New bike, struggling with shifter cable friction
 

I purchased my new bike recently which comes with full length cable housing for the rear shifting cable. It is causing me issues wrt the amount of friction it is generating in the system and is preventing me from shifting to the smaller sprockets. A couple shifts usually only sends it down one sprocket. Is there anything I can do to reduce the friction?

Full-length housing in and of itself does not cause friction.

Poorly run housing causes friction. The simplest answer is to return your bike to the shop where you purchased it and have them fix it, for free of course.

However if you are considering fixing it yourself or if you just want opinions about where the problem(s) may be, post some pictures. Take wide-angle pictures of both sides of the bike so that all of the housing is visible. We don't need to see it up close - it should be obvious where any sharp bends are at.

The bike has been bought from eBay so having the shop repair it is not possible. I will be attempting to repair it myself if at all possible. I do have a bit of bike knowledge so am not going into this blind.

I have attached a couple pics here.http://bikeforums.net/attachment.php...hmentid=470953http://bikeforums.net/attachment.php...hmentid=470954http://bikeforums.net/attachment.php...hmentid=470955http://bikeforums.net/attachment.php...hmentid=470956

Have you tried loosening the cable tension?

yes, any adjustment puts the shifting out of index unfortunately

It's worth a shot, but by the looks of the rear shift housing, there could be problems. the first pic makes the rear housing look ok, but then in the last shot it does look like the loop before the rear derailleur is a bit short. The bends up front aren't ideal and might be improved by pushing some housing through the frame, shortening the section up front and increasing the size of the rear loop.

One thing I would be curious about on your internal cable routing is if it's an open lower tube or if there are internal connectors between the left inlet and rear exit, and right inlet and front exit. If it's an open lower tube you could get all new housing and cables, then re-route the rear shift housing to enter the left side inlet. This would be a much smoother angle for both front and rear shifting.

I also noticed that the hydraulic hose into the rear brake is pretty awful. Usually you can loosen that banjo bolt and turn the housing forward so that it isn't making that >90 degree turn. Don't loosen it too much or you will lose fluid; just enough to rotate it forward.

Thanks a lot for your tips. The rear brake is a mech cable brake so I can't change the angle of the cable entry but I will have a look see if I can improve it. As for cable entry, that's another thing I will take a look at!

thanks a lot.

So i've just been out and had a quick look.....

adjusting the cable tension, like i thought before, does nothing to improve the situation. I did however notice that in the little chainring, the issue is much less prominent and doesn't happen as often. I also noticed that (when in the big ring) if i shifted down and got no movement, then shifted back up, then back down etc it would stay in the same sprocket and there was no cable movement at the derraliur. Is there likely to be a cable issue nearer the shifter? I cant see anything obvious.....

Its possible but you have to pay the shop out of pocket..

Installed with smooth arcs and appropriate lengths in lined housing with die slicked cables is minimal drag .

SIS housing needs special Cutters , and is best, if after cutting, the ends squared up on a bench grinder.
before slipping the ferrules over the ends.

for a foul weather bike, the continuous housing resists contamination , you will be fitting mudguards next, Right?

There's a couple loops which could maybe do with being a bit bigger but it would require new housing. I'll see how it goes for a week or two

I've got some fenders but took them off as they caused really bad toe overlap. Maybe i'll have to give them another shot.

In design, they may have intended it for Club CX racing on the weekends , not a Commuter .

that's a bit excessive.

I do use a quality housing cutter - I've had good luck with both Pedros and Park Tool - but then I just use a small punch or 2mm allen key and stick it in the housing and work it around in a slow, gentle circle. This spreads the end of the housing into a nice open circle.

That's all you need to. :thumb:

I agree. I have park tool cutters and use a punch to open up the routing. I have used sandpaper to smooth a sharp edge on occasion, but that happens more on brake cables in my experience. OP, if it were my bike, I'd first check that the hanger isn't bent. Then I'd check cable friction through the housing, double checking anything that compresses the housing (like a zip-tie) to be sure they aren't too tight. If that didn't get me what I needed, I'd run new cable/housings.

Bench grinder in the LBS shop so ends are quick to do. for class 1 job.

This is a common problem usually solved by new cable housing (and cables). The Shimano stuff works well.

Other advice is good - watch the cable bends and use good cutters.

A little light lube in the cable housing might help too - especially useful for un-gunking rear der. loops, although I doubt a new bike with full length cable has gunk buildup in the cables. Perhaps the rear der. adjustments are way off - have you checked the limit screws? You might try disconnecting the cable altogether and feeling for yourself just how much friction is in your cable setup. Also a thought - is your cable connected to the anchor bolt on the correct side - this can impact the pull ratio and jack up your indexing if the cable is anchored incorrectly. For rear derailer cable tension adjustments, I would stick to the barrel on the derailer itself and avoid the inline adjuster - they simply dont hold tension as reliably as a barrel adjuster. Jagwire and Ritchey both make good barrel adjusters that mount directly to the shifter too, if you want an adjuster within reach while riding - Jagwire Rocket I think it is called.


If the above all checks out OK, I would try to start over completely with adjustments. Disconnect the cable from the rear der., tighten the barrel adjuster all but 1/2 turn in, check the high limit screw, re-set the cable end into the shifter, cycle shifter to smallest cog position, pull cable taught and reconnect to rear der., then while pedaling shift up two cogs larger, and increase cable tension while pedaling still until chain just starts to skip on next largest cog, then back off tension 1/2 turn. Ensure that you can shift through all cogs, and check the low limit screw and B-tension screw. This method works for pretty much any Shimano setup, assuming shifter/cassette/derailer are meant to play together.

Done all of that. There's got to be something wrong though.... On the first downshift there is basically no cable or der movement unless I pull the der. It's like the spring in the rear der isnt strong enough :s

There are springs on both sides, levers and changers, and the cable runs shouldn't be limiting shifting performance. (For clarity purposes, can we call downshifts the change to a larger cog? Upshifts are to smaller cogs?)

If you're having trouble upshifting, it should only be a problem (if at all) between the 2nd smallest cog and the smallest cog. (You don't say which gears you're shifting.) This is where the derailleur is at its weakest and is usually sensitive to adjustments of the cable to take up any slack, as well as responding to the tension fittings on the derailleur itself and frame/levers.

First question: Did you assemble this bike yourself or have the help of a knowledgeable friend? I'm trying to understand if the derailleur was set at the factory and if so, was it in adjustment "out of the box". Many bikes arrive with the low gears (biggest cogs) set up so that a person can't shift the bike into the spokes unless they're determined to do it. This adjustment requires the low limit screw to be unscrewed a bit to get that last gear. It's a simple adjustment but one that can be confusing to the uninitiated. @SpeedyStein wrote an excellent description of how to set up indexed shifting, so you're already getting good advice.

Second question: Did setting up the bike require you to install cables? I've found many levers to have fussy cable stop fittings and unless you're careful, or experienced, it is possible to close the lever when the cable isn't properly secured. This leads to cable slack and horrible shifting performance in general. (How horrible? I guess it depends on the installation but you'd notice something is wrong.)

Tip 1: Shift the bike into the large ring in front, smallest (high gear) cog in back. Now reach directly behind the derailleur cable housing stop on the right chainstay and tug gently on the shifter cable. There shouldn't be any slack. It should feel lightly tensioned but not firmly so. Slack in the cable can be best taken up by pulling it though the rear derailleur cable anchor bolt. (It is helpful to screw the cable housing tension fittings (one on the rear derailleur and one on the frame/levers) in so that there is outward adjustment available later when you fine tune the shifts.

Tip 2: If the bike won't shift into high, try unscrewing the high limit screw slightly and pedal the bike again to see if it will drop. Check the cable tension as described in Tip 1. If there's tension on the cable and the bike won't upshift, you'll need to "feed" some cable to the deraileurs so that it can achieve a full extension. You can either screw the cable housing tension fittings in to see if you can get it to drop when pedaling. The other option is to let a little cable out by loosening the cable anchor bolt on the rear derailleur and letting the cable run back slightly towards the levers. Make adjustments in small increments. 1/8" of cable is actually a lot so be careful that you don't overdo the change. Make each change one at a time. Changing two things and finding out that it works better is all well and good but if you're not sure which adjustment made the difference, you could end up pulling something out of adjustment.

Tip 3: Pay careful attention to the cable runs. Most bikes are delivered with the rear cable stop (if there's one on the frame) on the right side (corresponding to the right shift lever). I prefer to use opposing sides because it can help reduce cable clutter but there's been more than one instance when I kept adjusting a barrel to add or take up cable only to find out that the adjustment wasn't going through because I was turning the wrong screw.

Tip 4: Lubricate your derailleurs often with a drop of light teflon lubricant placed on each of the pivot fittings. It is possible your shifting will improve with use so just keep shifting. Also note that shifter cables stretch slightly during first use. This leads to cable slack. Be vigilant against all slack! Haha

Cale, you make a great point about factory bikes being "setup" at the factory. I ordered a bike online and was surprised to find that an "85%" assembled bike arrived with none of the cables connected! They hadn't set the limit stops, b-tebsion screws, aligned calipers with discs, nothing. Even the headset was loose. Oh well, only one way to learn to do it! Good luck OP, hopefully you can get everything working correctly.

I think the wheels on my Motobecane were built around hubs that were defective. About a month into ownership and in a community that hadn't seen a drop of rain that entire time, I serviced my "gritty" front hub. There was some grease injected into the hub but the bearing faces and cones were corroded. I can only imagine that it must have been manufactured with little concern for where the grease was placed and then either sat on a shelf (or possibly took a trip to the bottom of some ocean) for an extended period of time. It looked like plain steel rust and pitting.

I cleaned and lubed the hub and it's pretty smooth now, so no permanent damage done. Glad I didn't wait another month.

I have had this shifting problem. Sluggish shifting to smaller cog on the rear. It was the grease that Shimano and Jagwire put into the cable housing before shipping.
When I pushed the cable through a big glob of grease came out. I cleaned it out with Breakfree CLP which is safe for plastic.