I Need a Lesson on Cranks

For cranks in the $60.00 range, you can try bikepartsusa.comview.aspOpen ↗

I cannot vouch for the quality of any of the cheaper cranksets that they have.

You can get a crankset with different tooth counts, but you will probably need to replace your chain to get the correct chain length for your new gearing setup. Usually all that you have to do is determine the radius of your chainring bolt circles and purchase new chairings with the same chainring bolt circle radius.

Use a Shimano TX71 Crankset, 28/38/48 tooth, 170/175mm
and a FD-CO51 48 tooth front derailleur
with your 122.5mm BB. 😄

Great Thanks. Will start the search for the crank and drlr. Looks mainly available overseas. Not sure yet if I have 17 or 17.5 mm on left side.

Give the bike a birthday,
fit a new 122.5 UN26 Sealed BB. 😄

what country? nothing in you details (left) 😕

My present arm length is 175 mm and can only find it so far in 170mm.

Im in Connecticut and have found both the TX70 and 71 at Bikman.com for $21. Ide be glad to add a new BB at that price.

1) What do I do about the left side arm. Do I need to by the left arm also someplace and will I notice a difference going from 175 to 170.

2) Is there an advantage of the 71 over the 70. The 70 is closer to what I have. So the 71 will still work with my present cassette and I add a new front derailer.

3) Why a new BB at this time Im not against it though. Not sure if I need the 68 x 122.5 or 73 x 122.5 but for $14 can't say its not worth a try.

Just need to find the other 170 mm arm and be assured the 5mm step down wont throw off any comfort. 5mm ~ .20 inches.

If I knew what tooth combos were compatible with my cassette, I could head to Ebay and get a crank set or browse easier.

TX70 is 24/34/42
TX71 is 28/38/48 (need new FD, FD-CO51)
They come as pairs, left and right.
BB is english 68mm, buy cause its his birthday!
How tall are you? 170mm may be OK.

If you are on the outer (big) ring a lot then the TX71 may be better value.

Im 5'-8" and like the outer ring for level ground/down hill.

So the set will have the left arm with it ?

Love to get a new front drailer.

Love to get a new BB UN-26

What tools do I need to replace the BB. I have casette socket on the way. I also need an arm extractor too (I used a gear pulley a while back).

Thanks
Signing off for the night.

Maybe search on chainrings. I know there are rings available for my old Schwinn road bike, maybe there will be rings for your newer mtb. amazon, nashbar, niagara, performance, jenson, bikepartsusa, etc.

I have a riveted crank set Gargesale (all one piece). Unless I can pop the rivets and bolt on a new ring, Im limited to my options.

Chris0382 said:

Im 5'-8" GET THE 170MM CRANK SET 😉

and like the outer ring for level ground/down hill. GET IT WITH THE 48 TOOTH BIG RING 😉

So the set will have the left arm with it ? YES 😉

Love to get a new front drailer. 😉

Love to get a new BB UN-26 😉

😎

Chris0382 said:

For my used Trek Year 2004 Model 4300 24-Speed

I may want to eplace a 8-speed SR Suntour 42/34/24T crank model #XCC-T102 42/34/24. The teeth on the outer ring are getting to the end of their life.

By the way, you do know that not all the teeth are supposed to look the same on your big ring, don't you? If your Suntour big ring is anything like a Shimano big ring, there will be two sections of teeth on your big ring, roughly 180 degrees apart from each other, that look like the tops have been squared off. These teeth are purposely designed that way.

When you first posted about this bike, I think you mentioned that you thought the bike had been sitting unused in a shed for a couple of years before your purchased it, and that it was a 2004 model. Imo, it would be unusual for chain rings to wear out with only one or two years use. Out of chains, cassettes and chain rings, chain rings are usually the last to go. 🙂

chainstay said:

When you first posted about this bike, I think you mentioned that you thought the bike had been sitting unused in a shed for a couple of years before your purchased it, and that it was a 2004 model. Imo, it would be unusual for chain rings to wear out with only one or two years use. Out of chains, cassettes and chain rings, chain rings are usually the last to go. 🙂

After further review I have noticed 2 pairs of short teeth 180 degrees apart. The things we don't learn until someone tells us.

Time to concentrate on the Cassette then and new chain.

You all have been a great help

Thanks

Chris0382 said:

Time to concentrate on the Cassette then and new chain.

Look for one with an 11 tooth top gear, say 11-28. 😉

Chris, regarding the Sram cassette you are taking off, on the tall end does it make a jump all the way from 26 teeth to 32 teeth on the last two cogs? I know that Sram made some 11-32 8 speed cassettes like that at one time. If that is what you have, I would recommend staying away from ordering another one that makes that big a jump, 6 teeth, between the two tall cogs. In my experience, a big jump like that tends to make for an uncomfortable big shift when you really would like to make a smaller, smoother change with your shift. You generally don't want to have more than 4 teeth per cog difference on the tall end of the cassette, and of course, much smaller changes on the small end of the cassette.

I would consider ordering the Sram PG-850 11-30 cassette rather than the 11-32 cassette if the 11-32 cassette has a 6 tooth jump. You could get both a Sram PG-850 11-30 cassette and a Sram PG-850 chain with Power Link for a good price at link below. You can also use any Shimano HG 8 speed cassette and Shimano HG 8 speed chain, and mix and match them with the Sram stuff if you want.

bikemannetwork.comFW6164Open ↗

We could all be recommending more expensive components to you, but as I mentioned earlier, you would mainly just be saving a little weight, which is especially inmaterial in your case since your bike isn't a lightweight race machine to begin with and you are just starting out. And the truth is, even when folks have a lightweight, race machine, the difference in performance gained by lighter components is still very tiny and immeasurable to most people.

Well just got back from the maiden voyage. An 8 mile ride thru the wet trails here in CT some quite rocky. I spent a lot of time on the broken cog with no problem. The front derailleur was akward but I had no major problem to get the full range or rubbing. The bike doesnt shift like or run like Big Ben but seemed to do well.

The seat was a PIA and I need fenders badly. I found a new trail that ended up in the back yards of an apartment complex and I rode thru loads of dog doo. I rode thru a shallow brook back and forth the get rid of it and I'm soaked to the bone. Glad I wore long nylon sweat pants.

I think Im going to like the bike and will swap the cassette maybe in the spring and will go for the 11-30.

So Fenders and a Seat.

Anyone recommend that longish Schwinn gel seat at Kmart for $20?

Fender recommendations?

The TX71 crankset is available for a song at Amazon.com. I've got an extra one for my 7-SP MTB. In fact Amazon handles orders for Niagara Cycleworks, so you could buy directly from NCW. But keep in mind that NCW's standard shipping method is notoriously slow (but their customer service is quite responsive).

Chris0382 said:

Well just got back from the maiden voyage. I think Im going to like the bike and will swap the cassette maybe in the spring and will go for the 11-30.

If you decide you like that cassette with the 11to 32 range, let me know. I just remembered that I have a practically brand new Sram PG 850 11-32 cassette in one of my parts box with less than 100 miles on it. I would sell it for $12.00 plus shipping if you wanted it. As I mentioned above, I didn't like the big jump from the 26 tooth cog to 32 tooth cog, but now I see that there were a lot of 8 speed mountain bikes which were spec'd with that very cassette, so maybe it does't bother other people as much as it bothered me.

I don't know anything about those shifters you have on your bike. If they ever start to wear out or fail you and you are looking to upgrade your shifters, that Bikeman website I listed above has a very large selection of shifters to choose from. If you needed new shifters, I suspect you could go up to 9 speed fairly easily. I am thinking that a new right shifter and a new 9 speed cassette on your rear hub might be all you need, but I am not entirely certain. You would need to investigate before doing it.

That being said, I have an eight speed road racing bike that I still use for training, and I still like the 8 cog rear cassette just fine. 😄

Well Chainstay

I have $15.39 in my PayApl account. Its all yours for the cassette if you like and I can send it to you.