Evans

Hi,
I just picked up two brand new Schwinn Midtown bikes for the fair price of free.
The catch...?
They both need new chains and front sprockets as they are bent pretty bad. The front sprockets seem to be all one piece and riveted to the pedal arm(sorry for not knowing the technical terms).
I can not find parts anywhere and was wondering if maybe somebody could point me in the right direction towards a place that sells parts for this bike?

I was also wondering if maybe the front sprocket/pedal can be cross referenced to another mdoel?

Any help will be Greatly Appreciated
Thank You

ScrubJ

You can probably straighten out the front sprocket enough to make it usable. Chain can be had atr your local Wal-Mart for not too much. While there, pick up an el-cheapo chain tool too.

Evans

Thanks ScrubJ
I have straightened out the front sprokets as much as I can but if I cant find new/used replacements I will drill out the rivets holding the unit together so I can better straighten each sproket individually.

As for the chain, is there anything I have to look for or will any chain work as long as it is the correct length?
And I will make sure I get a chain tool as well.

I Appreciate the help
Thank You

dabac

Good luck with that. Best as I can remember the riveted ones don't follow the same bolt circle diameters as the replaceable ones.

That might work, but you've got to consider being able to reattach them later. I'd spring for a new low-end crank before going through with that hassle though, they aren't particularly pricey.

The chain has to be the correct width, or at least not too wide. Count the sprockets at the rear, then look for a chain labeled with the same "speed" (e.g. 7 sprockets = 7-spd chain)

I haven't had much luck with el cheapo chain tools, and the only thing I regret about my Park is that I didn't buy it sooner. Then again I haven't tried them all, and maybe there's one out there that's a bit more than merely borderline useful...

Evans

Hi dabac ,
I am pretty sure I can drill out the rivets and then when I reassemble I can use some split rivets to reattach.

As for buying a new low-end crank...I wouldn't know where to begin? All I know is that the front sprocket/pedal attaches via a 1/2 inch or so square stud with a bolt...if that even makes since to you?
Could you explain a little further on how I would go about doing this?

Thanks for the info on the chain. That's simple enough to remember. This bike is a 21 speed so I will look for a 21 speed chain.

I'll keep an eye out for a good chain tool for right now though an el-cheapo is probably the way to go.

Thanks for your help

Bill Kapaun

You want cheap! How about $ 7.49?
https://www.nashbar.com/profile.cfm?sku=20985

Note that the arms are 160MM, which is short. Adult size is typically 170-175MM.
What are the tooth counts on your current rings. If they are less, there might be clearance issues with the chain stay.

BTW, I ordered 2 of them a few weeks back. Yotal price was about $21(S&H included) and it took 9 days to receive them. They said 7-10, so it was in their time frame. (USPS)

You'll need a crank removal tool ($15ish? although Nashbar lists one for $10) and a 14MM socket wrench for the crank bolts.

JJPistols

no - just count the gears on the rear wheel - should be 7, with 3 up front

7 x 3 = 21


so a 7 speed chain (most shops seem to stock 8 speed and you can remove links to fit 7, 6, or 5 speed) will work for you

Evans

Hi Bill Kapaun,
Great,that's exactly what I was looking for. It would probably cost me more in repair parts then it would to buy that crank set.
The crank arm length on my bikes are 170MM...is dropping down to 160MM going to be a problem?
I am what I consider average size,height wise.

From the site,I cannot tell if both side(pedals)come with the crank set or not?
I'm hoping this set will be a simple bolt on process?

As for the tooth count,they are 42T-34T-24T does is that tooth count going to pose a problem?

If this set will work Ill order a crank removal tool as well along with a good chain tool.

Hi JJPistols,
ok,Thanks for clearing that up. I got it now.
These bikes have 7 in the back and 3 up front as you said.

Thanks for the help guys I really Appreciate it.

Bill Kapaun

You get the crank (both arms) with riveted rings, bolts and dust caps.
You reuse your old pedals.
BTW, these are 9/16" pedals. Some lower end bikes (like Roadmaster) may have 1/2"

There is a very noticeable difference between 160 VS 170MM cranks.
You can spin faster, but have to use a lower gear. This post I made covers much of my experience with different length cranks and my bad knees- Read the first part and then skip to the end when I posted about installing the 160's.

https://www.bikeforums.net/fifty-plus-50/361045-your-cranks-too-long.html

In a nutshell, I'd probably be happiest with 165's, which happens to be the size I didn't try. (grass is always greener...?) I DO prefer the 160's over the 175's without doubt.

Tooth count MIGHT be a problem.
More teeth = larger diameter.
You'll need to get out your measuring tools!
24 VS 28. 4/24 or 1/6 larger diameter/radius. Radius is what matters here-
IF your 24T ring was 1/6 larger, would it hit the chain stay? Good chance it would, but it might clear?
42 VS 48. 6/42 or 1/7 larger. More likely to clear than the smaller, but maybe your chainstay is different.

In the first case, assume for purposes of discussion, that your 24T ring was 6" in diameter. 1/6 more, means it's now 7" diameter, or 1/2" greater radius.
I just measured my WORN 170 with the 28-36-48 and it appears the dia. from tooth tip to tooth tip is-
28- 4-9/16"
48- 7-13/16" (Kind of have to eyeball that some, since it's attached)
Note- I'm somewhat visually impaired too, so maybe some else could measure some loose rings they have laying around and chime in? ANYONE?
Now, "theoretically, a 24 should be 1/2 the diameter of a 48. BUT, I'm not exactly sure WHERE to measure. Tip to tip, valley to valley, in between (I think)???

IF there was interference, you could install a longer BB. That would lead to additional expense & tools, (and possible FDER problems?) that would negate the cost of these cranks.

Evans

Hi Bill Kapaun,
Wow,Thanks for the help.
That's a lot of info to take in and since I am new to bikes and riding it looks like I have a lot of homework to do.
I was able to find out that the cranks on my bikes are Shimano FC-TY40 but I can not find a seller of this crank anywhere?

As for the crankset you suggested I like the price a lot and would like to go with them so I will have to see if it will fit as I can not get a visual on the chain clearing the chainstay or not?
As for the length I don't know if I will notice anything since I am so new to all of this anyway?

Time to do some reading (my heads already spinning,LoL)
I Appreciate the help and for your patience with my simple questions
Thank You

EatMyA**

No. Your knees will thank you.

Aren't these guys here great? They helped me find the parts necessary to upgrade a schwinn varsity.

Bill Kapaun

You might flip the bike upside down for better access.
Take a short straight edge and try to lay it along the inner side of the small ring and measure how far back from the ring it goes before it hits the chain stay.

mike

Sounds like a typical ashtabula crank. I have some used if you want. Private message me and I will help you out. Measure the distance between the bearing cones so you have that information handy.

dabac

Don't worry about that, Shimano-compatible square taper is probably still the most common crank/bb interface out there. There shouldn't be a problem finding another reasonably priced unit to replace it with, and staying close to the original tooth count should be enough to avoid any clearance issues.
As far as general rideability goes crank length is entirely non-critical, you can slap anything on there and the bike will ride just fine. It's "only" when you begin to ride longer, more frequent, with more commitment that you might begin to develop preferences for a certain length.

Evans

Hi EatMyA**,
Yes,Everybody here is extremely helpful and no matter how simple the questions may seem nobody here makes you feel like an idiot for asking.

Hi Bill Kapaun,
Ok,Soon as I get home I will do some measuring and see what I can come up with.

Hi Mike,
PM on the way...
Thank you for the offer/help. Its very much Appreciated.

Hi dabac,
Thanks for the help and info I'm pretty sure with everybody's help here I should be set but knowing me Im sure to have more questions

Thank You everyone

dedhed

Here's one in Canada, eh! $25 Ca. Pretty far down the page. Don't look at the top of the page you'll cry at how much you can spend on bike parts.

https://www.bikecanada.com/list.php?prod=cranksets

Here's some compatability/adjustment help.

https://techdocs.shimano.com/media/te...9830642229.pdf

Thumpic

be sure you have enough seat post to accomodate the shorter cranks and riding position........

bkaapcke

Consider whether saving a free, ultra low end, bike is worth all this all this effort. After all, this is only the first repair you are doing. Many more may follow. bk

Evans

Hi dedhed,
Thanks for the link.
I'll be sending off for some new cranks in a day or so hopefully.

Hi Thumpic,
Definitely enough seat post,Thanks for bringing that up.

Hi bkaapcke,
These bikes are worth saving in my opinion as I will never be able to afford any other bikes more expensive/better then these. Some see a cheap bike,I see a good starter bike.
I can see an addiction forming though

Thanks for the help everybody