Paul_JL

Bought a 2nd hand Planet X pro carbon frameset last week and it came without the chain tension screws in the rear dropout. Contacted Planet X and it's not something they sell separately.

Not sure on the size, M3 or M4 at a guess but am I right in thinking I can use any generic suitable length screws?

Thanks

topflightpro

Probably. Though it may be difficult to find exactly what you need at your local hardware store.

VicBC_Biker

Are you looking for dropout adjusters, as in this picture?


Those aren't really to adjust chain tension, but to make sure that the axle is in the right spot to center the rim in the frame - that's my understanding, anyway.
The spring helps to hold the adjuster in position, and the flat end touching the axle helps to protect the axle threads.
Your LBS should have those, or you can easily find them online.
In the meantime, if your frame is 'square' you can probably just slide the axle all the way back and lock the QuickRelease tight.

EDIT: My apologies - I saw this in the 'new posts' listing and didn't pay attention to the sub-forum : Track Bikes
Please ignore the above....

Paul_JL

Thanks, i can't put a photo on as i'm a new member, but it's the bolts in a horizontal dropout

VicBC_Biker

A 'dropoout' like this? I think dropout is the wrong term, but anyway....
(pic of track bike end...)

79pmooney

That's not a dropout. It is a track end. A dropout is by both definition and purpose for being, a slot that opens forward or down to enable a derailleur wheel to easily "drop out" for fast racing tire (now wheel) changes.

VicBC_Biker

Thanks for that.

VicBC_Biker

Like this?

topflightpro

That is exactly what OP is talking about, and many people use the phrase drop out when they mean track end.

Paul_JL

Exactly the same bike as in your last pic VikBC Biker. I've always known that as a horizontal drop out. Anyways, it's the bolts in the rear drop outs / track ends i'm referring to?

CliffordK

@Paul_JL's Album:
https://www.bikeforums.net/g/user/540974
https://www.bikeforums.net/g/album/21671559

CliffordK

It does look like the Campy style adjuster screws might fit, although perhaps too small.

I'd take the frame to a hardware store to test screw sizes. At least that will get you the right thread diameter and pitch. Also verify the threads are still good.

Are those really for tension? I bet they are a bit of a pain to use as they'll have to be loosened and tightened every time the chain or wheel is mounted or removed.

bicievino

Personally I removed mine for mass start racing, and haven't ever had an issue that would compel me to put them back in.
I know a few folks who only put them in for standing starts, but I think that's mostly paranoia.

700wheel

You can ride the frame without the adjusting screws.
If you are a really strong rider there are alternative devices to prevent axle slip.similar to this https://www.amazon.com/BESPORTBLE-Bi...784778&sr=8-16

carleton

They are designed to keep the wheel from slipping forward during a high torque effort like a standing start or rolling jump.

In fact, that’s the preferred method for stopping this from happening as opposed to making the wheel nuts gorilla tight. This is why some manufacturers even make track disks using allen bolts which cannot be torqued down as hard as track nuts.

You can fabricate something using bits from a local hardware store. Look in the metric section. You may have to buy two nuts for the machine screw and tighten them against each other to make a tip that you grip with your fingers to manipulate the screw in and off. I’ve made such before. It all costs less than $5.

carleton

Also, your final product cannot be too long. Because, if the wheel has to go all the way forward and the tensioner all the way nearly out, then your heel will touch it.

It’s not catastrophic, just annoying.

So be prepared to cut the machine screw to some optimal length.

CliffordK

That makes some sense to prevent wheel slippage. However, I have never had the NDS slip (10-speed bikes), so is there any reason to have the screw on the left other than symmetry?

Morelock

this is the most overthought thread on something simple in a long time I love it

Just buy a couple of metric bolts the right size from your local lowes/home depot (in the drawers in the fastener section) there is some concern about thread pitch, but likely they'll be right on smaller size bolts. Buy some correct nuts for them.

Thread in the dropouts to correct length for clearance, thread the nuts on as your "stop" (or use loctite purple/blue, just something to keep it from turning in transport/etc)

Or just skip it... tighten down the wheel's nuts properly. Unless you are pulling big starts or using crappy locknuts you'll be fine.

carleton

I would suspect that you've also never done a maximal standing start on a road bike either. But, maybe you simply don't produce enough torque (which is not unusual).

Sometimes the plates of the track ends simply aren't the right material. Titanium seems to be optimal as it's soft enough to let the axle nut "bite" into it and hold. A lot of the higher end bikes use Ti. There were lots of bikes that were notorious for allowing wheels to slip, no matter how tight you wrenched on them. Serenity Bikes frames comes to mind. I've seen 150lb ladies slip wheels using those frames.

On the other end, Tiemeyer used Ti...and don't have any tensioners or allowance for such. And I never slipped a wheel using my Tiemeyer frames. And any big sprinter using a Tiemeyer probably didn't have any either. Ti is the key.

tobukog

The one's that came stock with my bike weren't long enough so I got my longer ones at the hardware store. It doesn't have the knob, but I basically made my own by using a couple of nuts. I used to think they were unnecessary, but it really makes adjusting the chain tension quick and easy so I've grown to really like them.

CliffordK

Try it without the NDS screw, but the bolt tight. I don't torque much, but Park suggests about 29.4Nm-44Nm or 266–390 inch pounds.

Test completed with in this case, DS chain stay rub (you can tape up the stay if you wish).

We really need Robert Förstemann on this board to run the test.

tobukog

The one's that came stock with my bike weren't long enough so I got my longer ones at the hardware store. It doesn't have the knob, but I basically made my own by using a couple of nuts. I used to think they were unnecessary, but it really makes adjusting the chain tension quick and easy so I've grown to really like them.

colnago62

For you, probably not. For a guy who is hitting 1,800 plus watts, yes.

Baby Puke

Use the screws. Your track ends and axle nuts will last longer.

carleton

Yup. “Track nuts” are significantly different than regular nuts that you get from a hardware store. Also, to those not familiar, you’ll appreciate buying fresh ones periodically. I suggest Dura Ace, even if you don’t have DA hubs. Just order the correct thread pitch for your hub.