Author Topic: Short Shocks for Breva 750  (Read 2042 times)

Offline GonzoB

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Short Shocks for Breva 750
« on: February 28, 2020, 08:30:53 PM »
Hi All.

I recently bought a pair of shorter shocks for my 07 Breva 750. I thought I'd document my thinking for others....

Note that I'm not sure this analysis applies to the latest V7s.

I'm quite short (163cm, 5'3") and had difficulty reaching the ground properly, despite having the genuine MG low-profile seat.  I had a look between the wheel and the back mudguard, and there is lots of room with the standard shock fully compressed, so a shorter shock was possible without hitting the mudguard.

I then considered the drive shaft angle (after asking the question here). The following diagram showed my approach.



The red line shows the centreline of the drive spline as it comes out of the gearbox.
I took measurements off my bike with the standard shocks and found that angle A is about 11 degrees and angle B is less than 1 degree - so the driveshaft is almost straight on full compression.

I then did some geometry and decided that if I shortened the shock by 20mm, the full-extension ride height would fall by about 25mm - about what I needed to reach the ground. The new values of A and B would be 7.5 degrees and 3.5 degrees respectively. It's actually a better solution that stock, as the drive shaft spends more of its time nearer the straight position.

I ordered shocks from Ikon here in Australia. I gave Ikon my weight, my passenger's weight, luggage, etc and they provided appropriate springs. I was looking for a plush ride - most of my riding is touring. Unfortunately when I fitted the shocks I found I was unable to preload the springs enough. I made some spacers and tried them, but eventually went back to Ikon and they exchanged the springs.

The final installation looks like this:


I still needed a spacer under the spring to get the right amount of rider sag. You can see the white 9.5mm UHMWPE spacer I made.

The end result is good, the shocks have very little compression damping, and adjustable extension damping. They give a nice ride. The only fly in the ointment is that I think the 3-position preload is inadequate. Between the lowest an highest setting you compress the spring by an additional 14mm. Now when my passenger gets on, the extra compression on the spring is 20mm, so I can't fully compensate for the additional load. That's where screw nut adjusters (as per the standard shocks) are superior, but the 3-position ones are much easier to use. In the end the shocks work OK two-up, but are not the best technical solution.

The service Ikon gave was good and the price was AUD825.

Other things I did were:
 > cut 15mm off the sidestand so the bike didn't fall over
 > push the forks 15mm through the triple-clamps to lower the front end


Gonzo

« Last Edit: February 28, 2020, 08:33:10 PM by GonzoB »
My '07 Breva 750 Projects: MCC cruise - Luggage - Shorter Shocks -

Offline Dharma Bum

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Re: Short Shocks for Breva 750
« Reply #1 on: February 28, 2020, 08:57:25 PM »
Nice work, Gonzo!

Offline greer

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Re: Short Shocks for Breva 750
« Reply #2 on: March 01, 2020, 06:35:41 AM »
What a good job, Gonzo!  Thanks for posting the careful details, too.  Never mind that much of it sailed right over my head, the sharper folks here will make good use of the info.

Sarah
Sarah '21 V7 Special, '17 XT250, '17 V9 Roamer sold August 2021, '16 V7 II Stone sold September 2021, '08 Nevada Classic sold August 2020 
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Offline hzbloke

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Re: Short Shocks for Breva 750
« Reply #3 on: March 02, 2020, 11:10:59 PM »
I've gotta say that I'm very impressed that when you buy a motorcycle you really make it your own. Without resorting to idiot paint jobs, stupid bolt-ons or ugly 'styling' you end up with a bike that is yours and no one else's. Like a bespoke suit. Well done.
« Last Edit: March 02, 2020, 11:19:15 PM by hzbloke »
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Re: Short Shocks for Breva 750
« Reply #3 on: March 02, 2020, 11:10:59 PM »

Offline GonzoB

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Re: Short Shocks for Breva 750
« Reply #4 on: March 03, 2020, 04:55:13 AM »
I've gotta say that I'm very impressed that when you buy a motorcycle you really make it your own. Without resorting to idiot paint jobs, stupid bolt-ons or ugly 'styling' you end up with a bike that is yours and no one else's. Like a bespoke suit. Well done.

Thanks hzbloke. A lot of that is based on need. As you know, I'm short and unless I quickly make the bike easy for me to ride, I usually end up dropping it in a carpark or similar. Also, most of my kilometres are touring, and I need space for stuff. I've decided that there's no value in putting off doing things that I know I'm going to need. Plus, I like projects....

PS: I got the Ikons on just in time for the the plant visit in Albury later this month!

Gonzo
« Last Edit: March 03, 2020, 04:56:02 AM by GonzoB »
My '07 Breva 750 Projects: MCC cruise - Luggage - Shorter Shocks -

Offline SIR REAL ED

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Re: Short Shocks for Breva 750
« Reply #5 on: March 03, 2020, 05:22:45 AM »
Thanks hzbloke. A lot of that is based on need. As you know, I'm short and unless I quickly make the bike easy for me to ride, I usually end up dropping it in a carpark or similar. Also, most of my kilometres are touring, and I need space for stuff. I've decided that there's no value in putting off doing things that I know I'm going to need. Plus, I like projects....

PS: I got the Ikons on just in time for the the plant visit in Albury later this month!

Gonzo

Nice work.  Good to see someone making adjustments.  Surprising how often one encounters a bike with hand levers, shifter, brake pedal, handlebars etc. in an almost unworkable position.  Little adjustments can have a huge effect on comfort and function.

Damn that Breva looks good in white.  So far, I prefer the white ones and the gray ones to the red ones.

Of course, the easier approach would have been to just let the air out of the rear tire.......   :wink:
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Offline Muzz

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Re: Short Shocks for Breva 750
« Reply #6 on: March 03, 2020, 01:20:33 PM »

Damn that Breva looks good in white.  So far, I prefer the white ones and the gray ones to the red ones.


The red ones are much faster. :thumb:

edit: that white does look good Gonzo.  We never got that colour down here.
« Last Edit: March 03, 2020, 01:21:56 PM by Muzz »
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Offline SIR REAL ED

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Re: Short Shocks for Breva 750
« Reply #7 on: March 03, 2020, 02:19:34 PM »
The red ones are much faster. :thumb:

edit: that white does look good Gonzo.  We never got that colour down here.

I'd definitely trade all the parts from my Nevada to convert it to a Breva with someone who wants to do the opposite......
"If reading shite on the internet will trigger your head exploding, please wrap your head in Gorilla tape before logging on.  Thanks!!!"

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Offline GonzoB

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Re: Short Shocks for Breva 750
« Reply #8 on: March 03, 2020, 03:14:32 PM »

Damn that Breva looks good in white.


Err... sorry to mislead everyone... That white Breva is just a photo I found on the web that had the bike in a nice side-on view that I could draw on. My Breva is a "not-as-fast-as-a-red-one":



Gonzo
My '07 Breva 750 Projects: MCC cruise - Luggage - Shorter Shocks -

Offline malik

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Re: Short Shocks for Breva 750
« Reply #9 on: March 03, 2020, 04:03:43 PM »
Yes, good work, Gonzo. On your plant visit, inveigle them to check over your settings, just in case they can improve it further.

Muzz, I've a white tank (& bodywork) surplus to requirements when/if you feel like a change.

Mal
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Offline SIR REAL ED

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Re: Short Shocks for Breva 750
« Reply #10 on: March 04, 2020, 06:25:54 AM »
Err... sorry to mislead everyone... That white Breva is just a photo I found on the web that had the bike in a nice side-on view that I could draw on. My Breva is a "not-as-fast-as-a-red-one":



Gonzo

Looks much better than the red ones.  I'd be tempted to paint the side covers and "air scoops" black to match the gas tank, like the white one in the picture.  Reverse the colors, paint the silver areas black and the black areas silver.  Cleans up the lines of the bike to my eye.

Experiment with tape first....... easy to un-do!
« Last Edit: March 04, 2020, 06:28:32 AM by SIR REAL ED »
"If reading shite on the internet will trigger your head exploding, please wrap your head in Gorilla tape before logging on.  Thanks!!!"

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Offline Muzz

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Re: Short Shocks for Breva 750
« Reply #11 on: March 04, 2020, 08:48:34 PM »

Muzz, I've a white tank (& bodywork) surplus to requirements when/if you feel like a change.

Mal

Thanks Mal, but if I wanted to go slow I can just ride with the brakes on. :grin:
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Offline GonzoB

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Re: Short Shocks for Breva 750
« Reply #12 on: May 18, 2020, 05:12:02 PM »
A couple of late additions:


I failed to mention in my original post the actual length of the shocks. The standard ones are 390mm, and my IKON replacements are 370.

When I ordered the shocks from IKON they came with a spacer on the rod to limit the travel so that they couldn't compress to a shorter length than the standard shocks. IKON obviously didn't want to be blamed for causing problems with the shaft drive. I got out the trusty Dremel and cut off the spacer, as I had satisfied myself that no damage would result.


Gonzo
My '07 Breva 750 Projects: MCC cruise - Luggage - Shorter Shocks -

Offline severely

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Re: Short Shocks for Breva 750
« Reply #13 on: May 18, 2020, 07:58:30 PM »
A couple of late additions:


I failed to mention in my original post the actual length of the shocks. The standard ones are 390mm, and my IKON replacements are 370.

When I ordered the shocks from IKON they came with a spacer on the rod to limit the travel so that they couldn't compress to a shorter length than the standard shocks. IKON obviously didn't want to be blamed for causing problems with the shaft drive. I got out the trusty Dremel and cut off the spacer, as I had satisfied myself that no damage would result.


Gonzo
This 390 mm measurement you speak of, is this an eye/center to eye/center measurement or overall length?

Offline GonzoB

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Re: Short Shocks for Breva 750
« Reply #14 on: May 18, 2020, 11:47:30 PM »
Eye-centre to eye-centre. It's on Page 60 of the Breva manual...



Gonzo
My '07 Breva 750 Projects: MCC cruise - Luggage - Shorter Shocks -

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Re: Short Shocks for Breva 750
« Reply #15 on: May 19, 2020, 12:09:40 AM »
Great job, thanks for posting this.  :thumb:
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Offline severely

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Re: Short Shocks for Breva 750
« Reply #16 on: May 19, 2020, 07:42:21 AM »
Thanks GonzoB :bike-037:

 

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