Direct Mount vs Standard Mount Rear Derailleur | GCN Tech Clinic #AskGCNTech

Direct Mount vs Standard Mount Rear Derailleur | GCN Tech Clinic #AskGCNTech


(intense music) – Welcome back to the GCN Tech Clinic, I’m sure you all know the drill by now, what it’s all about, but if you don’t, here’s
a little reminder. So if you’ve got yourself
a bike-related problem, so something’s not working, something’s annoying you, you want to know how
something works possibly, leave that question for me down there in the comment section below and I’ll try and answer
it in an upcoming episode, and sometimes you even
get your question answered by a fellow member of the tech community, which I think is pretty cool really, that we’ve got people who’re willing to help another one out. Right, let’s crack on. The first one in this week
comes from thebelly925. Now the belly says, can I highlight the differences between a direct mount
rear derailleur system and the standard mounting system that commercial systems have installed? Right okay, so I reckon you mean by that with a direct mount
rear derailleur hanger. So, with those Shadow-style rear mechs that you get on 105, Dura-Ace and Ultegra, you’ve got a linkage piece I guess, that you can remove and you can just clamp the rear derailleur straight
onto the mech hanger instead of screwing it into the thread, if that makes sense, hopefully it does. Firstly, a reduction of weight slightly. It settles, so to give a
slightly improved gear shift because you’ve removed,
obviously a link off there and it’s a bit closer into the cassette. Now some riders, they reckon
it gives you, you know, this crispier gear shift
and have really wanted that direct mount hanger. So I remember Dylan Groenewegen, his bike at the Tour of Dubai,
the Dubai Tour last year, back in 2018, he actually
had a custom one on his bike, I remember spotting that. Now a real benefit of this system as well, is that it means the rear
mech is slightly further back meaning that wheel changes are faster. So in the pro peloton that
can make a huge difference ’cause of course time is not
necessarily on their side when they have to change a
wheel at the side of the road. That’s probably about it really. I mean if you look compared
to an older style rear mech with those Shadow ones, the rear mech is in slightly further. It’s about 13 millimeters further in, so I guess you could say
it’s more aerodynamic and it’s more out of
harms way if you like. Next up is Simon_says. Simon says answer the question, so that’s what I’m going to do. Right, hello Jon, most likely
John, I absolutely love all GCN Tech videos and I
got soaked into bike tech so much that I’m building
my own bike from scratch. That’s good news, I love that, how people get so involved in it. That’s what I did, made a
mistake one day, school holidays, about 1994, ruined a wheel,
dad came home from work, told me off, I learned how
to build wheels the next day. I have a question regarding
bottom brackets, Simon does. They got themselves a Shimano BBR60, installed it according to
all the tips they found on the Tech channel
including a torque wrench. Also installed the crankset… Wanted to do a free spin test,
so no chain fitted to it. It’s all just spanners, cranks… It made maybe two revolutions and stops. When I rotate it with my
finger, the whole work of it, so the bearings and
everything is nice and smooth, feels no resistance yet it does not spin as long as I was expecting it too. With, you know, with a
crankset without a chain on it it should basically. Is this normal and I was
simply misled by information I found or maybe something is not right. Later on I found some information that brand new bottom
brackets may be like this and get better after the
first few kilometers, but now I don’t know which
information is correct. Please help. Simon, don’t worry, okay. Now maybe all bottom brackets
out there will spin like this. The old cup-and-cone ones were quite good because you could manipulate what was happening inside of it. So you could remove grease or you could add just a very small amount and you kept a spin for quite a while, but sealed units like the
BBR60 you got on there are sealed so all the
bearings and the grease are all in there behind these fancy seals and you can’t access it that much. If you were to wash out all of the grease, yeah it would spin for a bit longer but also it wouldn’t last very long because the bearings would start to pit against the cups of the inside. You don’t need to worry about it, okay. I don’t reckon you go for the hour record and that’s not in a disrespectful
way at all or anything, but this sort of friction
you are very, very unlike to feel it through your
feet or through the pedals while you’re pedaling away. And it will, most likely
become less viscous I guess you could call it, the grease. It will start to wear
a little bit thinner. Ultimately it will become
harder again when you stop, but the heat generated by the cranks turning around in that bottom bracket, the grease turns into a more liquid form, therefore it’s easier to go around so the spin test like
that isn’t that great. If you were to do that
in a really hot climate or in an oven or something, it would probably spin
a bit further around. Now, you probably got the idea it will keep spinning for ages because of ceramic
bottom bracket bearings, or ceramic bearings that tend
to spin a little bit freer, they don’t use grease inside of them, no lubricant or anything, they just work on the sort
of hard surfaces in there, they’re very tough. I think ceramic bearings,
the ball bearings, are 10 times tougher I think
than the steel bearing, something like that. I’m not going to go into
the can of worms though that ceramic bearings are because that’ll create a whole
different debate down below. I know half of you are
probably already typing this, but don’t worry about it. If you want really free spinning
cranks right from the off, then yeah, you can go
ahead and buy something that will do that, but
it is going to hit you pretty hard in your
wallet I’ve got to say. Next up is Gabriel Evangelista who says, Jon I need help ASAP, right
hopefully I’m in time. I have a Shimano 105 wheelset but it has a problem on the freehub. It just spins and spins
and spins when I pedal it, what could be the possible issue? I brought it to my local bike
shop but they can’t fix it. They can’t open the freehub because they say it has a
special tool to open it up. They say maybe it is the
pawls, can I still fix that? Thanks for the answers. Gabriel, Gabriel, the spinning freehub, absolute nightmare when this happens because some freehubs are
not usually serviceable, and the Shimano ones they’re
not intended basically to be taken apart and not
very many shops out there do in fact have those tools
to be able to split them, open them and have a look
at the inner workings. Instead, Shimano, they just advised to get a replacement freehub on there. But, okay what you could
do before going out and spending, I dunno, whatever
they are, 15, 20 pounds, depends on what freehub have you’ve got. Oh, you got 105s, so probably a little bit more than that. You’re going to want to take the axle out, ’cause you’re going to
have to do that anyway if you are going to get a new freehub, but you could be able to
rejuvenate this one temporarily and who knows, it maybe
lasts you a long time. So, get the axle out. You need then a hex wrench,
I think it’s an 11 or a 12, might even be a 10, it’s
a while since I’ve done it and it does vary from model to model. Get it inside of the freehub, release that from the actual hub shell
’cause it tightens into it. It’s got a big beefy old bolt in there. Take that freehub off. Now on the back of it, most likely you’re going to
have a little rubber seal on the back, prise it off
gently, really really gently. Do it over a cloth or a
towel or something like that, or some paper. Now underneath that seal, that
rubber seal, prise it off, there’s some ball bearings in there. Now they may be loose, they
may be in the retainer, or again, it all does depend. Spray that with some lubricant,
you know, WD-40, whatever. Just try and spray it and
also at the same time, once you’ve sprayed it in there, try and spin the freehub on itself. So, put your fingers inside
of it, hold it like that and then turn it around and
try and work that lubricant in. Who knows, it maybe, it could just free up some of the grit and
grime that was in there and has caused that sticking. Failing that, you probably
need a new freehub, but before you go out and do
this, what you could do is put it in a small little
bath of oil, like engine oil, I’ve done this before with a freehub. I’ve left it in there
for a couple of days. I know your question you
said you need help ASAP but I like to try and bring
old things back to life. So, put it in there for a couple of days, but say, I dunno, after the
first few hours, take it out. Of course wearing some protective gloves, and just try and spin it. See if it makes any difference. See if it does lock and
engage like a freehub should. If not, put it back in
there, after a couple of days if it’s not going to, it’s
going to flush everything out and you know, bring it back to life then yeah, you are going
to need to buy a new one. But I’d try and do that first really ’cause it’s good to try and, well yeah, try and make use of something
for just a little bit longer. Right, now we got Phil Watson who says, hi Jon, I have a 10-speed 105 groupset, can I add a GRX400 rear
mech for my cross bike? Also using a mech extender
could I push the GRX400 limit to 40 teeth? Right, yeah, the GRX400 is
one of the gravel series, you know, of Shimano’s groupsets. GRX400 is the 10-speed
version of the rear derailleur so that’s going to work absolutely fine with your 10-speed 105 groupset. The shifting ratio of
how much cable it pulls can be perfect. In fact, this is what I did on that garbage to gravel bike I did. I got a pair of old 105 10-speed shifters, matched them up with
that GRX400 rear mech, worked absolutely spot on. Now you said there as
well about putting in a derailleur hanger extender and seeing if a 40-tooth cassette will work fine. So, I use on a previous 1X Hack video, you may well remember
that one where I convert an old frame I had lying
around as well into 1X. Put a mech hanger on there, put
a short cage rear derailleur on there and I think I got it to work with a 38-tooth cassette on there. Fine that was a short cage one
like a real road race machine whereas that GRX is going to
have a slightly longer cage on there and it should be absolutely fine. You may need to play around a little bit with the B-tension screw adjustment there. It goes on the back of the
rear derailleur hanger, but I see no problems at
all with that, good luck. And the final one this week, a pretty complicated one I reckon. Toby Price, hi Jon, nice chatting to you outside the Cadex pop-up shop in Harrogate during the Worlds. Now I’m hoping you can help. I remember that Toby, it was
chucking it down with rain and it was about five
past seven in the morning and you were wondering what
on earth I was doing out. Anyway right, Toby, your question, I have a Giant Boulder
Alu-light MTB from 1999 and I was wondering if it’s
convertible to a gravel bike? Right, this one’s going to
be a bit complex, I reckon. It is got Tektro direct mount
side pull brakes, so V-brakes, and Shimano mountain bike gear levers connected to an Altus 7-speed rear mech and Shimano Tourney
triple front derailleur, so dual pull as well,
so presumably that means it can be pulled from
the bottom or the top depending on the cable really. Very versatile bit of kit that. How easy is it going to be to
find road bike brake gear levers that’ll work with this
setup or am I dreaming? I think you might be. If it’s not feasible, any suggestions for the cheapest way to convert it? Thanks Toby. P.S. how about a GCN Tech
show about all those tools behind you and what they’re all for. Well, that’s going to be
more than one show I reckon. We got masses over there you
can’t even see, trust me. Right. Okay, I love your thinking about this. You got yourself your old
mountain bike thinking, “this bad boy used to go
out and enjoy itself”, but you got 7-speed derailleurs okay. You’re not going to be able
to get a 7-speed road STI, or Ergo or SRAM, you know, a
shifter or anything like that is going to work, will it? Because they don’t exist,
they came out in 8-speed. So, what you’re going to have to do is go back to the drawing board. You’re going to have
to get your wallet out I’m afraid with this one. What I would advise with this, get yourself one of those
GRX400 rear derailleurs I already mentioned and
a pair of Shimano 105, or anything 10-speed, any
10-speed Shimano gear shifters, you know, STI levers. Pair that up… Get rid of the triple chain set as well ’cause you’re not tryna get a triple STI lever not necessarily
that easy either. Or you could just go 1X even, it won’t cost you as much. But you also then going
to get to have to buy a new rear wheel as well
because a 7-speed cassette, or Over-Locknut Distance, is
narrower than a 10-speed one, which is what I’m trying
to get you to go towards because you’re going to have
way more gearing options. 7-speed, you’re not really going to enjoy that off-road that much. Just thinking about what
else you’ve asked in here. I mean the brakes, they will
work okay with STI levers or any drop bar brake
levers providing you get, I think it’s called a travel adapter. So it goes onto the, just where the cable goes into the noodle, if you like, I think it’s what they call
it, the V-brake noodle. It goes in there and it
adjusts the amount of pull you get for each stroke of the lever and it adjusts it
accordingly because V-brakes, there’s a linear pull
and they work differently to a standard caliper brake. Essentially, you are
going to have to spend a little bit of money on this. Have a look at my garbage to gravel video and that’ll probably give you
some pretty good inspiration on exactly what to do there, but trying to get a 7-speed
drop handlebar shifters, it’s not going to work I’m afraid. You could get I suppose a old
cyclocross or bar end shifter, put that in friction mode,
that would work absolutely fine but that’s it really. Let me know next time I
see you how you get on or you know what just send me a message and I can discuss with you in more detail exactly what I would really go for. Right, I hope I’ve been able
to help answer and solve your problem this week. If not, leave it for me down
there in the comments section and I’ll do my upmost
best to try and solve it in a very future episode. Right, remember as well
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