williamskg6

Hi guys! I recently got a Jamis Renegade gravel bike for a really good price. I has needed a few things done since it sat unused for a couple of years. It has Shimano Sora R3000 components, and the main issue I need to resolve is the front shifting. The front derailleur will only barely move, and only does that with extreme amounts of force. I believe the problem lies in one (or both) of two places:
1. The cable housing isn't fantastic quality stuff
2. The cable route is along the top tube and down the seat tube, wrapping around a pulley attached to the rear of the seat tube

I believe that #2 is the biggest problem, since the pulley sits directly in the exact worst place to put a pulley, where it can accumulate grit and grime as it flies off the rear tire. I'm thinking this is what's causing the extreme resistance in the system.

What I'm wondering is if anyone has advice or best practices on dealing with these seat tube pulleys so they operate properly. I don't love the routing, but I understand why they did it. I haven't noticed a brand on the part, and I'm considering putting a sealed bearing Problem Solvers pulley in its place, but I figured I'd check to see if that's even worth bothering with or if others have maintenance procedures that they like for setups like this. Also, before anyone suggests it, there is no mount on the bottom bracket shell for a cable guide, nor is there a braze-on that I could use to re-route the front derailleur cable down the down tube. If this thing stays with a front derailleur, it's gonna have to use a pulley.

Or, I can just go 1X and be done with the front derailleur entirely.

I appreciate any input/advice/wisdom you can offer. Thanks!

Kontact 

Check that the housing isn't coming apart inside the little housing end stops. It will look like wires sticking out.

Make sure there isn't a housing gap under the tape going into the shifter body.

If the pulley is supposed to pivot, make sure it does. Pulleys generally work fine.


Generally, problems like this come from assembly, not design. Find where the cable is binding.

FBinNY 

GGGG

+1

Index housing extruding through the stop is a common cause of high cable friction. The wires pinch in as they would going into a funnel jamming against the inner wire.

The usual cause is an improper ferrule with a conical bottom.

Take things apart, replace the housing, and possibly the inner wire, making sure to use ferrules made for Index housing.

BTW, the least likely we cause is the pulley. That design is unbelievably tolerant of dirt and mud.

dedhed

A pulley is how they make a bottom pull derailleur work with top pull cable routing. you could find a compatible top pull FD

maddog34

Change the Cable NOW or regret it.. there's a high probability that the Cable is FRAYING inside the Brifter... Change Both shift cables before one of them Breaks in the Brifter and multiplies your task exponentially.

and +1 to cable pulleys working fine... although i've seen a couple all rusted and such, and a cable can derail to one side of them, occasionally, but that is easily seen.. the FRAYED CABLES are not easily seen, and happen way too frequently.

change the cables now or regret not doing it soon.

maddog34

after thinking about this.. I've NEVER seen a Jamis with a pulley in the FD cable line... EVER
then again, i've not seen every jamis model in my rural area, so.....

could you post a pic of the pulley and it's location, please?

is this like your bike?
https://roadbikeaction.com/jamis-ren...l-bike-review/

LesterOfPuppets

The 2020 S3, S4, and A1 renegades have em. I didn't download other years to look but here's the link to catalogs:


https://www.jamisbikes.com/support/catalogs/

LesterOfPuppets

Catalog pics don't really show them, so heres a NDS pic of the '20 S3

LesterOfPuppets

williamskg6 You can probably check to see if pulley is turning freely by shifting into the big ring, then without pedalling click the shifter to the low gear position. This should leave enough slack in the cable to see if you can turn the pulley with you finger. The pulley might be mostly obscured by plastic, so might have to try turning the pulley with something smaller than your finger

I'd go ahead replace housing and cable.

williamskg6

Nope. It's a 2019 Jamis Renegade Explore. It looks just like this: https://99spokes.com/bikes/jamis/2019/renegade-explore and it's also shown in the 2019 Jamis catalog - somewhere in the middle of the catalog.

maddog34

so have you determined where the binding is?.. Pulley? Cable? Shifter? Derailleur?

don't think or guess.. Find Out.

and trust us... change the cable.... or find out how darn tough it can be to dig a cable out of a brifter.... definitely not a task i want to repeat... but most likely will...

last time i did this was on a bike that completed the last 40 miles of the Seattle To Portland ride with only 8th gear in back and the front three to shift between... a passing rider helped him adjust the rear der. into 8th or he'd have been in tenth gear.
he now swaps in new cables every spring.

williamskg6

I haven't yet - I will hopefully find the time to dig in tomorrow and replace the housing and the cable.

Trakhak

But locate the source of binding first, as maddog34 suggested. That way, you'll know where to look if the binding eventually recurs. And please post your findings, since some of us here are curious.

cyccommute 

Well that’s a bad idea blast from the past! The pulley idea was used extensively in the 80s and 90s before the advent of top pull front derailers in mountain bikes. Manufacturers quickly got away from the issue by introducing top pull fronts for those mountain bikes but there’s never really been many road bikes that route the cable along the top tube so there aren’t many road front derailers that can be shifter by top pull. There are a few that are available in both top and bottom pull. One is the CX70 detailed in this article. There’s another one I’ve run across but can’t provide the model number right now that is set up like the one in Bike Gremlin’s articles. Look under the heading “2. Cable Routing”. The derailer I’ve found is a lower end one simply mark (if I recall correctly) Road Triple but it has that cable yoke that Bike Gremlin’s article illustrates. It should work with Sora as that is a 9 speed group and I’ve used this derailer on 9 speed systems.

Not many around.

williamskg6

Yeah, as you say, there aren't many of those around. They can be found, but they're uncommon enough that they're surprisingly expensive. I'm probably going to see if I can get the existing pulley setup working before I go dumping $70 into a front derailleur I won't be able to replace when it wears out/breaks (if that ever happens).

KCT1986

The FD-CX70 uses the older amount of front shifter cable pull, common on most 10 speed brifters (non 4700 series & ...). The 2x ST-R3000 uses the 11 speed pull amount, (interestingly the 3x has the older pull design). The longer pull on the '11 speed' brifters is not really compatible with the older FDs. It can probably be made to work, but trimming position may not be correct.

If you compare the Shimano EV tech docs of the FDs, you will see that the cable attachment arm length changes to adapt for the cable pull.

williamskg6

OK. Here's the status on this.

I took it all apart and it seems like it was actually the pulley causing most of the issue, but I found a couple of other problems. The cable was in perfect condition. It is a cheap cable, but it was not frayed, kinked, ground up, or otherwise. The cable housing was equally low quality and super stiff. I replaced it with some Jagwire housing. I also replaced the cable with a Jagwire cable. They're not the high end cable/housing but certainly way better than what was on there. The front derailleur had not been installed correctly either - it was impacting the big chainring teeth (instead of the 1-3mm gap) and was not aligned with the chainring correctly (angled inward a tiny bit). Either it was installed that way, or it took a hit. There aren't marks on it like it took a hit, so I'm guessing poor installation.

As I said, the primary problem was the pulley. It's a very low quality plastic pulley that rides on an aluminum bushing. The pulley spins on the bushing about as smoothly as if it was lubricated with sandpaper. I cleaned it as best I can and put some teflon lubricant on it and it's working much better, but it's getting replaced ASAP.




Regarding the info on the cable pull being different, thank you for that! I had no idea that the cable pull on front derailleurs had been changed on some of these newer Shimano groups. Honestly, would it kill them to not come up with a different cable pull "standard" every other week?

I'm actually thinking of installing Microshift Sword 2x10 on this bike to replace the Sora stuff, so this all might end up being just an intermediate fix until that happens. Either that, or go 1X and put SRAM Rival 1 on it like my other bike. The Rival 1 shifting is louder, but way more snappy than the Sora, and I don't have to muck with a front derailleur.

Kontact 

There's actually 3 cable pulls to worry about: Old road, current road, and MTB.

I would lube the pivot on that pulley with grease. It may not seem like a clever design, but it works just like your derailleur pulleys.

KCT1986

You may need to check the FDs compatible for the Sword group. Most of the non-MTB FDs they offer are bottom pull designs.

Trakhak

True. I would guess that the force acting on the guide pulley under discussion is considerably higher than that seen by derailleur pulleys, though. Thus, grease instead of a lighter lubricant is a very good suggestion.

cyccommute 

I suggest replacing that bushing with a true bearing. This one from SRP would work a lot better.

dedhed

GRX, CX70 likely work

Reynolds 

BITD I rode my 2 MTBs a LOT with such pulleys (but they were metal ones) and never had any problems.

Camilo

FWIW, the pully is on the seat tube, not the seat post.

I'm pretty sure my old Jamis Nova Pro had a pully on the seat tube and it worked fine.

Kontact 

GRX is the new long throw type while the CX70 has the pre-11 throw.