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Chain length with 13/40 final gearing

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Hey guys, Is anyone running 13/40 gearing? If so, what length chain are you running? I am currently running 16/40 and I like it on the road but I want to get a 13t front sprocket for off road riding. I am not sure what length chain I have (pretty sure it is the stock 108) but my axle is pretty much as far back as it will go. Dropping down to a 13t in the front would likely make my current chain way too loose, plus I think my chain needs replacing anyway.

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3 teeth can be a lot, going from a 16 to a 13. You're probably going to need to take a link or 2 out of the chain. I can post instructions how to do it if you don't know how and there's probably a zillion you tube videos out there as well.

I do gearing changes on my xr600 all the time and I use 2 chains, one for my road setup and one for my trail/racing setup.

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I would not go smaller than 14 on the front. It's too hard on the chain.

Besides...

 

Your 40/13= 3.077 ratio.

Stock: 45/15= 3.0 ratio.

 

Maybe you should consider a 43 tooth rear so a 14 tooth front gives you 3.071 off road, yet you should still be able to cruise at 80 on road with the 16 tooth front and not have to swap chains to go between them....   if you really wanna fine tune it.

 

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1 hour ago, Jack the Dogg said:

I would not go smaller than 14 on the front. It's too hard on the chain.

Besides...

 

Your 40/13= 3.077 ratio.

Stock: 45/15= 3.0 ratio.

 

Maybe you should consider a 43 tooth rear so a 14 tooth front gives you 3.071 off road, yet you should still be able to cruise at 80 on road with the 16 tooth front and not have to swap chains to go between them....   if you really wanna fine tune it.

 

80? I feel like 70 is really pushing it with 16/40. I’m sure t could do 75 or maybe 80 but it feels like the motor might explode. I have heard a couple people say a 13 is too small, but why would they make a 13t sprocket if it was too hard on the chain? I have also heard a few people say they run a 13 and it’s been fine. To be honest though, 14/40 might be fine for what I am doing so I might do that anyway. Anyone running 14/40?

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Yes, 80.

Do what you want. I like to stay between 15/45 and 16/45.

16/45 Tops out at 90 on my bike. 16/43 should go faster.

13/40 would be silly.

 

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5 hours ago, Jack the Dogg said:

Do what you want.

 

What I want is for someone with either a 13 or 14 tooth front sprocket and a 40 rear to chime in and let me know what length chain they are running ? 

I could buy a 108 link chain and then if it is too long I could take a couple links out, but if a 106 will work I would rather just buy that and not worry about taking links out. 

I have heard a couple people say a 13 is too small (although they didn't say they actually tried it themselves), but I have heard more people than that say it has worked just fine in their experience. Have you run a 13t yourself? I would be curious to hear about it. Also, I have heard of a lot of DR650 guys running a 13t with a 520 chain.

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On 9/26/2019 at 5:05 PM, teledan said:

80? I feel like 70 is really pushing it with 16/40. I’m sure t could do 75 or maybe 80 but it feels like the motor might explode. I have heard a couple people say a 13 is too small, but why would they make a 13t sprocket if it was too hard on the chain? I have also heard a few people say they run a 13 and it’s been fine. To be honest though, 14/40 might be fine for what I am doing so I might do that anyway. Anyone running 14/40?

If you feel that 70 is really pushing it with 16/40 then you don't know your bike, or are just plain afraid of it. 16/40 should take you up to about a 100mph red line in 5th gear. You came for advice, and got it.

My bike does 90 for short bursts with 16/45. It has never exploded. It cruises at 75 just fine.

It has been stated on here countless times that a 13 tooth front is a bad idea, but again.... do what you want. I'm sure you're much smarter than Honda's engineers, who designed these bikes to run with  a 45 tooth rear.

You are probably the only one here running a 40t rear, sumo's excluded. Maybe you should call Honda and tell them they've been doing it wrong.

If 14/40 is too tall... go 14/43 or 14/45 like it was designed for.

13/40 is retarded. Don't be retarded.

Edited by Jack the Dogg

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Thanks, I appreciate it. The bike is fairly new to me so I do agree that I probably don’t know the bike well enough yet. The advice I am looking for with this thread though is chain length. I ended up just buying a 108 link chain and I’ll shorten it if needed. I have counted 3 or 4 times that someone has told me a 13t is hypothetically a bad idea, but I have read many posts and articles that talk about using a 13t sprocket with no mention of issues, so I guess what I am saying there is that I am getting mixed messages. There are a lot of XR650 and DR650 guys running a 13t (and some a 12t!) with no problem, so I am having a hard time understanding why it would be a bad idea on the XR400. Anyway, that is probably a topic for a different thread, my original question was more or less answered. 

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4 minutes ago, teledan said:

Thanks, I appreciate it. The bike is fairly new to me so I do agree that I probably don’t know the bike well enough yet. The advice I am looking for with this thread though is chain length. I ended up just buying a 108 link chain and I’ll shorten it if needed. I have counted 3 or 4 times that someone has told me a 13t is hypothetically a bad idea, but I have read many posts and articles that talk about using a 13t sprocket with no mention of issues, so I guess what I am saying there is that I am getting mixed messages. There are a lot of XR650 and DR650 guys running a 13t (and some a 12t!) with no problem, so I am having a hard time understanding why it would be a bad idea on the XR400. Anyway, that is probably a topic for a different thread, my original question was more or less answered. 

Cool man. But the smaller the sprocket, the more stress it puts on your chain, and the faster your sprockets wear down.. Having broke a chain or 3.... I tend to stick with 15 or 16. Just go a 14/45 or a 14/43. It'll do what you want without all the extra wear.

Edited by Jack the Dogg

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Chains can be replaced for wear easily after running them on too small of a counter sprocket. One thing that hasn't been mentioned is the fact that the chain wears thru the swingarm slider at a faster rate in the area where it wraps around the front of the swingarm. The chain slider is probably one of the most neglected parts on the bike and it's wear never assessed.

You do that with running too small of a CS sprocket and you'll it will some saw thru the slider and start sawing thru the swingarm itself.

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4 hours ago, Trailryder42 said:

Chains can be replaced for wear easily after running them on too small of a counter sprocket. One thing that hasn't been mentioned is the fact that the chain wears thru the swingarm slider at a faster rate in the area where it wraps around the front of the swingarm. The chain slider is probably one of the most neglected parts on the bike and it's wear never assessed.

You do that with running too small of a CS sprocket and you'll it will some saw thru the slider and start sawing thru the swingarm itself.

ouch.

Honestly, I hadn't thought of that... But I do keep an eye on my slipper/slider.. Hasn't been an issue for me, but the smallest sprocket I have is a 15. :excuseme:

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3 hours ago, Jack the Dogg said:

ouch.

Honestly, I hadn't thought of that... But I do keep an eye on my slipper/slider.. Hasn't been an issue for me, but the smallest sprocket I have is a 15. :excuseme:

I tried to find a good picture of this very thing, that is floating in cyberspace on the forum somewhere, but couldn't locate it.

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