alexk_il

Finally! My chain slipped and got stuck between the spokes for the first time.I was going up a very steep hill, changing the gear way too late, heavy pedalling through the quick shift of 3-4 gears in one go. Not intentionally, just happened. Always worked, but there is always a first time.

The chain was properly stuck, took me 30 minutes to release it without tools. Luckily managed to fix it, I was lucky and there was no damage to the bike.

So... Do dork disks for 46t cassettes exist? Any recommendations?

Barry2 

“Recommendations ?” Change gear sooner

sorry had to be said



Barry

maddog34

"no damage", huh? didja Remove The Cassette and Look At The SPOKES..? If the chain was stuck as badly as you mention, guess what took the brunt of that force....

An external scrape or two is ok, but any sharp bending and/or gouges with burrs means you should replace those outbound spokes.

search: "Spoke guard for Bicycle" on ama-Zone or Fleabay... they list the overall diameters in the ads, or they should. Spoke Count plays into fit, btw... 36 count uses a 3 tab mounting.. 32 spokes uses a 4 tab mounting system... and drilling holes to use zip ties is not unheard of with lower or higher spoke count wheels. "Freewheel" types don't usually work on Cassette hubs....

Oh.. and CHECK YOUR DERAILLEUR ALIGNMENT..that is the typical cause of chains munching spokes.

veganbikes

Check your derailleur and hanger alignment, make sure your limit screws are set properly and maintain your bike well and you won't have those issues and if you do a plastic disc(or disk) is unlikely to do much as you have probably crashed or hit your derailleur on something. I have had plenty of issues with spoke protectors but never a situation where one has helped at all. Maybe an old school metal one might help but I wouldn't bother. If your limits are set properly and everything is aligned it would be really tough to have a problem. My old school 8 speed XT derailleur (running 9) on a 1X set up gets shifted poorly often and is a bike I do let others ride (which is rare and it is one of my favorite bikes which is even more crazy) but everything is set correctly and given some maintenance and I haven't had any chain coming off issues at all and I have intentionally tried to do some bad shifting on it just to see if I could and no dice.

I would also recommend working on your shifting. I am not a great shifter truth be told so I am not judging anyone but trying to work on it will help.

I would as maddog34 remove the cassette and check the spokes it is hard to assess damage without assessing all the potential damage areas.

alexk_il

Well, the chain was actually stuck below the line where the spokes are attached. Took a lot of fiddling to unstuck it. But, no damage do the spokes, cassette or the wheel.

Can't find anything that covers 46t, I need 195-200mm. Do they even come in this size?

Thanks, I just built this bike from scratch and did the alignment before installing the derailleur. Maybe it somehow got out of whack. It's more likely the high-low screws aren't properly done.

alexk_il

In my defence, I was trying to avoid being hit by a speeding car on a narrow road in a field, had to cycle through nettles and bushes as a result. Got a bit distracted from the correct shifting technique. Also, my all other bikes are quite forgiving, I can pedal through any gear change uphill on them, so wasn't expecting this to happen.
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Bill Kapaun

Probably have to make your own out of a 3/lb. margarine/potato salad tub lid.

Don't you love when you admit you shifted late and others have to tell you how to shift?
Put a few pieces of reflective tape on it and you could have the elliptical-spiral effect like your wheel reflectors

veganbikes

Fair dinkum then glad you were OK. Most bikes if careful you can pedal through not that it is ideal or recommended but yes possible. If everything is adjusted and aligned properly it shouldn't happen but in a panic situation all sorts of bad stuff can happen without you intending it to happen.

maddog34

the damage to spokes happens near the hub, not out further on the spokes... get a large one with the proper mounting pattern for your bike and all will be ok

with a low gear like on your bike, the guard does NOT have to extend past the largest sprocket to do it's job... it only needs to shunt the chain away from the base of the spokes.

maddog34

and if you insist on preventing the derailleur from tangling with your overgeared mtb spokes... search this on ebay.... Bike Spoke Protector Cover WI-7149-235.

however, it will NOT protect the spokes at the hub, which is where they get damaged by an overshifted chain.... add a normal sized spoke protectorto the biggest dork disc i've ever seen to prevent worry.

you're installing a burglar alarm after the break-in and theft.

alexk_il

Thanks, that's the model to find, great.

I'm confused though, why it won't protect the wheel/spokes? Isn't it going to prevent the chain from slipping at all?

maddog34

Gee, i don't know either... maybe BECAUSE IT'S A BIG OPEN RING instead of a disc that protects further towards the hub and the base of the spokes...

and your massive 50t gear sets how far away from the spokes at it's maximum diameter...???

PS.. the chain didn't "Slip".. it OVER-SHIFTED.

soyabean

Genuine Shimano does make spoke guard protectors and they all have their part numbers.

A local bike shop may help here.

The problem if you mail order, you risk getting one that won't match your spokes and/or freehub.

Schweinhund

Schweinhund

I have been through the damn catalog, the biggest I've found in the wild is 7.5 inches and it's not spoke mounted,{freewheel for sure not sure about freehub fitment} so there's jhuuust a bit of frisbee there.
https://www.modernbike.com/sunlite-s...36-1.375-x-7.5

alexk_il

Chain slipping is a result of ovesshifting. Similarly to whiplash injury that is caused by car accidents.

As usual, there are two ways to address the problem

1. Preventing
2. Mitigating the results

​​​​
#1 is obvious, pretty much everyone on this forum is intelligent enough to understand that avoiding car accidents is the best way to prevent the injury, avoiding overshifts is the best way to prevent the wheel damage.

Surprisingly there are quite a few forum members that think otherwise. Anyway, since their intentions are good, I give them kudos anyway. Well done, thank you!

Anyway, since "S..t Happens" I am focusing on #2 and I use the words that describe what happens after ovesshifting.

I'm now compelled to rephrase my question though. So.. Is anyone aware of "dork disk"-like device that works with 11-46t cassete and

• Either effectively prevent chain slipping
• Or effectively prevents it from causing further damage when it slips

Schweinhund

Here is the biggest dork disk available.



https://wheelbuilder.com/aerojacket-disc-cover/


Or if you really want to get crazy, make one out of a nylon sheet and zip tie it
https://www.amazon.com/Clear-Flexibl.../dp/B00BOUUX6G

katsup

Visit your bike shop, they may have some. Spoke protectors come with new bikes that have 51t cassettes, surely one of these will work if you can't find a specific 46t.

Schweinhund

I love dork disks, and reflectors too, but honestly the best prevention is proaction.
Set your derailleur stops by eyeball before installing a cable or chain.
Set them a bit short and then do your final adjustment after installing the cable and chain.
Before you ride, EVERY TIME, inspect for problems.
A dork disk won't help if you bend the lower cage or hanger towards the wheel, Unless you've got one like I linked to. It's gonna get sucked into your spokes.

maddog34

yep.. i set the limit screws before hooking the cables up or installing the chain, if it's a new build, then fine tune during final testing. Maybe the limit screws SLIPPED on the OP's bike.

as to bike reflectors, i have a couple/three hundred that i'm planning to mount onto one rim, then aim a 3 color party laser at it and spin up a cloud of random light beams on a foggy night....... .

Schweinhund

I have not even once seen that, but I ain't seen nearly everything

maddog34

one of my first questions to a person complaining of a badly shifting bike.. "have you ever dropped the bike on the right side, or crashed recently?"
They almost always answer "No!",,, so i then show them the scrape marks on their derailleur knuckles, as i laugh internally. They listen much more accurately after that, and the ego preservation usually ceases too.... if they pause and contemplate before answering, no matter the answer, i believe them more frequently.

i had a "Power" derailleur in here that had stripped out limit threads... the heads of both screws showed no sign of abuse... factory "tolerances", i guess? Power is also in the running for "worst bike parts" awards, along with DNR and C-Star. Most Power rear Ders are too sloppy from the factory to repeatedly shift gears when indexed...Their front ders are copies of the Shimano design that was too stiff for most people to get to move from it's relaxed, resting position, with a twist shifter... the bottom pull lever on the der is shaped to position the clamp screw nearly directly above the cable pull line....

how does an engineer mess up a simple bell crank?
ask Power, they could tell ya!....

alexk_il

I am in the UK, we drive on the wrong side of the road so I fanatically taught myself to always fall on the left side. Ideally into bushes (i.e. netles, thorns, a fence) or a pavement. Unless I fly over the handle bars and land on my back while holding the bike upside down. Doesn't happen too often, but rest assured, the bike is always safe, no derailleur misalignments.

Anyway, I am confident none of these accidents has ever happened to the most experienced cyclists on this forum, but I have already accepted that my skills are unlikely to improve to the point of a complete avoidance of cycling, steering or shifting mistakes.

alexk_il

Or I might have messed up my screw limits. My dyi bike is completely out of specs, I have Ultegra road 2x brifters shifting MTB FD and RD with 40/26t and 11-46t. I'm sure it creates a lot of stress for RD, maybe getting to a point of smooth shifting across all gears potentially requires a tiny bit of overshifting. Not sure, could be either my mistake or a price to pay for that combo to work.

Schweinhund

I high sided a bike (bicycle) once, that hurt like hell.