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-   -   Grab this you SH clucthes! (https://www.superhawkforum.com/forums/technical-discussion-28/grab-you-sh-clucthes-35255/)

CaryDG 01-23-2019 01:21 AM

Grab this you SH clucthes!
 
As most SH owners know our clutches can be a bit grabby when trying to launch at high RPM or even causing stalls when trying to leave from a stop by slipping the clutch. I've read about the reasons (poor design, V twin torque Etc.) and the remedies (weaker springs, Varadero cable clutch conversion, Etc.) over the years. Last year I installed a 800 VFR master cylinder as I wanted the built in reservoir. I discovered that it has a 14mm bore vs the stocker at 15.87mm. (5/8 in) This changed the lever to slave ratio a bit and made the engagement point a little broader. I was willing to put up with slightly longer lever travel and it helped but , not quite enough. And then, Thanks to Erik and this forum, I found the Oberon slave cylinder. Installed it last night and I can now slip the clutch without the gabbiness! I think it is due to the 2mm increase in bore size over stock. Yes it increased the lever travel slightly as it increased the ratio even more coupled with the VFR master. This even widened the engagement point more. But, it worked! It behaves like I was hoping. Smooth action, broad engagement. If I did the math right the stock ratio was 2.24:1 and the VFR/Oberon is 2.69:1 That slight change was all it needed. The only bad thing is that took me 6 years to figure it out!

Felix Barrao 01-26-2019 10:09 AM

I own my VTR some months ago, ( I have done 5000 Km so far) and one of the things that I donīt like is the clutch performance. Most of the handle movement is useless and the clutch actuates just in the last part.
I changed the clutch disks the first month, thinking that maybe they were worn, but it didnīt solve anything about this " issue" then I noticed that the problem was, ( in my opinion ) an excessive travel in the clutch.
Thinking about your smart solution, I have been looking for handle clutch with 13mm piston, diameter, that combined with the oem slave piston should act like your actual VFR-Oberon. There are many around, ( some expensive brembo units also) and Iīm trying to find a motorcycle that uses a 13mm piston in order to buy a second hand unit..

Edited:
Seems that the brembo PS13 rec from ducati 600 and 750 can be an option.

CaryDG 01-26-2019 03:47 PM

I have a SH riding buddy that put an Oberon with a OEM Master and it works really well.

mikstr 01-26-2019 04:13 PM

I have been running the radial Brembo MC from a Monster 1100 for a number of years now and it works great....

Felix Barrao 01-27-2019 12:12 AM

Is it a 13mm piston diameter?

mikstr 01-27-2019 06:18 AM

In the event that the question is for me, the radial MC is a 15 x 18, meaning the piston diameter is 15 mm and fulcrum measurement is 18 mm, the latter measurement being just as important as the first when considering the mechanical advantage it affords. In the end, it works...

Felix Barrao 01-27-2019 07:14 AM


Originally Posted by mikstr (Post 408972)
In the event that the question is for me, the radial MC is a 15 x 18, meaning the piston diameter is 15 mm and fulcrum measurement is 18 mm, the latter measurement being just as important as the first when considering the mechanical advantage it affords. In the end, it works...

Yes, the question were for you thanks.

Felix Barrao 01-27-2019 10:35 AM


Originally Posted by CaryDG (Post 408941)
As most SH owners know our clutches can be a bit grabby when trying to launch at high RPM or even causing stalls when trying to leave from a stop by slipping the clutch. I've read about the reasons (poor design, V twin torque Etc.) and the remedies (weaker springs, Varadero cable clutch conversion, Etc.) over the years. Last year I installed a 800 VFR master cylinder as I wanted the built in reservoir. I discovered that it has a 14mm bore vs the stocker at 15.87mm. (5/8 in) This changed the lever to slave ratio a bit and made the engagement point a little broader. I was willing to put up with slightly longer lever travel and it helped but , not quite enough. And then, Thanks to Erik and this forum, I found the Oberon slave cylinder. Installed it last night and I can now slip the clutch without the gabbiness! I think it is due to the 2mm increase in bore size over stock. Yes it increased the lever travel slightly as it increased the ratio even more coupled with the VFR master. This even widened the engagement point more. But, it worked! It behaves like I was hoping. Smooth action, broad engagement. If I did the math right the stock ratio was 2.24:1 and the VFR/Oberon is 2.69:1 That slight change was all it needed. The only bad thing is that took me 6 years to figure it out!

My manual says that the master stock piston is 14 mm, not 15,87, are you sure that yours were 15,87?


https://cimg6.ibsrv.net/gimg/www.sup...b7c76e6e0c.jpg

E.Marquez 01-27-2019 11:56 AM


Originally Posted by CaryDG (Post 408966)
I have a SH riding buddy that put an Oberon with a OEM Master and it works really well.

That is how mine is set up now, early year non integrated res OEM master cylinder with a fresh all service part rebuild, new res cup, SS braided line and the Oberon slave...Very happy with it

Felix Barrao 01-27-2019 12:09 PM


Originally Posted by E.Marquez (Post 408981)
That is how mine is set up now, early year non integrated res OEM master cylinder with a fresh all service part rebuild, new res cup, SS braided line and the Oberon slave...Very happy with it

Seems that the Oberon is the best option then, before trying smaller master cylinders..

CaryDG 01-28-2019 11:22 PM

Felix, You are correct, my bad! Apparently the PO had put an unknown (possibly Suzuki SV) 5/8" (15.87mm) master on in an effort to widen the engagement point. As some of us have discovered, that was going the wrong way. You can imagine how grabby my clutch was with that setup! My old ass really thought I was on to something when I changed to the 14mm integrated VFR master. Regardless of my faux pax, 14mm with the Oberon works perfect.
Sorry about any confusion.

Felix Barrao 01-29-2019 12:09 AM

OMG I can imagine how it works with the 15,87 mm master!
Nice to know that the stock piston works fine with the Oberon, I will install it asap
Thanks for the input.


Felix Barrao 01-29-2019 09:29 AM

Oberon already ordered... :cool:

rothmans 02-02-2019 06:32 AM

I have a spare set of SP1 RC51 and 6th gen VFR masters here (brake and clutch). Has anyone experimented with other brake masters?

8541Hawk 02-02-2019 09:23 AM


Originally Posted by rothmans (Post 409046)
I have a spare set of SP1 RC51 and 6th gen VFR masters here (brake and clutch). Has anyone experimented with other brake masters?


Yes but it also matters what calipers you are running. Then it is what "feel" you are going for.
I haven't run a VFR master but with the SP stuff I found The SP2 master a much better option but it is also what works for me.
Granted I do have a complete SP2 front end on my bike but I have also set up bikes with stock calipers & SP2 master and have had good results.
Though now days, if I was starting over, I would source a newer style radial master cylinder.

E.Marquez 02-03-2019 01:11 PM


Originally Posted by rothmans (Post 409046)
I have a spare set of SP1 RC51 and 6th gen VFR masters here (brake and clutch). Has anyone experimented with other brake masters?

Only a 1/2 dozen or so...lol
Current set up is a Brembo 18mm radial master and Nissan calipers from an F4i

CrankenFine 02-12-2019 04:55 AM

Guess I found the next mod I need to jump on.:p

JamieDaugherty 02-12-2019 03:29 PM

Original OEM clutch, 45,000 miles, and never a single problem.

I'm wondering if there is another explanation. I wish every motorcycle I owned has a clutch as good as the VTR.

E.Marquez 02-12-2019 04:57 PM


Originally Posted by JamieDaugherty (Post 409220)
Original OEM clutch, 45,000 miles, and never a single problem.

I'm wondering if there is another explanation. I wish every motorcycle I owned has a clutch as good as the VTR.

Its not a problem, just better

JamieDaugherty 02-12-2019 06:11 PM


Originally Posted by E.Marquez (Post 409226)
Its not a problem, just better

The OP mentions this as being a problem that has affected everyone. It's the first I've heard of it!

E.Marquez 02-13-2019 04:06 AM


Originally Posted by JamieDaugherty (Post 409227)
The OP mentions this as being a problem that has affected everyone. It's the first I've heard of it!

Ahh, I got you, missed that or forgot it.

Yes not sure, I never thought there was anything wrong with the VTR clutch other then the chatter if you released it way to quickly. I needed to rebuild a slave cylinder so thought Id try the Oberon... It not only worked, but it does in my opinion give a better lever feel then the OEM slave,

CaryDG 02-13-2019 08:51 AM

Jaime and Eric, Yes, "Chatter" is more descriptive. It must be random as out of two fellow SH owners and myself, two chatter and one is fine. In fact one (a '99) chatters if you slip the clutch at speed. So, I guess I should have stated "Many" instead of "Most" The only time it happens is when launching from a standing start. As when running on a drag strip, Etc.
Both of the "chatterers" were cured with Oberon Slaves. I think due to the design and the 2mm bigger cylinder.

CaryDG 02-13-2019 08:54 AM

In fact there are numerous references to this in the forum. Search "Clutch grab"

Felix Barrao 02-16-2019 09:38 PM

Oberon improves the feeling vs the oem one due to the 2mm bigger diameter. Probably a 13mm master ( vs the 14mm) and the oberon should be perfect.

GlockPointer 02-18-2019 12:00 AM

where does one find this oberon piece ?

E.Marquez 02-18-2019 05:48 AM


Originally Posted by GlockPointer (Post 409302)
where does one find this oberon piece ?

Pick a dealer or order direct
http://www.oberon-performance.co.uk/...n-Dealers.html

CaryDG 02-18-2019 07:04 PM

I ordered mine from the Oberon in the UK and had it in 9 days.

E.Marquez 02-19-2019 04:38 AM


Originally Posted by CaryDG (Post 409317)
I ordered mine from the Oberon in the UK and had it in 9 days.

Same here, same time frame....
And post service with leadership at the company was excellent as well.

The buddy I learned about Oberon from, bought his off a Oberon Ebay ad... and had it in the same time frame, but it came from a Canadian dealer

smokinjoe73 02-19-2019 09:19 PM

For me the VTR clutch is by a mile the worst clutch set up I have ever experienced. If you rev the motor even a bit too high and try to release the clutch you get violent chatter and grabbing that is in my opinion dangerous. On my CBR600 I could redline the bike and slip the clutch all the way to turn 1 if I had to but try that on the hawk and you'd get flipped violently. I have 2 hawks and they are both like that and everyone else on here seems to have similar experience.

Felix Barrao 02-19-2019 10:27 PM

First think I did after buying my VTR was to change the clutch discs, thinking there were something wrong with them... Nothing changed after. The Oberon has been a big improvement. Iīm happy now, but probably next think will be a 13mm brembo clutch master instead of the 14 oem one.
I bought the oberon directly from the manufacturer


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