episodic

I have the Fuji Crosstown 4.0

I was looking over the bike after a ride and found that on the 34 tooth (granny gear) of the rear cassette, one of the teeth were broken off. The bike is only 3 weeks old - 200 miles.

I had my son run it by the LBS and they said one tooth wasn't a big concern. Guess I should have went instead. Should this be a warranty item? Just curious. You wouldn't know anything was wrong if you didn't look. Is this an expensive thing if I ask them to fix and it isn't warranty?

If it is no worry, then well I won't worry. Thanks!

Mr. Beanz

Hmm, eventhough it's not an expenive part, I'd prolly insist on a replacement. But it is a Fuji part so I'd prolly end up replacing it sooner or later.

Depending on model. Performance has Forte brand for $11- 7 speed, $15 -8 speed and $17 for 9 speed in mtb type cassettes.

https://www.performancebike.com/bikes..._400002_400021

episodic

Since my bike is only a 7 speed (no front derailler) - how would a 9 speed cassette work? Would I need new shifters in the front to access all 9 gears? Just curious - don't really understand how components can be swapped around, etc.

Mr. Beanz

7 speed shifters only have 7 clicks so you couldn't get to all 9.

Spacing difference too as the cogs are thicker than the 9 speed. But I won't confuse you, won't work!

episodic

So for the untrained bike mechanics of the world, from what I gather -

A. This isn't anything to worry about for now.
B. It is a 'cheap' and easy fix?

bautieri

A: Get it replaced as a warranty swap out. This will come to no cost to the shop (Fuji will reimburse them) asides from the mechanic's time. I'd be concerned about the chain jumping off under load and premature chain wear. If the mechanics insists this isn't a big deal, ask him if he would mind if you snap a tooth off each cog of his personal bicycle with a pair of channel locks. I bet he will whistle a different tune.

B: Yes, it is cheap to replace the cassette. Pretty easy to do too. If you do it yourself you will need a chain whip and a lock ring tool. They're not too expensive but I would have the shop do it.

dscheidt

This bike has no cassette. It has a freewheel. Make the shop replace it. But make them order the part, and ride the bike until they've got it in.

Mr. Beanz

How did you determine that from the specs?

CASSETTE: Fuji 13-34T 7-speed

dscheidt

First clue: it's a bike sold in 2010 with a seven speed rear. Second is:
https://www.fujibikes.com/LifeStyle/P...osstown40.aspx
which says
Freewheel Sunrace MFM4S7 13-34T 7-speed
Sunrace parts numbered MFM are freewheels. The crosstown 4 is fuji's bottom of the line bike; they cut corners to sell it for 300 bucks. In general, though, anything sold new these days with a seven speed is going to have a freewheel. A freewheel hub is cheaper than freehub for a cassette; if you're installing a freehub, you might as well install an 8 speed cassette.

Wogster

At 3 weeks old, it isn't a big concern, but it should be repaired under warranty as it is defective. The shop can order the part, you can ride the bike until the part comes in, the shop can switch it in under 5 minutes.

episodic

Ok I'm learning what is the difference between a freewheel and a cassette? Does that mean they have to swap the whole wheel?

dscheidt

No. They're both easily replaceable.

A free wheel is a mechanism that contains both the cogs (the gears), and the ratchet mechanism that allows the wheel to run without the chain driving it ("freewheling"), so you can coast. It screws (with threads) onto the hub of the wheel.

A cassette is just the cogs mounted on the carrier. The ratcheting mechanism is part of hub (called the "freehub"). The cassette slides on to the hub, and retained with a locking ring. There are a bunch of advantages with the cassette system. First is that the ratcheting mechanisms in either system last a long time, and so with freewheels, the cogs wear out, but the ratchet is still good. You end up having to replace things that aren't worn out. Second is that it allows the axle to be better supported by the bearings, which means you don't break axles as often. Related to that, you can have more gears in the back, because of the better bearing support.

Freewheels are generally obsolete. they're found (as single gear freewheels) on kids bikes, BMX bikes, and some single speed bikes. As multiple gear freewheels, they're found on older bikes, and cheap modern bikes. A freehub wheel costs a few bucks more than a freewheel wheel, so on ~$300 bike, it's a noticeable cost. Decent quality ones should last a long time, though, so it's not necessarily a bad thing, and seven speeds don't have large amounts of unsupported axles.

I'm more than a bit surprised that you broke the big ring, though. Usually it's the small ring that breaks. There are fewere teeth engaged at one time, so they're carrying higher loads. What often happens is that a big or strong rider doesn't shift down for a hill, and smashes his way up in low gear, causing the maximum loads.

episodic

I use my gears religiously. I rarely ride in the hardest gear except maybe downhill. I hit hills as fast as I can but I drop through every gear when the strain is too much and since I'm out of shape that happens quickly and then I get to granny gear most everytime. I downshift at stops too so I use my gears alot . Around here I'm probably in granny more than I'm in the hardest gear due to the rolling hills. I don't like standing to pedal I loose some balance and it seems harder to me.

fietsbob

Shimano K cassette is a 13-34t 7 speed, likely a direct replacement ..
if you have a Shimano hub, in the wheel.
perhaps just re-badged as Fuji?

Mr. Beanz

Ahh the Fuji site. I was looking at the Performance specs, Pffft!

Wogster

I think the last part, you meant to say HIGH gear, at the back the smaller the cog the higher the gear. Mind you there are a heck of a lot of strong riders who power up steep hills all the time with old freewheels that have full tooth complements. Generally to break off a tooth, you need for something to get caught in the chain that gets carried around and strikes the tooth, breaking it off, or the casting the cog is made from was defective or contaminated during manufacture and the tooth was a weak point.

IIRC there were no 8 speed freewheels, because 7 speed was the transition point between freewheels and freehubs, in that there are 7 speed freewheels and 7 speed cassettes, while 6 speed or less are freewheels and 8 speed or more are freehubs. Most of the trouble with bent and broken axles due to an unsupported axle are with 6 and 7 speed units, which is one of the reasons they moved to cassettes in the first place.

Now for the OP, generally freewheels work okay for the average rider heck I have two bikes here with freewheels (both 6 speed), however if for some reason after the warranty is up, you need to replace the rear wheel or rear wheel hub, the general recommendation is to move to a freehub. You can use a 7 speed cassette on an 8 speed freehub, if the 7 speed is hard to find, but you need to reset the limit screws. Cassettes are easy to find, even now.

CraigB

Yes it should be a warranty issue. Whether it's a big deal or not in terms of performance and longevity, the fact remains that it's a part that broke under warranty. Make them replace it.

bigdaddy10028

get it fixed, complete bullshyte that it broke that fast. A new freewheel is $13 bucks. The labor to replace it consists of undoing a quick release, taking a freewheel remover and taking off the old one. putting grease on new freewheel and screwing on by hand, putting wheel back on bike and pedaling around the block to complete tightening. This is literally a 3 minute fix. If they don't keep freewheels in stock, have them order one and just ride it around until the part comes in and then take it by there for the repair.

dscheidt

Yes, indeed.
No, there were eight (and even nine) speed freewheels. they don't work well, too much axle extension. People did occasionally break axles with six and seven speed freewheels, but mostly on older hubs that had been adapted, so which had more unsupported axle.

Wogster

I stand corrected on 8 speed freewheels (that's why I said IIRC), but according to Sheldon Brown, there were no 9 speed or greater freewheels. Looking into it a little more, the parts are no longer common, with most being NOS. This is largely because after you broke the 2nd, 3rd or 4th axle you replaced the hub with a cassette based one, so there are very few of them still in service. 6 speed and 7 speed are still common.

bigdaddy10028

for a bike called a "crosstown" that doesn't have a front deraileur and is obviously designed for leisurely cruising a freewheel is more than adequate. I have a vintage bike with friction shifting and 7 speed freewheel and it rides BETTER than my modern bike with 8 speed cassette. in my opinion, the biggest limitation with freewheels is that your top end can only go down to 13 teeth as opposed to 11 and you can only have 7 speeds (yes you can go 8 but major issues reported with doing so for anyone other than 150lb riders. may build my 130lb gf a 8spd freewheel bike since it's so cheap.)

DieselDan

Chances are the tooth is missing by design to ease shifting onto that cog.