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Trek T900 chain specs

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Trek T900 chain specs

Old 06-15-24, 01:19 PM
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Trek T900 chain specs

Does anyone know the specs on the chains on a 2004 Trek T900?
Thanks.

Last edited by jethro00; 06-15-24 at 06:16 PM.
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Old 06-15-24, 06:33 PM
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What specs are you looking for? The rear will be a regular chain, for however many cogs the rear wheel has. Timing (front) chain will probably be extra long, or made from 2 chains combined, and usually can be either 1/8Ē single speed chains or 3/32Ē 5/6/7 speed chains - this will depend on thickness of the timing chainrings. Both will have to be cut to length for the specific bike and drivetrain.
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Old 06-15-24, 07:18 PM
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Unless it's been upgraded at some point, it seems like it was originally equipped with a 3x8 drivetrain. 2004 Trek T 900 – Specs, Comparisons, Reviews – 99 Spokes

So, if it's still got an 8-speed cassette, you should be able to use any 8-speed chains. There are actually often referred to as 6/7/8 speed chains, so they should also work just fine for both the drive chain and timing chain. As for length, it's easiest to just either shorten or lengthen the new chains to match the old ones--assuming that you still have them. On my older bikes, I've happily used Shimano chains: Universal Cycles -- Shimano CN-HG71 Chain [ECNHG71T116Q]
You will need a chain-breaking tool like this: Universal Cycles -- Park Tool CT-3.3 Chain Tool [CT-3.3]

An important consideration when changing chains is whether the cogs and/or rings also need replacing. A good place to start is to buy a reputable chain-measuring tool like this one: Universal Cycles -- Park Tool CC-4 Chain Wear Indicator [CC-4]. If the chain is really worn (stretched), you will likely need a new cassette and maybe new rings.

If you don't have the old chains for matching lengths, reply to the thread and I'll help. Alternatively, you can also just take it to a trusted bike shop if you are bit overwhelmed at this point.
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Old 06-16-24, 09:55 AM
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Thanks for the replies. Some additional information might help. I have a chain-measuring tool and a chain-breaking tool. The derailleur chain on our daVinci Grand Junction and Trek T900 are both stretched. We ride every morning. My LBS (2 blocks away) won't work on any bike they didn't sell. We got the T900 from them. But they have about a 2-week backlog to get to anything mechanical. I ordered a set of chains for the Grand Junction from daVinci. They will come with the correct number of links already done for me (9 speed - 116, 50, 124). That helps as I have very limited time to work on the bikes. If all I have to do is pop off current chains and install new ones. I can do that. For the derailleur chain, I have to take a series of pictures to look at so I can see how to route the new chain. Think "Routing a derailleur chain for dummies" I agree the Trek T900 should be 8 speed. I was hoping to get lucky and someone might know if the chains are a standard length like 116 or other lengths that can be ordered online. If I have to figure out the number of links and cut and join chains, it would be doable, but probably take longer than I have time to do.
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Old 06-16-24, 12:26 PM
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Sounds like you have all of the tools, which is great.

Breaking and joining chains may be faster and easier than you expect. You don't even need to count links--just lay the chains beside each other on a smooth surface to match lengths, and then break or join accordingly. If you haven't used your chain breaker before, Park Tools has some good videos like this 6-minute one:

As for the lengths, I'm not sure about the 116, 50, and 124 that you list. That sounds like 3 chains, but doesn't the bike just need 2 (timing and drive)? What's the 50 for? Regardless, I've rarely seen chains come in lengths other than 114 or 116 links. Based on the lengths that you list, the 116 is a standard size, but you'll need to two chains to build the 124 unless you can find something longer.

All of that said, it seems like buying chains from your bike shop is a fine solution if you don't want to break and join chains yourself. Routing a chain through your derailleur is a piece of cake with a photo or YouTube video. Setting the tension on your timing chain is probably the most important part of the whole deal, so hopefully you already have some experience with that?
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Old 06-16-24, 10:39 PM
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Donít forget that depending on how worn the chain is, a new cassette may be in order too. A sign this is the case is the new chain skipping when pedaled hard.

Sounds like you need a new LBS, do you have others nearby? Iíd be skeptical of any shop that only works on bikes theyíve sold.

Last edited by bboy314; 06-18-24 at 02:59 AM.
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Old 06-17-24, 03:32 PM
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All good input and appreciated. The daVinci Grand Junction has 3 chains. It has ICS. The 50 link is for the middle chain. daVinci sells the chains already cut and joined to size for a reasonable price so that helps those of us with limited time.
The LBS (2 blocks away) only works on bikes they sell in the post-Covid world because they no longer have the staff they used to have. They sell a lot of new bikes because there are multiple universities nearby so they spend a lot of time assembling new bikes, selling bikes, etc. So they limit the repair work they take in to what they sell.

There are other LBSs in town but we have no convenient way to transport a tandem and that would take time we would have a hard time finding. So I look for ways to save as much time as possible on repairs so I can get to them.

I'll check the cassettes. I have replaced them before so I can do that.
I can rotate the eccentrics and tension the timing chain(s).
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Old 06-17-24, 03:35 PM
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Instead of wasting money on a chain measuring tool, use a ruler. Almost everyone has one already!

Pick a 12" section of chain and measure it. A new chain is exactly 12" pin to pin. I measure the edge of the pins from 1" to 13" so I'm not at the end of the ruler. Use one with 1/32" fractions so you can evaluate your "stretch" more easily. Basically, if you chain has less than 1/16" stretch in a 12" length, you're good to replace it with a new chain and you won't have skipping issues. This is the gold standard - keep your stretch to 1/16" or less and you'll only be replacing chains and not cassettes, or worse, rings. If you go over 1/16" then you may experience smaller cog skipping under load. (There is someone on YouTube who shows you how to "re-shape" worn cog teeth with a Dremel. So worn cassettes CAN be repaired, but I've never tried. On my list of "fun things to try someday!"

And although your old chain may be the "proper" length already, it's always good to confirm this. There are a couple of standard chain length determining methods for 3X8 systems, so look them up if you're not familiar. If planning a tour in the outback, one could argue to add two extra links as preparation for a future chain failure. If it breaks, you remove the bad link(s) and install a quick-connect. Your chain will still be appropriate length after the repair.
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Old 06-17-24, 07:02 PM
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I already have a chain measuring tool. I like it. It's easy to use and idiot proof. The only chain I can't use it on is the 50 link chain on the daVinci Grand Junction. The tool is too long to use on such a short chain.

I ordered a new cassette for the Grand Junction. Looks like I last replaced it 3 years ago. If the new chain slips after I install it I'll be ready to replace the cassette. I am s-o-o-o-o thankful for those people who make YouTube videos of how to do things like replace a cassette.
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Old 06-18-24, 01:58 PM
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Originally Posted by jethro00
The only chain I can't use it on is the 50 link chain on the daVinci Grand Junction.
Ah, I understand. I thought that we were still on the original topic of this thread, "Trek T900 chain specs"
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Old 06-19-24, 08:43 AM
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<<Ah, I understand. I thought that we were still on the original topic of this thread, "Trek T900 chain specs">> We are, but you asked what the 50 link chain is for
I have a set of chains coming from daVinci for the Grand Junction and a new cassette for that bike coming as well. The plan is to replace chains on that bike and get it running good and then drop the Trek T900 off at the LBS for a week or 2 for them to replace the chains unless someone replies with the number of links in those chains and I can order the exact size. Based on experience, even though the LBS says they are 1-2 weeks out for any mechanical work, they tend to find our tandem is big and in their way and get it back to us faster than that. We keep 3 tandems just for these situations because I have limited time to work on them and we always have at least one good to ride.
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Old 06-21-24, 04:34 AM
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I donít think anyone will know the number of links offhand, or sell them pre-cut, but why not just size them yourself? Do you have chains on there currently to compare for length? If not, itís still not difficult to size them.
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Old 06-22-24, 08:49 PM
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There are some people on this list with T900s so you never know
I have the current chains but to take the time to figure out what length to order and lay out the old chains and figure out the length, etc. is more time than I have now. I don't mind doing it. It's just a time issue.
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