KTM RC125 Upgraded chain and sprockets...

KTM RC125 Upgraded chain and sprockets...

Author
Discussion

Richard-M-sportE90

Original Poster:

4 posts

82 months

Sunday 8th July 2018
quotequote all
Hi everyone. I'm looking to upgrade the chain and sprockets for my commute bike.
It's a 2018 KTM RC 125CC. Does anyone have any recommendations

Cbull

4,464 posts

171 months

Monday 9th July 2018
quotequote all
I've just replaced my sons chain and front sprocket only, it was for a 2017 Duke 125. Try and stick with Renthal sprockets if you can (the front is cheap enough). I opted for this chain, it's good value for money but you can get better at almost double the price (from what I remember).

https://www.ebay.co.uk/itm/DID-Heavy-Duty-X-Ring-M...

https://www.ebay.co.uk/itm/Renthal-14-T-Front-Spro...

Obviously check sizes for yours first if you opt for them.

cwis

1,158 posts

179 months

Monday 9th July 2018
quotequote all
I've got a 2013 Duke - it's obviously had a few chains and sprockets on by now. It's a 390, but I imagine there's not a great deal of difference...

One thing to watch - the standard front sprocket has a big old rubber damper built into it. The drivechain is noticeably harsher and very noisy if you use an aftermarket sprocket instead.

I've actually taken off sprockets after a week and stuck a standard one on because it was doing my head in - there's such a difference. If the 125 uses the same part number, I'd heartily recommend using it over an aftermarket one.

Also, not sure whether the 125 uses a different design, but the rear cush drive rubbers don't last longer than a chain. It's about 15 quid for a set though... Makes the gearchange far less clanky.

Richard-M-sportE90

Original Poster:

4 posts

82 months

Monday 9th July 2018
quotequote all
Cheers for the replies. When changing them over to what you've both mentioned, is there a notice in how the bike performs? Is there more torque etc due to the different sizes? I've been looking at it for that reason. I can find things regarding bigger engines and sprockets meaning it runs quicker. (I'm new to bikes so forgive me if I sound simple)

Cbull

4,464 posts

171 months

Tuesday 10th July 2018
quotequote all
Personally, I wouldn't be bothering to change them unless you have to.

My sons needed changing as both the chain and sprocket had worn in only 3000 miles from new. However, when we originally bought it, we bought it with a non-standard rear sprocket with a different amount of teeth on to give it more torque. He has had noting to compare it to.

If no one on here can give you some specifics from the top of their head then you'll have to do some research and figure out exactly how many teeth on each sprocket you'll need to maximise the torque and find a suitable purchase. Not sure replacing the chain would help much, unless its old or cheap.

Pothole

34,367 posts

282 months

Tuesday 10th July 2018
quotequote all
Oh dear. Changing sprocket sizes will not "give it more torque" at all.

OP, it's a 125. Changing anything to do with chain and sprockets may, I say MAY, make it marginally less slow at accelerating (or gathering speed as it should more accurately be termed) or give you a slightly higher top speed. NOT both.

I'd struggle to find a reason not to keep it stock.

Weso

446 posts

204 months

Tuesday 10th July 2018
quotequote all
I think you're over thinking this op.
Just get a chain and sprocket kit and whack it on. You could even use one of those clip chain link jobs on a 125 save having to rivet it.
If you want renthal sprockets and did chain go for it, they will be better than some unbranded crap.
HTH
Wes

Richard-M-sportE90

Original Poster:

4 posts

82 months

Saturday 21st July 2018
quotequote all
Cheers for the replies. When changing them over to what you've both mentioned, is there a notice in how the bike performs? Is there more torque etc due to the different sizes? I've been looking at it for that reason. I can find things regarding bigger engines and sprockets meaning it runs quicker. (I'm new to bikes so forgive me if I sound simple)

CoolHands

18,606 posts

195 months

Saturday 21st July 2018
quotequote all
The bike you have has no power. It will always be slow and gutless. Changing the chain and sprockets won’t change that so save your money and put it towards doing your bike licence and getting a bigger bike.