corwin1968

My new bike has forward facing dropouts and small screws to set the spot where the rear axle goes. These are simply screws with no springs, nuts, or anything else and it doesn't take much for them to turn and become loose. I'm a bit intimated by getting the rear wheel back in straight so I want those little screws to be as solid a space marker as possible. Should I just screw them up tight against the axle? Should I loctite them in place? I'm leaning toward just loctiting them but I want to make sure there will be no detrimental effects from that.

Al1943

Is this actually a "new" bike or do you mean it is vintage bike new to you?

If you are going to use Locktite I would use blue #243
https://www.loctitesolutions.com/file...king_Guide.pdf

Some horizontal dropout set screws have a lock nut on the back to hold position. If yours don't have the lock nut I suppose you could add some.

FBinNY 

I would not locktite these in, because they're fairly delicate and have a history of being problematic. Usually these have been retained with a spring like the ones in ball point pens. If they're straight, turn easily and you can remove them easily, take them out and fit a spring under the head so it's inside the dropout. Or turn them in one direction or another, put some stiff grease on the threads, and turn them back to carry the grease back in. This will prevent rust on the threads, and provide enough traction to keep them in place.

dddd

Blue Loctite could easily be too strong for such a long and small-diameter screw.

I recommend springs or the specifically low-strength version of threadlocker.

Alternately, I have used rubber vacuum hose tubing of precise enough length to compress slightly and hold adjustment for over 10 years.
You can sort of see one of them here, only about 1/4" long, with a washer under the screw head compressing the tubing:

dsbrantjr

Adding locknuts is attractive not only because they will hold your adjustment but also in case the screw gets bent or broken off the nut will preserve enough of the screw that you will have something to grab to back the stub out with. A treatment with Vibra-tite VC-3 Threadmate will also help keep the screws from moving out of place yet allow easy adjustment.

Airburst

Apologies for going off-topic, but what on earth is that bike? Are those chains holding up some kind of rear rack? It doesn't seem to have a seat tube big enough for a standard seatpost either...

Andrew R Stewart 

My first thought about D4's reply was "how long has he been saving that photo to post it". We could have a guessing game or he could post the rest of the bike's design. Perhaps a Pederson? Andy.

corwin1968

I like the locknut idea but where would I get them? Do hardware stores carry locknuts that small? I've got grease and can go that route if needed but prefer the locknut idea.

Also, this is a brand new frame.

dsbrantjr

"I like the locknut idea but where would I get them?"

My local Ace Hardware stocks a wide variety of metric hardware in stainless steel. Just bring one of the screws with you to match up the size/thread.

ThermionicScott 

I just take those screws out.

Kimmo

No perhaps about it.

HillRider

No, they do make rear wheel installation a lot less fiddly if set properly. Nice to have when you just repaired a flat along the road in the rain.

As noted, suitable locknuts are available at any hardware store that carries metric fasteners and most do these days. The bolts are typically M3 or M4. Also, if the OEM bolts are a lot longer than needed, you can replace them with shorter ones and reduce the chances of bending one.

jsharr

Once you know the size of the fastener, you could remove the originals and save them, and replace them with new stainless fasteners that you cut to exact length so that they can be run all the way in and not have to worry about adjustment. Just a thought.

SJX426 

Cureous to know if the head is on the rear or facing the axle. Campagnolo has the adjustment from the rear, but the SunTour DO adjustment must be made prior to the axle being installed. Or.... am i missing something like the PO switched them?

Andrew R Stewart 

The only DP adjusting screws (maybe bolts is a better term) that I know of that had no outside the slot heads were the Shimano UFs semi horizontals. The screw was only about 1/2" long and it's range of adjustment was about 3/16". Otherwise classic horizontal DOs usually had a thumb knob or finger/wing nut on the outer end, unless it was lost or miss installed. Andy.

Camilo

Why not just buy new "dropout adjustment screws" (hint: this is a search term you could use to find 1,000,000 offerings, or just go to your favorite online or local shop). They will come complete with springs! And this set up has served 100,000,000 cyclists well for 50 years. Locktite, locknuts... bah, just get new stuff intended for the purpose, and splurge for the $5.00

dddd

Airburst wrote:
"Apologies for going off-topic, but what on earth is that bike? Are those chains holding up some kind of rear rack? It doesn't seem to have a seat tube big enough for a standard seatpost either..."


I've posted it in a few threads by now, but since they aren't usually made for or thought of in terms of racing, here's another couple of views of my racing Pedersen:

corwin1968

For one thing, I'm having trouble visualizing how the springs would work. One poster said they are inside the dropout but wouldn't they just pop out when the wheel was removed? Are they on the portion of the bolt that is between the back side of the dropout and the head of the screw?

dddd

The normal assembly has the springs and screw head inside of the dropout slot.

A threaded cap is then tightened onto the rearward-pointing tip of the screw, making it externally adjustable.

I sometimes use a common 3mm nut on the end of the screw, held in place with LocTite. This for when the cap goes missing.
On the cap nut, the threaded hole doesn't go all the way thru, and the thing is knurled instead of a hex.

Camilo

What he said. Here's a couple of pictures from the quick search I did: