Bent Axle- Advice Needed

Was at my local yesterday and there was a bunch of first time drivers on the track. Had the inside line, but had a dude tag me and our wheels made contact. Afterwards, my kart was vibrating pretty bad.

Damage assessment, my original 50mm axle has a decent bend in it. Axle wasn’t in the best shape when I got the kart, bent and repaired (sledge hammered) into submission on a few occasions prior to my tenure as the karts owner.

So I’d like to replace it. Its currently a 50mm (medium?) TB Kart OEM axle. TB quoted me $270 plus shipping which seemed pretty steep. I’m going to stay with a 50mm as I’ve heard rumors of those with my chassis who changed to a 40mm and said they wished they didn’t.

What options do I have? Seems like a pretty straight forward part to replace without having to pay that much.

I’d either get a TBKart axle or contact your local PKT Axles dealer to make the switch to a really strong American-made axle

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270 is about right. I’ve replaced a couple, AED 1000 each ($271)

Remember the axle is one of those parts that has a big effect on how the kart drives, don’t go cheap on it lol

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I’ve paid $270 for a new Birel axle, so that’s about the cost of new axles. PKT can straighten a 50mm axle for $55 and they do a very good job and are very quick about it. Even if you buy a new axle, still look into getting your existing axle straightened.

PKT has my axle for $169.00 (I think)

Precision Karting Technologies Store?

I was looking at this one from TS Racing for $115.00:

I meassured my TB Kart axle as the thickness advertised on various vendors ranged from 1.5mm to 3.0mm. Mine came in at 2mm thickness. I believe mine is a medium? If the logic goes . . .

1.5mm Soft
2.0mm Medium
2.5-3.0mm Hard

I have no idea if my assertions are correct . . .

Get a Swift brand CRG axle of equal hardness for a TB. Thickness is not what you want to match. Look for the marking on the axle or let us know the paint color inside.

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I second PKT, they did a good job straight my old axle which is now a spare. I will also talk to your local track people. One of the kid dad I race with made a rig to straight axle for much cheaper.

How do I tell what hardness? I pulled both hubs and I didn’t see any paint on the inside, nor are their any markings/ engravings on my current axle except for a logo that reads TB Kart.

No paint and no mark (m# or t#) means it’s gonna be a crapshoot on guessing the right stiffness most likely. :man_shrugging:t2:

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Whatever you do, you’ll probably want some sort of guarantee that you’re getting the same hardness you had in there. So if you can get an aftermarket axle for cheaper that is known to be the same hardness as your OEM axle, that’s good. Otherwise you’re comparing apples to oranges in terms of where you are in the hardness range if you go to a different brand other than OEM. I know some aftermarket brands say “this axle is equivalent to OEM medium” or whatever.

Axles are unfortunately an expensive piece of tube that tend to get bent and beat up pretty good.

As Matthew said, there should be some marking somewhere. If there isn’t, there’s no way to tell. I would assume it’s a medium in TB’s range, as that’s what the kart would’ve come with new.

If you can’t get a definitive answer on what stiffness it is, I would just go with a medium in whatever brand’s range you chose to buy. Medium works in most karts 90% of the time, and at your current level, you’re probably not going to tell the difference on-track anyway. Once you get the to point where you’re ready to tune with axles, you’ll be so invested the $270 per axle is going to seem like a necessary evil!

Might be worth it to check your local TB dealer and see if they have used axles. I know sometimes we sell off some of the used team axles that are still straight for a pretty good discount.

Reached out to TB and they said its M2.

When I look at other websites they read (for example) T1, T2, T3, T5, S25, M30.

Don’t know what these numbers mean. Is a M2 for one manufacturer the same as a T2 from another manufacturer?

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Every manufacturer has a different numbering/labeling method.
OTK’s range is HH, HD, H, N, Q, U, E.
Parolin uses colors painted on the inside of the axle.
Merlin uses colors (but different colors than Parolin).
Other brands use numbers.

But as axles are voodoo basically, no one really knows for sure if OTK’s N (medium) is equivalent to Merlin’s Green (medium) for example. That’s why it’s important to either stick with OEM or get a guaranteed aftermarket equivalent.

Is TB still made by CRG? If so, this chart might help:

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While I agree with all the axle advice here and they are 100% correct in that tuning with axles is very important and switching brands/stiffnesses is important to keep track of. However, I think when you are looking at this from a new person perspective, you need to just get one in there that fits and get back on the track. Pick a medium axle from any brand and put the thing back together. Have your old one straightened by someone at the track who knows what they are doing and keep it as a spare. This winter or even next year, when you have some more seat time, start looking at your tuning options. Until then, I highly doubt a $270 axle will help get you faster than a $100 axle.

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I’d be fairly cautious when switching brands. Unless you can find an attestation from someone that a specific brand and axle has translated well for your specific chassis brand/model/tires.

I’ve found that the “wrong” axle on a kart can make it handle pretty bad, even for a newcomer who’s running club level, it can mess up the kart if it’s out of whack. I remember one driver in particular who started out with a new CRG. The kart handled like a dump truck and I could not figure it out. Several races scratching my head.

Turned out the dealer at the time accidentally shipped it with a “soft” axle. Swapped for a medium, and it was like a different kart.

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TB isn’t made by CRG anymore but they carried over the axle stiffness range. The CRG range is harder than all the others. A soft CRG is like a medium on the others.

@IRQVET go with a medium Swift brand CRG replica.


I’ve heard a soft T3 CRG is real close to a OTK H hard. We actually theory to practiced this not long ago when my buddy bent his H axle. Didn’t have a replacement, but had a new swift T3 replacement. He said it felt the same as his H axle. 🤷 Axles being all different stiffness and very little info in conversion from one brand to other is annoying for sure. :unamused:


Just popped for the Swift/ CRG in M20 (medium) for stiffness. Spoke to the company and they said its about as close as I can get to the TB Kart OEM 50mm axle (M2) stiffness.

I found someone who can straighten my old axle. He said he can normally get them down to about .002. It won’t be perfect, but he could get it close in most cases. At least that way I’d have more than one option for a spare.

Plan on replacing my cassette bearings while I’m at. Between the new axle and the new bearings it was $264 shipped.


The CRG M20 is very similar to the TB M2, and I have used them interchangeably in the past. I’ve never tested Swift axles, but they seem to make a good product, and have a very strong reputation. You should be in good shape with what you ordered.

I’m surprised that there weren’t any additional markings on the axle. Usually there will will be a small stamp in one of the outer keyways.

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You are 100% correct. Once I removed the axles completely, under one of the key holes there was an M2 stamp. Didn’t think to check under each of the keys, but it was indeed there when I took a second look.

New axle is in! Swapped out the bearings while I was at it. Spins like a dream now compared to the old set up. I’ve yet to test it on the track, but I’m hoping it works out.

Thanks everybody for the advice.

New axle