inner and outer brake and gear cables

[eezeeriderr]

Hi everybody
I've just refurbished an old tourer into an everyday runabout (i've got 2 other bikes, a roadie and a hybrid). I swapped the drop bars for a straight, fitted new sprocket set, new rear mech, indexed shifters on the bars instead of down tube shifters, and brake levers. I ordered new inner brake and gear cables on ebay, (i didn't realise that these were different thicknesses before), it seems the gear cables are usually 1.2mm and the brake cables are 1.5mm. I ordered brake outer cables and gear outer cables, the latter being more expensive for some reason, but when they arrived they had sent me the correct total length but all of the same type (brake outer). Anyway i fitted it all and it seems to work ok but was a bit miffed that they had charged more for the gear outers, so i left some negative feedback. My question; is it ok to use brake outer with gear inner, and indeed is gear outer different to brake outer or will it be detrimental so that I should change it? This all sounds a bit long-winded but I would be grateful for some technical know-how on the subject. Thanks for any help.

[tooley92]

Modern gear cable outers have the strands in the sheath orientated in the same direction as the cable (along the length of the outer) - this is to prevent the outer compressing, giving a more accurate shift (needed with index gears). Brake cable outers are similar to the old type of gear outers and have the strands in the outer in a coiled configuration.

The only problem that you may incur in using the brake outers in your gears is inaccuracies in the indexing of your gears - it will depend on the length of outer that you have in your set up, I don't think that the ammount used for the rear mech in a system using down tube shifters would make much difference but as you are using MTB type handlebar shifters you will have quite a lot of outer cable (shifting will depend on how many speeds you are using).

[CREPELLO]

It's a shame you fitted the cables because gear and brake outer is not the same and brake outer won't work well for gear cable housing and you could have got it exchanged. Brake outer is a steel coil in construction and gear cable outer is straight wires lined up to make the tube shape. Unless you have the 5mm gear outer that Shimano do - you need to check the structure; it does look similar to brake outer.

[eezeeriderr]

Thanks chaps for your comments. That's the great thing about cycling, you learn something new nearly every day! I'm only using a 6 speed sprocket set with the original Stronglight double up front; I fitted a clamp-on cable backstop where the down tube shifters had been so the front outers from the shifters are about 500mm long and the rear outer from the chainstay stop about 400mm. It all seems to work quite well so perhaps I'll give it a couple of months riding to see if any problems occur.