Wheel Trouble

A_Sober_Paddy

Hey all,

I'm relatively a noob on the bike and I've a couple of wheel related questions...

Q1: If a spoke breaks what are the dangers of continuing to ride on the bike?

Today I was out on my spin and at the half way mark I noticed a noise coming from the rear wheel, low and behold...one of the spokes had broken(at the hub end, not the rim end(screw in end). So I removed it...

I continued to cycle on it, as I was on my way home, but I was very weary, so took it handy.

Was there any chance that with 1 spoke broken and removed of the wheel failing?

Q2: What difference does the number of spokes have?

I've seen bikes with 32 spoke wheels (the ones I have), others with 16 spoke ones. What's the difference?

Cheers in advance for your help

rflynnr

Tensioned spokes allow a relatively small amount of material (i.e. the wheels) to carry significantly greater weights (i.e. the cyclist). Tensioning also maintains the shape of the wheel (i.e. keeps it round and true). For this to work at its optimum, all of the spokes should be present and correctly tensioned. However, this does not necessarily meant that a bike wheel will not function if it's missing a spoke: if I was out on a long spin and a spoke failed, I'd probably turn around immediately and head home, taking it easy as I went. But I'd only abandon cycling entirely if the wheel was so out of true it was difficult to make progress or if I thought continuing was placing a potentially damaging amount of strain on the rest of the wheel.

As for numbers of spokes: this is usually related to what the wheel is expected to do. If it's a racing wheel, carrying a relatively light cyclist (70 kgs) or less the wheel may only need a limited (20 or less) number of spokes. If it's for a touring bike which may carry weight equivalent to two riders then a stronger wheel is necessary and thus the spoke count increases.

And relating this back to the first paragraph: losing a spoke on a 20 spoke wheel is more likely to have an immediately deleterious effect than losing one on a 36 spoke wheel.

smacl

I had to ride about 10k with a broken rear spoke a few months back (only way of getting home). It didn't take long for the wheel to go badly out of true such that the brakes were binding and I had to disconnect the rear brake. By the time I got back I noticed that the rear tyre had also been rubbing on the frame, and was damaged, and I imagine going much further would have led to either frame damage and/or a blow out.

These days I carry a spoke wrench, such that if it happens again I'd have some chance of re-truing the wheel road side. If I was touring, I'd also consider stashing a few spare spokes somewhere.

As for the number of spokes, the more you have so far as I'm aware, the sturdier the wheel, at the cost of extra weight. Rear wheels will have more than front wheels as they bear more load.

A_Sober_Paddy

Cheers guys,

I'm going to drop it into one of the bike shops next week, should be able to get a lent of a replacement for the time being

Mycroft H

A_Sober_Paddy wrote: »

Hey all,

I'm relatively a noob on the bike and I've a couple of wheel related questions...

Q1: If a spoke breaks what are the dangers of continuing to ride on the bike?


Was there any chance that with 1 spoke broken and removed of the wheel failing?

Q2: What difference does the number of spokes have?

I've seen bikes with 32 spoke wheels (the ones I have), others with 16 spoke ones. What's the difference?

Cheers in advance for your help

Q1)

Well, you've broke one spoke, there is now additional stress on other spokes and and increased chance of further broken spokes.

The chances of it failing? Well it depends on how well the other spokes were tensioned. If the other spokes we're tensioned well, then it's low enough. But seeing that a spoke broke you can assume that other spokes may not be tensioned right and there is a good chance of others breaking.

Q2)

Depends on the type of spoke. The traditional spoked wheel is stronger with more spokes. A touring bike rear wheel might have 36 or even 40 spokes for strenght. A tandem might have a 48 spoke rear wheel. A racing bike might have 32 or less.

16 spoke wheels? For the ultra light weight weenie concerned about minimising aerodynamic drag. Used on front wheels with bladed spokes sometimes.

route66

A_Sober_Paddy wrote: »

Hey all,

I'm relatively a noob on the bike and I've a couple of wheel related questions...

Q1: If a spoke breaks what are the dangers of continuing to ride on the bike?


Was there any chance that with 1 spoke broken and removed of the wheel failing?

Q2: What difference does the number of spokes have?

I've seen bikes with 32 spoke wheels (the ones I have), others with 16 spoke ones. What's the difference?

Cheers in advance for your help

Q1. With a 32 spoke wheel, you'd be ok making your way home with 1 spoke missing. You'd still have to get it repaired asap though as the uneven tension would mean other spoke / alignment troubles would be just around the corner.

Q2. Generally speaking, the less spokes there are, the less tolerence there would be for problems. Certainly if 1 spoke breaks on a 16 spoke wheel, I wouldn't cycle it at all. With only 16 spokes, they are all under a lot of tension, and you'd be only asking for trouble.

Wheels with less spokes tend to be lighter. Weight is a big deal with wheels because it represents rotational mass. Loosing a half KG on a wheel set is not something you can replace by loosing the same amount by dieting! And if you are going to loose weight on wheels, its best to loose it at the rims because weight loss here will further reduce any gyroscopic effect of a rotating wheel. Some of the more expensive wheels have the spoke nipples at the hubs for this very reason.

If the spokes are bladed, they can also be more aerodynamic. Some say they look better as well.

You would also find that 16-spoke wheels have proprietary spokes - by that I mean you would have to replace any broken spokes with the exact type and there isn't just 1 spoke type per wheel either!

I recently bought 36 spoke wheels because:

• I wanted something robust, not sporty
• I am too mean to pay for the sporty ones
• I wanted something that was easily servicable, so no bladed spokes (but lots of regular ones), Shimano 105 hubs that I can maintain myself and get parts for, etc

But should I have bought Fulcrum racing 5s instead ???