Marin Mount Vision Pro Build

[old_coyote_pedaller]

@cheesebutt666 the RaceFace Evolve DH cranks I put on the Wolf Ridge have an external bearing BB similar to a Hollowtech BB, had no problem fitting it and cranks.

@hawkhill97 agree with you saying the chances of breaking frame with longer forks is low especially with the longer travel better able to absorb the shock loads unless stupidity involved with what you're trying to ride.
The perception that handling wasn't improved by longer travel forks and suspension on these frames is what I felt when I first did it, but then I was going from a hardtail Cannondale with steep head angle to the Marin with a slacker head angle leaning more towards more modern bikes. It felt really weird to me, tried changing stem and bars, but persevered with short stem and wider bars. Got used to it then realised bike felt better downhill than steep angle 100mm travel Lefty. Not how the rear felt but how the front end performed with slacker head angle giving more stability and confidence not being so over front wheel.
This was confirmed when I started riding my modern geo hardtail, a Sonder Transmitter, it also felt different at first but because I'd had experience with the Marin it didn't feel "weird". Now with the Wolf Ridge having a longer travel fork and slacker head angle it seems a bit better again. As I said it'll never be quite like a modern bike but for a 20+ y.o. frame it's not bad.

 

[hawkhill97]

Ah didn't realise the m950 crankset was octalink, thought it was a little older than that and still on square taper!

@old_coyote_pedaller that's interesting - you do see a fair few of these frames with longer forks so I guess a lot of people must enjoy the ride that way. Hmmm, you've kind of made be want to build up a "modern" style MtV now to go with my classic one

 

[legrandefromage]

Unless you could stump up for decent Marzocchis, these frames were way ahead of the available forks at the time - super plush rear action (oo-er missus!) and only so so front ends - at least this is how it was in 1997 when I got my first Mt Vision!

 

[cheesebutt666]

Yep, you could put a hollowtech BB and matching crank on if you wanted, no issues with that that I'm aware of.

@old_coyote_pedaller I reckon the chance of breaking a frame with longer travel forks is negligible unless you're riding crazy hard, but having tried doing this on a few older mtbs designed around shorter forks I don't think it improves the handling - especially on a bike like the Mt V that has a pretty high BB to start with. But at the end of the day it's all personal preference, as long as you like how a bike looks and rides it's a good bike!

Do you think a 1x12 system would fit? I was thinking maybe the chainring might be too big and not have enough clearance from the torque tube.

 

[old_coyote_pedaller]

A 12 speed cassette needs an entirely different freehub body, you'd need a new wheel. Also, if my memory is correct, the 12 speed cassette biggest sprocket is dished so it overhangs freehub body to clear the spokes close to hub, maybe this would put chain even closer to tyre even if you could fit it all together.
Think 12 speed also has wider hubs as well, therefore frame is wider. My new hardtail is 12 speed, it has a Boost rear hub which is 148mm wide, the front is are 110mm. All completely new stuff, that's why I just used a 10 speed cassette. I found I don't miss the extra 2 gears on Marin compared to the 12 on new hardtail.

 

[cheesebutt666]

A 12 speed cassette needs an entirely different freehub body, you'd need a new wheel. Also, if my memory is correct, the 12 speed cassette biggest sprocket is dished so it overhangs freehub body to clear the spokes close to hub, maybe this would put chain even closer to tyre even if you could fit it all together.
Think 12 speed also has wider hubs as well, therefore frame is wider. My new hardtail is 12 speed, it has a Boost rear hub which is 148mm wide, the front is are 110mm. All completely new stuff, that's why I just used a 10 speed cassette. I found I don't miss the extra 2 gears on Marin compared to the 12 on new hardtail.

Ahh okay I gotcha, at the moment The bike is basically bare bones, just the frame, headset, handle bars and fork. So I’m not too restrained besides what will literally not fit on the bike itself. I would rather fit it with newish parts, preferably a 1x system though I don’t know exactly what will fit with it. Do any reputable brands produce 1x10 systems that would fit the MtV frame? And would any of those systems work for 26in tires?

 

[hawkhill97]

1x is somewhat over-rated IMO (well, this is retrobike ) and 3x8 is hard to beat.

However if you wanted to go down this route, you could definitely fit a ~32t single chain ring - it'll go in around the middle position of a triple to give a reasonable chain line, and is the same size as the middle chain ring of a triple crankset so there won't be any clearance issues.

The issue you'll have is that even with 1x10 you won't get a really wide range of gears. I find this isn't a problem for top speeds (32/11 is plenty high enough for a MTB being used off-road), but can be absolutely killer if you like epic cross country rides with lots of climbing. I'd want something like 32/50 as a bottom gear, and a 11-50 10 speed cassette would have some pretty big jumps between the gears (if it's even available), plus the rear mech wouldn't follow the shape of the cassette properly (it'd either hit the sprockets in the lowest gears, or dangle way below the sprockets in the top gears = noisy running, chain skipping, poor shifting etc).

So yes, it's do-able but IMO you'd be far better off going 3x8 with nice XT components.

Another point worth considering - the pedalling dynamics of these single pivot full sus designs change depending on chain ring size. Something around 32t (chain line equal in height to the pivot) is good for general riding. Going down to a 24t granny (chain line below pivot) induces more anti-squat on pedalling, which makes the back end firm up and dig in under power. This can make up for an older rear shock lacking any fancy platform damping, which may otherwise result in a bit of a wallowy feel when climbing.

At the end of the day it's all compromises, part of the fun of doing your own custom builds.

I personally love 3x8 as it's cheap as chips to replace stuff when it wears out!

 

[old_coyote_pedaller]

What I did with my Wolf Ridge when it went 1x10 was fit an XT RD-M786 Shadow Plus clutch mech, an XT 10 speed shifter, an XT MT800 BB with RaceFace Evolve DH cranks with NW ring. The cassette is 11-50 which as you say causes problems for rear mech, but I fitted a cheapo ebay Goat link which drops the mech down to clear cassette plus a longer B tension screw. This seems to work no problem, not any different to the Sram GX 1x12 on my Sonder Transmitter, no noise, nor noticeable jumps. This might be because the Marin has 26" wheels, 2.5/2.3 tyres compared to the Transmitter which has 650b+ wheels, 2.8/2.6 tyres which lowers the gearing a bit smoothing any jumps.

 

[was8v]

Course you can go 1x12

The info above is wrong

You can get cassettes 11-50 12 speed in standard hg freehub body fitment. The SRAM pg1230 and sunrace make them too. This will fit any 8spd+ freehub.

This will give you the latest gearing. You'll obviously need the 12spd shifter chain and mech to match.

Only if you want to go 10-50 will you need the latest hub with a shimano microspline or SRAM xd freehub

I run a sunrace 11-52 11 speed setup on one retrobike.

 

[old_coyote_pedaller]

Jeez, I knew that ......read the word system and my thought process just went that way, sorry. Good job you were paying attention......

I had looked in to doing it 1x12 instead of 1x10 but buying XT 1x10 mech and shifter was cheaper than the Sram equivalent. Sram 12 speed being newer than the 10 speed XT it was easier finding the older stuff on the cheap, a major consideration for bike's rebuild. As you say if you want 10-50 as opposed to 11-50 or 52 you need the Shimano microspline or Sram xd with the 10t sprocket being too small to fit on the conventional HG freehub.