I think the main thing to look out for is not to damage the oil seal behind the sprocket.

 

I have done the front sprocket on my speed, and I'd really like to change rear sprocket but I am waiting until they are more available here in the US.

 

Is the front sprocket nut left or right thread

 

Right thread.

 

Hi anyone know where i can get 16 tooth sprocket for speed 400 in the uk, Hitchcocks have a 6 week back order has anyone fitted one from KTM 390 Duke ! .

 

Hi anyone know where i can get 16 tooth sprocket for speed 400 in the uk, Hitchcocks have a 6 week back order has anyone fitted one from KTM 390 Duke ! .

KTM does not make a 16t sprocket for the Duke. The largest they make is 15t. All the 16t sprockets for KTM and Triumph 400 are aftermarket.

 

Hello all, first post here, so be kind!
On my Speed 400, I have recently changed to a 16 tooth on the front, and a 41 tooth (2 teeth less than stock)on the rear.
So far I am loving the results. Obviously the revs at cruising are lower, and I seem to be using all the gears for longer duration now, including first.
I thought I might encounter some engine protests or labouring, but nothing discernable. It seems to run sweet to me.
I live in the UK and had difficulties finding a 16 tooth, so I got the 16 tooth from MJ Corse in Spain that was 39 Euros, The 41 tooth came from Hitchcocks and that was about £40.
both fitted with no issues.
I didn't need to change any links on the chain, and the whole job took about 3/4 of an hour.
Anyone else done this mod, would love to compare notes, cheers.

Hi Dave, I am a new member too, and I just did the front/back sprocket swaps as well. 16 front/ 41 rear. Just great! Very happy with the longer gear durations and the little 400 still has plenty of torque for shits and giggles. I have also put a little fairing on the front, DNA air filter, adjustable levers, ( I have short reach), and by tomorrow, my Arrow pro race muffler will arrive from Italy. I do plan on getting a Fuel-X lite controller in the near future. Best of all is the mpg. These bikes are great. 😎👍

 

That's great Speedy! an essential mod in my opinion, no sign of the engine struggling at all, cheers, Dave

 

ebay UK?

 

What about M. J. Corse in Spain?

 

Honestly...I rode the bike today with the 16T, and I barely noticed the difference to the 15T. In my opinion, it's not worth the effort.
I wouldn´t do it again.

 

Seemed the same to me as well. So I looked at it from a mathematical perspective.
This spreadsheet comparing the 15T to 16T bears out your thoughts.

An OEM up/down quick shifter on this bike would be a whole lot of fun. Would make the close ratio gear box exciting if Triumph remapped the throttle body and ignition timing to take advantage of it.

 

Hi anyone know what make of chain is fitted to speed 400 just trying to source link to re-join chain after fitting new 16 tooth front sprocket Triumph only sell complete chain

 

Hi anyone know what make of chain is fitted to speed 400 just trying to source link to re-join chain after fitting new 16 tooth front sprocket Triumph only sell complete chain

The chain is an Indian brand, and others here have not been able to source a link.

Instalation of the 16 tooth sprocket does not require a longer chain. Many were able to remove the old sprocket with the old chain on it. In some cases, like mine the sprocket would not come off without a puller. My puller would not fit with the chain in place, so I had to break it. I replaced the chain with a new one, with the same number of links as the old one.

 

They are a indian branded chain maybe just swap it out for a branded better quality one. My original black one lasted me 6k miles and it was completely worn out and I run a oiler.

 

How did the rear sprocket look? I have over 7k on my chain/sprockets and hope to make it until an aftermarket steel sprocket hits the market.

 

From the Sprockets thread.

https://www.triumph400forum.com/threads/sprockets.21/page-13?post_id=3928#post-3928

#250·Oct 16, 2024

Toxigig said:
Yes, the stock chain remains a mystery. Hopefully someone will figure out what brand it is, or at least a brand of master link that fits.

Enjoy your new useful 1st gear and reduced highway rpm.

It is Indian made Rolon brand and Pulsar 220's .520 pitch chain lock is direct fit.

 

I changed out my front sprocket with a small puller. had to keep reseting it, since it was an odd angle. once off, I used a hook tool like this (there are cheaper ones, just shop around https://www.amazon.com/dp/B000RG5UMA?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_15
to lift the chain off the sprocket (rear wheel forward as far as it would go). Hard to get your hand there to lift the chain, hence the tool. a bit of fiddleing and back on. Chain intact

 

Hey all, I have a 2024 400x scrambler and the previous owner has already done the 15t swap on the front sprocket, I didn't know this when I bought the bike from the dealer so ordered the 15t from TEC



Pulled the covers off, and looked at the already fitted one and realised I should have checked that first.

Its sat in my box of things I bought by mistake and cant send back so if anyone in the uk needs one let me know.

Anyway I don't ride the bike off road so am looking to bump the gearing up a bit more for less rpms at 50-70 mph.

I believe a 16 tooth will fit in there as I'm sure the casings are the same as the street 400.

Triumph uk list this which fits the 400 street

triumph drive sprocket TA141010 (cant post links yet)



Has anyone fitted one to the scrambler 400x ?

If that doesn't work I'll need to source a smaller rear sprocket 39 - 41t anyone got links for uk suppliers ?

 

Hey all, I have a 2024 400x scrambler and the previous owner has already done the 15t swap on the front sprocket, I didn't know this when I bought the bike from the dealer so ordered the 15t from TEC



Pulled the covers off, and looked at the already fitted one and realised I should have checked that first.

Its sat in my box of things I bought by mistake and cant send back so if anyone in the uk needs one let me know.

Anyway I don't ride the bike off road so am looking to bump the gearing up a bit more for less rpms at 50-70 mph.

I believe a 16 tooth will fit in there as I'm sure the casings are the same as the street 400.

Triumph uk list this which fits the 400 street

triumph drive sprocket TA141010 (cant post links yet)



Has anyone fitted one to the scrambler 400x ?

If that doesn't work I'll need to source a smaller rear sprocket 39 - 41t anyone got links for uk suppliers ?

I've ordered a 16t and 41t from MJ CORSE in Spain they make them to order and have different rear sizes. Just waiting for delivery

 

Hello and welcome to the forum from North Yorkshire.

A 16 tooth sprocket will fit your bike. TA141010 is for a 15 tooth sprocket.

For differing sizes you need to go aftermarket but there are no suppliers in the UK.

I sourced mine from MJ Corse in Spain who would make sprockets to your exact specification.

Please do a search on sprockets on this forum, lots of information on what has already been done.

I would expect you will have to shorten the chain.

 

JTF1536.16RB JTSPROCKETS Chain Pinion Number of Teeth: 16 | AUTODOC price and review

ahhh it might be this one for the 16 t

 

Or there is this one from Hitchcocks

16T GEARBOX SPROCKET (TALLER GEARING), Triumph Speed 400

accessories.hitchcocksmotorcycles.com

 

Fitted the hitchcocks one on my scrambler, fits ok with no rubbing issues did a 110 ish mile quick ride with friends on much more powerful bikes yesterday (100 hp +) did need to play with the gearbox a bit to get some of the overtakes and saw 93 gps on the private road at one point also did a little green lane I know well with no issues, I do have the 41t rear yet to fit as I need to get the rear wheel off to do it.

 

As of early September, 2025, I could not find a 16T countershaft sprocket to fit the Speed 400. Even MJ Corse said they were out. Earlier, on this forum, someone suggested looking up "motorcycle sprocket 2290-520-16T and I did that a week ago. I found that the big USA bike parts and accessories house Dennis Kirk had one ("Last one") for the KTM-390. It was a bit pricey at about $36.99USD plus $8 shipping and $2 tax, but beggars dtc, etc... It arrived 2 days ago and I'll be fitting it soonest.

I just did such a search and "Driven Racing, USA" says they have them for $36.99USD plus shpg and tax. For some one with no alternative source, this should be worth a try.

Ralph
"You don't stop riding because you got old; you got old because you stopped riding".