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Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 3:04 pm
by familyguy
So, I bought a McLachlan. It has a Suntour top mount shifter boss rather than a boss each side of the DT. This means I can't use the plentiful cable stops for DT bosses for STI/Ergo cable runs. Short of designing and 3D printing an alternative, is there a readily available unit or device (which my Google-Fu has let me down as far as sourcing something goes) that will do the job?

This is the lever boss location:
Image

Jim

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 3:22 pm
by 10speedsemiracer
Is made for the SunTour Symmetric shifter, which came in the downtube-brazed boss mount (such as your example) and a clamp on :

Image

Image

I have seen something similar by Shimano in the same era, think it was in the Touring line, however don't know whether the thread is the same.

The shifters (friction) are floating around on eBay via a couple of different European sellers.

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 3:36 pm
by familyguy
I do have a set of those (I think, or something similar, someplace in my parts boxes). I need a method of cable stop/adjustment to run 10s Ergo. Would usually use these on the side-bossed DT:
Image

I may end up machining one yet.

Jim

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 3:40 pm
by 10speedsemiracer
Origin8 make a clamp on for dt shifter mount. Maybe use one of those and somehow remove the top-mount or repurpose it...clip in pump mount ? (I dunno, just hypothesizing)...

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 3:46 pm
by familyguy
3D printed metal? Now that'd be nice... 8)

Jim

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 4:00 pm
by 10speedsemiracer
This is the shifter boss adaptor I was thinking of :

Image

Some LBS stock Origin8 or can grab it off the eBay.

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 4:02 pm
by Thoglette
familyguy wrote: Short of designing and 3D printing an alternative, is there a readily available unit or device
Hmm, Shimano had something similar. See this Ricardo Elite (c. 1983). I've probably still got one at home.
Image

Or look on ebay
Image

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 4:28 pm
by familyguy
The question is...how to adapt the Suntour or Shimano unit to become simply a cable stop. I won't be running levers.
10speedsemiracer wrote:This is the shifter boss adaptor I was thinking of :
Yep, jut saw those. Rather inelegant, though would work for a while until I machined something up. I won't be pulling fittings off the frame, rather not go to that extent and have to repaint it.

Jim

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 4:37 pm
by Thoglette
familyguy wrote:The question is...how to adapt the Suntour or Shimano unit to become simply a cable stop. I won't be running levers.
I'd be finding a length of alloy and cutting a groove across it to mount on the frame boss (bolt hole also needed) & then drill/tap holes for adjustable cable stops at either end. A prototype in wood might be a good idea...

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 5:29 pm
by Clydesdale Scot
familyguy wrote:3D printed metal? Now that'd be nice... 8)

Jim
Go
https://www.shapeways.com/materials/steel and the data sheet

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 5:31 pm
by LG
Temporary fix could be an old set of chrome shimano or suntour double cable stops, just clamped in front of the current boss. Like these, should be lots around on old bikes https://harriscyclery.net/product/shima ... e-2458.htm

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 6:09 pm
by find_bruce
familyguy wrote:The question is...how to adapt the Suntour or Shimano unit to become simply a cable stop. I won't be running levers.
10speedsemiracer wrote:This is the shifter boss adaptor I was thinking of :
Yep, jut saw those. Rather inelegant, though would work for a while until I machined something up. I won't be pulling fittings off the frame, rather not go to that extent and have to repaint it.

Jim
It is possible, but you will need to butcher the mount to get this
Image
an account of the butchery here

What you want is this
Image
which I understand is left behind by rocking horses

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Tue Jun 12, 2018 6:10 pm
by familyguy
Yep, that's my understanding as well...

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Thu Jun 14, 2018 10:35 pm
by gm6046
I'm going to do a run of new rocking horse poo replacement ones shortly. CNC machined. Just waiting to get some dimensions from someone who is measuring one up.

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Fri Jun 15, 2018 8:50 am
by familyguy
Ooh. I'll send you my email address.

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Fri Jun 15, 2018 2:52 pm
by find_bruce
gm6046 wrote:I'm going to do a run of new rocking horse poo replacement ones shortly. CNC machined. Just waiting to get some dimensions from someone who is measuring one up.
Are you copying the design for top mount round tubes (like Jim's) or aero tubes ?

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Fri Jun 15, 2018 3:02 pm
by 10speedsemiracer
find_bruce wrote:
familyguy wrote:The question is...how to adapt the Suntour or Shimano unit to become simply a cable stop. I won't be running levers.
10speedsemiracer wrote:This is the shifter boss adaptor I was thinking of :
Yep, jut saw those. Rather inelegant, though would work for a while until I machined something up. I won't be pulling fittings off the frame, rather not go to that extent and have to repaint it.

Jim
It is possible, but you will need to butcher the mount to get this
Image
an account of the butchery here

What you want is this
Image
which I understand is left behind by rocking horses
Looking at the top example, I'm not sure that would result in the ideal cable route, but the lower example is properly clever and would keep everything running and even looking almost OE. That is very cool.

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Fri Jun 15, 2018 5:23 pm
by gm6046
find_bruce wrote:
gm6046 wrote:I'm going to do a run of new rocking horse poo replacement ones shortly. CNC machined. Just waiting to get some dimensions from someone who is measuring one up.
Are you copying the design for top mount round tubes (like Jim's) or aero tubes ?
It will be for the Aero tubes, but it wouldn't be hard to machine up something for round tubes if there was interest.

Cheers

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Fri Jun 15, 2018 9:55 pm
by find_bruce
gm6046 wrote:It will be for the Aero tubes, but it wouldn't be hard to machine up something for round tubes if there was interest.

Cheers
I will stick my hand up for an aero version. I don't need it for my frame, but if I ever do, its now or spend years searching

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Sun Jun 17, 2018 9:50 am
by familyguy
Would be interested in the round tube version, as above. Which aero tubes are you getting thrm done for? Are they all somewhat similar?

Jim

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Wed Jun 20, 2018 4:04 pm
by gm6046
familyguy wrote:Would be interested in the round tube version, as above. Which aero tubes are you getting thrm done for? Are they all somewhat similar?
I'm not sure if all the Aero tubes are the same or are close enough to interchange. I'll post up some pics and dimensions shortly. Either way, I'm happy to machine them up to match specific tubes profiles if someone has an oddball size.

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Sat Sep 08, 2018 3:55 am
by baybiker
gm6046 wrote:
familyguy wrote:Would be interested in the round tube version, as above. Which aero tubes are you getting thrm done for? Are they all somewhat similar?
I'm not sure if all the Aero tubes are the same or are close enough to interchange. I'll post up some pics and dimensions shortly. Either way, I'm happy to machine them up to match specific tubes profiles if someone has an oddball size.
Hi, I just found this through a google search. I am interested in a round-tube version as well for a 1982 Univega, which has a 28.6mm diameter downtube. Have you moved forward with machining this part? Thank you...

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Sat Sep 08, 2018 6:22 pm
by gm6046
Sorry for the delay, here is where I am at. I have done the CAD/CAM for a few different versions. Both for round and aero shaped tubing as well as two styles of drilling for the cables. The one pictured is for the round tube and drilled/tapped for barrel adjusters, I also have a version that is drilled for the cable and furrule only and you'll have to adjust your cables via any adjustment you may or may not have at the derailleur etc. It mounts via the a M5 cap screw like bottle cages etc use.

I think there may be some variation in the depth of the square boss that the mount locates on, but that can be machined to suit if needed.

Here are a few pics. I don't have an aero frame on hand, so I have just sat it on another frame to give everyone an idea of what it looks like.

Image
Image
Image
Image

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Wed Sep 12, 2018 5:47 pm
by Clydesdale Scot
getting some publicity here

Re: Suntour/Shimano top mount shifter boss adapter

Posted: Wed Jan 15, 2020 10:44 am
by Stevensb
Hey GM6046. Do you have any of the shifter boss adapters available. I have 2 Miyata 710s and a Cougar (all from the mid-80s) that have the shifter boss on the top tube and would like to convert at least one of them from friction to something more modern.

Cheers.

Brad