curiousabe

So last time I had a mtb was over 20 years ago, since then I've only had road bikes so how I naturally have a million questions.

I've found this amazing Colnago master mountain that im really tempted to buy, it comes with 26" wheels and a deore xt 3x6 groupsets. I'd really like 1x in front. I will mostly be using this as a gravel/commuter bike. So now to my questions:

*given that is 6x id assume it has a freewheel as opposed to cassette?
* if above is true, can I swap the freehub for a cassette compatible one? I'd really like to keep wheels
* if not possible to swao freehub can/should I upgrade wheelset to 27.5"?
*What groupset should I get? I reckon if I need to find another pair of 26" wheels an 1x11 groupset that mounts to standard HG freehub is the way to go? Can't imagine 26" with microspline is even a thing?
*which cassette / spacing should I go for for an allaround gravel/commuter setup?
*any other pitfalls I should be aware of?

prj71

You'd be money ahead just buying a used 1x bike that exists right now.

curiousabe

Most likely but I'm not looking to save cash, I really want this frame

Jeff Neese

The rear dropout spacing may be a limiting factor if you're considering an 11 speed. What you definitely do NOT want to do is let anyone convince you to bend the frame in order to accommodate that. Do you know what rear spacing is? Hopefully it's 135mm which would let you do almost anything you want.

You're right that a 6-speed is most likely to be a freehub. If you want to go cassette, you're going to need new wheels. Technically you could change hubs but with the labor involved in rebuilding both wheels you might just as well buy a new wheelset. Then you'll still have the originals, which would enhance resale value.

That's actually a fairly special and valuable bike. If you are going to change a bunch of stuff, be sure to keep ALL the original parts. Don't turn a nice collectible into a Frankenbike, without the ability to turn it back. Actually, you haven't even ridden it yet so how do you know you want to change anything at all? Is it just because 1x is the current fad? There's nothing wrong with a triple.

curiousabe

Thanks! Will measure rear dropout when I see the bike. What are standard spacings for rear and front dropouts on MTB? I'm used to working on vintage steel road bikes.

Will probably look to get new 27.5" wheels then if they fit the frame and save of wheelset and components.

As for the 3x, Iaure it might work great but I never liked 3x, not even 20 yeara ago. 2x works but then again I might just go 1x and reduce the added complexity and maintanece that comes with having an fd .

Jeff Neese

My four vintage MTB frames range from 1989 to 1996, and they are all 135mm. But they're all 7 speed, both originally and now. Since the Colnago has 6-speed, you should definitely measure.

Do you mind sharing how much you're paying for the bike? It's a rare one.

curiousabe

Thanks! They are asking 1100 EUR for it which seems OK for what it is

t2p

absolutely get the bike - but I would keep it in original or near original trim

get another bike to go 1x etc

Jeff Neese

It does seem reasonable for what it is, but keep in mind it wouldn't be worth that if someone had done a 1x conversion, changed wheels, etc. It's only worth that because it's all original. Don't eff it up.

I'm with t2p - I would lean toward keeping it as original as possible. But then I'm someone that has toured many thousands of miles on a 3x6 setup (Trek 720) and I definitely appreciate the granny gear. Front derailleurs are pretty much "set it and forget it" and don't require much maintenance after the initial setup. And I still ride the hell out of my 3x6 Trek Elance. My Fuji is only 2x6 and that's actually enough gears too, even without the granny gear. I think people have too much of an obsession with how many gears their bike has. The 18 speeds on your Colnago were just fine then, for any type of riding someone might want to do, and it's still fine now.

Kapusta

Just to pile on… if that is a vintage bike worth some money, I would not go paying the collector premium just to kill the value with a modern 1x system and a new rear wheel.

If you do go that route, at least try to keep the cranks and find a silver N/W chainring.

If the rear is not 135, forget it.

veganbikes

I would keep it close to as is because it is a cool bike but not the candidate I want for a commuter with a modern set up. I would still get the bike, I got my Phil Wood Apple VeloXS frame for that very reason I had to have it but I tried to make it a bit more period correct and really don't want to change it even if less practical for my usage.

staehpj1

I love my 1X bike, but I'd keep that bike original or close to it though. That is what I did with my old MTB race bike of a similar vintage and mine isn't a collectors gem like yours is.

PhilFo 

Mother of Gawd that's an amazing bike. Where are you commuting? Will it be locked up outside? I don't know if there is a lock strong enough to hold that bike.
If it's actually XT 6 speed, then the rear triangle is no wider than 130mm. Your hub will be either freewheel or freehub, with that spacing. If it's a freewheel and it's stock, the unit on there will probably be a Shimano 600. If it's an XT freehub, the hub is an M730 Uniglide that can probably be spaced to 7 speed. You can use modern HG cassettes on the Uniglide freehub, you just have to dremel off a few millimeters of the large tab to fit on the freehub. I built up my Breezer Lightning with a NOS set of M730 hubs, running 3x7 and it is amazing. I use XTII topmount thumbshifters, so I know the shifting will simply work, and it works beautifully; one of the nicest drivetrains I've built since 1994. Anyway, that bike amazingly sweet the way it is. Please try to give it a chance as a 3x6 or at least 2x7. With the Uniglide cogs, you can customize your gearing with 12 teeth as the smallest (exception is Dura Ace EX, but you don't have that) and 34 teeth as the largest cog. You won't be able to put anything other than a 26" wheel on, unless you have some crazy reach cantilevers. If you attempt to put a bolt-on disc brake adapter in the same room as that bike, the whole universe will be after you and I'm hoping Ernesto himself drops by to take it away. The brace at the chainstay probably won't allow a 27.5 anyway.

2old

As most of the above, it's almost certainly a 130mm rear spacing which means stretch for any 1X. It's almost sacrilegious to do anything to change the appearance of that bike IMO. Plus I doubt that its efficacy as a commuter will be enhanced.

bikemig 

Yeah this is likely 130 OLD with 3 x 6 gearing and quite possibly has a uniglide cassette as well. There is no reason why you can't use the bike a gravel bike/commuter pretty much leaving it intact. I'm running the original 3 x 6 shimano gearing on my late 80s Specialized Stumpjumper Comp which I use as a commuter. I never use the granny but I tried to change the bike as little as possible to get it operational. My Stumpjumper Comp has 130 OLD spacing and a uniglide cassette.

PhilFo 

One thing I noticed when rereading the OP's first post is some terminology mix up.
Freehub = cassette cogs.
Freewheel = freewheel cogs.
Uniglide (UG) cassette cogs use a threaded locking cog instead of a lock ring as all Hyperglide (HG) and similar later systems use. The locking cog is available in 12, 13, 14, 15 teeth. All the larger cogs in the UG system have equal sized splines to engage the freehub. UG freewheels exist as well, most you see these days are Shimano 600 corncobs.
The 6 speed spacing on all stock UG drivetrains is different than 7 speed by a fraction of a millimeter. If you choose to move to 7 speed, you need to have the proper width spacers between each cog. You can get these from a used, throw away HG cassette, you'll need 5 of them. The spacing of the smallest cog is provided by the threaded portion being wider. The plastic Shimano 7 speed spacers are great, but there are little plastic bits that need to be sanded down smooth.
Since the 6 speed and 7 speed differ in cog spacing, you'll need to get a new rear shifter. The XTII 7 speed shifter is, in my opinion (along with a few others) the greatest, most reliable shifter ever made. It has an extra "bump" so it can be used with 8 speed but 8 or more is not for this Colnago. Suntour 7 Speed thumb shifters are not quite compatible (let's just say not compatible) which is why they can be found relatively cheaply. Don't go down that road.
You could conceivably change to a 1x7, by setting your front derailleur to the middle ring and leaving it. You can even change the middle ring to whatever 110BCD ring you want and be good to go. Stick a pants guard ring where the outer chainring goes and Bob's your uncle. Get a 9 speed chain, which will deflect a little more.
With all that information and what others have provided on this thread, I'm still hoping the bike stays 3x6, because you will have a domino effect of changes that need to happen once you start swapping things. Eventually you'll be at a low value frameset with headset and stem and a rear triangle bent out to accept a wider hub with a modern 1x drivetrain.

georges1

I would keep it as is because it is a nice and rare bike.

tungsten

They won't.

Accept that you have an antique. Ride it on sunny days only and DON'T DROP IT!

Jeff Neese

I would not call that antique. It's certainly vintage, but that's what's so great about it. It's from the Golden Age of cycling. I'd keep it mostly in stock form, and ride the hell out of it.