Help me fix these jacked up dropouts!

[yoothgeye]

Sorry I don't have photos, it's been a long day.

I got a Redline RL180 race BMX bike on Thursday. It's old and beat, but for a beginning racer for my son, it will be fine. Someone took it upon themselves to replace the stock wheels with a set of large axle wheels off of a Haro BMX, you know the HUGE axle hubs.

It looks like they basically just stretched the rear and fork dropouts until the larger axles fit (I see no signs of cutting, drilling, or grinding).

How would all of you go about bending the dropouts closed to better fit smaller axles? I don't want to use heat as this is already a heat treated chromoly frame.

Give me your ideas.

For those still lost, imagine the dropouts should look like this: = But instead they look like this: <

 

[sensor]

Well, I would say heat them cherry red, bend them back to normal, and quench with oil. But If you don't use heat you are running a risk of fatiguing the metal and having it snap on you child. Only other things I would suggest is cut the drop outs off and use new ones or scrap the frame and get him something else(yeah I know, none of those are probably what you want to hear but it is you child's safety!). I'm sure there are other ways to half __ it, but if it was my child I wouldn't risk it.

 

[mikeeebikey]

Well, I would say heat them cherry red, bend them back to normal, and quench with oil. But If you don't use heat you are running a risk of fatiguing the metal and having it snap on you child. Only other things I would suggest is cut the drop outs off and use new ones or scrap the frame and get him something else(yeah I know, none of those are probably what you want to hear but it is you child's safety!). I'm sure there are other ways to half __ it, but if it was my child I wouldn't risk it.

He said that it's a 4130 frame, oil quenching will make the metal brittle and crack prone without annealing and tempering.
Golly, they beat the axle into the frame? Ewww that's gotta be U G L Y !
From my 80 freestyle riding days; straighten out the drop outs best possible without cracking them, stop there. I removed the cone locking nuts and replaced them with the biggest dia. ones I could find, sometimes I had to "thin," them out which I am getting to.
Get some, "fender washers," that'll fit the 3/8ths axle, put them on the inside of the dropouts, closest to the lock nuts. Make sure it doesn't stretch the frame, if it does you must thin the lock nuts(belt sander works great) untill there is no preload.
Use fender washers on the outside also and back them up with a, "machine washer," also called a hardened washer.
Use chain adjusters!
Worst comes to worst, make a dropout that matches the original and bolt it to the inside of the drop out from 1/16th mild steel.

 

[LukeTheJoker]

Worst comes to worst, make a dropout that matches the original and bolt it to the inside of the drop out from 1/16th mild steel.

You wouldn't use 1/8th instead? There would be a lot of point load with a 1/16th contact patch...
Pretty sure it would not take much tweaking to get the extra width between the dropouts.

Luke.

 

[mikeeebikey]

Worst comes to worst, make a dropout that matches the original and bolt it to the inside of the drop out from 1/16th mild steel.

You wouldn't use 1/8th instead? There would be a lot of point load with a 1/16th contact patch...
Pretty sure it would not take much tweaking to get the extra width between the dropouts.

Luke.

Actually what I used was "60" guage, and it worked fine, for as long as the frames lasted.... Usually it was "second," season on them, they were on "street," duty status. Meaning they cracked or broke that season! I was riding Gt Greg Hill pro frames, so thicker may be better!
Also I was a little, "style," rather than function back then~! I blame the 80s hair band music.

 

[deorman]

I have successfully reformed spread dropouts by clamping them in a vise so they don't go sideways and slowly peening them back together a little at a time with a big hammer, then flattening them on an anvil. Obviously not as strong as never bent. If they tear (i.e. develop a "crack"), give it up, they're not safe.

 

[Wildcat]

If they were bent once, that's enough. Any further bending will weaken them even more. I'd use big thick washers on both sides of each dropout, 4 of them for the back wheel. The same may work for the forks also.

 

[sensor]

Well, I ASSUMED since it was a newer bike, the front triangle only would be 4130(don't know for sure either way). That's what most are now unless they are extremely high end BMX frames. If they are 4130 then I would cut them off and make some new ones with some 11-7 gauge 4130 and have them GTAW welded on. Or, worst case scenario, weld them on with oxy/actelyne and use a temp crayon(Sorry don't know the correct term. That's what I've always heard them call around the shop). DON'T USE GMAW for this!! You cant control the temp well enough and it will be more prone to failure! Sorry for ASSUMING that only the front was 4130. I still don't know if it is or isn't I'll let you research that. If it isn't chro-mo, Do what I said about cherry red,bend, quench. If is 4130 go the other(or another) route. DON'T go the just bend them back cold route since 4130 is harder so it is more brittle and, thus, more prone to fatigue cracking/failure.


*Sorry. I meant 11through 7 gauge plate. NOT 16 gauge sheet(was thinking about something else and accidentally typed that ).

 

[yoothgeye]

4130 cro-mo full frame.

 

[deorman]

I would have to say my method is not applicable if the dropouts are alloy. Works with plain steel.

 

[yoothgeye]

You are right on target CeeBee.

 

[user 135]

I would use some BMX axle adapters. These ones have the washer built in.
http://compare.ebay.com/like/2308274541 ... s&var=sbar

Here is a different style. http://www.albes.com/albesaxleadaptors38to14mm.aspx

I would say drop by your local BMX shop, but that is tough for you. I needed some once and the shop charged me a dollar a piece. I have a set like the first link, send me your address. :wink:

 

[clamdigger]

I like those adapters,didn't know about them. Either way,consider Wald 318 serrated rear axle washers.Pork Chop has 'em.

 

[yoothgeye]

I would say drop by your local BMX shop, but that is tough for you.

:x :x :x :x :x :x :x

I actually have some of those washers, so I'm going to do that. I call them "top hat washers."

I worked on a kid's bike, it had the large rear axle and it was microdrive. He had messed up the microdrive hub and wanted me to just put another wheel on it that he had brought, but his wheel didn't have the big fat axle. I started looking at the original wheel and realized that it didn't actually have a big axle, but instead an adapter, threaded inside to fit the smaller axle and outside threaded like the big axle. I was able to just screw them onto the other wheel and send him on his way.

http://www.amazon.com/ACTION-ADAPTOR-CU ... roduct_top

Thankfully, they didn't open the dropouts fully, the wheels were not fully in the drops, so I think with some "top hat washers" I'll be fine.

 

[user 135]

The box store bikes with Micro drive always seem to implode.

 

[yoothgeye]

The box store bikes with Micro drive always seem to implode.

Yes, but his was a bike shop bike! He decided to adjust his bearings, instead opened up the freewheel hub, losing all the bearings and then tightened it back down completely immobilizing it. He told me I could have it, I figured it out, put in some bearings and it's on my shelf ready for the next kid who shows up with a busted one.

 

[yoothgeye]

I was out in the shop today and took some photos, maybe I've exaggerated a little, they don't look so bad anymore...