Stuck in between - what would you do with post mount front, flat mount rear.

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Buddysnack
Posts: 48
Joined: Thu May 14, 2015 11:22 pm

by Buddysnack

I just received my new Mosaic XT-1 cross bike that I had built up with a flat mount for the rear discs. The bike came with an Enve CX fork, which is still post mount. I asked Enve if they were going to be coming out with a flat mount CX fork any time soon (the GRD has insufficient clearance for the tires I plan to run), and the answer was no. Apparently they are not in any rush to make a direct mount CX fork and have a lot of stock of the old standard.

I am building up my bike with Di2 1x11 (XTR Rear). For levers, I may use the shimano R785 which are currently available, or I may wait for the 9170 levers which Performance Bicycle say are coming out 11/11/16. I am not in a huge rush...although I would prefer to ride the bike before x-mas if possible.

The issue is this - with a rear direct mount and a front post mount, I won't be able to use the DA calliper for the front brake if I get the 9170 levers, so I will either have to have mismatched callipers, or go to a different standard. Any suggestions as to what to do? Here are the main options I see:

1 - Get either the 785 or 9170 levers, and use XTR race callipers with a direct to post mount adaptor on the rear. (apparently the XTR callipers are compatible with the 785 levers...don't see why the DA levers wouldn't work). This would be lighter than the 785s, and kinda trick if it worked out.

2 - Mix the callipers - either DA rear with XTR or 785 front

3- Stick with full 785, which I believe come in both post and direct mounts (easiest option).

4 - Something else?

I like the idea of the XTR option as they will likely be beefier than the DA and more suitable for the monster crossing I like to do (any opinions on this). I sorta like the idea of the DA in that this is Weight Weenies and I am here for a reason (apparently the xtrs are lighter than the 785s), but I hate the idea of mixing callipers front and rear. I am willing to settle on 785s, but this just seems not special enough.

Finally - does anyone know about the suitability of the new DA callipers for CX duty vs. the 785s (which I believe are just rebranded XT callipers)?

Can anyone help me with my first world problem?

Buddysnack
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Joined: Thu May 14, 2015 11:22 pm

by Buddysnack

A few photos. Image

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mattyNor
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Joined: Wed Mar 19, 2014 3:18 pm

by mattyNor

Why not just get a different fork?

Also I see Jessie in the back there, are you Toronto based or just visiting to get the frame?

*Edit actually have more to add

785 calipers are just rebranded xt calipers which is why xtr calipers work. For the new DA I wonder if they will go to a new system that requires less fluid volume to move to save weight and master cylinder space. The flat mount to IS adaptors are quite heavy and will offset any weight you'd save going xtr. From a weight weenies standpoint xtr front with 785 rear is the way to go, from an aesthetic point (which I would choose) xtr f/r with an adaptor is your best bet. Xtr comes in race and trail, the race ones are much slimmer but have less braking power than the 785 calipers (again which are rebranded xt).

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Buddysnack
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Joined: Thu May 14, 2015 11:22 pm

by Buddysnack

Hey mattyNor,

Yep...I'm Toronto based, and that is Jessie. The build has a full Enve front end and came with the fork. I would prefer to keep it in the family. Perhaps the best solution is to just get the full 785 set up and then upgrade to full DA when Enve comes out with a new fork.

I still love the idea of the 9170 levers and xtr callipers, but that is a pricey game to play unless I know it's going to work.

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Last edited by Buddysnack on Tue Oct 25, 2016 1:17 pm, edited 1 time in total.

Buddysnack
Posts: 48
Joined: Thu May 14, 2015 11:22 pm

by Buddysnack

Post topper and Di2 battery holder. Image
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mattyNor
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by mattyNor

Wicked! I've got a very custom Stelbel coming soonish, maybe I'll see you around!

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Buddysnack
Posts: 48
Joined: Thu May 14, 2015 11:22 pm

by Buddysnack

For sure. Do you know if there is a Toronto custom bike club? Would love to hang and shoot the shit with others who have walked a similar path.

Which Stelbel you getting, and what will make it really custom?

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ms6073
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by ms6073

Buddysnack wrote:Post topper and Di2 battery holder. Image

Looks nice and while my experience may be unique, I was not impressed with Enve's single bolt seat clamp despite torquing to 10-11.5 nm, having experienced slippage I ended up switching to a new seatpost with the two-bolt design clamp. Topic drift but it would sure be cool to see custom toppers with 3T's difflock clamp mechanism.
- Michael
"People should stop expecting normal from me... seriously, we all know it's never going to happen"

Buddysnack
Posts: 48
Joined: Thu May 14, 2015 11:22 pm

by Buddysnack

I think you are not alone ms6073. Hopefully this won't be an issue for me. Don't know the 3t system.

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mattyNor
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by mattyNor

Buddysnack wrote:For sure. Do you know if there is a Toronto custom bike club? Would love to hang and shoot the shit with others who have walked a similar path.

Which Stelbel you getting, and what will make it really custom?

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It's based off their Nina but I changed the rear dropouts to thru axle, 44mm headtube, and 1x specific di2 routing. Hanging around Blacksmith is "custom club" enough for me lol!

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ms6073
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by ms6073

Buddysnack wrote:Don't know the 3t system.

The only reason I know about it is I replaced the Enve single-bolt seat posts on the wife's cross bike with a 3T Palladio which has the Difflock clamp mechanism which affords a very fine 0.5º of adjustment, not to mention her saddle is not going to change angle:

Image
- Michael
"People should stop expecting normal from me... seriously, we all know it's never going to happen"

Buddysnack
Posts: 48
Joined: Thu May 14, 2015 11:22 pm

by Buddysnack

mattyNor wrote:
Buddysnack wrote:For sure. Do you know if there is a Toronto custom bike club? Would love to hang and shoot the shit with others who have walked a similar path.

Which Stelbel you getting, and what will make it really custom?

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It's based off their Nina but I changed the rear dropouts to thru axle, 44mm headtube, and 1x specific di2 routing. Hanging around Blacksmith is "custom club" enough for me lol!

Checked their website. Bella Machina!

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Subira
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Joined: Sat Sep 12, 2009 10:42 pm

by Subira

I would go with a mix and match, i.e. Post Front and Flat Rear. That's what your frame and fork were designed for, and the adaptors either way add weight and look rubbish.

I've swapped between the two on the current R785 levers, and they both work fine. I would say that the XT/785 caliper 'feels' a little more powerful (I have the XT setup on my MTB), so would be a good choice up front with a 160mm disc.

I think someone will need to look at the master cylinder volume of the new DA and existing R785, to know if the will play nicely. Looking at the price in the UK at the moment, they are mighty expensive to be throwing at the gravel!

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