How to: Lowering kit (DIY) and high speed wobble fix

[Szymon]

Hi. This is my first topic here So let it start!

LOWERING

I had to get my MT 09 Tracer Lower. It's caused by my fiance height - she is going to ride Yamaha when it gets proper saddle height.
MT09 Tracer saddle height is 850 to 865 milimeters. I need to get something closer 800mm.
I started with lowering link kits and decided I gonna create lowering kits by my friend who got workshop (some kind blackmisth).
I decided to make lowering links which can make my motorbike 20mm or 25mm lower. I could get it more but somewhere in the Internet I read that some construction problem can occur and swingarm modifications would be required.

So, we knew the shape but need dimensions. In topic here: https://www.tracer900.net/topic/2948-lowering-link-installation/?do=findComment&comment=33530 , timg gave us all we need to start designing process. Thank you timg!

From dimensions of links: stock, Yamaha -15mm and PSR -31,75mm,  I extract equation how to get -20mm and -25mm links (thanks wolframalpha). Here is the function: f(x)=63.05 + x*(-0.127165) + x^2*(-0.00706555), where f(x) is our holes axis to axis distance and x is height drop we want to achieve. Down here are some notes I have made.

 

After design work was done, I made an order to my friend so he can craft links. I decided to make them with steel SS400. Unfortunately my friend got only SS350 at the moment so we decided to make links of that sheet and made them 8mm thick what is 2mm more than original ones.
So, when I finaly recieved links/bones from my friend:

I started to install it on my moto. Basically I followed the link video linked bellow. Rear wheal lever tip is great. https://youtu.be/BH8jLWxYx5I?t=84

For me it was much more easy to uninstall exhaust. I started with -25mm links but I met some problems when was installing it. I couldn't put both bolts inside mounting holes. I gave up with that and with -20mm kit it was really easy, same as shown on the upper youtube video. After links were installed, I installed exhaust system and that was the end of rear suspension lowering. It can be done in less than 1 hour.

WOBBLE FIX

For me, of height 182cm, my Tracer got wobbling at 155km/h. That was annoying me so decided to fix it while lowering suspension.
First of all I made rear suspension harder. It was set to half of scale of hardness. I set it to 3/4 of scale.
The second was to lower down front suspension in the tripple tree. You need to unscrew a little 6 bolts (3 per side), shown on pictures bellow.

As you can see on the picture, I have lower suspension for 15mm.

After ride with my girl on my back, with speed of 175km/h I didn't notice any wobbling.
Conclusion is that, you can make your tracer great again without puting any extra money with OHLINS like rear suspension set.
 

Edited September 19, 2019 by Szymon

[Cruizin]

On 9/19/2019 at 6:57 AM, Szymon said:

Hi. This is my first topic here So let it start!

LOWERING

I had to get my MT 09 Tracer Lower. It's caused by my fiance height - she is going to ride Yamaha when it gets proper saddle height.
MT09 Tracer saddle height is 850 to 865 milimeters. I need to get something closer 800mm.
I started with lowering link kits and decided I gonna create lowering kits by my friend who got workshop (some kind blackmisth).
I decided to make lowering links which can make my motorbike 20mm or 25mm lower. I could get it more but somewhere in the Internet I read that some construction problem can occur and swingarm modifications would be required.

So, we knew the shape but need dimensions. In topic here: https://www.tracer900.net/topic/2948-lowering-link-installation/?do=findComment&comment=33530 , timg gave us all we need to start designing process. Thank you timg!

From dimensions of links: stock, Yamaha -15mm and PSR -31,75mm,  I extract equation how to get -20mm and -25mm links (thanks wolframalpha). Here is the function: f(x)=63.05 + x*(-0.127165) + x^2*(-0.00706555), where f(x) is our holes axis to axis distance and x is height drop we want to achieve. Down here are some notes I have made.

 

After design work was done, I made an order to my friend so he can craft links. I decided to make them with steel SS400. Unfortunately my friend got only SS350 at the moment so we decided to make links of that sheet and made them 8mm thick what is 2mm more than original ones.
So, when I finaly recieved links/bones from my friend:

I started to install it on my moto. Basically I followed the link video linked bellow. Rear wheal lever tip is great. https://youtu.be/BH8jLWxYx5I?t=84

For me it was much more easy to uninstall exhaust. I started with -25mm links but I met some problems when was installing it. I couldn't put both bolts inside mounting holes. I gave up with that and with -20mm kit it was really easy, same as shown on the upper youtube video. After links were installed, I installed exhaust system and that was the end of rear suspension lowering. It can be done in less than 1 hour.

WOBBLE FIX

For me, of height 182cm, my Tracer got wobbling at 155km/h. That was annoying me so decided to fix it while lowering suspension.
First of all I made rear suspension harder. It was set to half of scale of hardness. I set it to 3/4 of scale.
The second was to lower down front suspension in the tripple tree. You need to unscrew a little 6 bolts (3 per side), shown on pictures bellow.

As you can see on the picture, I have lower suspension for 15mm.

After ride with my girl on my back, with speed of 175km/h I didn't notice any wobbling.
Conclusion is that, you can make your tracer great again without puting any extra money with OHLINS like rear suspension set.
 

Great write up, thanks! 

[Ed Q]

I just finished fabricating and installing links on my 2017 FJ. I used 1/4" Stainless flat bar, which is marginally thicker than the stock 6mm links. I lowered the exhaust as I have hands larger than a 4 year old. The stock bolts are 10mm with a fine thread, be careful not to foul the nuts, they are soft. With the exhaust lower at least then you can get 14mm wrenches or sockets to the bolts.

I used a cargo strap to compress the suspension ,It gave me more control. Make sure you file or sand the SS bar flat, the rolling process makes ridges on the bar. I also used a 10mm reamer to get the holes perfect ,you can layout the bolt holes with a digital caliper , the calculations and dimensions listed here are correct. A 9/16 crowfoot wrench comes in handy to run the nuts on if you don't take the exhaust off. All in all a great write-up!

 

[spicciani2]

Does this wobble fix only apply to a lowered bike?