Jim’s Tech Talk
By Jim Langley
Let’s start with a quick update on Dick’s clipless pedal problem, which we helped him with last week: Clipless Pedal Trouble. He emailed me saying he’s tried some of our suggestions and tips and he was pleased to report that his right pedal is releasing a little more easily. Plus, great ideas keep coming in, which he appreciates and will try, too. Thank you all for helping!
Introducing Stephen Weeks
Today’s technical question comes from Wisconsin wheelman Stephen Weeks who I’ve been cycling penpals with for years. A dentist by trade, Steve has a nice little fleet of bikes that he maintains, and he’s been known to commute to work on some of them even when only the snow plows are out.
Recently, he decided to switch his Airborne titanium road bike from dropped to trekking handlebars due to arthritis in his wrists. If you’ve never heard of trekking bars – visit this page on the wonderful Sheldon Brown website and scroll just a wee bit to see the bars and some of the typical hand positions they provide:
https://www.sheldonbrown.com/deakins/handlebars.html
Steve’s Question
“I need advice, Jim. I have the bars, grips, shifters, and brake levers in their approximate places on the new trekking handlebars. I’m starting my adjustments with the front derailleur (Shimano Ultegra triple).
I have the front derailleur limit screws set correctly, and the front derailleur shifts nicely onto the big ring. However, one release click of the lever puts the chain on the granny gear, and it really slams down. Can you think of anything obvious that I may have messed up? The levers are Shimano XTR trigger shifters. Thanks for any suggestions!”
So that there’s no confusion, what Steve is describing shouldn’t happen. It should take two clicks of a front triple shift lever to shift from the largest chainring to the smallest chainring (the “granny”). He’s saying it happens on the first click.
My Two Ideas for Steve
Idea 1
Do you have access to the bare front shift cable, Steve? In other words is the bare wire/cable visible beside the frame somewhere? (It won’t be if the housing is routed completely through the frame).
I think your bike is nice enough and old enough though that you might be able to see the front derailleur shift cable and have access to it. [NOTE: Steve let me know he did.]
If you do, I want you to pull on the cable and see if it has any slack. I am thinking what happened is that when you hooked up the cable, one of the end caps (called “ferrules”) on the ends of the housing sections might have lifted off the end of the housing. Or maybe the housing somewhere along its path to the front derailleur may have become dislodged from its stop on the frame.
Please see the photo of one of my bikes on which I labeled the stop, cable and housing. You’ll also see in my photo that the coiled wire inside my housing has begun to work its way out but yours won’t look like this if it’s brand new and I think it is.
If the housing or ferrule came out or off, when you tightened the cable anchor bolt on the front derailleur, the cable would be tight – no slack. So all would seem right.
However, by shifting, the housing or its end cap could seat into its stop or onto the housing (for end caps). When that happens a lot of slack is created in the shift cable. And that slack can make a front triple derailleur do what yours did: shift right from the big ring to the granny and hard, too. Because the cable tension has to be tight enough for the front lever to be able to shift properly.
If that’s the problem, to fix it is just a matter of loosening the cable anchor bolt on the front derailleur, inspecting the housing all along its path to ensure it’s seated everywhere (and any loose ferrules are pushed back onto the housing), pulling on the cable to remove any slack and tightening the anchor bolt again.
Give this a try and let me know if I’m on the right track, Steve.
Idea 2
If not, you might check the shift lever to make sure you didn’t somehow end up with a double instead of a triple shift lever. XTR was offered in both for a while. It might say what it is on the lever, a double or a triple. But, you can tell by the number of clicks it has. A double has only one shift. A triple has two clicks.
To feel for this, pull on the shift cable by hand to keep it under tension while you operate the lever to count the clicks.
If you do have a double shift lever you’ll need to replace it with a triple so I hope that’s not the issue.
Your Turn
We covered a couple of fun issues here. If you use trekking bars, it would be interesting to hear about your favorites and how you have them setup. And, if you have ideas to help Steve with his shifting issue, please share them. Thank you!
Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s cycling streak ended in February 2022 with a total of 10,269 consecutive daily rides (28 years, 1 month and 11 days of never missing a ride). Click to read Jim’s full bio.
Oh Shimano! Thou ways are most beautiful and confounding! Twenty years ago, every Shimano indexed shifter worked with just about every front and rear derailleur they made. Of course, that level of drivetrain intercompatibility would just not do for an outfit that wants to sell you a whole group-shebang whenever you want to change a single component. That trend has only gotten worse of late (e.g., a Sora front double derailleur will only work with a current Sora front shifter, not an older Shimano front shifter). The cable pull ratios (how much the cable moves to create shifter movement) are different. I suspect that your XTR shifter needs an XTR compatible MTB front derailleur that has the same cable pull ratio. The good news is that Shimano MTB front derailleurs are (relatively) cheap and plentiful, and a used one from a bike shop’s parts box or from an online auction site should work just fine. Hope I helped! Dale in Mid-MO
Thanks, Dale!
Heh… Jim gave me a heads-up that he was going to use my scenario for subject matter this week. He didn’t warn me that he was going to “out” me by name! LoL!
Never mind that. I hope I can find a solution to my problem.
As for the shifters, they are NOS; they’d pretty much *have* to be, because the rear shifter is 9-speed. I guess the triple front derailleur could be more recent, but these came as a set in the original factory box. So, for the present, I’m assuming they are both from the time when 9 speeds were popular. According to Sheldon Brown’s site, 9-speed road and mountain shifters have the same cable travel and pull ratio.
I’ve tried the things that Jim suggested. Here are some observations:
1) All the ferrules are seated, and there are definitely 2 clicks on the shifter in each direction, so it’s not a 2-speed shifter.
2) Pulling the cable by hand (cable attached to the FD) shifts nicely through the three chainrings.
3) Pulling hard on the end of the cable (*not* connected tot he FD) does not interfere with the functioning of the FD; I though maybe the spring on the FD was somehow overloading the shifter.
4) (This is the weird thing) Once connected to the cable, the FD will shift to the big ring, but a single click of the release lever makes the chain slam down hard onto the granny. It’s as if one of the shifter’s “positions” has disappeared.
The only things I can think of that might cause this are 1) the FD spring somehow has too much tension for the shifter to work properly, and 2) the cable pull is different. The first seems unlikely, and the second isn’t supposed to happen. But I’ve heard the legends of Shimano incompatibility, and even though I own a copy of “The Dancing Chain”, I’m not that technically gifted. I can (and will) measure the cable pull; sadly, it never occurred to me to do this with the old STI shifters so I wouldn’t be able to compare them. I guess I could set up the old shifter and make that measurement…
It’s good to know that a replacement FD is probably available, and I may go that route if nothing else pans out. I can always go back to the original drop bars and STI shifters too.
Thanks again!
Steve
Steve, it would be helpful to get a bit more detail about your shifting. When shifting from the granny ring, do you get two clean shifts, first to the middle and then to the big ring? If so, that’s a fairly good indicator that you have a compatible shifter for a triple ring. Then, when shifting back, you say that a single click of the lever releases the FD to the granny. Is there then a second click available, which would release more cable (and presumably result in a lot of slack in the cable)? Or is that single click all you get? If it’s two clicks up and only one back that would seem to suggest a shifter problem.
The shifters have two spring loaded pawls that engage with ratchet teeth, one for up-shifts and one for down. Are the shifters new? If not, it is common for the pawls’ lubrication to get gummy, and then the pawls do not engage quickly. To lube and free them up properly, you need to remove some of the shifter housing for access, but some people flush the shifters unopened with WD40 while working the levers, and follow that up with a spray lubricant.
Thanks, Thomas!
The shifters are “New Old Stock”, so, though never used, the original lubricant is present. The shifter feels like the pawls are performing smoothly, so I’ll keep additional lubrication on the back burner for now. I have tons of WD-40, and a spray can of WD-40 white lithium grease in case I need to go that route!
Steve
It would be easy to test. Disconnect the cable from the derailleur and then shift up and down through the shifter’s range while holding a light tension on the cable with the other hand. You’ll feel each shift in the cable.
Good Morning, Steve! To your credit, you have tried and checked everything that would obviously hamper the shifting action. However, within the last 20 or so years, Shimano (May their name be ever blessed!) made changes in shifters and derailleurs that created incompatibilities between their road and MTB components. Also, they started specifying exact minimum and maximum chainring teeth differences for triples (i.e., between the outer, middle, and inner rings). I have run into the fussiness of that issue even on friction (bar end) shifted road triple front derailleurs. In short, (potential) incompatibility was built into the system. I am still guessing an MTB front derailleur of similar vintage to your shifters would work (if it gets along with the chainring tooth counts on your road triple crank.)
Here is the Rosetta stone for Shimano compatibility: https://productinfo.shimano.com/#/archive
Find the part numbers on your XTR shifters (and Ultegra front derailleur), look them up in the PDF tables, and see what they say about compatibility. Good hunting, Steve! Dale in Mid-MO
Many thanks for the Rosetta Stone!
I will have fun with that. Meanwhile, there’s a ride this weekend (Bicycle Club of Lake County “Ramble”), which I’ll have to do on a mountain bike with street tires or an old French 10-speed with friction shifting!
Steve
Well, for the “Rosetta Stone” analogy to hold, there would have to be a parallel text in a language I could understand! 😉
I’m going to have to study that document a while before I can understand it.
Also, my original components were from 2001… the present list starts in 2004. I expect that’s not a crucial factor.
Steve
Best of luck on this weekend’s ride! Friction shifting might be a bit slower and more prone to small inconveniences, but it is almost fool-proof. (I would previously have described it as “bullet-proof,” but that is a poor choice of words given recent events.)
There are many hidden passages in that big rabbit-hole known as https://productinfo.shimano.com. If you put the parts numbers in the search function, it will likely pull up something (e.g., instructions and specifications), even for pre-2004 components. I have found it to be a big help. Also, if you send me those Shimano parts numbers (shifters, derailleurs, and crankset), I would be happy to try to help out.
All the Best! Dale ([email protected]) in Mid-MO
Thanks, Dale!
I’ll have to get busy harvesting numbers off the parts.
Thanks for the offer of assistance!
Steve
Thanks for helping Steve with all the great tips readers, much appreciated!
Jim
@ Stephen Turk:
Hi, Stephen. First, all the “shifting” that’s discussed is with the bike on a rack. The FD falls into the granny position with no tension on the cable. If the shifter is connected, I only get one action by pressing the thumb lever: the chain goes to the big ring. (Pedals turning, of course!)
Further pressing the thumb lever obviously has no effect. Then a single click of the release lever causes the chain to jump back to the granny, and no “clicks” remain. SO it’s really one click up and one click down. With some adjustment of the cable tension, I can get it to drop from the big ring to the middle ring, but there are still no clicks left.
@ Thomas Horne:
I said this above:
“3) Pulling hard on the end of the cable (*not* connected to the FD) does not interfere with the functioning of the FD; I though maybe the spring on the FD was somehow overloading the shifter.”
What I meant was that the *shifter* function is normal (ie, 2 clicks) when pulling (even very hard) on the cable at its end when the cable is *not* connected to the FD. Sorry for the lack of clarity. In other words, the shifter works fine by itself.
I’m starting to get a feeling that there’s an incompatibility between these components… but I’m not giving up! 🙂
Steve
Steve, one click up and one down certainly suggests that the shifter is pulling 2x more cable than the FD expects. I’m a bit surprised – Shimano FD cable pulls do vary, but in my experience not that much.
What happens if you adjust the cable (slacker) such that the first click takes you just to the middle ring rather than the big ring? Maybe less than ideal, because the cable may be very slack in the granny., but maybe worth a try.
I’m going to try to measure the cable pulled by the shifter, and also how much cable movement is required to move the FD. This should provide the definitive answer. It may take me a while, but I’ll report my findings.
Thanks to everyone for the responses!
May be too simplistic but I was thinking of the FD cable connection might not be correct. Seem to remember getting confused about how the cable feeds into D . When you shift does the action of the D look logical. Or does the cable look like its binding?
Thanks, John! I’ve sent Jim a photo of the cable attachment and he assures me it’s correct. I only wish it were something that simple!
Steve
Here’s the latest:
I did some experimenting this morning and I am pretty sure it sinks the ship as far as my FD is concerned.
I attached a paint stir stick to the down-tube so I could place a ruler alongside the cable. A piece of tape on the cable was my reference. With the other end of the cable weighted down, I went through the cable positions. After this, I re-connected the FD and observed the cable positions while rotating the pedals and using the thumb lever to shift from small to middle to big ring. Here are my findings:
Cable Movement with Shifter
Small-to-Middle Ring: 12mm
Middle-to-Big Ring: 8mm
Total movement: 20mm
Cable Movement with Derailleur:
Small-to-Middle Ring: 8mm
Middle-to-Big Ring: 4mm
Total Movement: 12mm
So… it seems obvious that these components are not compatible. If I have to change any part of the set-up, I’d prefer it to be the front derailleur so I can keep the shifter. Now I just need to find a derailleur that has the right cable travel.
Cheers,
Steve
Steve, thanks for giving me an excuse to take a mug of tea, a roll of tape and a metric ruler out to the garage. I checked my old 9-speed MTB with triple, and cable pull was very similar to what you saw at your shifters. Maybe 1mm less (11+8). That’s with LX shifters and crank, XT FD.
I don’t have a triple road bike, but it’s easy to see that the road doubles are pulling a lot less cable – maybe 5 to 7mm for the shift. And the reason quickly becomes apparent. On all the road FDs I have, the length of the arm from the cable slot under the pinch bolt to the pivot is about 15mm. On the MTB FDs, it’s about 25mm. So, more cable pull for the longer arm.
Thanks for teaching me something new. I’ve been building my own bikes, swapping components around, etc. for 30 years and never realized that road and mountain FDs had substantially different cable pulls.
maybe the shifter is just faulty – old grease, or some dirt, or a flaw – causing a pawl or ratchet to skip a stop in releasing tension..
or maybe it shifts up correctly, one ring at a time. but when shifting down, what it is really doing is not ”skipping the middle ring’, per se, but ”completely releasing all tension”, which causes the middle ring to be skipped — but from a different cause
if you think about it, a triple really has 2 tension holding positions, high, and middle. the granny ring is reached by letting all tension go, and depending on the limit screw to stop at the granny. so possibly either the middle one does not work when going down.
or it might be that thing someone else said about the ferrule slipping out of its holder
Hello from the other side of the pond.
The MTB XTR shifter is outputting too much cable – hence double shift on the Road Front derailleur.
To reduce the MTB output to a road input you can use a converter. I’ve a JTek Shiftmate on the bicycle with XTR shifter and 105 Front derailleur. There is also a Wolf Tooth Tanpan which does similar.