Brammo Owners Forum

Brammo Empulse Discussion => Brammo Empulse Mods => Topic started by: barboo on March 30, 2014, 01:27:32 PM

Title: Steering Damper
Post by: barboo on March 30, 2014, 01:27:32 PM
Curious if folks have tried going down this path. I look at the RR pix and didn't see a damper on it (that I could see). Was hoping to get an idea on what they've used.

Looks like NHK would be the way to go as you'd have some options on frame+fork mounting.
(http://www.redlinecycle.com/Steering%20Damper.JPG)

Anyone try getting a steering damper on their Empulse R?
Title: Re: Steering Damper
Post by: BrammoBrian on March 30, 2014, 02:01:22 PM
Here's the arrangement we run on the TTX race bikes:

(http://brammoelectricmotorcycles.smugmug.com/Racing/AFM-Thunderhill-June-2nd-2013/i-v98KgvH/0/M/20130602-IMG_7481-M.jpg)

(http://brammoelectricmotorcycles.smugmug.com/photos/i-9kK6Fgz/0/M/i-9kK6Fgz-M.jpg)

It requires the longest Ohlins damper they make, but is pretty easy to mount up and the leverage ratio on the damper makes it more effective than a top mount IMHO. 

Title: Re: Steering Damper
Post by: 7racer on March 30, 2014, 02:14:55 PM
brian,

do you have a part number?

Do we need any specially fabricated brackets to get this to work?
Title: Re: Steering Damper
Post by: BrammoBrian on March 30, 2014, 03:20:12 PM
brian,

do you have a part number?

Do we need any specially fabricated brackets to get this to work?

The Ohlins 150mm steering damper part number is: SD 005

The aluminum bracket on the body of the damper comes with it, but we did have a custom bracket fabricated to attach that bracket to the chassis of the bike on the same frame edge that the battery brackets attach to.  I'll see if I can take a better photo of this part on Monday.  That bracket mounts through a spherical bearing so that the damper doesn't bind as it moves through its travel.  We put a piece of foam rubber around it (covered with neon yellow tape in the photos) to keep it from clanking against the chassis.

The clamp that attaches to the fork leg is a standard "off-the-shelf" part that you can get from several suppliers - like this one: http://www.protekk.com/index.php?main_page=product_info&cPath=72&products_id=231 (http://www.protekk.com/index.php?main_page=product_info&cPath=72&products_id=231)

You should take a set of calipers and measure the fork tube diameter just below the lower triple clamp to ensure you purchase the correct one.  We've had so many different fork combinations that I can't remember exactly which diameter is correct for the stock R fork legs. 
Title: Re: Steering Damper
Post by: barboo on March 30, 2014, 08:40:14 PM
Thanks much, Brian! Measured with calipers, looks to be 53mm.
Title: Re: Steering Damper
Post by: barboo on April 14, 2014, 08:49:47 PM
I ended up installing mine slightly different than the pictures Brian provided.

Parts:
Ohlins 150mm damper - SD 005
Protek fork clamp - 53mm
2 x SS M8 1.25x30mm bolts
1 x SS M8 1.25 lock nut
3 x SS M8 1.25 nuts
1 x SS M8 washer

1) I pulled the M8 bolt that attaches the first battery bracket under the frame.

2) I used the M8 SS bolt + 3 nuts + 1 washer to mount the Ohlins bracket to the frame. All of this combined created a sturdy mount point without needing to create a special bracket. If someone comes up with better bracket idea feel free to share.

3) The Protek fork clamp was butted up to the bottom of the black bracket. I used the Ohlins damper in the bracket to find a good angle point that would travel well with the steering from left/right. I left the Ohlins bracket somewhat loose so that I could optimize where the damper would sit to ensure there was enough free play. I didn't find a specific torque spec from Protek, but I tightened it down to 10ftlbs/13.56nm. Ohlins bracket was torqued to 3nm per instructions.

4) I used the remaining M8 bolt + lock nut to fasten the free end of the damper to the Protek fork bracket. The Protek clamp has two holes. For my install, the free end of the Ohlins was installed in the Protek hole closest to the fork tube (inner).

5) I didn't use a protective material as the damper doesn't touch any surfaces at this mounting point.

Below is the result:
(http://img.photobucket.com/albums/v469/Bagherra/damper_zps726fa618.jpg) (http://smg.photobucket.com/user/Bagherra/media/damper_zps726fa618.jpg.html)

Looking forward to trying it out at the track. I'll adjust it as I work with it more.
Title: Steering Damper
Post by: 7racer on April 16, 2014, 03:22:33 PM
Nicely done!!!
Title: Re: Steering Damper
Post by: barboo on April 16, 2014, 04:19:03 PM
Nicely done!!!
Thanks! Below are some better during the day pix. I really like this mod. Like the sprocket/chain change (thanks 7racer for that idea :) ) this positively enhances of the overall feel of the bike. The steering is smoother and less twitchy at speed.

(http://img.photobucket.com/albums/v469/Bagherra/photo2_zps2198e29f.jpg) (http://smg.photobucket.com/user/Bagherra/media/photo2_zps2198e29f.jpg.html)

(http://img.photobucket.com/albums/v469/Bagherra/photo1_zps7b0564e0.jpg) (http://smg.photobucket.com/user/Bagherra/media/photo1_zps7b0564e0.jpg.html)