Living Jackson

Benefits of cycling

Derailleur Alignment, Gear Cables & Cheap Power Meters | GCN Tech Clinic

(whooshing) – Welcome back to another
episode of the GCN Tech Clinic, where I aim to help and solve
your bike related problems. So if you’ve got one, leave it for me down there in the comments section and I’ll do my very best to help answer it in an upcoming episode. With no further ado, let’s crack on with the first question this week. And it comes in from Theo Hernandez. Their question is, “Can
you use break cable housing for a shifter cable?” As Theo is all out of shifter housing and needs a little piece to go in between the rear derailleur and
chain stay cable stop, about six inches. “Would such a short length compress enough to make my 7-speed indexed
shifting unreliable?” Theo, do not do that, my friend. The reason being is that the outer cables are created differently. In that a break cable is made of a spiral-bound bit of outer, which the indicator then runs through. Whereas a gear outer
cable, has its length done well, in one long line, if you like. So it’s made of many, many
strands and they can’t compress. Whereas that spiral one on a brake, can compress, giving you well, a slight bit of modulation I
guess, if you lock up a brake. But it’s not going to give
you like an ABS style feel. But yeah, the purpose behind
the gear cables being made in that way, is they don’t compress because your gear cables have to be really, really
exact in their tensioning. So stick with some outer gear cable, if you want to have perfect gear shifting. And next up a question from Luis Sanchez, “I was wondering if we will
ever see budget power meters, ones you can simply glue onto your cranks, or something of that sort for us peasants who don’t want to drop
hundreds on a new crank?” Right, Luis, possibly, there have already been a
couple of examples of this. The Watteam Powerbeat
and also the iQsquare. Their first product was a
bit of equipment basically that went in between the pedal and also the crank kind
of screwed into the thread and then you put the pedal in on there. Although, now I’ve
looked on their websites, neither of them are
currently shipping anymore. But keep your eyes peeled, this sort of thing does
pop up on Kickstarter and Indiegogo, that sort of thing, but right now, there is nothing in production that I’m aware of. Next up is zurjon23, who
says they love the Tech show, which is brilliant. Their problem is though,
recently their rear mech fell off and it got caught on the wheels and bent the derailleur hanger. Now zurjon says they tried to straighten the derailleur hanger and
installed a new rear mech as well. The problem is, it seems
that they can’t index the rear mech properly anymore. Ooh, zurjon, right then, that rear derailleur hanger
alignment is absolutely crucial. Doing it by eye is really not good enough, which I reckon you’ve probably done there. What you are going to need is a derailleur hanger alignment tool. So, when you fasten that
on, you can actually line up in a few different
places on the back wheel to make sure it is in the correct place. So, laterally adjusted as
well as vertically adjusted. It’s amazing what a few
degrees out of place can actually make when it
comes to your gear indexing. Along with that, I would
get some new gear inner and outer cables too, if you’ve put a new rear derailleur on. Because it’s amazing the
difference to indexing performance that a new set of cables can make. Next up is Athur S, who says, “Hi Jon, I’m using a
Tiagra rear derailleur in my cyclocross bike. But when I go off-road
the chain flies everywhere on the rough terrain, hitting the frame and sometimes skipping on the cassette. I thought maybe changing derailleur for Deore with a clutch mech would help. Does this make any sense and what’s more, will it work together?” Right Artur, firstly, Shimano
road and mountain bike components don’t really
work that well together. The reason being the amount
of cable that’s pulled by the shift lever isn’t
the same across road and mountain bike components. But, there is a handy
little solution for you here and it comes from a
brand called Wolf Tooth and they make something called a Tanpan. Which is a tiny little metal wheel, which the chain, sorry which
the cable can roll around and in turn can work absolutely perfect. Check out their website and
make sure it’s compatible with your levers, but
yeah all should be okay. Next up is Ben Carley-Macauly, who says, they’re thinking of going
one-by on their road bike as they rarely use the inner chain ring and have had problems
with front derailleurs. “Apart from a narrow wide chain ring, is there anything else that I would need to ensure the chain would be secure, whilst preferably keeping
my current rear mech? All the best, Ben”. Ben, nice question and also good as well you want to keep that rear mech on there, because, well, you’re
going to save yourself a little bit of cash there. Now I’ve done this on my own
bike, well one of them at home and with a good deal of success actually. I’ve never lost a chain, but something you could consider on there, is a chain guide or a chain
catcher, that sort of thing. Which could clamp onto your
existing front mech braze on, if that’s what you’ve got on the frame. If not actually a clamp on one. And Wolf Tooth as well as K-EDGE even make these solutions for you. Good luck mate and let
me know how you get on with those bits of kit. Right next up is olly cook, who says, “Can I put a SRAM 11-speed cassette on a 10-speed Shimano Freehub?” Ooh, yeah you can, but not always. If it is a Shimano actual branded Freehubs on a Shimano wheel, very unlikely. In fact, I’ve never seen it done before, unless you do some machining of a cassette on a lathe to remove some
excess material and everything and then you are able to do that. However, if you’ve got yourself a Shimano Freehub on a Mavic wheel then the chances are it’ll
work absolutely fine. Because I’ve seen all sorts go on them. They’re one of the few companies out there who have a Freehub which seems to be able to accommodate anything you throw its way. – Next up is, Jason M, who
says, “Hi Jon, great show. Is there a minimum tire
clearance between tires and fork on a disc brake bike? I’ve recently upgraded
my wheels and tires, going from 25 to 28mm. The 28mm front tire has
1.5 to 2mm gap all around.” And Jason says they
actually had to pull off all the little new tire nubs ’cause they could hear
them hitting the fork. Jason, I would be a little
bit concerned to be honest. The reason being, if your wheel
goes slightly out of true, there’s a good chance it’s
going to start rubbing on the inside of the fork there. And that’s not what
you want, let’s face it because you’re going to start
wearing away the material. Personally, I’d go back to the 25’s. It sounds to me like it’s probably an older generation disc brake road bike, because it can’t accommodate 28’s. Most of the modern ones
or recent additions, tend to be able to do that. This reminds me of the
old time trial bikes back in the 80’s and early 90’s. Where the clearances used to be so tight that if you picked up
a little bit of gravel on your tire, it would
actually start rubbing on the frame and it would cause quite horrible gauges on the paintwork. In actual fact, I just got one of these. This is a bit of fag paper and we used to call that
fag paper clearances. Because they used to say it was so tight you could just about put
one of these through there. Yeah, you don’t want that on
your bike, not in my opinion. – And the final question this week comes in from Phil Weatherley who says, “Hi Jon, here’s a question. I’ve made a bike light.” Right, okay. “6W LED at the front, 1W at the back. Cables between them, it works well. Currently using twin
flex, supply and return. What do you think about
using the frame as the return so I only have one
conductor to each light? It’s only 1A at the front
and 350mA at the back. So I thought to use copper
tape, suitably insulated, stuck where you can’t see it on the frame, so removing festoons of visible cable. Your thought sir?” Phil, what an electrifying
question there my friend. I really don’t know
how to answer this one, because I’m not an electrician. I have just done a rewire, but I’m not a qualified electrician. What I would certainly
not suggest is doing this, if you’re unsure really
and you’ve asked me and I wouldn’t, I just don’t like the idea of sending electrical
signal through a frame. I know there’s not a
massive amperage or watts or anything like that actually
going through the frame. But you are going to be wanting
to send an electrical signal through the frame that you’re riding on. On the safe side of caution
you’ve got one heart, don’t risk giving it a
shock, please my friend. I know that someone out there will be able to answer this question comprehensively in the comments down below,
so look out for that one. But my personal thought
would be, please don’t do it. Right, I hope I’ve been
able to help answer or solve your problem this week. Let me know down there
in the comment section if you’ve got a question
and I’ll do my very best to help answer it in an upcoming episode. And now, don’t forget too,
to like and share this video with your friend and
also, why not check out the GCN shop at And for two more cracking
videos how about clicking just down here and just down here.

Leave a Reply

Your email address will not be published. Required fields are marked *