Chain & Front Sprocket Questions

[Charp]

I've been hearing a sort of dragging noise as I pull away from a stop. Other than the noise, the bike is running great. When I put the bike on a stand and spin the wheel, I can tell the chain is not spinning smoothly. I think this is the source of the noise. So, now I want to inspect and clean the front sprocket, which brings me to my questions.

I have 15K miles on this bike. Is that a reasonable life span if it turns out the chain is bad?

When changing a chain, should you always replace the front and rear sprockets?

How do I access the front sprocket? I removed the outer cover and the two screws for the inner cover, but the brake mechanism (pump?) is still in the way. In the image below it looks like I just need to remove the screw (1) and maybe unfasten the wire connector (2). Is there more to do? Any hints for making this job easier? And, is there a torque spec for that screw (1)?

Thanks in advance!

 

[sikatri]

Oops that looks like a few items to remove! Sorry I can’t offer advice other than to get a shop manual or perhaps a Street Twin owner will chime in. On the positive side, I’m sure it can be fixed. Perhaps needs a cleaning and chain wax.

 

[shanered6]

Yes you should replace both sprockets and chain at the same time , look for stiff points in the chain if there is it needs replacing .
In the pic it looks like you take the bolt out you have circled and the lower one below the foot peg and it should then all come as one unit , I have not worked on one of these bikes before but that is what it looks like to me .
As sikatri says im sure some one will be along soon .

 

[sikatri]

Looks like some zip ties might be useful to keep the brake cylinder out of the way. Disconnect the wires at point 2 and do what shanered6 noted.

 

[Charp]

Thanks @sikatri and @shanered6 , I will give that a try.

One more question, does anyone know what size socket is required for front sprocket?

 

[sikatri]

No, but…
https://bellacorse.com/product/front-sprocket-for-triumph-t100-street-twin-street-scrambler/
https://sprocketcenter.com/c-1392503-street-triumph-street-twin-900-all-models-2016-2021.html
These might help. Don’t know your year, but there would appear to be some aftermarket vendors if you don’t want dealer parts. I’d count the teeth on yours when you get it open.

 

[Philois]

Also check your chain adjustment, make sure the chain is running true (straight).

 

[Charp]

UPDATE:

Removing the lower bolt for the foot peg did allow me to gain just enough access to give the front sprocket area a decent cleaning, but not enough if I had to replace the front sprocket. The hose that runs up to the left in my picture above goes to the rear brake fluid reservoir and restricted how much things could be pushed out of the way. So I think I would have to remove the screws holding the reservoir to allow it to swing freely in order to gain full access to the front sprocket.

The dragging noise I was hearing is gone after a good lubing and small adjustment to the chain alignment, but I suspect it won't be long before I need to replace the chain. For reference, Triumph sells a kit for the Street Twin that includes a chain and both the front and rear sprockets (T2017591). The cost of this kit at my local Triumph dealership is $236 USD. The front sprocket nut is 36mm.

 

[sikatri]

Glad you got it figured out and have a solid idea how to approach a sprocket and chain change. Cleaning and lube goes a long way.

 

[rodhotter]

Glad you got it figured out and have a solid idea how to approach a sprocket and chain change. Cleaning and lube goes a long way.

your bike model + year gets better info + your location might get local help!! a Haynes-Clymer repair manual is great for cheep IMO

 

[sikatri]

your bike model + year gets better info + your location might get local help!! a Haynes-Clymer repair manual is great for cheep IMO

Factory shop manual is even better.

Agree, identifying clearly the motorcycle, model and year helps in any discussion.

 

[rodhotter]

i used the sprocket center + an EK chain + their screw screw link EZEr there are NO paper OE service manuals anymore on newer bikes. the pic looks to be a T120 as my 18 is, a bit of a PITA compared to air cooled models!

 

[Charp]

This is a follow up to my original post. I getting ready to replace my chain as well as the front and rear sprockets. At this point, all I need are some torque specs that, for the life of me, I can't find on the internet. I even tried ChatGPT - no luck there LOL.

Does anyone know the specs for the following on a 2019 Triumph Street Twin (900)?

• Font wheel nut
• Front sprocket nut
• Bolts for attaching the rear sprocket

Side note: Triumph chain kits are an back order - it took 8 weeks to get a set.

Thanks!

 

[Philois]

Sorry I don’t own a speed twin , but may I suggest you purchase a workshop manual, best $ you will ever spend. If you plan to do any work yourself they are invaluable.