I recently got a bike that has horizontal dropouts and when I ride the right side pulls forward causing the back wheel to go be off even with the left screw all the way in... Any ideas on how to keep the wheel straight???

Is the axle nutted or does it use a quick release ?

In either case the tension may be insufficient to keep the wheel from shifting under load.

Its quick release... I will see if I can tighten it more or pedal softer...

Get a Surly Tugnut

A properly ****ioning QR should hold that wheel in place... here is a good how to.

https://www.bicyclinglife.com/HowTo/UseAQuickRelease.htm

What kind of quick release? Modern "boutique" quick releases are designed to be used in vertical dropouts and have less clamping force than traditional enclosed cam quick releases. These often slip on horizontal dropouts (particularly chromed dropouts). See Sheldon Brown's article on quick releases: https://www.sheldonbrown.com/skewers.html

+1

Tugnuts in horizontal forward facing dropouts always look kludgey, and they are. I think a good quick release is the answer here, and learning how to make sure it's properly tight.

Kind of defeats the whole purpose of having a "quick release" on the hub. May as well use a bolt-on hub and be done with it.

The axle may be off center, causing it to protrude past the outer edge of the dropout. The QR will feel tight, but it's just pushing against the axle instead of sandwiching the dropout between the QR and Axle nut.

Does the OP have horizontal dropouts or track fork ends?

They are horizontal... Dont think I would have that problem with a track fork end...

Try a Shimano quick release and see if that solves the problem. Shimano QRs use the internal cam action and they provide superior clamping force.

Your QR needs to be really tight.

You can have the same slipping problem with track fork ends. The solutions are the same. With track fork ends you also have the option of a tension device like the Surly Tugnut. I can't imagine using one with horizontal dropouts... it would be a pretty big hack IMO.

Wrong solution.

And wrong + bad advice.

Verify the axle is not too long, then throw on a good Shimano QR. Most bikes come with crap external cam design QR's that are not worth using as a paper weight.

clamp a crown/serrated washer between the skewer and dropout surface for more bite. it worked for my SS conversion for a while but nonetheless, i eventually switched to a solid axle with track nuts.