Converting a triple to a low/low

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Johnny Alien

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Jun 29, 2019, 10:18:19 AM6/29/19
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So I posted a thread looking for a crankset because I didn't want to spend a ton and didn't feel like piecing one together. The New Albion wide/low has different gearing than the old Sugino one and what I really would prefer is a low/low gearing but at the Sugino price.  Then it occurred to me that the triple minus the large ring is pretty much a low/low and you can grab those pretty cheap. And Sugino quality (while not as great as Silver I am sure) is pretty high.  Would there be any hangups with getting an XD triple and removing that large ring?  Anything that I am not thinking of? 

Dave Johnston

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Jun 29, 2019, 11:59:04 AM6/29/19
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What size rings are you talking about? 36t-26t?

I've done it and didn't even replace or move the front derailleur down at all, which gives a gap that does look a little weird. I did cut off the teeth of a 49t larger outer ring to act as a guard, and eventually replaced the 36t with a 39t for a bit more range. I thought the 36t-11t combo a bit limiting.

I have a unused "Silver" 170mm crank w 35t, 24t if you are interested, at slightly less than Riv pricing. I have other chain rings available and we'd have to figure out a solution to the outer ring.

-Dave J in VA

Johnny Alien

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Jun 29, 2019, 12:30:07 PM6/29/19
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Thanks Dave. I shot you a message.  Yes removing the large ring would leave 36/26.  It looks like Roman at Riv did the exact thing I am talking about. I am just not sure if it is as simple as removing a ring or if there is more I would have to do.

Deacon Patrick

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Jun 29, 2019, 12:38:19 PM6/29/19
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It's even simpler: don't ride the outer ring, consider it a rockguard with teeth, and a "holy smokes this is a wonderful 10 mile gentle descent with a tailwind that never happens" gear. Grin. But yes, nothing fancy. My QB has a single front chainring on its stock triple, leaving the two inside slots open, and it rides beautifully despite the chainline being "wrong". Quiet and smooth as a mouse. If I ever decide to add a ring, I likely have some thread cleaning to do, otherwise no biggie. Purists may say you need to do xz,y, or z. Only if you're a purist. I'm not. I'm a dirtist. Grin.

With abandon,
Patrick

Johnny Alien

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Jun 29, 2019, 12:43:01 PM6/29/19
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Yes I agree that is the simplest method! The main reason I would remove it is because I don't use it and prefer the look of a crankset with small rings.  It's a visual thing for me.

Dave Johnston

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Jun 29, 2019, 1:01:44 PM6/29/19
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For what Roman did you would need shorter "track" style chain ring bolts. I googled $22 for Sugino at Ben's or $8 shipped for generic on ebay.
You might have to experiment with F derailleurs for optimal placement. Maybe a shorter cage double road derailleur or an old Micro Drive front would work better. Many mountain or road Triple derailleurs will hit the chain stay if you lower them, see how high the derailleur is in the pic below, and the tail just clears the stay.

Be warned: An indexed front shifter will probably not work well when changing rings.

I prefer cutting down an outer ring to act as a guard, but that gives you a large ring "look".

Willow Guard.jpg

Marty Gierke, Stewartstown PA

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Jun 29, 2019, 3:26:42 PM6/29/19
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Here's a 36/20 with a larger-than-needed chainguard I find not aesthetically objectionable at all. Shifts fine. 

IMG_5809.jpg


Elisabeth Sherwood

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Jun 29, 2019, 3:53:18 PM6/29/19
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So, how does one go about cutting down the teeth on a chainring?  I practically never use my large chainring; on another bike I replaced it with a chainguard, but would be happy with another option!

Thanks in advance,

Liz
Washington, DC

Garth

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Jun 29, 2019, 3:57:54 PM6/29/19
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  You could also remove the large ring and don't use anything in that position.  Replace the double chainring bolts with single chainring variety for the 36t and so you have just the 24/36 alone. 

Johnny Alien

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Jun 29, 2019, 4:13:23 PM6/29/19
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I think that is exactly what u am going to do. I wasn't sure if I needed to replace the bolts so that is helpful. Thanks!

Patrick Moore

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Jun 29, 2019, 4:43:45 PM6/29/19
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I turned a 46-36-24 XD2 into a 36-24 XD2 by removing the outer ring and adjusting the throw of the front derailleur cage; worked just fine. Later swapped the 36 for a 38 and added a guard in the outer position, but didn't change the fd height. Continued to work fine.

My Matthews has a Logic (triple) crank with 42 and 28; don't know if that qualifies as a low low, but it works fine.

I expect Sugino makes the Silver cranks.

On Sat, Jun 29, 2019 at 8:18 AM Johnny Alien <johnny....@gmail.com> wrote:
So I posted a thread looking for a crankset because I didn't want to spend a ton and didn't feel like piecing one together. The New Albion wide/low has different gearing than the old Sugino one and what I really would prefer is a low/low gearing but at the Sugino price.  Then it occurred to me that the triple minus the large ring is pretty much a low/low and you can grab those pretty cheap. And Sugino quality (while not as great as Silver I am sure) is pretty high.  Would there be any hangups with getting an XD triple and removing that large ring?  Anything that I am not thinking of? 

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David Johnston

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Jun 29, 2019, 6:06:23 PM6/29/19
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Another problem to keep an eye out for if you don't use an outer ring
at all, is that some front derailleurs may not have enough adjustment
in the outer limit screw to keep the chain from falling off the
outside. I think most derailleurs won't have this problem but it can
happen.

I had a problem on an LX low clamp model where when the outer limit
screw was adjusted centered over the middle the adjustment screw
interfered with the derailleur movement as it swung towards the small
ring, since I was using a guard as an outer I just backed off a bit on
the screw and the guard keeps the chain from falling off.
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Johnny Alien

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Jun 29, 2019, 7:20:01 PM6/29/19
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If I am understanding things correctly I could also get a Sugino triple, remove the outer ring and install a Silver chainguard.  It should mount properly to the Sugino and they have a small guard designed for a 34-36T outer ring. Then I would not need to buy new bolts and it would only be about $15 more than going that route.  Still maintains the small ring look and would prevent the chain from coming off if the derailler was not properly adjusted. I am not sure which way I will go.  Roman's bike looks great with just the outer ring removed.  I should ask him if he has any problems with that setup.

Scott G.

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Jun 29, 2019, 7:30:53 PM6/29/19
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On Saturday, June 29, 2019 at 7:20:01 PM UTC-4, Johnny Alien wrote:
If I am understanding things correctly I could also get a Sugino triple, remove the outer ring and install a Silver chainguard.

Eric Karnes

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Jun 29, 2019, 8:46:18 PM6/29/19
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Ben's Cycle sells (what I assume is) the chain guard that was on the XD2 wide low that Riv used to sell:


Probably worth shooting them an email for a photo before shelling out $50 bucks. Though if the Silver works on only Sugino cranks, I'd rather give my money to Rivendell.

Eric

Eric Karnes

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Jun 29, 2019, 8:47:54 PM6/29/19
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* 'old' Sugino cranks...not 'only.' Phone autocorrect.

Johnny Alien

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Jun 29, 2019, 8:57:01 PM6/29/19
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The problem is that the guard is for 44t coverage so it will be way larger than I need and result in a larger looking crank which I am trying to avoid.  The New Albion that Rivendell sells comes in a wide low but the large ring is 40 and I assume the guard is around 42 or 44 like the Sugino. I really would like a low/low with the largest ring being no larger than 36.  That would be achieved perfectly by taking the large ring off a Sugino triple.  I just need to decide on keeping it guard free ala Roman's bike or try to use the Silver guard which is a 36 size and would keep the overall look of the crank smaller.

Dave Johnston

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Jun 30, 2019, 8:08:55 AM6/30/19
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Johnny,

What else are you going to do to the drivetrain?  What rear cluster are you planning on using, 9 speed and 11-28? Is this a utility bike where you will just coast downhills, and will it see mostly paved use?

I have found 36-11 to be a bit limiting on the pavement and I am not a strong rider and tend to slow-roll in a 60-65 gear inch range. Also having your most used gears having fewer teeth like a 36-13 means they will wear out faster.

With a 36-24 up front you can run a shorter cage rear derailleur if desired.

-Dave J

On Saturday, June 29, 2019 at 10:18:19 AM UTC-4, Johnny Alien wrote:

Johnny Alien

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Jun 30, 2019, 8:13:27 AM6/30/19
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Yeah it will be a standard 9 spread in the back. I have an Atlus rear I was planning on using. I have used a Wide/Low on a Sam Hillborne for awhile and it covered everything and that was a 40 largest.  My plan for this was largely easy trail usage.  Some pavement for errands and such.  There are lots of hills around me and I tend to be in lowish to mid gears all the time when running errands. I have an older Cannondale ST that I use for most of the pavement stuff though.

Dave Johnston

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Jun 30, 2019, 8:17:45 AM6/30/19
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Liz asked about how to go about removing teeth. I would say that is a topic for another thread. I use a bandsaw with a metal blade and clean up with a belt sander. With power tools it's easy, but without I would recommend buying one from Riv, BBG bashguard, Salsa or one of the euro dealers.

-Dave

Jeremy Till

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Jun 30, 2019, 9:06:35 AM6/30/19
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I've removed teeth from a chainring without power tools. I clamped it in a vice and used a pair of channel lock pliers to bend each tooth until it snapped off. It was easier than I thought it would be (with an aluminum chainring, I doubt it would work for steel). After removing the teeth I used a file to smooth down the stubs.

-Jeremy Till
Sacramento, CA

Joe Bernard

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Jun 30, 2019, 12:51:26 PM6/30/19
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I've used a Silver guard on a Sugino with a 36t ring. Works great, looks great.

Ana Candela

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Jun 30, 2019, 2:55:27 PM6/30/19
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Johnny,

I recently did this. I had a 170 double with chain guard. I bought a 165 triple, and I just swapped the cranks between them. Works great!

I think you could just take the big ring off, like some here are saying. I have it if you’re still looking for one. It’s disassembled. Rings are new, cranks are about 4,000 miles.

-Ana

Nick Payne

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Jun 30, 2019, 4:57:41 PM6/30/19
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On Sunday, 30 June 2019 00:18:19 UTC+10, Johnny Alien wrote:
So I posted a thread looking for a crankset because I didn't want to spend a ton and didn't feel like piecing one together. The New Albion wide/low has different gearing than the old Sugino one and what I really would prefer is a low/low gearing but at the Sugino price.  Then it occurred to me that the triple minus the large ring is pretty much a low/low and you can grab those pretty cheap. And Sugino quality (while not as great as Silver I am sure) is pretty high.  Would there be any hangups with getting an XD triple and removing that large ring?  Anything that I am not thinking of? 
I've done that on several cranks. I usually hacksaw / file the teeth off an old chainring to use as the chainguard. Here's a Sugino XD crank setup that way:

Nick


Johnny Alien

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Jun 30, 2019, 6:13:06 PM6/30/19
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Thanks for the info Ana! I shot you a message.

Benz, Sunnyvale, CA

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Jun 30, 2019, 7:12:36 PM6/30/19
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On Sunday, June 30, 2019 at 1:57:41 PM UTC-7, Nick Payne wrote:
I've done that on several cranks. I usually hacksaw / file the teeth off an old chainring to use as the chainguard. Here's a Sugino XD crank setup that way:


How ever did you get those ex-chainrings to be so…refined? Your workmanship must be master craftsman level if you used only a hacksaw and file. 

Johnny Alien

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Jul 2, 2019, 5:51:37 PM7/2/19
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Had a long conversation with Roman today.  He claims that the conversion is simple (as we discussed) but that the front derailluer can be an issue.  So most FD's have a longish cage and setting it that low will cause it to hit the chainstay.  BUT Rivendell sells a 34/24 as their Low/Low and that comes with a 36 Chainguard.  So my guess is that the CX FD is small enough to handle it.  Roman indicated that going to one of those FD's would cause me to need a wider BB than the 110 that comes stock on the Clem.  I can't wrap my head around that.  So are all of you guys running the CX70 using a wider BB? Is Rivendell really selling a guard and crankset that doesn't easily work with the FD's that they sell?  When I look at the Low/Low crank photos they look like they are using that CX70 FD and many are on Clems which I have to assume have the stock 110 BB?  I don't want it to be this hard. I am fully ready to remove that ring.

Joe Bernard

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Jul 2, 2019, 6:37:12 PM7/2/19
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I would not assume the fully built Clems come with a 110 spindle. Frankly I think that's an odd spec which seems to come on all the MIT framesets, and makes a heckuva lot more sense on Roadini than the touring/townie bikes.

The problem you're trying to work around is there are no FDs specifically designed to shift a low/low crank with a small chain guard. Normally what you see is a triple FD in its normal triple position over a guard the size of a big ring.

Now enter CX70. As the name implies it's a double for cyclocross bikes..the ring positions are where your middle and large are. You want it to shift to a granny because your double is small/middle. The only way to get there is with a BB that will move the granny out far enough for that double FD to drop the chain on it. Easy!😋

PM me for a deal on the stuff you need. I have a near-new 118 Shimano BB and CX70 derailer that were on my recently sold Atlantis. I'll hook you up.

ted

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Jul 2, 2019, 7:08:31 PM7/2/19
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I believe I have a 107 bb, wide low double with chain guard (from rbw) and a cx70 fd on my bombadil. Works fine.

Dave Johnston

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Jul 2, 2019, 8:01:49 PM7/2/19
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My go to derailleur for middle inner double is the XT fd-m737 90's era Microdrive Front that was designed for a 44-32-22 rings. The LX from the era is also good. I have not tried a CX70, but I would try your current spindle first. I would also consider putting a 1-2 mm BB spacer on the drive side before replacing the whole BB.

-Dave

Garth

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Jul 3, 2019, 4:25:38 AM7/3/19
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The FD doesn't need to be altered from the position it is already working with all 3 rings.  Taking off the big ring and just using the 2 small rings(no guard, single ring chainring bolts) doesn't change that, as obviously it's no different than simply never shifting into the big ring in the first place. 

I don't know what FD you have currently, but I know from experience older road FD's shift even a 26 to 44 just fine as I previously was running 26/44/48 rings with a 1999 105 double FD. If you did by change need/want a shorter cage road FD the older SunTour Superbe Pro have shorter cages. 






David Johnston

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Jul 3, 2019, 7:45:03 AM7/3/19
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I'm not sure if Johnny the OP has a fully built up bike yet or how
many parts he has to start with. If he has any front derailleur,
particularity one that was originally designed for a 46-36-24
crankset, I would suggest trying that first.

I have heard the Mtn derailleurs produced in the last few years are
designed to have the rings more outboard so they may not swing enough
inward for a roadish chainline. So even though there are some current
mtn doubles designed for really small rings like 46-22 they may not be
the best choice. I have a stash of 90's stuff and haven't made it past
9 speed so I haven't tried this stuff yet.

On 7/3/19, Garth <gart...@gmail.com> wrote:
> The FD doesn't need to be altered from the position it is *already working
> with all 3 rings. *Taking off the big ring and just using the 2 small
> rings(no guard, single ring chainring bolts) doesn't change that, as
> obviously it's no different than simply never shifting into the big ring in
>
> the first place.
>
> I don't know what FD you have currently, but I know from experience older
> road FD's shift even a 26 to 44 just fine as I previously was running
> 26/44/48 rings with a 1999 105 double FD. If you did by change need/want a
> shorter cage road FD the older SunTour Superbe Pro have shorter cages.
>
>
>
>
>
>
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Bill Schairer

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Jul 3, 2019, 7:51:14 AM7/3/19
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I’m running my Atlantis with a 42/34/19 triple and a Suntour Cyclone fd. I can’t mount the fd as low as I would like but it handles all the shifts well. I do use a chain catcher on the inside. I’ve only dropped the chain once to the outside since I’ve been running this but shouldn’t think that would be an issue in your setup anyway and it is well within my standards. It has worked so well I never had to try the CX70. There are many cyclones available on ebay.

Patrick Moore

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Jul 3, 2019, 9:22:46 AM7/3/19
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+1. My experience with the LX fd on my Fargo when converting from triple to double.

On Wed, Jul 3, 2019 at 2:25 AM Garth <gart...@gmail.com> wrote:
The FD doesn't need to be altered from the position it is already working with all 3 rings.  Taking off the big ring and just using the 2 small rings(no guard, single ring chainring bolts) doesn't change that, as obviously it's no different than simply never shifting into the big ring in the first place. 

I don't know what FD you have currently, but I know from experience older road FD's shift even a 26 to 44 just fine as I previously was running 26/44/48 rings with a 1999 105 double FD. If you did by change need/want a shorter cage road FD the older SunTour Superbe Pro have shorter cages. 






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Towards the Moon or to the Sun.

David Johnston

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Jul 3, 2019, 9:56:45 AM7/3/19
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I had meant to say "So even though there are some current mtn doubles
designed for really small rings like 36-22 ....

Joe Bernard

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Jul 3, 2019, 10:05:47 AM7/3/19
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Yes a triple FD will work, no it won't be pretty set up high above that small chainguard. The CX70 and BB I'm sending should cover his bases, and might even work without swapping BBs.

Rick Thompson

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Jul 3, 2019, 4:40:09 PM7/3/19
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FWIW, I have an old bike with Ultegra triple converted to low/low just by adjusting the FD stop and replacing the big ring with one of these bashguards to act as chain guard: https://bbgbashguard.com/

The bashguard was around $14, seemed worth it compared to trying to cut and file off the teeth on the old big ring.

Nick Payne

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Jul 3, 2019, 7:03:28 PM7/3/19
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On Monday, 1 July 2019 09:12:36 UTC+10, Benz, Sunnyvale, CA wrote:

How ever did you get those ex-chainrings to be so…refined? Your workmanship must be master craftsman level if you used only a hacksaw and file. 

I was able to initially get the ring pretty close to exactly round with the hacksaw and a file, and I finished it off once I had the ring mounted on the crank. With the bike on a solid workstand I got my wife to turn the cranks while I used a succession of files. I did this before I had derailleurs mounted and chain installed, and I could brace my hands against the the seat-tube and down-tube to hold the file as still as possible. If I'd had a Dremel with a drum band sanding attachment I probably could have done the same considerably quicker.

For the amount of fiddling around, next time I think I'll just buy a chainguard, so long as I can find one to match the crank - Rivendell sell some quite nice looking ones.

Nick

Nick Payne

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Jul 3, 2019, 8:22:57 PM7/3/19
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On Wednesday, 3 July 2019 08:37:12 UTC+10, Joe Bernard wrote:
The problem you're trying to work around is there are no FDs specifically designed to shift a low/low crank with a small chain guard. Normally what you see is a triple FD in its normal triple position over a guard the size of a big ring.

Sure there are - 2x MTB derailleurs. Here's an XT 2x10 FD and a 94BCD triple setup as 32/22 low/low double plus chainguard. I have similar setups on other bikes, though not with such small chainrings:


Nick



Joe Bernard

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Jul 3, 2019, 9:43:53 PM7/3/19
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Your chainguard looks sized similar to the 42t it replaced.

Nick Payne

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Jul 3, 2019, 11:51:11 PM7/3/19
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On Thursday, 4 July 2019 11:43:53 UTC+10, Joe Bernard wrote:
Your chainguard looks sized similar to the 42t it replaced.  

No, they're not close to the same size - the 42t chainring is more than 30mm greater diameter than the chainguard - 174mm vs 142mm. Here's the crank with a 42t chainring in front of the chainguard for comparison:


Nick


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Joe Bernard

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Jul 3, 2019, 11:56:57 PM7/3/19
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Cool you win. I didn't know about modern 2x MTB derailers, I didn't even know that was a thing.

Nick Payne

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Jul 4, 2019, 4:37:32 AM7/4/19
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On Thursday, 4 July 2019 13:56:57 UTC+10, Joe Bernard wrote:
Cool you win. I didn't know about modern 2x MTB derailers, I didn't even know that was a thing.

Yeah, they're designed for pretty small chainrings. The XT M786 that I have on several bikes (intended for 10s) is specified by Shimano as being designed for big chainring between 38t and 44t, and the M8000 11s version for big chainring between 34t and 38t. The M786 works fine for me with 9s, 10s, and 11s setups, and on the bike I showed the photo of, it's completely problem-free with a 32t big chainring, plus I didn't have to raise the derailleur from its optimal position just above the chainring so that the bottom of the derailleur cage cleared the chainstay.

Johnny Alien

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Jul 4, 2019, 7:55:54 AM7/4/19
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Roman spoke of those MTB derailleurs but mentioned needing a much wider BB.  I am going to roll with the new BB and CX70 I am getting from Joe as I think that will work out perfect however if it's not optimal I may look at one of those new fangled MTB FDs.

Benz, Sunnyvale, CA

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Jul 6, 2019, 2:52:14 PM7/6/19
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On Wednesday, July 3, 2019 at 4:03:28 PM UTC-7, Nick Payne wrote:
On Monday, 1 July 2019 09:12:36 UTC+10, Benz, Sunnyvale, CA wrote:

How ever did you get those ex-chainrings to be so…refined? Your workmanship must be master craftsman level if you used only a hacksaw and file. 

I was able to initially get the ring pretty close to exactly round with the hacksaw and a file, and I finished it off once I had the ring mounted on the crank. With the bike on a solid workstand I got my wife to turn the cranks while I used a succession of files. I did this before I had derailleurs mounted and chain installed, and I could brace my hands against the the seat-tube and down-tube to hold the file as still as possible. If I'd had a Dremel with a drum band sanding attachment I probably could have done the same considerably quicker.

Ah! A makeshift lathe, powered by the wife! 

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