(dramatic music)
- Welcome back to the GCN Tech Clinic
where I help solve your bike related problems
and all sorts of conundrums that you send in.
How do you send them in, then?
Well, easiest way, leave it down there as a comment
in the comment section down below,
and I'll do my very best to answer it
in a forthcoming episode.
But as ever, let's crack on, shall we?
With the first question this week
and it comes in from Phil Adams.
Phil says, "John, I'm building a bike for everesting
"and I want really low gears.
"I can get some mountain bike cranks
"or a derailleur extender to allow up to 40 teeth
"on the back.
"Would one be better than the other?
"Any disadvantages?"
Right then, Phil fancy a cheeky bit of everestng, do you?
Now, for those of you who don't know
what everesting is out there,
it's when you find yourself a hill
and you repeatedly ride up and down it all day long
until you climb the equivalent height of Mount Everest,
which is I think 8,848 meters.
Now, Olly did it recently.
He did it pretty well, as well, I do believe.
Anyway, enough about Olly, enough about everesting.
What about that tech problem?
Right, those mountain bike cranks.
Yeah, they'll be absolutely fine I imagine,
providing of course you can get your front neck
low enough to accommodate
the inside chain ring on there.
But personally I would not go for that
because your Q factor is going to be pushed out
compared to what you're used to, I imagine.
And if you are riding all day, that's not what
you want to happen, is it?
So I'd go for the derailleur hanger extender
so you can use that big old 42 cassette at the rear.
Just make sure, though, that your chain is long enough
to be able to accommodate it.
And also it doesn't make foul or anything like that
if you do go onto the bigger ring.
I don't imagine you will be going on the big
ring though much of that day.
But anyway, good luck with that everlasting.
And I reckon derailleur hanger extended.
I'll use one on a one by hack a couple of months ago
on a video I did here on GCN Tech
and I found it to be absolutely brilliant
and now we've got a question from Jesper who.
Jesper has a problem.
They're riding Dura Ace 7800 on the TT bike
and they're finding jockey wheels is a pain.
Is there any chance that an Ultregra 6700 derailleur
will fit with the current leavers?
Nice to hear from you, Jesper.
But do you know what that 7800 Dura Ace
group set was stunning.
One of my favorites actually of the Dura Ace offerings.
Now, yet those parts are all
interchangeable with one another.
There was a Shimano Dura Ace group set, I think it was the
original eight speed STI one that wasn't
compatible across the other offerings.
So one of five and Ultregra,
these days they are all interchangeable.
However, as for putting that 6700 derailleur on,
yet you could well do that but I would actually hunt around.
You aren't going to have very high,
you're not going to have very low.
You are going to find some replacement
11 tooth jockey wheels to go inside of that rear mech.
And you'll be able to carry on using that 7800 one.
So have a look around, you'll be
easy to find them and put those in there.
Just remember though, they are upper and lower
specific for a reason.
So just bear that in mind when you're fitting them in.
And good luck.
Keep riding that TT bike.
I'm jealous of that 7800.
Next up is the question from Adrian Hearne.
Now it was quite a lengthy question as you can see on
screen right now, but the long and short of it,
or I've got to the crux of it, really,
Adrian's problem is that they're free hub
is spinning the cranks when you freewill.
So I imagine it's more noticeable
actually when you're in a work stance.
So imagine the bike is up and it work stand,
you spin the cranks away, walk away from the bike
and the cranks are still going around, albeit quite slowly
in comparison to the rear wheel.
What could it be then on those Mavic wheels?
Well, actually, it's a really,
really well sealed freehub design,
in my opinion, from Mavic.
And it looks kind like this.
So on the freehub in between where the
freehub sits onto the actual hub shell, you have
a rubber washer like this and I'm pretty sure
that's what your problem is.
This rubber washer does an amazing job
of keeping all the water and the grime out.
However, the job it doesn't do so well
is dealing with friction.
So the rubber washers from time to time
can go up against the actual hub shell
and in turn as the hub shell spinning,
the freehub starts to spin with it too.
Now that can also cause a noise, which you also
touched on in there and I had a pair of Mavic wheels at
one point and they had one of these washers on
there and it made a really, really loud screeching
noise when I was free wheeling only on occasion though.
So it wasn't too bad.
How did I solve it then?
And also that kind of grippy or sticky
freehub well, I've got that rubber washer off
and I actually cut along it
so I'd cut probably half of it away.
Now, the downside of that obviously
is that he's not going to be as well sealed
or protected against the elements, but the good side
is basically it worked a little bit better I guess,
so it wasn't as screeching.
In fact, it got rid of all the screeching noises
and also it meant it was a smoother
or less resistance drive train when freewheeling.
So that is certainly an option for you.
Next up we've got Toby R. who says,
"Hey John, I want to change my 33 millimeter
"Cyclocross ties to road ties.
"On the rim it says 21-622.
"Can I put 28 millimeter road
"tires on there or should I stick with 32?"
All right then Toby, that 21 of those digits denotes the
internal rim width.
So in your case, 21 millimeters.
So you are going to be absolutely fine to put a pair
of 28's on there.
Now it's not always plain sailing,
believe me, when you're trying to put tires
and rim combinations together because sometimes you can
lose a lot of skin on your thumbs and also strain them,
that kind of thing.
Recently it happened to me,
a friend of mine asked me around,
could you fit this tire on for me?
I'm having a bit of a problem.
Yeah, about two hours later we got it on.
Anyway, yeah.
Sprained a thumb actually doing that.
Some combinations are just a nightmare,
but you'll probably be okay on that.
It's quite a wide internal rim width.
You'll also be traveling quite a bit faster from now on
because you're not going to have the extra resistance
of Cyclocross tire, so yeah, 28 on those rims.
Spot on.
Go ahead.
Do it.
Okay, now we've got EatRideGrow,
who says "John, could you help me?
"I was wondering if it's possible to use
"a Shimano Alfine DI2 road shifter set
"with an Ultegra RX 800 DI2
"rear derailleur and a one by 11 transmission?
"I'm not sure if the Ultegra DI2 set up
"will work with that front derailleur
"and I'd like to know before investing any money in it."
Right then.
I check the compatibility sheets from
Shimano, the most up to date ones,
and it will work absolutely fine.
As for using it without a front derailleur,
again, that is absolutely fine.
All that will happen is when you set it all up within
the YouTube app or the YouTube software,
it just won't detect a front derailleur,
obviously, because you don't have one,
but nothing to worry about there.
It will work, it's all plain sailing and well,
you're going to have yourself a nice little set up there.
It's something that I've looked to in the past
because ultimately you still got a great
lever shape and it's quite a good cost effective
way to do it.
Nice one.
Next up is TritGeRizZ,
who asks, "is there any problem with running all
"purpose grease as a lubricant?"
Right.
Great question.
I'm going to do my very, very best to answer it.
I'm not a grease or an oil expert,
but let's just get to the nitty gritty of
it if you like.
So grease is actually oil plus a thickener
and you're looking for using it as a lubricant.
Now, the only place really you're going to use
a lubricant on a bike is going to be on your chain
because a lubricant is more oil based.
So if you were to put an all purpose grease on there,
it's going to be too thick, really.
It's getting to the inner workings of the
chain and it is going to be pretty messy.
I have seen people use an all purpose grease as a
lubricant for a chain in the past and those were
a few pro mechanics just before the start of a
torrential downpour at a bike race.
The thinking and the reasoning behind that
was actually to try and get the lubricant they had already
applied to stay on the chain for longer
because all that rain was going to wash it away.
There was, in fact, another team there.
They lubricated up the chain and then they covered it
in Vaseline of all things
because of course it's water repellent.
I wouldn't recommend doing that on your own bits
and pieces at home because you're likely to
destroy the chain pretty quick.
So in short, now I wouldn't use an all purpose grease
as a lubricant, certainly not for your chain.
Next up is Lucas and Lucas recently replaced their
23 millimeter wide tires with 25s.
Since doing this, basically gravel and dead leaves
stick to the tires and jams up in between the bike.
So the frame and the fork and the tires,
it rubs against the tires and Lucas says it slows them down.
And to actually get rid of them from jamming up,
they have to stop, get off and poke them away.
Now this Lucas, I can genuinely feel for you here.
Some bikes out there sadly have been designed
in such a way that 25 millimeter tires
just simply don't work.
They don't allow the clearances
and they don't allow the tire to
actually pass through, which is really, really
sad because the state of most people's roads
out there these days, the change from going to a
25 millimeter tire from 23, it's pretty noticeable
in terms of comfort.
The bike I recently upgraded to one by Hack.
The clearances on that, again, are mega, mega close.
I can't fit 25 millimeters in there.
I've got a friend of mine with a very,
very high end premium bike.
I put some 25 millimeter tires in there
and it was rubbing on the underside of the forks too.
So unfortunately it seems like 23 millimeters
are the only way to go, I'm afraid.
So it looks like you will be having to get those 23s.
Sorry.
Now, Simon H has got a disparate question.
Now, Simon asks, "on the question of disc brake upgrades,
"how about running calipers at the back
"and upgrade discs with a new fork
"and wheel at the front only?
"So similar to older cars who had discs at
"the front only, would be a lot cheaper than
"getting a new frame."
Right Simon, that's certainly a possibility.
And in fact riders have done that.
The only thing to consider would be how the controls feel.
So how your break leaders field,
particularly if you're using drop bar leavers,
because obviously those hoods are going to feel different.
On a flat bar, less of an issue really
because you don't tend to ride on them as much.
But your controls are obviously really key
to both stopping you as well as controlling the bike too.
So that'd be my main concern there.
But yeah, it can be done.
Final question this week comes in from Fillet o'Fish.
Now, Fillet O'fish asks, "odd problem Ultegra DI2 related.
"The front derailleur seems to need the battery
"to be at no less than 75% to work reliably.
"Battery Stroke firmware issue?"
Right, and first up, make sure that firmware is up to date,
so plug it in to the YouTube app or software
and just actually upgrade everything when necessary
if it's needed.
Now something else to consider is
that the cable, so all of your DI2 cables are plugged in.
Absolutely, spot on.
There's no water that's got in there, anything like that.
And also they're not snagged anywhere.
I do know someone who managed to somehow pierce
a cable with a water bottle cage bolt
that went through and every now and then
that cable would just bash against the bolt
and essentially would short circuit it
and give them all sorts of problems
basically with their shifting.
So make sure that nothing like that's happened,
I noticed a lot of work potentially to actually go
inside of your frame and check all those cables,
but well it is going to be worth it.
In rare or exceptional circumstances,
yet it could well be the battery.
If that is the case and I suggest you pop along
to your local Shimano dealer who will be able to
help you out with that but really that's as far
as we can go with these sorts of things because
they are of course electronic components,
but I do hope Phillip o'Fish or Fillet o'fish
even though that's been able to help answer or
get you a little bit further along the problem.
Now, I hope that I've been able to answer your
question this week.
If not, make sure you leave it for me down there
in the comment section down below
or on all forms of social media using the hashtag on
screen right now.
Now remember as well to like and share this video.
Give it a big thumbs up.
Share it with your friends,
especially if they've got a bike related problem.
I love to tackle them, so if you've got a club mate
who's out riding and their bike is giving them havoc,
make sure that they leave it for me down there.
Don't forget to check out the GCN Shop at
shop.globalcyclingnetwork.com
We have a whole heap of goodies for you
to spend your pocket money on
and now for another great video.
How about clicking just over here?