Is 2024 KTM 300 EXC Chain Tension Spec Wrong?

In this video I check whether the KTM chain tension specification is OK, or not.
2022 TPI 300 Case Crack Video: • 2022 KTM 300 Engine Ca...
2024 KTM 300 EXC TBI
Webshop: www.tokyooffroad.com/
Facebook: / tokyooffroad

[@JasonSouthAfrica]

You are using TM design chain guides, if you read the TM installation instructions you’ll see they say it changes the spec on how much chain tension you need to run

[@onthethrottle7104]

Another great video by Tokyo Offroad! I have always run my chains slightly over max recommendations just for the reason you show. I also ride with an expert rider and his chain is way way loose, and has never had an issue other than one derailment out of 600 hours of gnarly riding. Loosen those chains! I see tight chains all the time...

[@dewimtbmoto7586]

I imagine the spec slightly changes with sproket size too as you are measuring inside a triangle. A bigger rear sproket would give a bigger reading even if too tight. Lots of variables once anything is non oem.

[@Lloydbar]

Surprisingly useful! Thanks.

[@sorin.n]

Thank you! Good to know!

[@CoBryan]

65-68mm on a 23xc. Believe me I found out the hard way. Mine came from the dealer @55mm

[@chaynetylerluczon7037]

Huh... my 23 250xcf calls for 58-61mm of slack. But i did encounter some countershaft oil leak even while in spec

[@GTM55]

Slack measurement will vary depending on sprocket sizes also. Always best to measure with shock off to establish measurement.

[@TokyoOffroad]

Agreed...

[@richardkay6171]

Excellent info vid, this is an issue. I did similar full swingarm travel testing and came to the same conclusion. The manual is incorrect for chain slack on the new '24 chassis, there should be a updated slack spec sticker on the inside of your airbox that calls out 58-61mm (at least that's where KTM put the sticker on my '24 300 XCW ) . I set my slack to 64mm just for added safety if I ingest sand or mud.

[@TokyoOffroad]

The chain tension spec I showed in the video is from the 2024 KTM 300 EXC/XCW Owner's Manual I downloaded today (2024/3/23) from the KTM website. Not good that they haven't updated the owners manual if the recommendation on airbox diagram is slacker. A relaxed spec of 58-61mm seems reasonable to me, based on my finding that 55mm is tight (although not actually binding)...

[@BjorkOffroad]

My Gasgas ec300 also has the 58-61mm sticker in the airbox while the manual lists the lesser 55-58

[@E63s_Scott]

What’s the cause of this? Is it the “anti squat” they came out with on the new frame ? Is there any real upgrades to improve it for mx especially? And has the 24.5 frame solved this? My 23 350 fc you can definitely feel it binding the second it’s not right I always run it on the slightly loose side and replace rear sprockets more often than I probably should. The suspension never feels that “good” no matter which direction I go

[@alangolightly9850]

3mm tolerance is crazy

[@TeamStruggleBunny]

My '23 XC has the same 55 - 58 mm specification. I tend to run closer to the maximum spec of 58. Not as easy to pull the shock on the linkage bike to test but I may just do that, especially as I've move from stock 14/49 to 13/50 sprockets.

[@1176hambone]

People are saying it takes 72mm to not bind beyond mid stroke on linkage models 23-24.

[@TeamStruggleBunny]

@@1176hambone 72mm? That is significant from the manual eh? I'll have to pull the link and run it through the full stroke to confirm what's good as I'd hate to break a case.

[@1176hambone]

@@TeamStruggleBunnyThis is coming from a well known Suspension tuning house. KTM has corrected the problem for 24.5 Factory editions and forth coming 25 models by shaving the swingarm and changing the chain slider. problem was, it kept getting tighter once passed mid stroke / the "longest point". This stems from tilting the engine without making necessary adaptations to the drive train pathways...

[@TeamStruggleBunny]

@@1176hambone Solid info TY!

[@1176hambone]

@@TeamStruggleBunny i cant find the convo where I got the 70-72mm. The JBI video explains, says 68-70 seems to work.

[@andrecontois8510]

Looked pretty snug even at the max. As you said add some mud and the chain will get tighter.

[@TokyoOffroad]

It was tight at the minimum spec of 55mm, but not binding. The max spec of 58mm felt OK. Yes, with mud, or sand it would get tighter. As such my recommendation is set at the max spec of 58mm. You could run with even more slack, but the chance of rerailing the chain will increase.

[@milosbgd]

What I found interesting is that in service manual says different measures for chain adjustments then on the sticker which is located in the airbox. Check it. On my bike sticker is written Min 58mm and Max 61 mm

[@TokyoOffroad]

Yes, the manual needs to be updated...

[@lukaluka2089]

It is also such a minimum I set at 65 mm.

[@robertm7717]

My 2 24s Husqvarna Tx 300 Fx350 have the same specs

[@carbonjelloid8045]

You have an after market chain guide which looks to be longer than the original part, so you are measuring in the wrong place also the shape of the guide under the swinging arm is taking up some slack.

[@TokyoOffroad]

I just measured the stock chain slider and the TMD slider I have fitted is the same length. As such The TMD slider does not change the measurement point. Regarding difference in shape, wear and also sprocket sizes, this is why I think it's important to do a full travel check with the shock off and verify that the chain tension is not excessive.

[@Motoinc]

Yeah.....but your TMDesign is bigger around and make the measurements different from OEM chain guide

[@TokyoOffroad]

I don’t see a difference compared to stock. Either way it’s a very good idea to perform a measurement like I did (with the rear shock removed) to figure out the minimum slack you can safely run.

[@Motoinc]

@@TokyoOffroad Yeah it's good to do the measurements yourself but the circumference is bigger then stock....like your videos👍

[@TokyoOffroad]

@@Motoinc It should be noted that I'm not running stock gearing. Stock on the 2024 is 13/45. I'm running 13/50. Another reason to do the no rear shock measurement. Personally I prefer to run with plenty of slack to avoid damaging anything. I'll make a follow up video to discuss this more...

[@Motoinc]

@@TokyoOffroad Ok then it's really good to do the measurement. I've done this 1 time on my old KX but I will do it now on mine and my wife's bike just because you remember me it's a good thing to do. Cheers from Sweden

[@richardhartley7094]

👍👍

[@rodriou1326]

Another symptom of a loose chain is a delayed traction to the rear wheel. Very annoying when doing hard enduro, feels sloppy and rolls backs slightly

[@chadrides914]

Lol

[@sendit6011]

65 for me. No less. KTM really put the screws to us with all the problems these bikes have been having. Anyone want to buy mine

[@chadrides914]

For real man

[@alang3991]

I’ll give you $500 sight unseen. Should be a fair price since you think it’s such a POS.

[@sendit6011]

@alang3991 sounds like you already have one

[@onthethrottle7104]

Sendit = troll

[@sendit6011]

@@onthethrottle7104 Then buy one if you haven't yet. Or mine. 28hrs, I'll take 11