(technical noises)
- Welcome to Ask GMBN Tech.
It's our weekly Q and A show.
If you want to get some questions into ask us,
there's an email address at
the bottom of the screen right there
or you can add them in the comments below.
Just make sure if you're asking questions,
use the hashtag #askgmbntech
and the same goes for the email
and you put it in the subject line header there.
So this week, we've got a lot of
suspension related questions.
So I thought I'd group them all together.
So first up is from JJ Wood.
"Hi Doddy and the GMBN Tech crew,
I recently bought an older model Rockshox Domain coil
from around 2010/2011.
It has had a U turn unit fitted."
U turn, in case you don't know, is Rockshox's old system
for winding down the travel
without affecting the spring rate.
Recoil systems, you could literally pick up anything
from say 140 to 110, just by winding a dial on the top.
It was very cool at the time.
"I measured my sag to be around 30%
and I would like to lower this to 20 to 25%."
So basically meaning the fork's gonna be a little stiffer.
"How can I do this?
I don't think any preload spacers can be added
to the U turn unit or that the spring can be replaced.
What would adding a larger volume of oil do to the fork?
Would this have the right effect?
Sorry I have sent so many questions.
I'm 15 and looking at using for
downhill racing if that helps."
Okay, so as far as I know,
I don't think you can change
the preload on the U turn system.
You can change the fork springs,
but getting that much difference,
only like 5% difference in the sag,
I'm not sure if there's gonna be enough variety of springs
in order to do that.
Now, I think there's two options you can really do
and one of them would be to have
the U turn unit removed from the fork,
so you lose the ability to adjust that travel.
It will remain at the full travel of that fork.
I guess that wouldn't be too much
of a problem for you though,
because you're using the fork for downhill racing,
so you want all the travel on there.
And what that would enable is under the top cap
which would not have the U turn system,
it would mean you could fit preload spacers.
Now, preload spacers will not affect
the spring rate of the fork.
They won't make it a harder fork,
but what they do mean is you'll basically resist
the amount of the fork will move initially
with your body weight.
So you can actually affect the sag on there slightly,
so that might be what you want to do.
The other option is to remove the coil unit full stop
and have an air unit fitted into that fork,
which is quite a common process
for people to do with coil shocks
and vice versa actually,
depending on your preference
and what you want out of the fork.
Rockshox are quite good,
they've got a lot of interchangeable components
between forks like the lyric, the domain,
the revelation, the pike, stuff like that.
So definitely something worth checking out
with your local or your national suspension tuners,
depends on where you're based.
If that's in the UK,
someone like TF Tuned will be able to help you with Rockshox
failing that, you should be able to find a local person
near you that will be able to help.
"Hi guys, great videos, keep up the great work."
Thank you.
"I've recently got back into mountain biking
and I've bought myself a Vitus bike.
I've found that I'm still the aggressive rider I used to be
and I find I can bottom out my fork quite easily,
with some runs at Bike Park Wales.
I have a Rockshox recon silver RL 27.5, 120 mil fork,
and I want to make it more progressive.
I've reached out to Rockshox,
who confirm they do not produce air volume tokens
for my specific fork.
Are you aware of any third party token
that I might be able to use
or any way that I can make it more progressive?
Thanks in advance."
No, unfortunately I think there's no options.
That was the fork I used to have on my Nukeproof Scout here.
Now it is possible to put volume spacers in that fork,
but you would have to make them yourself
and the reason for that is
you can't get any way of volume spacers
fitting into the top cap system there.
So it's possible that you could make some
that could slide in or perhaps you could bond them in,
but of course would definitely invalidate your warranty
if you did do that.
It was something that I was gonna do myself,
but I never actually got that far,
a million other things all racked up.
I can still look at doing that,
although I wouldn't want to recommend it
if you were going to do something like that yourself
'cause it would definitely invalidate your warranty.
If you do want to do something like that
and reach out to a suspension tuner,
give Sprung Suspension over at the Forest of Dean a shout.
If you speak to Jake, he's your man there
and he'll tell you if it's something
that they would be happy to do for you.
Of course, they might not want to interfere
because of warranty issues,
but it is definitely something they could do
if they wanted to help you.
Okay, next up is from Christopher Walden.
"Now, I really enjoy your channels and appreciate
all the work you guys put into each episode.
I've been researching mountain bike rear suspension designs
and I feel like I've got pretty good understanding
of the goals and issues inherent to common designs.
My question is, why don't we see bikes
with a simple fork on the rear?
Is there a structural problem with such a design?
I included a photoshopped picture of what I mean.
Basically, the frame would have another fork
that is mounted to another rear triangle of kinds.
Let me know if I'm way off target with my summary
of what I think would be good."
so he thinks frames would be simpler,
more standardized, no pivot servicing.
Okay, so this is with your own design.
First up, I just want to call you out Chris,
it's a great idea, but your particular design
wouldn't work for various reason.
But I'm just gonna show you a really old design
on the screen there now.
So the bike in question is a Manitou full suspension frame.
This particular one is actually
manufactured by Marin Cycles
and conventionally, they used to have a pair of Manitou's,
front and back.
And this bike in question was raced by the late
Earthquake Jake Watson.
So he was a huge dude, as you could probably see by
the size of the frame on his bike.
He was sponsored by Rockshox.
So we've got a pair of Rockshox forks on the front.
The fork in question was actually one of the early
DH, which came before the box zone,
who's known as the Diablo.
So quite a cool and rare fork on it.
And on the rear, as you might be able to see there,
looks like a pair of what looks to me
like a pair of Mac 21s that have been modified
to fit it on the rear of the bike.
So, it's a great idea because you've got a nice low
pivot behind the bottom bracket there.
So it's not really gonna interfere
with your chain line too much with chain tension.
It's got a horse link over the bottom there,
so your braking's not really gonna affect the suspension
and of course, you've got the suspension design built in.
But of course, it is quite a lot going on there.
There's a lot of extra weight that you don't really need.
Of course, you've got two legs there.
The legs have got air and oil inside them, it's expensive,
it's everything about it costs more money to manufacturer,
where there's no reason to do it.
You think how much a pair of suspension forks can cost,
it can be £1000 these days.
So of course, rear shock absorbers are very expensive,
but they're also a lot smaller, they're a lot lighter,
they can do a lot more with the design of them
and also allows manufacturers to tune
the feel of a bike a lot more
and change the frame design and frame layout
by using a single shock absorber,
as opposed to having a twin legged fork on the back.
Now that design concept came originally from Manitou,
so that's Doug Bradbury.
He was the maker of the original Manitou suspension fork
and the Manitou suspension bike, the FS,
which you can see in this picture.
That's from 1991.
So, it's been there, it's been done before,
but as you can see, it just didn't quite work out
to be the best solution in the long term.
However, I do think it's one of
the coolest looking bikes of all time.
What do you guys think?
Okay, next up is from Ewain Johns.
"What is the best air fork for 27.5 wheels,
with a straight inch and an eighth steer tube
or is there any way I can adapt anything from tapered?
Any help appreciated."
As far as I know,
I looked on the Rockshox site, I looked on a Fox site,
and I looked around a bit,
you can get some X Fusion forks,
but a bit sketchy on the details on which particular model.
So Rockshox have got the Reverb available
in a straight inch and eight steer tube,
which is a great fork.
27.5 inch wheels and it's got various
different travel options in 10 millimeter increments,
from 100 millimeters up to 150.
So it didn't say which travel you wanted,
so I'm guessing something between 100 and 150
will hopefully suit you
and the Reverb is a great fork too.
Okay, next up is from Christopher De Santis.
"Watched all the tech shows, awesome."
Thanks, Christopher.
"My Monarch Plus shock always has oil on the shaft,
is it a leak and how can I fix it?
I've watched your service videos,
but what should I be looking for?
Cheers, Chris from Morro Bay, California."
It kind of depends how much you've got
on the actual shock itself.
So you've got to bear in mind
that shocks do kind of ooze a little bit out
because there's lubrication oil on the inside,
much like the lower leg lube you get on forks
and the whole idea is to keep the bushes on the fork
nice and lubricated so everything's sliding nicely
with no friction on there.
And of course, to help the seals slide and not get caught
or binded in any way.
Now also part of that job is preventing water
and other muck getting in there.
You've got lubrication there,
obviously water doesn't like oil.
It tends to sort of move away from it.
At least that's part of the theory.
So it does tend to be that.
However, how long was it since
you last had your shocks serviced?
It might just simply need a bit of a service
and a fresh seal on there.
It's unlikely that it's gonna be any other kind of leak
other than just a bit of lubricant coming out via that seal.
Otherwise, you would definitely have noticed
severe lack of performance,
lack of damping, or even the air spring failing on there,
if there's any of the main seal on that shock.
So I'm hoping it might, if anything,
just be a new wiper seal needed
or perhaps it's just leaking a bit of that oil
that lubricates the shock in the first place.
Next up is from Kristian Farrujua.
"Hey Doddy, love you show and all the GMBN shows.
I've got a Mondraker Dune."
Great choice, dude, love Mondrakers.
"And would love to mount the shock
in reverse order, if it clears.
It's a Monarch Plus RCT3.
Would the shock work well or could it get damaged?
My main reason for doing this is that I never use the switch
and would rather have the shaft more reachable
for easier cleanup access."
To be honest, I don't see why you would put it upside down.
Effectively because it doesn't limit any adjustments
that you do want to make,
even though you said you don't make adjustments.
I still think it's nice to have that stuff to hand.
Generally, people do frown the shocks
that are mounted upside down.
But as you can see on my Scott here,
as part of the design to have cables internally rooted
on the frame and keep it looking neat,
the shock is actually upside down.
It has no affect on the performance on the shock whatsoever
despite what people will say.
People will look at you and be
oh, your seal's gonna get dirty isn't it.
Look at the seals on the fork.
They're exposed in the exact same way
as the shock is upside down.
There's no problem, especially if you look after your bike
and suggest you do look after it
by sending on axis for cleaning.
However, it does mean by having the end
of the shock up that way,
the suspension is a bit more exposed.
So by tucking them away down the bottom end of the shock
there on the Mondraker,
you've got the little mudflap
that tries to keep it sheltered away from wet stuff,
it does mean it's a bit more prone to scratching,
if you say you put your bike on the bike rack,
uplift wagon, anything like that.
So from that point of view,
it's actually not the best idea,
but I don't think it's really gonna affect your performance.
So if that's what makes you tick
and it doesn't affect how the back end of the bike works,
go for it.
So there we go, that's another Q and A session in the bag.
Hopefully you enjoyed Ask GMBN Tech.
Get your questions in below in the comments and email us,
we love getting your questions.
For a couple more videos, click down here,
if you want to see how to change an inner cable,
as part of our essential series,
and if you want something more suspension related,
click down here to see what some of those
tuning differences do when you're actually out on the trails
so you can see the suspension working there.
As always, click on the globe to subscribe to GMBN Tech
and if you love mountain bikes and working on them,
give us a thumbs up.
For more infomation >> 新加坡斷崖式衰退，能夠依靠的只有中國了 - Duration: 9:33. 
For more infomation >> 塔罗牌：这段感情即将面临的是什么问题？ - Duration: 6:46. 
Không có nhận xét nào:
Đăng nhận xét