New Shimano shift cables on old 7800 group

[timsmcm]

I just purchased a new cable kit (Shimano 9100 series). Checking things out I find that the rear derailleur housing shimano sis ot-rs900 is way too short for the rear derailleur to the frame stop on the chain stay. Do you know if I can find that flexible derailleur cable housing in a longer length? I have looked everywhere and can't seem to find it.

[djg21]

I just purchased a new cable kit (Shimano 9100 series). Checking things out I find that the rear derailleur housing shimano sis ot-rs900 is way too short for the rear derailleur to the frame stop on the chain stay. Do you know if I can find that flexible derailleur cable housing in a longer length? I have looked everywhere and can't seem to find it.

Why not just cut a piece of regular derailleur cable housing in the correct length?

[bward1028]

I'm pretty sure you arent supposed to use those polymer coated cables on the non-11 speed stuff, as the cable fixing bolt does not clamp hard enough to keep the cable from slipping.
That's from Shimano, though, so it might just be a CYA thing, and from some quick google, looks like it might only be an issue with the brake cables.

[zzy]

I'm pretty sure you arent supposed to use those polymer coated cables on the non-11 speed stuff, as the cable fixing bolt does not clamp hard enough to keep the cable from slipping.
That's from Shimano, though, so it might just be a CYA thing, and from some quick google, looks like it might only be an issue with the brake cables.

Does Shimano really say that?? The coating will in no way prevent proper clamping force from being achieved. The system does need the nosed ferrules to protect the coasting and prevent fouling.

[bward1028]

This was back at the beginning of the polymer cable era. things may have changed since then. I can't really find any info online anymore.

Or i might have just dreamed it all.

https://www.racycles.com/product/detail/9296
Shimano is quick to stress that you cannot use the polymer coated cables in non-Dura- Ace BR-9000 or 9070 set-ups. The brake cables use a special polymer coating that will not work with older Shimano brakes. The potential is very high for the cable simply to slip out of the brake causing a complete loss of brake power. In fact, Shimano discourages anyone from trying to use these brake cables with anything but their 9000 and higher series since the risk of brake failure through slipping is just way too high.



Looks like it's just brakes, though i can't find anything from a shimano source.

[dddd]

The coating is quite easy to strip off, near the end where clamping occurs.

And, if there were ever enough force on the derailer cable to cause slippage, I would argue that this would be good, so that the lo-limit screw could be readjusted properly before the cable suffered breakage.

I usually use these (Glyde brand) cheap 1.1mm black-coated cables on bikes with internal cable routing. The thinner wire conforms better where guide bends otherwise tend to cause a thicker cable to bow (along what should be straight sections within the frame). The bow-effect makes the cable feel more like a rubber band in response to small cable movements, so is detrimental to indexing accuracy. The black coating also doesn't seem to impair clamping of the cable, though would also be easy to scrape off.

I used one of these (Glyde brand) black gear cables just last night on a Specialized Ruby S-Works after first trying a new 1.2mm cable. The 1.1mm cable gave me a lot more leeway in terms of a usable range of cable tension adjustment giving good shifting in both directions, especially while on the big ring.

The black 1.1mm cables I buy also have both Campag and Shimano ends, so one gets cut off. I do then sometimes have to insert the cut end through a pre-curved housing under the bar warp, which necessitates some twisting of the cable to make it through, but I think the smaller diameter helps a bit here.

These thinner 1.1mm cables are also the only size that fits in a SRAM road shifter, and are by far the best for use in the older-model Grip Shifters (the ones made for use with Shimano derailers).

[oldpotatoe]

I just purchased a new cable kit (Shimano 9100 series). Checking things out I find that the rear derailleur housing shimano sis ot-rs900 is way too short for the rear derailleur to the frame stop on the chain stay. Do you know if I can find that flexible derailleur cable housing in a longer length? I have looked everywhere and can't seem to find it.

Use any 4 or 5mm der housing..LBS sir has rolls of it.Needn't be the 9100 series specific stuff.

[kgreene10]

I’ll also add that I use shop cables on 9000 and it works really well, but I save a bundle and avoid the inevitable frustration of watching the coating peel off the expensive stuff day by day.

[dave thompson]

I’ve had 7800 shifters for years and I can’t recall anything about a requirement, or even a recommendation to use those coated cables on them.

I use the SRAM 1.1 cables and any good quality lined housing that I can buy at the LBS.

[dddd]

I’ve had 7800 shifters for years and I can’t recall anything about a requirement, or even a recommendation to use those coated cables on them.

I use the SRAM 1.1 cables and any good quality lined housing that I can buy at the LBS.

It's the cable path of some modern frames and handlebars, more than the 11s derailers, that I believe makes coated cables a near-necessity on some of today's bikes. But as people are noticing, thinner cable wire achieves the same benefit as Shimano's coated wires when the cable path is challenging. Perhaps the coated 1.1mm cable offers the best performance of all(?). They don't have to be expensive either, I got them at normal prices a while back.
One problem is that their packaging often doesn't make any mention of the cable diameter, so you may need to have them in your hands to verify that it's a 1.1mm cable (though of course SRAM'S road cables are all 1.1mm)

As for the rear cable housing "loop" being of a new super-flexible type, this is to accommodate the derailer swinging about during wheel removal, since the housing is super-short now with the 9100 and 8000 derailers. A very short and stiff (normal SIS type) housing may show an inability to retain accurate cable adjustment when wheel removal causes it to bend so sharply, hence the new-style, super-flexy cable housing segment that comes with these new gruppos. I suspect that normal housing may crack or otherwise deteriorate when subjected to such severe bending!

[Gummee]

IME when the housing goes under the bar tape a coated or polished cable makes the shifting much better. Old-style exposed cables don't need fancy cables

The Jagwire Pro or Elite Polished work very well and don't cost quite what the coated cable from Shimano cost.

If you DO go with the Shimano coated cables, use the new new green-colored cables instead of the older brown cables. Far fewer problems with the coating coming off.

One of the $ saving tips I've used is to re-use the old right cable as the new left cable. Do that once or twice and you have the nice cables on both sides without spending a ton per cable change

M

[doomridesout]

I've done it, works great.

[fffuhq]

It will work. only weird shifter housing/cable is Campagnolo.

[oldpotatoe]

It will work. only weird shifter housing/cable is Campagnolo.

Since 2009, same diameter housing as sram/shimano..for info. Yes, smaller head for der cable but certainly not weird.

[dddd]

Shift cable housing briefly went as small as 3.6mm with Shimano's SP36 housing and (presumed) thinner inner wire, but that was about 20 years ago.

Something made them go back to 4mm housing and 1.2mm cable wire.

Seems that systems like SRAM Exact Actuation and Campagnolo would work better with the thinner wire and housing since their derailers have a lower actuation ratio (greater cable travel to cage travel ratio).

But current Shimano road systems (Tiagra on up) use a lower derailer actuation ratio as well, so would seem to benefit from thinner wire, especially where the cable makes it's sharp turn feeding onto the shift lever's spool and where thicker wire bows coming off of guides in/on the bike's frame.

Especially as the newest STI levers feature travel limit stops (and with their 9100 and 8000 front derailers no longer having a hi-limit screw), thinner wire might easily be as reliable as their current cables, and lighter as well.

[dave thompson]

I got turned on to the SRAM 1.1MM cables years ago when i did my first install of the then new 6700 STI shifters. Never had the widely reported fraying problem than many others have experienced. I also use Phil grease on the head and the few inches of the cable where it winds around the spool. I dont know if that does anything but it makes me feel good.