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Maxton GP20


bentebent

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Yep, both bottoming and top-out are controlled with long nylon bushings over top of the piston rod. That's something that Pattonme saw and didn't like when he 1st opened one of these.
 
I have a cable tie on one leg. !st bike I've ever bothered doing this with - in 44 years of riding.
 
I'm a long way from bottoming obviously. Next time I have 'em open, I'm definitely gonna add another turn of adjustment - as the adjuster screws into the cap and uses the cap as its full open stop, it's easy enough to dial in 5 turns into the cap before screwing the cap onto the rod. That should allow some more flow thru the valve. 150mm air gap - won't take much fluid to get there.
 
Oh, btw, while I was in there, I drilled 2 holes above the new small gap bushings - just cause I could. Those new bushings had no wear showing in a bit more miles than the OE ones which did have wear at the gap ends. Maybe some day we'll get to the bottom of that issue. My money's on the OE ones being wrong - one way or another.
 
Thankfully, with not much in the way, it's really only about 30 mins to pull these forks out. Almost takes as long to get the front fender off, lol. sooo many screws for one little fender.

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Is there a price difference between 'top side' and 'bottom' options? because it sounds like 'bottom' is a traditional cartridge config while the 'top side' either reverts to the simplified config and/or they haven't done the R&D to figure out how to get the mid-valve to flow sufficiently and still have a shim stack on it.
Yeah the compression adjustable fork tops are quite a bit more I think as the fork tops are more complex. 
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@robsoup just buy a known entity with top-side controls - Andreani, Matris, NIX-22, AK20, with or without their respective updates. (I'll make you a deal on the the NIX-22 I have on the shelf) or buy the Maxton and send it to me or to tear apart and simulate/test their 'top side' config, see what I would propose to improve it, and then live happily ever after. 
I believe the Maxton came to light only because the OP was in UK and wanted to try something local since international shipping for my Showa kit or the AK20 was perceived to be too much.
 
As a little side-job I'm rebuilding a set of '67 Velocette Thruxton forks. I'm hoping I can put modern cartridges into them. Otherwise I will just make a one-off piston and clean up some of the poorly machined bits.
 

Yeah I live in the UK too, and was choosing between Maxton and K-Tech, but have chosen Maxton as I believe they build better road compliant kit.  They are very highly rated in the UK, and supply a lot of the IOM TT bikes (which is a bumpy road race) with good success. 
From the comments on here I think I may just go with rebound adjustability (and not bother about compression) as it sounds like you only really need rebound adjustment at the front and rebound and preload at the rear (preload for carrying pillions mainly).
 
At some point I'll be giving Richard at Maxton a call to go through all the options as they build it all based on your requirements (weight, riding style, track or street, firm or compliant etc.).  I'll then be able to make a better judgement on whether I go for full adjustability or just the bare minimum that I need to enjoy the bike!
 
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Right, I forgot you were in UK @robsoup. Yes the Maxton guys provide product to IOM teams but those self same teams have spent thousands getting them revalved this way and that to suit their needs. And I very much doubt they are using anything but the 4-valve setup and/or at least the 25-30mm kits as a starting point.
 
I'm sure they'll do their best with your request but it's not exactly a deep pool of FZ07 riders upon which to draw on. I'm sure it will be a dramatic improvement over stock regardless.
 

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I believe they use very similar setups on the sv650 and er6 as they use on the mt07 and they all seem to have glowing reviews.
 
After weighing up all the reviews and research I've done Maxton seem like the best option buying from the UK.
 
They seem to be more road orientated than KTech (who look like another great option) and sadly your reviews have shown that Andreani, Matris and Ohlins all have compression side issues, which I can't really fix over here.
 
I've been looking at suspension reviews for six months now, so at some point in just gonna have to make a choice! :)

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Pull the rip cord! If the valving is not to your liking for some reason you can always go back to them and ask for a re-do. If your complaint is valid you should get it for a significant discount or free. The third time you darken their door though...now you're a troublemaker. heh heh  :D
 

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  • 1 month later...

I got the full setup done last week - front forks and rear shock.
 
I weigh about 78kg in riding gear (70kg without) and they put 0.825kg/mm springs in the front with SAE 5 oil. Rebound and compression in both legs.
 
The forks feel really good - very happy with them.
 
However on the rear I think they used a 13.8kg/mm spring, which I am finding too hard. I am going to go back to see the shop that fitted it for me to check my rider and static sag next week. But if they cannot tune the right amount of sag, I wonder if I can do a spring swap for a softer one...

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Hi @robsoup, I'm happy to read that you're happy with your setup.
You use SAE 5 oil in the fork, but can you provide some details about that?
Who makes the oil that you have?
The value of cSt@40° will be very useful, for me (if you know this detail)
 
About the spring of the shock:
In my Bitubo I have a 12 kg/mm spring, and I have 14 mm of preload in order to the the right Sag.
I weight about the same of you (79 in gear, 69 without). I'm wondering if, with an harder spring, I can obtain the same right Sag with less preload.
I think I can speak with Bitubo technicians at Eicma in Milan the next week, in order to have her thoughts.
 
Happy ride!

www.MT-Series.it
Yamaha Official MT-Series Club

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I believe these are the details of the oil in the forks: http://www.putoline.com/en/catalogue/maintenance_fork-oils/374/hpx-r-5w/1738/
 
Forks seems really good.
 
So you are a similar weight, and find 12kg/mm a bit too soft? Interestingly, I think the Ohlins specs show that their rear shock has an 11.8kg/mm spring rate, which is a tad softer than yours.
 
I haven't had the rider sag on my bike checked yet. The static sag was setup by the shop with 10mm. But I feel like I am just sitting at the top of the spring, and my weight is not actually compressing it by very much...

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Thank you, @robsoup !
I've seen the specs of the fork oil.
The Putoline HPX-R 5W reports 22,50 cSt@40°, similar to the Motorex 5W. For the Motorex the VI is a little higher, indeed.
But the relevant point is: with this oil, a spring a little softer than the original (8,5) and the hydraulic of the GP20 you are happy with your MT-07.
One info about your GP20: is a LC - RR type?
Or do you have all the two registers (compression and rebound and preload, obviously) available on the top of the two forks?
On the Maxtons web site there's a lot of options for the GP20.
It seems that the GP20 have both the pistons (comp and rebound) in both the two legs, but we can only control one function on the L leg and the other on the R leg?
This would be strange...
Schermata_2016_11_07_alle_12_19_21.png
If you can, please, add some pict of your forks, thank you!
 
Anyway: maybe Maxton is the only suspension maker that have centered the needs for the road use on the MT-07.
The only cartridge not tested in the MT-07, at this point, is the Bitubo JBH.
 
 

www.MT-Series.it
Yamaha Official MT-Series Club

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> 22,50 cSt@40°, similar to the Motorex 5W
 
damn that's a heavy 5W. Normally "5W" is around 16.
 
> The only cartridge not tested in the MT-07, at this point, is the Bitubo JBH.
 
That will change in ~4-6 weeks. :)

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The GP20 which is their right-way-round cartridge has compression and rebound pistons in both forks (the GP30 upside-down kit has seperate rebound and compression sides).
 
They give you different options when you chat with them with regards to adjusters between any combination of: roubound top / preload top / compression bottom.
 
After chatting for quite a long time on the phone I went with the simplest option of just rebound top adjuster on both legs. I figured that on the MT-07 I'd never want to add more preload as the forks already have so little weight over them. Also I didn't bother to add the compression adjuster as I won't be taking it to track so decided I didn't need to pay the extra for it.
 
I'm very happy with the forks though - nice and pleasant and well controlled.
 
The fork cap that I have from your photo above, would be the bottom left one (but with a pink rebound adjuster). I believe that the black one in the centre is from the GP30 kit. The two on the left and right hand side are rebound and preload adjusters.
 
I'll also feed back with details on my rear shock after I've had a chance to speak with them and describe how I am finding it.
 
cheers
Rob.

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  • 2 weeks later...

So I was very happy with the forks but found the rear shock too harsh...
 
Took it to the garage today and turned down the compression damping by a whole 4 clicks (didn't touch rebound) and it's like a different shock - very smooth over all surfaces. I will do some further testing to see if I've gone too far in the soft direction. Almost wishing I went for the remote version now so I could easily adjust compression without removing the shock every time!

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  • 3 weeks later...
So I was very happy with the forks but found the rear shock too harsh... 
Took it to the garage today and turned down the compression damping by a whole 4 clicks (didn't touch rebound) and it's like a different shock - very smooth over all surfaces. I will do some further testing to see if I've gone too far in the soft direction. Almost wishing I went for the remote version now so I could easily adjust compression without removing the shock every time!
What, you seriously have to remove the entire shock when adjusting it?
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well hot damn, that's a nifty idea! I wonder what the rate is on that shim preload spring. Reminds me of how they do Comp adjustment on BPF forks.

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Yep I didn't go for the remote compression adjuster, but I figure once it's set right I won't need to touch it. It makes quite a difference when it is adjusted!
 
Fyi the rebound adjuster is accessible, located at the bottom of the shock body.

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  • 2 weeks later...

After trying compression +1 click from soft and using OE ride height - this was too soft even for me.
 
Now I've got compression set at +3 clicks from the softest position, and ride height is +5mm over OE, the rear shock feels great now!
 
For reference, Maxton had supplied it at +5 clicks from soft, and +15mm ride height, which I found too hard and high up.

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> 22,50 cSt@40°, similar to the Motorex 5W 
damn that's a heavy 5W. Normally "5W" is around 16.
 
> The only cartridge not tested in the MT-07, at this point, is the Bitubo JBH.
 
That will change in ~4-6 weeks. :)
Any news? 
Thanks.
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