pjkovie

My son bought a new bike from Dick's Sporting Goods a few years ago to take back to college with him. He has since returned home and is living with a few former classmates and storing the bike there. He explained to me take there was something wrong with the rear sprockets and asked if I would look at it for him to see if it could be fixed. What I discovered is that the freewheel or freehub (not sure which is correct) is missing a sprocket and spacer from the factory. There is a lot of lateral play between the plate sprockets (there are only six when the shifter handle has numbers 1 through 7) that appears to be the width of one sprocket and spacer. The stamping on the lock-ring says "Slick Shift System by DNP". Has anyone ever heard of something like this? Naturally, the warranty has expired. I still am going back to Dick's to let them hear of this. My son has never tampered with the bike - that's why I got involved. Dad is the fixer! Anyhow I would like to get this bike ride-able for him again. My question is - What would be the best and most cost effective way to repair \ replace this cassette that's missing a sprocket. I don't know if the missing sprocket was a 13T or 14 Tooth. I have not done the calculations to determine what the smallest sprocket would be acceptable without the plates of the chain touching the rim of the lock-nut. I guess I need to do that. The sprockets that are there are 15, 17, 19,21, 24, & 28T. I have seen cassettes that have 13 to 28 and others that are 14 to 28 teeth. The 12 tooth inner spline of the lock-nut is 32.5 mm (1.279) and that would be the major diameter of the removal tool required. All of the "Park Tools" that I have seen seem to be smaller than that, 23.4 mm from what I remember. Sorry for being so long-winded, but I am just trying to be as descriptive as I can. Any advice what be very helpful and much appreciated.

tomacropod

Sprocket has split and broken off at some time in the past. It happens, sometimes. Get a new freewheel. Price around 15-20 dollars.

- joel

Bill Kapaun

You need to identify if a cassette or free wheel-
Pictures?

Freewheel or Cassette?

Bezalel

I wouldn't blame Dick's. If it was missing from the start it probably would have been noticed it sooner. It probably cracked while mashing uphill in the highest gear. Based on your description it sounds like a Long Yih LY-1007CFJ but you probably can't replace the 13 tooth cog. I'd replace the entire cluster with a SunRace 14-28 freewheel.

pjkovie

Thanks to all for the replies. The suggestion that I should replace this cassette with the Sunrace cassette is something that I will pursue. Hopefully this will resolve the problem (if it fits correctly). I would be a little skeptical that the sprocket has broken off though, due to that the spacer, more than likely, would still be on the hub. I also believe that with such a failure would have been noticed while riding. Doing the calculations, the 13 tooth sprocket would have a large enough caliper diameter (root of tooth) to allow for clearance of the chain side-plates over the major diameter of the lock-nut. Thanks again for the advice!

xenologer

seen sprockets crack and fall out of those freewheels often when they get old, seriously doubt it was a factory assembly error
work on a lot of student bikes (shop in college town) and they're a lot more oblivious to bike problems than you'd think, happens when you're rushing between class and don't have the time or money to investigate all the wierd cracking sounds the bike is making

you will need a new chain to go with the new freewheel given the obvious amount of drivetrain wear*, possibly cranks/sprockets
mismatching new with worn parts causes issues with chain slipping, etc, so full replacement almost certain


* years of college daily riding without maintenance, worn to point of cogs falling out....

demoncyclist

The outside cog has the spacer built-in. It broke and fell out- not an uncommon issue with dept store level components. Figure out if it is a cassette or a freewheel, and replace with something of higher quality and a new chain to match. Teach son about routine maintenance while you are at it.

pjkovie

Thanks! These forums are a great to draw upon the experience of others. Your advice and sharing of knowledge is much appreciated!

Wilfred Laurier

sounds very much like a freewheel
with the description of the lock ring given

many freewheels have a large lockring holding everything together
but these are seldom actually removed
and i dont know that i have ever seen a tool for one
usually the whole freewheel is a ten dollar part that is replaced all at once

and I have also had freewheel cogs break apart and fall off the body of the freewheel

wheelreason

Bicycle parts mysteriously break, disappear, and/or get swapped out by gremlins in college campuses (and BMX parks) all the time, both with and without the owner's knowledge. Its a common occurrence for angry parents to come in and demand warranty repairs and replacements on bikes that "nobody touched". I'd be surprised if that's the original wheel...

Wilfred Laurier

it does happen
but seems very unlikely
given the ops description of the freewheel

those things are seldom disassembled for repair
let alone
to steal an individual cog under cover of darkness

pjkovie

OK - I can see how the missing sprocket could be explained. Now I just have to resolve the problem at hand. In looking at the pictures at are shown on Freewheel or Cassette?, to determine what type I have, the one that I am dealing with is a different type of stepped diameter splines. I want to be sure that I purchase a cassette that will fit onto this hub, or do I need to buy a removal tool and replace everything? I am trying to insert an image, but I receive "upload of file failed" after many attempts. What is the file size limit?

RoadGuy

Take the wheel off the bike, and carry it into your LBS.

Ask for the removal tool that fits the freewheel, or cassette lock ring.

In the old days, seems like every freewheel manufacturer used a different removal tool. I have three or four different freewheel removal tools, AND one tool that that fits all the Shimano cassettes on my bikes (7, 8, 9 speed), regardless of the number of cogs on the cassette. So the easiest way to get the right tool to remove the freewheel or cassette is to take the wheel to a shop and match the tool to the freewheel/cassette.

You might be able to figure out whether it's a freewheel or cassette by looking at the wheelhub behind the largest cog. Freewheels go onto a threaded wheelhub, and cassettes go onto splines on the wheelhub. Often times you can see the ends of the splines used to mount a cassette onto the wheelhub behind the cassette.

pjkovie

Thanks, I see that there is a size limit for images.

demoncyclist

Looks like a freewheel to me...

Bezalel

If it's the same as the one in my previous post, it's a freewheel. It can be removed with the Park FR-1.2.

RoadGuy

Have freewheel designs changed since freehubs and cassettes took over the market?

I've never seen a freewheel that has splines to the inside before. But then until I started coming to BF, I didn't know that freewheels were making a comeback.

Wilfred Laurier

not sure what you mean about splines to the inside

and they arent making a comeback
they just never completely went away on less expensive bikes
and some companies trying to squeeze out every penny of profit
will sneak freewheels onto bikes that could certainly afford a basic freehub

i have seen not too long ago
an eight speed freewheel on a box store bso
that did not have removal splines
so not only are you at high risk of bent and broken axles
due to the very long unsupported driveside of the axle
but also
worn cogs = time for a new wheel

RoadGuy

On the freewheels that I'm used to the wheelhub has threads machined onto it so the inner body of the freewheel screws directly onto the wheelhub. No separate lockring is used to secure the freewheel to the wheelhub.

On the freewheel in the photo, looks like the freewheel slides onto splines on the wheelhub that match splines on the inner body of the freewheel, AND a lockring (like that used on a freehub with a cassette) is used to secure the freewheel to the wheelhub.

tomacropod

All freewheels have splines to keep the sprockets on. Then either a lockring or threaded final sprocket to hold them on. The lockring is for assembly of the freewheel only, it still threads onto the hub. That's what makes it a freewheel. Most people don't disassemble freewheels, the op has nothing to gain by doing so, he is just curious, and still has to buy a new freewheel.

- joel