not a pleasant thing. It can lead to a long walk too if you can't get someone to come get you.

Cheers

zjrog

Oh no! Not the assplode! (I thought that was what happened a couple months ago when I had Diverticulitis !) Trainer duty it is...

25 is as narrow as I will go. If I could fit wider, I would get wider. I have seriously considered a newer fork for the old KHS just to fit 28s or 32s... For that matter though, I have a second set of wheels for my 29er. So I can run 40s or 42s on one set, the 54s, maybe wider on the other. The previous owner of the 29er called it a "Monster Cross", as he also ran 700x38 CX tires on it.

Very very little material was removed to smooth the brake track. Still, I will sleep better knowing I'm not counting on this wheel at 35 mph+ on a downhill... I have enough people to call if I'm in a blind. But the cost of the friend tax would be high...

The Alexrims wheelset is going to be tried and pressed into service for now on my KHS, the Rigida set with 105 5600 hubs is on the CAAD8. Winter will be used saving for a new wheelset.

davidad

From Bike Gremlin. Over 30 years ago, most bicycles had 36 spokes on each wheel. British standard at the time was 40 spokes on the rear, and 32 on the front wheel. 72 spokes in total in any case. Only “fancy” racing bikes had less, usually 32 spokes on the rear wheel.

Then someone from the marketing got an idea: “Let’s make 32 spoke wheels. They will use less material, be cheaper to produce, but we’ll present it as an ‘upgrade, better, newer, like the wheels racers use!’ ” The result was weaker, less durable wheels, at the same (if not even higher) price. For an average user that doesn’t load bike heavily, these wheels were good enough to hold until the guarantee had passed. So everyone was happy (wheel producers a bit more than the others).

This trend was continued, so now there are wheels with 24, or even just 16 spokes! The main selling point of such wheels was they are lighter and more aerodynamic.

From Sheldon Brown.
How Many Spokes?

Up until the early 1980s, virtually all adult bikes had 72 spokes. 32 front/40 rear was the standard for British bikes, 36 front and rear for other countries. The exception was super-fancy special-purpose racing wheels, which might have 32 spokes front and rear.

The Great Spoke Scam: In the early '80s a clever marketeer hit upon the idea of using only 32 spokes in wheels for production bikes. Because of the association of 32-spoke wheels with exotic, high-performance bikes, the manufacturers were able to cut corners and save money while presenting it as an "upgrade!" The resulting wheels were noticeably weaker than comparable 36-spoke wheels, but held up well enough for most customers.

Since then, this practice has been carried to an extreme, with 28-, 24-, even 16-spoke wheels being offered, and presented as it they were somehow an "upgrade."

Actually, such wheels normally are not an upgrade in practice. When the spokes are farther apart on the rim, it is necessary to use a heavier rim to compensate, so there isn't usually even a weight benefit from these newer wheels!

This type of wheel requires unusually high spoke tension, since the load is carried by fewer spokes. If a spoke does break, the wheel generally becomes instantly unridable. The hub may break too; see John Allen's article.

If you want highest performance, it is generally best to have more spokes in the rear wheel than the front. For instance, 28/36 is better than 32/32. People very rarely have trouble with front wheels:

• Front wheels are symmetrically dished (except with disc brakes).
• Front wheels carry less weight.
• Front wheels don't have to deal with torsional loads (unless there's a hub brake).

If you have the same number of spokes front and rear, either the front wheel is heavier than it needs to be, or the rear wheel is weaker than it should be.