GT RTS disc conversion - silly idea?

[ishaw]

Just thought I'd ask on here before embarking on something that could end badly.

I have a lovely, mint, nos aside from a hundred miles at most GT Team RTS. It's a bike I will be unlikely to part with.

Despite its low mileage, I've rebuilt it a few times, its had a lot of nice kit on it during these builds but I've found v brakes a limiting factor.

The next build I plan to throw some x0 10 speed parts on it, probably go 2x10. While mulling this over I wondered if a rear disc conversion would be an option.

I have a spare, spare seat stay so thought i could get some disc tabs welded on, but have a few reservations:

1. The chain stays are prone to cracking. Never had an issue on the various ones I've had, but plenty of examples out there. Would a disc tab add to the possibility that this may happen?

2. The rear stays are alloy on mine. Any issues with welding tabs on them?

3. Is or post mount?

4. Try with an a2z adapter first?

5. Max rotor size on the rear?

6. Cable routing?

7. Any other considerations?

I'll always have the option to return to a v brake rear end (well it should be canti, but hey ho, I like vs more).

 

[jimo746]

1. Possibly, probably in a different place from the usual due to the disc brake.

2. Just find some one who can Weld ally (decently).

3. Depends on brakes you want to use? Post mount for modern brakes.

4. Yeah why not? I've used them on various frames.

5. 160 is a safe bet, think that's standard for the A2Z adapters.

6. Hose routing? Stick on guides, cable ties, drill the stops out if you're brave.

7. Cost /time?

I'd try an A2Z adapter first and cable tie the hose on to prove the concept and see how you like it.
One of the disc adapters with a torque arm to the brake post would be a decent reversible longer term option.

 

[ishaw]

Re:

Cheers. As I have a spare stay I'm not too fussed about reversing it, more concerned about stressing the chain stays and pivots.

I have an a2z adapter somewhere so could try before I buy I guess, but kind of tempted to go all in to save the interim period of a fugly adapter.

 

[66 triumph daytona]

Re:

Deffo go with A2Z,Im running one with zero problems,not the prettiest but it beats what was on there by a country mile.Welding a heat treated frame will open up a myriad of issues.

 

[Thias]

Disk on the rear? What for? I'd just go Magura HSxx and that should be plenty and then some. Disk up front: Yea. That should make a difference.

 

[ishaw]

Re:

Non matching brakes? I cant do that to myself. I can barely cope with non matching seat post and stems or tyres.

With rims harder to find with v brake track, seems it is something I can do to keep it rolling and evolve it. It wears modern kit well,discs are just something I'm exploring the viability of, plus it will make it a little bit different.

 

[66 triumph daytona]

Re:

I`d imagine your sights are set on a Spin disc wheelset .....

 

[ishaw]

Re:

Actually no, as I'm realistic and have only ever seen one set. I'm mulling over rebuild options as I started stripping it with a pmanin mind, but before I continue with it, thought I'd stop and contemplate other options. I have v brakes in avid ultimates, 32mm sid world cups with v mounts (and a set of disc only lowers), all new, spin or crossmax ceramic zicral wheels etc, but I've had a set of spinergy disc wheels with yellow spokes, and some yellow reba forks for a while and thought they would play nicely with the yellow in the decals. Other options too.

Trying to use what I have rather than buy more, as ultimately I am having a big sell off and want to get this build sorted so I dont sell something I regret, as its hard enough parting with things as it is.

That said, disc spins would be icing on the cake.

 

[66 triumph daytona]

Re:

Keep Spengle in mind,they are still doing them in 27.5 and 29er,Ive seen a few earlier 26" sets on sale and I was offered a set last year.Would look the biz on an RTS.

 

[richbike]

Find a fabricator? Get an equivalent of the the lts rear brake adaptor milled. Out of platinum;-)