Thruxton Rear Suspension Too Firm

Hi Dave,
I am no expert and certainly not a "fast group track" rider but I do ride on pretty poor road surfaces here in Scotland and like to make "progress". I am now on my second Thruxton R having covered over 20,000 miles on both bikes. I guess I am a little smaller and lighter than you at 5' 5" and under 11 stone but I have found the comfort settings from the hand book (+/- a couple of clicks) a really good starting point for a controlled / more comfortable ride. I also found the lower comfort seat an (expensive) but useful addition.
Cheers
Steve

 

Firm suspension is nothing to do with sag. Sag controls ride height and operating range. Certainly the shock is overdamped on the standard settings. put the settings to Comfort. Spring rate is about right for a 12 stone rider so standard setting position 1 should be fine

 

You have to get your sag (preload) right. If the suspension is working at the extreme top or bottom of its stroke, your going to have a hard ride. It's designed to work best in the middle of its range. I had a Thruxton R and it was always a little hard admittedly.

 

I took mine to MCT and had front and back RR valved and new fork springs to suit my 12 stone a real difference on the road

 

I’m booked in at BG motorsport next to silverstone track they are an Ohlins specialist, he is going to setup my sag and settings correctly, in addition they ordered in some upgraded springs for the rear based on my weight. as soon as I told him my model of bike he said they have upgraded the rear springs of many a Thruxton r.
I have already played with the settings as per the manual but BG are confident with their adjustments it will be like a different bike

 

Hi Dave
Not sure if your suspension issues have now been sorted, but have been trying to make my '16 Thruxton a bit less harsh on bumpy roads, I've backed off the damping (comp & reb) but left the preload on softest, which has helped, but it's still not right so......
When I first started reading the forums, I read this:
".....I found setting all the damping to comfort settings helped, along with using the spanners to move the shock preload to position 2.
Basically, the bike is under sprung and overdamped, causing too much sag at the rear and a harsh ride......"
This seemed a bit counter intuitive, but today I checked the sag on the Ohlins.
Using a zip tie around the piston rod to check the movement, I found that static sag (without rider) was about 4mm (which according to Superbike Coach website; is about right).
Then, I added my own weight without riding kit, (that's about 75kg/11stone 11 pounds) the sag then increased to about 35mm.
By my measurement that's about 50% of the total available travel, according to the Superbike Coach website, it should be in the region of 28% to 33% for a street bike.
That seems to confirm that a higher preload and a bit more damping may actually improve the ride and possibly the steering, I feel my TTR understeers on a trailing throttle. That "can" be caused by soft rear suspension not letting the front end drop into corners (I have read).
As the Triumph "C" spanners have a reputation for scratching the Ohlins, I've bought some Harris Products spanners (cheaper than Ebay) and will try upping the preload. Fingers crossed!
There is a very extensive article about setting up motorcycle suspension at:
https://www.superbike-coach.com/coachs-blog/coachs-motorcycle-support/motorcycle-suspension-guide

 

Hey Dave, did you sort your suspension? What did you do?

 

Sorry I should have replied since visiting BG motorsport. Firstly check out my review of BG motorsport. Secondly I learnt the springs on the thruxton R needed upgrading.

 

Hi Timboo
I'm not sure where your review of BG Motorsport would be, if you could give me a pointer?
Your findings mirror something I read on one of the forums, which I quoted on 14th Oct.
".....I found setting all the damping to comfort settings helped, along with using the spanners to move the shock preload to position 2.
Basically, the bike is under sprung and overdamped, causing too much sag at the rear and a harsh ride......"
Following this, I jacked my rear suspension up to the middle notch and backed off the damping to near minimum.
And I also replaced the standard fork oil with one that is about 2/3rds of the weight. (Silkolene RSF5) and turned up the fork preload to about 2.5 full turns out from hardest,
A professional setup could improve on it, but I am VERY happy for about £75 expenditure including the fork tools and Harris shock adjusters.
Seasons greetings to you!!

 

Hi Timboo
I'm not sure where your review of BG Motorsport would be, if you could give me a pointer?
Your findings mirror something I read on one of the forums, which I quoted on 14th Oct.
".....I found setting all the damping to comfort settings helped, along with using the spanners to move the shock preload to position 2.
Basically, the bike is under sprung and overdamped, causing too much sag at the rear and a harsh ride......"
Following this, I jacked my rear suspension up to the middle notch and backed off the damping to near minimum.
And I also replaced the standard fork oil with one that is about 2/3rds of the weight. (Silkolene RSF5) and turned up the fork preload to about 2.5 full turns out from hardest,
A professional setup could improve on it, but I am VERY happy for about £75 expenditure including the fork tools and Harris shock adjusters.
Seasons greetings to you!!

 

Hiya

It may well be you read my review on the other forum

https://triumphmotorcycleforum.com/t/bg-motorsport-silverstone-ohlins-suspension-thruxton-r/1093