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-   -   Dropout Conversion (https://www.bikeforums.net/framebuilders/680328-dropout-conversion.html)

DRietz 09-14-10 09:28 PM

Dropout Conversion
 
Hey there. I've recently been bitten by the 'cross bug and have been doing a local race series for about a year now.

Anyway, I've raced and ridden SS mtb for two years, and absolutely love it. Based on my experience thus far with 'cross, I'm almost never shifting. In fact, I just started limiting my derailleurs to a narrowed gear range.

I've come across an old steel touring bike with cantilever posts, but no signs of brand. It is, however, an incredibly light frameset, weighing in at around 4pounds with the fork. What I want to do is knock out the dropouts currently on there, and braze in new, truly horizontal SS/track dropouts myself. Before you try to talk me out of it, I already contacted my local framebuilder. $200 for a dropout conversion. Uh...no.

So, what I'm wondering is if there are track dropouts that are available in the opposite of a plug-in lug. What I'm talking about is a dropout with ports in which the seat and chain stays insert into.

Also, what materials will I be needing besides the gas/torch, brazing material, flux, and lug? That's it, correct?

Thanks very much for any advice and tips.

unterhausen 09-14-10 11:52 PM

I don't think I have ever seen a track dropout with sockets. The problem with sockets is that the dropouts have to have the same angles as your frame, tabbed dropouts can be made to fit almost any angle.

The quote of $200 was no paint?

tuz 09-15-10 08:10 AM

Ceeway has some track ends with pugs (here). And I'm pretty sure Nagasawa used track end with sockets but I don't know where you can get some of that kind. Like said above not only those ends have a given angle (I'm sure they can be changed a bit), you also have to deal with a narrow ID or OD range for the stays. I'm not sure I understand why you would need those.

Moreover, replacing drops is a job for the experienced. I've never done it (I've only build one frame), but it takes a lot of heat (heard many stories of people braking the stays in the process) and you have to be careful if you want to preserve the geometry of the bike.

So if the bike has standard foward-facing horizontal drops I would talk you out of it. They are perfect for SS/fixed, and are way more practical when removing the wheel for a flat (and for fenders if you go that way).

Otherwise you have the list of materials right. Apparently firebricks do help for this operation. But you'll need some know-how to make sure the slots are parallel, at the same height, same distance from the BB, etc., and to make sure you won't end up with a slightly slanted TT and/or different head angle.

DRietz 09-15-10 08:49 AM


Originally Posted by unterhausen (Post 11466963)
I don't think I have ever seen a track dropout with sockets. The problem with sockets is that the dropouts have to have the same angles as your frame, tabbed dropouts can be made to fit almost any angle.

The quote of $200 was no paint?

I suppose you're right, that would be a little risky.

$200 was the quote for parts ($30 dropouts) and labor. No paint.

DRietz 09-15-10 08:51 AM


Originally Posted by tuz (Post 11467855)
Ceeway has some track ends with pugs (here). And I'm pretty sure Nagasawa used track end with sockets but I don't know where you can get some of that kind. Like said above not only those ends have a given angle (I'm sure they can be changed a bit), you also have to deal with a narrow ID or OD range for the stays. I'm not sure I understand why you would need those.

Moreover, replacing drops is a job for the experienced. I've never done it (I've only build one frame), but it takes a lot of heat (heard many stories of people braking the stays in the process) and you have to be careful if you want to preserve the geometry of the bike.

So if the bike has standard foward-facing horizontal drops I would talk you out of it. They are perfect for SS/fixed, and are way more practical when removing the wheel for a flat (and for fenders if you go that way).

Otherwise you have the list of materials right. Apparently firebricks do help for this operation. But you'll need some know-how to make sure the slots are parallel, at the same height, same distance from the BB, etc., and to make sure you won't end up with a slightly slanted TT and/or different head angle.

It's really that hard? I might have to reconsider, as I've done nothing like this before. I mean, I've welded, but I figured that stock dropouts that weren't sockets already had slots in the stays...

bobbotron 09-15-10 08:56 AM


Originally Posted by DRietz (Post 11468106)
It's really that hard? I might have to reconsider, as I've done nothing like this before. I mean, I've welded, but I figured that stock dropouts that weren't sockets already had slots in the stays...

For bonus points, you could take a set of slotted drop outs, and gas weld on the sockets, at the desired angles, and then braze that into the bike.

unterhausen 09-15-10 10:17 AM

Before I had done it, I was rather surprised to see a framebuilder charge $150 for the job. But after I did a replacement, I wouldn't do it for less. It's somewhat painstaking work. And the stays are always in the way.

tuz 09-15-10 10:51 AM

I'll let the experienced say how hard it actually is. But I found building the rear triangle challenging enough to get the wheel to centre nicely (hint: it didn't), so I can see why it is harder to additionally remove the drops and replace them with a different type. Pictures won't tell you how to do it, but you can get an idea from this photo series (link).

So does your bike have horiz. drops already?

JohnDThompson 09-15-10 10:56 AM


Originally Posted by unterhausen (Post 11466963)
I don't think I have ever seen a track dropout with sockets. The problem with sockets is that the dropouts have to have the same angles as your frame, tabbed dropouts can be made to fit almost any angle.

Nagasawa made socketed track dropouts. The seat stay socket was a separate piece to allow angle adjustment for different frame sizes:
http://www.os2.dhs.org/~john/track0005.jpg

Those ones were from the mid-80s; not sure if they're still available.

unterhausen 09-15-10 12:49 PM

I was inexact with my language; I've seen socketed track drops on a Nagasawa, just not for sale. Thanks for posting the picture, looks like you could do that with tubing.

DRietz 09-16-10 04:33 PM

Hm. My dropouts are vertical, unfortunately. If they were horizontal, I wouldn't be asking because that's so much easier. I'll try to see what I can figure out, thanks for the help guys.


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