Saturday, March 11, 2023

Singular Cycles Gryphon Mk3 Build: Update 2

Derailleur cleaning time
 Moving on with the build of this Singular Cycles Gryphon Mk3, my next task after figuring out the brakes and that the triple crank would work was to fit a front and a rear derailleur. 

The rear derailleur was a slam dunk, of course, and I had a good candidate for the job in an old (ancient?) Deore XT model. While I was at it I cleaned up a few other derailleurs and my new choice for a front derailleur. 

You might recall that I had pulled a Deore XT front derailleur for the job but later on I realized it was a "top pull" model and I needed a "bottom pull" design. This "Top" and "Bottom" refers to where the cable "pulls from"- topside or from underneath, thus the nomenclature.  

So, I had to dig through my stash of front derailleurs and lo and behold! Here I found an XTR front derailleur, bottom pull, with the hinged plates in the perfect clamp size! It had been a bit abused in a previous life, but it was serviceable and perfect for this application. I cleaned it up and then I had to do some "thinkering". 

As previously mentioned, there is no cable stop for a housing to terminate on and for a bare run of cable to run up to a front derailleur on the Gryphon Mk3. The down tube cable guides support a front derailleur cable housing though. All I needed to do was to figure out a solution. Easier said than done! 

The 1990's were a fun time in mountain biking for the inventive, chi-chi bits you could buy.

I pondered how I would approach the problem and I started to formulate some ideas. First, I would need to make a stop for the housing, (cable stop) and I was planning on anchoring this to the fender mount on the chain stay bridge, just behind the bottom bracket. I figured my cable could run up between the space made by the chain stay bridge and the bottom bracket shell. 

The bracket I would have to fabricate would necessarily be one that would have to clear the width of the chain stay bridge, but be rigid enough that when a shift was initiated, it would not just bend like a flimsy piece of paper against the shifting pressure. This was a tough nut to crack. But I came up with a beefy bit of aluminum rack stay material that I thought I could make work. 

My bracket would be "L" shaped with the slotted part allowing for adjustment to aim what I would have to come up with for a cable stop. That bit was arrived at by modifying what originally was a bit of Shimano metal brake cable guide for an STI lever into what I needed. 

It may not be pretty, but it'll do what's asked of it.
A view from the rear of the bike looking at the back of the seat tube.

As you can see, I canted the bracket to point directly at the front derailleur, thereby reducing any friction and allowing the cable to have no bends as it travels up to the cam of the front derailleur. I will have to put some blue Loctite on those threads, and I should be good to go. Not shown: I fabbed a Presta valve cap into a 'hood' to cover the exit port of my new cable stop to help prevent the ingress of water and dirt.

Next up I had to do the brakes, and that required some thought as well, since I wanted to add in some in-line adjusters, have smooth cable runs, and then I had a couple used cables from the old bike I was going to re-use. I probably should have just gotten new ones right away, but I ended up spending way too much time trying to make the rear one work, and in the end, I just went and bought a new tandem length one at Waterloo Bicycle Works instead. 

3 X 9 utilizing some Dura Ace bar end shifters and Gevenalle levers.

 So, all of that was promising after I got up to this point. The 3 X 9 thing was looking good. Now.....if the rear tire clears the front derailleur! I had to mount the Teravail Coronado 29" X 2.8" tires on the PWGWv2,(wheels described in the previous build post), stick that into the frame, and that would pretty much be the final word on whether or not this thing was going to be viable in this format. 

Next: Checking the wheels for fit and finishing up.

10 comments:

Steve said...

Back in the day I had a similar conundrum with a bottom pull front derailleur. The older mechanic at the shop told me he had success with just terminating the housing right where your shop-made stop is. It seemed kind of sketchy but I tried it and it worked!The tensioned cable kept the housing in place without a stop.
Just sayin', not suggesting....

Steve

Arky said...

Not elegant on a beauty of a bike! You’re better than that. I’d get another front derailleur with a proper cable stop; set it up 1x with a 2x crank, a ghost ring, and manually move it down when needed; or re-think it.

Guitar Ted said...

@Arky - Sorry if that offends you, but that is what I have and what I am going to use. No sense in buying something if what I have works, especially on my budget. Your mileage may vary.

Skidmark said...

Greets GT, I believe we are several generations removed now from our forerunner’s who knew and taught: Use It Up, Wear It Out, Make it Do, or Do Without.

Guitar Ted said...

@Skidmark - I hadn't heard that one before. Thank you!

baric said...

Amen to what Skidmark said there. When it comes to having to make a part and I've had to make a few and it comes between form and function, function wins out every time. If it also ends up looking good that's a bonus. And that cable stop looks like a pretty fine example of fabrication to me, especially with the addition of that cable adjuster. If it works but you don't like the look of it then don't look at it, just use it !! ....

MG said...

Nice thinkering… You’re a badass with a wrench!!

Guitar Ted said...

@baric - Yeah, that was pretty much how I thought about that. I know it doesn't "look good", but will I care about that when I pull off that shift under power out on the gravel somewhere? No, I will only care that it works. Thanks for your thoughts and for making the comment.

Guitar Ted said...

@MG: Thanks Brother! Appreciate you very much!

Daniel said...

One of the owners of Singular is in the states right now. He stopped by my place of work last week for a couple of days and the marketing team was showing him around town. Nice guy.