MTBMaven

I need some help from the frame builders out there. I have a custom steel frame and would like to know if it is possible to replace the chain and seat stays on this bike. The intent is to 1) increase wheelbase, 2) increase tire clearance, and 3) install disc tabs.

I have purposefully not gone into the reasons for this request to stay focused on the primary question and not write an essay on the background. If some more details are needed I can elaborate.

Andrew R Stewart 

Yes, it is possible to replace the stays as asked. I have purposefully not gone further in my answer to stay focused on the OP's question.. Andy.

MTBMaven

Ha ha thanks Andy. Great closing comment! I just didn't want to get into the whole back story of wanting to make the frame more off road/gravel/monstercross ready and my 3 bike limit, blah, blah, blah. That has a tenancy to devolve into some whole other topic.

Does it matter if the frame was TIG welded? I'm seeing references to the process being very easy and 'good as new' if silver was used in welding. (I'm clearly not a frame builder so likely not using the correct terms here).

tuz

Yes it can be done. You cut the tubes, grind the stubs (watch out!) and weld new tubes. I won't ask "why" you want to do it, but you should think about "how much". With the new paint and the labour to remove the existing tubes it may cost as much as the frame.

Andrew R Stewart 

As Tuz says if the frame was welded. And if welded the same basic material is used for the welding filler as for the tubes. If the frame was brazed (using a different material as the filler rod like brass or silver) then there's some difference if the frame is socketed (lugged shell) or filleted. But the basic process remains and the financial questions still should be considered. You might find that for about the same cost a second frame that does the different job better (what about the fork?) and leaves you with two bikes is a good choice. Andy.

unterhausen

I don't think that's a very good idea, because you are essentially left with a kluged together bike at great expense. Or at least if an f-builder has any self respect that modification is going to cost you. One thing to consider is if the rear triangle doesn't fit big tires, neither does the fork. So you are radically changing geometry if you put another fork in the frame.

I say sell and start over. If a custom isn't in the cards, there are options for this kind of bike that will work just fine.