Converting a ti frame

loismustdie

Just wondering, I have a (much loved) VN Astraeus - when/if disc brakes become standard, would it be possible to convert the frame by adding disc tabs? Is there anyone in the UK who'd do the work? I'm not really planning to get this done, just idle curiosity.

marksteven

i think enigma says on its web site they can do this , count ya self lucky , ive got 2 ti frames to worry over

Yossie

Yes - simple job if you find the right person - Enigma as above, any bespoke frame maker who dies Ti, most of the m/bike dudes would probably do it as well (Racefit, etc)

loismustdie

Thanks - might give Enigma a call and see what they think. It'd be years before I'd actually get the work done, but good think there may be options.

Monty Dog

Also consider that most disc hubs are 135mm OLN and your frame is likely to be 130mm so your frame drop outs will need a tweak. Also go for a chainstay mounted brake as your seatstays are less strong.

loismustdie

Was wondering about spacing - I think White Industries do a 130mm disc hub, but that would obviously seriously limit my choice of wheels.

Thanks for the advice

flasher

You'd need new forks anyway, so why not try that first before messing with the frame. Personally I tend to use at least 75% front braking.

loismustdie

Agreed, and that's most likely what I'd do. That said, it would mean buying just one new STI and front brake. You'd then need mismatched wheels because you'd be 'stuck' with needing a rear wheel with a braking surface for a caliper brake. I'm sure all of this would be available, but my guess would be that buying things in singles won't be that cost effective. It would imho be better if everything matched, especially if adapting a ti frame is doable.

My guess actually is that by the time hydraulic discs are sorted and standard on road bikes (if it happens, I'm far from convinced) even with a decent ti frame, it'll work out more sensible to buy a completely new bike. I was an early adopter with mtb discs, but wouldn't be making that mistake with road discs.

rolf_f

loismustdie wrote:

My guess actually is that by the time hydraulic discs are sorted and standard on road bikes (if it happens, I'm far from convinced) even with a decent ti frame, it'll work out more sensible to buy a completely new bike.

Discs are never (IMO!) going to be a standard since there is simply no point in them once you get towards the sunnier latitudes. They are a negative in the dry and a positive in the wet so if there is little rain they make little sense.

loismustdie wrote:

Agreed, and that's most likely what I'd do. That said, it would mean buying just one new STI and front brake. You'd then need mismatched wheels because you'd be 'stuck' with needing a rear wheel with a braking surface for a caliper brake. I'm sure all of this would be available, but my guess would be that buying things in singles won't be that cost effective. It would imho be better if everything matched, especially if adapting a ti frame is doable.

Actually, disc front, caliper rear makes some sense as on a light road bike I suspect even in the wet there is no real benefit to a disc on the rear. As for cost effectiveness - it maybe cheaper to buy the pairs and sell half than to have the frame modified I suspect.

loismustdie

Inclined to agree about discs - my worry is that the manufacturers will simply stop producing decent kit for calipers and over time we'll all get forced to change. I really hope I'm wrong with this, the braking on my VN (Dura Ace 7900/C24 wheels) is one of my favourite things about it - it's very rare I want anything better. My winter bike on the other hand...

Enigma have the adaptation for £100 on their website - FWIW I'd be very surprised if I got this work done, not least because it would kill my warranty (which I've already needed once!)

naive

Rolf F wrote:

loismustdie wrote:

My guess actually is that by the time hydraulic discs are sorted and standard on road bikes (if it happens, I'm far from convinced) even with a decent ti frame, it'll work out more sensible to buy a completely new bike.

Discs are never (IMO!) going to be a standard since there is simply no point in them once you get towards the sunnier latitudes. They are a negative in the dry and a positive in the wet so if there is little rain they make little sense.

loismustdie wrote:

Agreed, and that's most likely what I'd do. That said, it would mean buying just one new STI and front brake. You'd then need mismatched wheels because you'd be 'stuck' with needing a rear wheel with a braking surface for a caliper brake. I'm sure all of this would be available, but my guess would be that buying things in singles won't be that cost effective. It would imho be better if everything matched, especially if adapting a ti frame is doable.

Actually, disc front, caliper rear makes some sense as on a light road bike I suspect even in the wet there is no real benefit to a disc on the rear. As for cost effectiveness - it maybe cheaper to buy the pairs and sell half than to have the frame modified I suspect.

(Have been discussing front disc/rear anything elsewhere on the forums, because you could upgrade fork and front-wheel more easily than doing the whole lot in many cases, and, personally, I rarely even grab the rear brake). The down side for a light road bike (as outlined in a recent Cycling Plus article) is that a disc-brake system has to transfer the braking force from the hub area to the tire and the road, obviously via the spokes. For the rear wheel, these kind of forces are not dissimilar to what you might get from the drive train (if you stomp a bit), so that's all ok. However, a light weight front wheel will tend to have a lower spoke count than the rear wheel, because there is no driving force from the hub, and with a calliper brake, no braking force either. When you use a disc brake, you need a stronger--and so heavier--front wheel, and it is not clear that any reduced rim-weight would compensate for that. When you have disc brakes front and rear, with the rear wheel not needing beefing up to deal with the extra forces, and lighter rims all round, you have more chance of winning or breaking even on weight/rotational weight.

(I fall into the category of those for whom these minor weight issues are too small to be significant, and also the category of those who favour disc-brakes for low-maintenance rather than stopping power--which should include most residents of the UK).

Cheers
N