Fixing spokes/chain/cassette

[User6179]

I've been fascinated on several occasions to observe the vitriol that those little plastic spoke protectors engender. Could someone please explain the rationale to me?

Steve

Their fine when new but usually end up covered with oil and are hard to clean and serve zero use if you set the bike up correctly

 

[mrandmrspoves]

Their fine when new but usually end up covered with oil and are hard to clean and serve zero use if you set the bike up correctly

However as the OP proves, they do have a use, when the gears have not been set up correctly, so it's a bit like saying a cycle helmet is of no use so long as you don't fall off your bike!. (Some would argue that helmets are of little use even then - but let's not go there!)
I think calling them dork discs is a bit
of cycling snobbery in the same way that the term suicide levers was used for dual lever brakes in the 80's.
Having said the above....I have always removed the discs on my cycles - but am confident that I can set up a rear derailleur so it won't go into the wheel. It's also fair to say that in my experience, I have always found that the plastic discs degrade and become brittle after a few years.

 

[S.Giles]

My (secondhand) cycle didn't have one when I bought it, so I put one on as part of a refurbishment. If it degrades in a few years (and before I degrade!), I'll buy another and install it. They don't cost or weigh much, so there's no downside that I can see. The upside is clearly demonstrated by the OP.

I'm contrary by nature, so the fact that they've been called stupid names just confirms my opinion.

Steve

 

[User6179]

However as the OP proves, they do have a use, when the gears have not been set up correctly, so it's a bit like saying a cycle helmet is of no use so long as you don't fall off your bike!. (Some would argue that helmets are of little use even then - but let's not go there!)
I think calling them dork discs is a bit
of cycling snobbery in the same way that the term suicide levers was used for dual lever brakes in the 80's.
Having said the above....I have always removed the discs on my cycles - but am confident that I can set up a rear derailleur so it won't go into the wheel. It's also fair to say that in my experience, I have always found that the plastic discs degrade and become brittle after a few years.

They do have a use if you don't set up the gears properly but you might find the derailleur catches the spokes anyway even with the disc , best not to rely on them and learn how to set up your gears.

 

[John the Canuck]

............. , best not to rely on them and learn how to set up your gears.

however, as can be seen from the many many posts from newcomers asking for advice - we are not 'all' DIY mechanics at the start

so leave them on a newly purchased bike
then take them off when you know what you're doing
which implies knowledge learned about tools for cassette removal and limit screw functions

 

[S.Giles]

Why go to the bother of taking them off? I know how to set up gears, but it's a little (almost) free insurance against a mishap. I certainly don't place any reliance on them, but adjustments don't always stay accurate, especially on a mechanism that is subject to vibration and dirt ingress.

I'm still not up to speed on the hatred I'm supposed to be feeling for a little plastic disk!


Steve

 

[andrew_s]

insert 1 new spoke - true wheel with spoke key using a brake block as a guide
remove 2nd damaged spoke and repeat
only do 1 spoke at a time

I would recommend replacing all 3 spokes before truing the wheel.
a) assess the tension of a pair of undamaged gearside spokes by squeezing them against each other*
b) replace the 3 broken spokes, tightening them until they are about the same tension as the test spokes at (a)
c) true up the wheel using the brake blocks as a pointer

* if you have a good musical ear, you can also assess spoke tension by the pitch of a plucked spoke.

If there are any other damaged spokes, like those shown in post 11, replace those between (b) & (c), tightening them up to the same tension as the test spokes too.

Trying to true a wheel with two missing spokes is going to mean making adjustments that wouldn't be necessary if the spokes were there. Undoing those adjustments after adding the missing spokes isn't going to be simple, so you are much more likely to end up with uneven spoke tensions. Provided none of the other spokes or the rim is damaged, you should in theory be able to return the wheel to its previous trueness just by bringing the replacement spokes up to the same tension the broken spokes had.

 

[John the Canuck]

^^^^

''Trying to true a wheel with two missing spokes is going to mean making adjustments that wouldn't be necessary''

where do that statement come from.?

i advised to replace 1 damaged spoke [and to true the rim] 1 at a time - thus keeping the rim as close as possible to its original lateral position

 

[mrandmrspoves]

Why go to the bother of taking them off? I know how to set up gears, but it's a little (almost) free insurance against a mishap. I certainly don't place any reliance on them, but adjustments don't always stay accurate, especially on a mechanism that is subject to vibration and dirt ingress.

I'm still not up to speed on the hatred I'm supposed to be feeling for a little plastic disk!


Steve

I take them off because as they become brittle they often shake loose as the holding tags snap - and I am confident in my abilities to adjust a derailleur. I would certainly not recommend a novice cyclist to remove one. As for learning to hate them, you're simply not trying hard enough!

 

[I like Skol]

The pie dish/dork disc debate has rattled on for years and has IMO descended into a stand between vanity, fashion following and weight weenieism against common sense, prudence and independence!
It is quite wrong to say that properly set-up gears cannot send the chain over the top sprocket and into the spokes. The chain can easily be misdirected by a foreign body like a twig or carrier bag no matter how well maintained and adjusted the gears are. There is also a possibility that the bike may receive an unnoticed knock to the rear derailleur which results in the same unfortunate outcome. I suspect this may be what has happened to the OP as he has said his indexing was out earlier in the ride before the event that damaged the spokes, I am really surprised that nobody has suggested checking the gear hanger before putting it all back together! The dork disc will help prevent the serious damage that this can cause with minimal down side.

I have always left them on my bikes if fitted and did try to buy replacements for my 36 hole XT wheels I built for the MTB and commuter. I couldn't find good ones at the time due to the flange size and spoke count but would buy some without hesitation if they became available (I don't want the nasty ones that 'spin' onto the spokes, they have to have the proper claws that fit the hub flange ).

Just checking my bike shed and as suspected the dork disc is still in place on my best summer road bike, ironically probably the one that least needs it, but it is doing no harm so can stay where it is

Somebody did suggest that the derailleur may still catch the spokes even with a dork disc fitted but that is a different fault altogether and not what the OP experienced. The dork disc stops the chain sawing at the spokes if it over shifts. If the derailleur is touching spokes then it is either a bent mech, a bent hanger or a badly adjusted set-up (or all three?). A large pie dish might help?

 

[livpoksoc]

So I wussed out & took it to my lbs, they've just rang to quote me £60 for a wheel rebuild that won't be done today, or £120 for a new wheel...thoughts?



Edit: £69.99 all in for new rear wheel & to put the parts back on. It was £120 if I wanted the pair so I had a match on the front. I elected to not have a matching front.

 

[Chromatic]

So I wussed out & took it to my lbs, they've just rang to quote me £60 for a wheel rebuild that won't be done today, or £120 for a new wheel...thoughts?



Edit: £69.99 all in for new rear wheel & to put the parts back on. It was £120 if I wanted the pair so I had a match on the front. I elected to not have a matching front.

Don't try and change to the big cog at the back while doing c40 mph.

 

[livpoksoc]

Don't try and change to the big cog at the back while doing c40 mph.

Lol sound advice

 

[Chromatic]

Lol sound advice

You're welcome.

 

[livpoksoc]

^^^^

''Trying to true a wheel with two missing spokes is going to mean making adjustments that wouldn't be necessary''

where do that statement come from.?

i advised to replace 1 damaged spoke [and to true the rim] 1 at a time - thus keeping the rim as close as possible to its original lateral position

My lbs replaced the wheel & gave it a brief gear service, but when I took the bike out, the chain was chattering & hopping all over the place. I took it straight back to the lbs who reindexed, but advised the mech was bent, but not enough to replace it. It means I will get some 'occasional' skipping. This 'occasional' skipping was constant on the second cog of the rear cassette. Should I replace the mech now?