Track bike and MKS CA-MX10 chain tugs … won’t fit?

Hi there, long time listener, first time caller.

So anyway, long story short, got a pair of the MKS CA-MX10 chain tugs to put on the track bike (8mm width version with recessed bolts, here). Now the width of the fork ends works fine but …. for some reason they will NOT go over the axle as they are too small?

The axle measures something like 9.7mm diameter with calipers (going from memory here) so these should be fine as they are designed for 10mm axle right? Yet the hole for the axle is only something like 9.4mm when I measured it?

Now I know if its too small, its too small but …. wtf? Any ideas? Should I just get the 10mm drill bit out 😜😄

I wouldn’t bother with tugs. I have a track bike and three other fixed wheel road bikes. None have chain tugs. Do you regularly have a rear wheel slip and lose chain tension? If so just get a longer spanner to crank up the torque. How do you tension the chain. Do you walk the back wheel backwards alternating the tension on each side? I normally tension by the NDS and the wheel slightly off centres then push the wheel into line and tighten the DS nut. Too tight and you will have a tight spot because chainrings never sit perfectly on a spider.

If you must for a statement then drill them out.

It’s just a shit for slipping. It has to be torqued far, far beyond what I’ve had to torque any other track bike beyond. I don’t know if it’s the fork ends or the poor grip of the washers on the hub. There’s loads of “bite” still to the washers on the nuts.

Torquing it like that all the time also makes it an absolute shite to get the bloody nuts undone again, as both sides just spin the hub 🤬🤬🤬 I have to hold one side with a cone spanner at the cone to get things undone (more tools to carry around!).

Oh well, a better second hand frame is in the offing, so maybe that will help, especially if I pair it with new wheels 😜

I’d still like to know why something advertised as for a 10mm axle doesn’t bloody fit though …

Yep, a good excuse for new frame and wheels. I have never needed to use chain tugs in 20 years of fixed gear riding and they really shouldn’t be needed if wheel and frame don’t have any issues.

As to why they don’t fit, no idea as they should be for 10mm so guessing incorrectly made.

I’d still like to know why something advertised as for a 10mm axle doesn’t bloody fit though …

Paint? Worn out drill in the factory?

You’ll have a job drilling out 9.4 to 10mm, the corners of the flutes will just grab at the edge. Wouldn’t take long with a rat file though.

Something doesn’t sound right then, I had chain tugs on my my Plug, took them off as they didn’t allow the full range of adjustment when I snapped the chain mid ride and had to take some links out. Hasn’t budged since.

Dunno about sizing, I have to take a file to the dropouts every so often to de-bur them just to get the axle in and out (which probably says I over torque them somewhat), so I can see how just a bit of paint would stop it passing through the tugs smoothly.

As TiRed said, get an idea for how much slack is required with the NDS done up and the wheel slightly off center, push the tyre to the center and nip up the DS nut. I’m playing around with fixed and freewheels at the moment so I’ve been doing that faff a lot!

Well I for one like chain tugs on my fixed gear (though I have them built into the frame anyway). I find them very helpful for getting chain tension just so.

Dunno about the duff axle holes on yours though!

No tugs on five track bikes and one fixed road bike, something sounds odd. If you really have to use them then drill them out to 10mm.

Well I for one like chain tugs on my fixed gear (though I have them built into the frame anyway). I find them very helpful for getting chain tension just so.

Yes, having an allen bolt at the front of the dropout allowing you to tension the chain perfectly is very good (I have had a couple of frames with those) and only really need the drive side one.

However, they are just for getting the tension right whereas a chain tug is more of a bodge if using it to stop a wheel slipping. Fine if it saves buying new hub or frame though.

You’ll have a job drilling out 9.4 to 10mm

Adjustable reamer is where it’s at for that sort of change in hole size.

Like this but from somewhere with stock

https://www.amazon.co.uk/Adjustable-Range-9-25mm-10mm-Reamer-Cutting/dp/B012ZFG77M

Btw most fixed chains are too tight. You want about a cm of slack to reduce friction. But not so much that you ship the chain on bumpy roads. On the smooth track the slack. An be even more. And there are some nice spanner’s for the job, also the pdw tyre lever spanner lives in my seat pack and can be tensioned with a foot.

I never need two spanner’s to tighten and remove nuts. Perhaps your axle threads are a little rusty. I had this recently on the winter wheels where unscrewing was hard as the axle would rotate. I then removed the nuts cleaned the threads with wd40 then added some light grease to the axle. Now no problem. The summer wheels never have this issue.

Thanks for the replies everyone.

I already went and got a new frameset (a used Planet-X T.O.R.) which has built in chain tensioners, but, as I think has already been pointed out, these aren’t supposed to take the “load” of your drivetrain, just to get the tension right to start with (and you back them off again once the wheel is done up). Hard to tell for sure, but I think I had a bit of wheel slip when I was trying it out on Wednesday which was saved by the tension guides. I think it’s the shitty cheap wheels that came with the shitty cheap track bike.

Whilst new wheels to go with the new frameset would be nice I can’t quite spend out on them yet. I have some velodrome shop hub washers which look like they have much more “bite” than whats on the hub now, but they are much thicker (4mm I think), so I don’t think they will go on the hub and still be able to get the wheel in …..

Maybe I just need to find some thinner serrated washers from Screwfix or something….

I have a pair I might consider selling on, can check tonight if they’re actually 10mm diameter.

Lovely bits of kit though, I’m just not riding singlespeed any more!