Trying to replace a wheel

Question

I am a big dude, I weigh 250 lbs, and I kill bikes.

The best thing I have found so far is putting 12 gauge spokes on my Mt. Bike, which has reduced the number of spoke I break monthly.

I have a Cannodale Adventure 5, and I destroyed the rear wheel in February. Anyhow, it had 700c wheels, and I want to replace the 700c wheel with another, but with 12 gauge spokes.

I've been to 2 bike shops, and they seem confused, asking questions like

• how did it break,
• how many spokes do I break in a year?
• do I have them fixed?
• why do things wear out so fast for me?

... which all comes back to being a big dude putting loads of miles on a bike.

They want to know more pertinent things too, like freewheel or cassette, and type of rim. Which the answer is I don't think I care. Then they ask other questions like what the wheel spacing is, and I have no idea what that even means.

So, what details do I need to be able to replace a wheel for a frame which I do not have the original wheel to?

What details should I consider to get a sturdy wheel for someone of my girth?

Answer 1

First off, the number one cause of broken spokes is not enough tension. When spokes aren't tight enough they load and unload with each revolution of the wheel – basically they are getting bent back and forth each time they go around. Over time they break, just like bending a paperclip. The most likely place for the spokes to break are at the bend at the hub.

Any good wheel builder knows this and will take great care to get the spokes uniformly tensioned. Once the spokes are tight enough they don't load and unload on each revolution and they will last a good long time.

Here's what you need to know to order a new wheel:

1. The size of the wheel: 700 C on your bike.

2. The rear dropout spacing: you can measure this by taking out the rear wheel and measuring the distance between the dropouts (the part of the frame where the wheel attaches) in millimeters. Odds are good it will be 135 mm, although 130 mm is also likely. They need to know this to choose the right hub width.

Beyond that the wheel builder should be telling you (or at least making recommendations). I think the bike shop questions were being asked to learn about how you ride and care for your bike.

Unless you've been riding hard (jumping curbs, bouncing through pot holes, etc.) I'm very suspicious that your spokes were too loose. Really, you're not "too big" for a decent bike. Trek, for example, says their road bikes are good for riders up to 300 pounds, and mountain bikes are good for 275 (if I recall correctly). I'd guess that the mountain bikes are lower due to the rough service they are likely to get.

Some things I'd expect your wheel builder to recommend:

• Don't use heavier spokes, use more. I'd go with more (at least 36 or even 40). On our tandem our wheels are built with 40 14-gauge double butted spokes. They are holding up just fine, and our team weight is 360 pounds, with the bike and bags the load is up around 425 pounds. We're using nice sturdy rims, but the big thing is that I built them with good tension on the spokes.

• Use the biggest tires that will fit and run them with relatively low pressure. This will enable the tire to absorb road shock, and being big it let you run a lower pressure without risk of "snakebite" punctures in your tubes.

• Consider using an asymmetrical rim in the rear. Asymmetric rims offset the spokes to the left a bit to help equalize the bracing angles of the spokes (on a symmetric rim the drive side (right) spokes are much tighter because they are at a steeper angle. This is because the flange of the hub is moved to the right to make room for the cassette.

Answer 2

By "cosset" you probably mean "cassette". It's a type of rear hub construction and is the norm for modern bikes. Freewheels were used in older bikes.

Wheel spacing is the distance between rear dropouts, ie the width of the hub that fit in the rear fork.

If you can manage it, the easiest way to answer all the questions by bike shops is to take the frame with you. That way the mechanics can take all measurements themselves. If that's not possible, providing year and model of the bicycle should do the trick.

For sturdier wheel, go for more spokes and good quality components. 48 seems to be maximum spoke count available for wheels. You might need to have the wheel custom built to make it fit your frame.

Answer 3

That is technically not a mtn bike. The width is not published on the site and as it is a hybrid it could be a few widths. Take the bike or wheel to the shop. If you no longer have the wheel then take the bike. You should have saved the wheel if for nothing more than I need one of these. Even if it is a freewheel you may want to go freehub if you get a higher end wheel. If it was a cassette and you threw it out then you threw away a cassette.

A ballistic wheelset is going to be more than you paid for the bike. I would not put a lot of money in a wheelset for that bike. If you have broken several spokes then you are going to break that bike sooner rather than later.

At 250 lbs you may want to consider a steel mtn bike or touring bike. That is not a bike built to take a beating. A bike like a Surly Cross Check or Org. Higher end a Niner or Salsa - or lots of others that are getting back into steel. Don't put a $1000 set of wheels on a throw away bike.

You have not ridden since the February but you put loads of miles on a bike?