CliffordK

Ok, doing some building and hacking.

I just mated a vintage Suntour bar end shifter with a RD-M8000 rear derailleur.

Unfortunately, it rapidly became obvious that the cable pulls were way off, with the shifter being able to shift about 8 out of 11 sprockets

I am not sure I've ever used bar-end shifters. They were convenient, but I found myself reaching to shift in all the wrong places.

Anyway, the Suntour shifters range of motion was from about 90° downward, up to horizontal. I'd probably get my last few sprockets if that dynamic range could be increased somewhat, maybe to a 45° up angle.

Shimano Cable Pulls:I have the Tanpan 10 on order. That should give me an equivalent shift ratio of (1.7/1.2)*1.1 = 1.56, and by my calculations should be able to shift my cassette. Had I realized the issue, I probably would have chosen a 9s MTB derailleur, and limited my cassette size to 34T or 36T or so.

But, I'm wondering if there are other options. Do other bar end shifters with a friction mode have a greater dynamic range? Moving the lever a little further should also aid with shifting accuracy.

I suppose there are a few 11s indexed shifters available, but they'd still run into the need for the Tanpan.

HillRider

If your barend shifter will only reach 8 of 11 cogs it won't do much better with a 9 or 10-speed cassette as their overall width is only a mm or 2 less. Any current Shimano or Microshift barend lever should work fine with an 11-speed cassette if used in friction mode.

Microshift makes actual 11-speed barends in both road and MTB format and those will obviously work.

CliffordK

My 8 sprockets... is essentially the Suntour shifter being able to shift from the small sprocket in 8 sprockets or so on an 11s cassette... or from #2 to #9 (about).

The issue is not as much the width, as Shimano has changed their pull ratio. SRAM is supposed to support both pull ratios, but I'm having troubles seeing the notes of which is which. One older SRAM derailleur I have seems to have a small cable guide that says 1:1 on it... so there may be different guides they used, if one could just find the right one for the right derailleurs.

Anyway, a 9s rear derailleur probably could be pulled across a 11s cassette, but the other issue is derailleur capacity, with the M8000 taking both a larger rear sprocket and having more overall wrap. A "goat link" might help with capacity, but then also increases the guide pulley to sprocket distance for the smaller sprockets, potentially reducing precision.

Thanks for the suggestion for the Microshift.
BS-M11 ? microSHIFT ? Cycling Transmission Manufacturer



Apparently it will also work in both friction and indexed modes. I'll have to think about those.

I'll post how the Tanpan works when it arrives.

I'm trying to improve my ability to carry/pull cargo, so I'm trying to increase the dynamic range of my shifting. Unfortunately, still quickly running into pitfalls with not enough capacity to get quite what I want.

Retro Grouch 

I can tell you for sure that a vintage Suntour bar end will shift a Shimano 9-speed quite adequately. I'd have to go downstairs to see what rear derailleur I have on that bike. It might be a 105 long cage, it might be an LX. I'll go look if you want me to.

Are you sure the cable routing to the anchor screw is on the correct side?

tyrion

Ultra Romance ground down a bar end shifter to give it range to work a SRAM Eagle 12 speed. FWIW.

Benedict?s 2020 S-Works Fuse Ultra Baja Buggie | The Radavist

Kontact

Just use something other than a Shimano 11/MTB or SRAM rear derailleur. Pick just about anything else that has the capacity will work fine.

CliffordK

That is a little different design than I have, but yes, I was wondering if that would be possible. Perhaps I'll look at my Suntour shifters a bit more. I always hate to destroy vintage stuff, but it isn't in perfect condition anyway... And so keeping it in use is a good thing.

Plus, I like the idea of the added range of movement for individual sprockets.

I suppose the other advantage is that I've chosen to support small/small rather than big/big... yeah, I've heard the arguments. I think the "shadow" derailleur design may be safe anyway, it may just jam up the pedaling (and potentially rip up the chain). Anyway, moving the shifter beyond horizontal may make it easier for the rider (me) to feel where I am on the cassette.

CliffordK

Shimano started making their change with 10s.

But, the issue is whether I wish to have the added capacity that they've incorporated into their 11s derailleurs.

As far as I can tell, ratings:

Cable Pull: 1.7, I think. M592 (9s), Largest Rear: 36T, Wrap: 45T
Cable Pull: 1.1. M8000 (11s), Largest Rear: 40-46T, Wrap: 47T

I really don't know if I need to go that big. I probably should look at going smaller up front. But, it does give some food for thought. Maybe eventually I'll be able to design my own cages.

Andrew R Stewart 

I guess I'm hung up on terms sometimes. I read Vintage SunTour and I think of friction, or what ST called "Power". Actually a ratchet driven friction clutch. Not an indexed system where cable pull ratios are in play at all.


But it seems that you're talking about the indexed generation of ST bar ends. These were designed for the ST cable pull needs. St took a rather different approach to lever/cable/der/cog spacing relationships and tried for more consistent cable tension through the range. This meant that some cogs were closer together then others. This is why when you use a ST indexed FW (of the 1980s to 1990s) with a Shimano system the shifting sucks. So to when using a same era ST indexed shifter with a current der and cog set there's no reason to expect anything to work well. (Why would a 1974 Ford starter motor fit in a 2005 Chevy?). Remember that back in the friction day the rider would need to trim the lever to eliminate chain rub. Having a smaller cable spool diameter (at the lever) makes for a finer trimming ability. (Funny though as the ST ratcheted shifters could trim only in amounts of a ratchet tooth one way but infinitely in the other).


So my suggestion is to not try mixing different families of compatibility without the expectation of things not going well. Andy

CliffordK

Yes, that is what I have. A bunch of little clicks going one direction, and apparently just friction going the other direction (with some spring assist).

Cable pull ratios do come into play because the levers go through about a 90° or 100° range.
With the new MTB derailleurs, the shifter goes from full down to full up, and only moves the derailleur across 3/4 of the sprockets of the cassette.

I have to think that Suntour chose to use only a 90° or 100° total range for their levers so that the levers would not interfere with using the drops.

However, as one increases the number of gears to select, that also means touchier adjustments, so a wider range of lever movement would also be handy.

Aubergine 

Another thing to consider, besides the derailleur pull, is how much cable the bar-end shifter can wrap up. The old Suntour Barcons have a relatively small amount of wrap. Newer bar-end controls have a bigger diameter for the cable track and thus can wrap more cable.

Tandem Tom

Just a bit off topic. I recently obtained by another set of SunTour Barcons for my VO Polyvalent that I have set up with a 9 speed cassette. Works great. I really prefer thesecover the Shimano's. Just the other day I brought them by the LBS where I work PT. Russ, the guru mechanic who has taught me so much, suggested I open up and put a bit of his Phil Wood grease on his words, an extremely simple mechanism! Yep I love these Shifters!!

fietsbob

Pull amount is related to how large the diameter of the part of the lever that the cable wraps around.. Is..

Andrew R Stewart 

I see what you are saying I just don't think the term "cable pull ratio" is the one to use in your case. "Total cable pull" for sure. Cable pull ratio was never a reference until indexing came about. So us old guys see it as a rear der reference as in how much cage sideways movement per one lever click. As friction levers have no indexing aspects the cpr isn't what is really the issue.


But you do seem to understand what you need to do. Use parts that can match up and not those that don't. One possible adaptor is a Shift Mate. They are made to convert different shifting parts from incompatible to compatible. (Like campy 9 speed levers being used with a Shimano der and cassette). Will one of their models change the total cable pull amount so you can run the ST bar ends with current rest of the drivetrain? I don't know. Andy

fietsbob

7th picture shows increasing the swing arc further as I interpret the ground away part,

so in friction mode you have 150 degree swing instead of 100 or 90 degrees?


pretty much confirmed in this Quote, in link..

CliffordK

Yeah... as mentioned, I have the Tanpan on order, which is like the Shiftmate, but designed specifically for the issues of Road vs MTB derailleurs.

But, I'll probably also look at increasing the range of motion of the levers.

As far as matching parts, one of the advantages of friction shifting is a bit more flexibility... except when the new derailleur designs pull far too much cable for each shift. And, I think part of the reason for that choice is the design of the derailleur bodies to move the guide pulley away from those big really rear sprockets.

Friction shifting also helps in that I got stuck with my Front Derailleur straps just being in the wrong place, until I found a vintage Campagnolo derailleur with a low mounting strap. No need to worry about derailleurs.

Yep, considering a similar mod quite a bit. Probably not done on a grinder, and may not cut to the full 180° point I'll have to look at my levers closely, including whether the cable groove was ground all the way around, and whether the semi-friction component was designed for the increased range of motion. Strength of the shifter body? Also, if say I cut a smaller angle, such as a 45° angle, then that means I'll have to cut bottoming into a "V" which complicates matters.

fietsbob

I hear my father's voice with a reprimand against using a bench grinder on aluminum ..

CliffordK

Aren't most of the grinding wheels made up of Aluminum Oxide?

But, yes, it does tend to gum up the wheels a bit. On the bright side, less sparking.

Andrew R Stewart 

The newer rear ders with large cable pull ratios are in response to the otherwise decreasing cable travel per shift that having 10+ steps produces. Cable friction is a *****, with these tiny steps of travel any small hindrance becomes a mountain.


Cable pull choices have very little to do with pulley/cog clearances. That's the geometry of the parallelogram and cage design. Andy

Andrew R Stewart 

Whatever future readers do don't follow this as being OK to grind a soft metal like AL on the wrong stone wheels. Really this is not right. AL will gum up the wheel's surface and can cause heat induced fracture, at how many RPM?


Sorry to pick on you Clifford but you post will influence others to trust what they read and try it. Some number of these people will experience what common shop rules are created to keep from happening, an exploding grinder wheel. Andy

CliffordK

I suppose we're heading off topic a bit... will drag it back soon.

It is interesting to read about Aluminum and grinding wheels.

I think some home users are just fine. Yes, it loads the wheel some, but it depends on how much grinding one is doing. For many home users, it is typically non-continuous grinding, and using a mix of materials, with the aluminum loading the wheel, and the steel cleaning it.

The "exploding wheel" issue is apparently due to continuing to use a heavily loaded wheel beyond the point where it is no longer cutting, and perhaps an unbalanced wheel.

One can, of course, also dress the wheel if desired, helping with both loading and balancing.

There apparently is a risk of a "thermite reaction". Although, I can't tell if that is occurring on the wheel, or on the shop floor. Perhaps it is best to keep the steel and aluminum from mixing on the shop floor. Nonetheless, the reports of actual shop thermite burns seem to be few and infrequent, and often rather limited depending on the material buildup.

fietsbob

Nicholson Vixen files take off a lot of aluminum quickly, NB; they were made for the Aircraft industry.





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