Does the GT swingam fit the FJ09?

[stephen falco]

Hi team

Has anyone fitted the longer GT swingarm onto a FJ09 / MT09 Tracer? I would like to give the conversion a go.

From some images, the design of the GT forks look to be diferent which may impact clearance to the exhaust.  I haven't had a chance to do any measurements.

Thank you for any insights.

Cheers

Stephen 

Edited November 25, 2022 by stephen falco
Typo

[roadrash83]

The GT swingarm should fit, the FJ09 police bikes used a longer swing arm. Which is the same arm that was used on the Tracer 900GT, if I remember correctly.  

[texscottyd]

Hi @stephen falco - There was a fairly detailed thread about this previously, but I can’t seem to find it with a quick search.  

The summary is that ‘yes’ the longer 900 GT swingarm will reftrofit onto a Gen 1 FJ.   You’ll definitely need a longer chain, and possibly need to lengthen or reroute the rear brake line and ABS sensor wiring (not sure if there’s enough slack to move back 2 inches).   

The unknown to me is the shock.  The aftermarket lists different shocks for the FJ vs the 900GT (Ohlins 535 vs 537), which I assume is related to valving and spring rates to accommodate the extra leverage of the longer GT swingarm.   They look identical externally, so while the FJ shock might physically fit with the GT swingarm, it may not perform optimally.   

I haven’t done it myself, so can’t help you with the details.   Is it a stability concern that has you considering the swap? 

-Scott

[bwringer]

Agreed; I'm wondering what concern you might have.

Having ridden both (the newer bike only briefly) I dunno... I kinda like the added agility of the FJ-09. I'd never call it "twitchy", even with my aftermarket luggage loaded, so I've never been clear what problem Yamaha thought they were solving with the change.

Perhaps they wanted to nudge the bike more to the "touring" side of "sport-touring". It may have also been related to the stock luggage added to the GT so there would be a little more room for an aft CG when loaded. 

It is definitely a readily perceptible difference, which surprised me a little. I thought it would be one of many small details, but it really does change the character of the bike a little bit.

[stephen falco]

Hi @bwringer and @texscottyd

Thank you for your messages and the information provided.

The problem I am looking to improve is to keep the front wheel down a little more. This is a fun problem and I enjoy it, but a little more steering at times under throttle would be nice!

I usually ride with luggage and, being tall, my weight is a fair way back so I figure that with a longer rear arm I can keep more weight on the front.

I did a search previously however I found this today by chance, it may be the article referred to: https://www.tracer900.net/topic/11050-tracer-swingarm-on-fj/

Thanks again and I will let you know how I go.

Cheers

Stephen

[skipperT]

Have you upgraded your shock or at least set your preload on the rear suspension?

that would probably be an easier solution than changing the swingarm…

-Skip

[stephen falco]

Hi @skipperT

Yes, I have a Mupo GT1 shock with remote preload. The spring and damping are set for me.

I also have their fork inserts.

I do enjoy doing work on the bike so that part isn't an issue. In fact I am looking forward to it 

Cheers

Stephen 

[skipperT]

10 hours ago, stephen falco said:

Hi @skipperT

Yes, I have a Mupo GT1 shock with remote preload. The spring and damping are set for me.

I also have their fork inserts.

I do enjoy doing work on the bike so that part isn't an issue. In fact I am looking forward to it 

Cheers

Stephen 

Good stuff, Stephen. Sounds like you are good to go. Post back if you need any assistance and have fun with the project!

-Skip

[duckie]

Hmmmm….gonna take this opportunity to discuss the difference in setting up a motorcycle for ride quality v handling. 

My guess is the motorcycle wants to run wide when exiting a turn hard on the gas. A longer swingarm aint gonna cure this but a properly setup rear suspension will. The engine is still strong enough to lift the front when hard on the gas even with a longer swing arm.

The biggest reason for wanting to run wide is the rear squats under hard acceleration changing the steering geometry. Controlling squat is the key to holding the line out of a turn when hard on the gas.

This is where shock preload and ride height comes into play. Preload controls the force needed to move the shock which helps prevent squat and compression dampening controls the rate of squat. Ride height is used to put more weight on the front by moving the center of gravity forward.

But there is a trade off……ride quality. A stiffer rear will feel harsher.

A longer swingarm aint gonna do squat about squat.

Sometimes you have to set up the suspension to how you want the motorcycle to handle and forget ride quality. You can not have good ride quality and razor sharp handling at the same time…….

 

[HGP61]

I have the earlier Mk. one Tracer and my friend at that time had the Mk.2 Tracer 900 with the longer swing arm and riding both back to back along the same road I really wasn't aware of any noticable difference between the two bikes. With that in mind it is one change or "upgrade that I don't think I would consider. I was aware of the slightly narrower handle bars and is something I would possibly change. But in saying that, I wouldn't criticize anyone for adding stuff to their bike 

2 hours ago, duckie said:

A longer swingarm aint gonna do squat about squat

Thinking the same but what man wouldn't like an extra two inches.

[littlebruv]

Upgrade both rear shock and fork internals if you can afford, if so then get someone who really knows how to setup your suspension properly to get the full benefits. My 2017 Tracer 900 now is fully fitted with Ohlins and the difference is a lot, especially the for cartridges and springs

[PhotoAl]

I've always thought of the Ohlins as being the best.  However the quandary I find myself in is how to balance.  Set it up so that it is a perfect canyon carver and it will be tough on the 500 mile ride to get there.  Soft and comfy will be great on the way there but not so much when you arrive at the canyon.  My last trip was 6,500 miles and didn't have enough curves - still a wonderful trip with lots of great scenery and memories.  Been reasonably happy with the stock suspension with preload and damping dialed up.  Best curves were on the interstate going into Helena MT.  Later in Montana hit a road with lots of undulations and the suspension was perfect.  Would come off of a hump and then drop into the depression where the suspension would soak up the forces as it made it way up the next hump.  All the while remaining firmly connected to the road surface and not bouncing around.  3 years ago hit a similar but worse stretch south of the Badlands.  Was on my BMW F800GT and at the speed limit it was no effort.  Passed a motorhome pulling  a small trailer.  WOW they were really struggling with that stretch which went almost to Rapid City SD.  By the time they got there they were probably sea sick.  That is an area where the active suspension seems to be of value, soft but able to tighten up the dampening when needed.

[stephen falco]

Good contributions, thank you all. 

After my first test ride later in December / early January I might well need to re name this thread:

19 hours ago, duckie said:

A longer swingarm aint gonna do squat about squat.

Cheers

Stephen

[duckie]

I was doing a track day on my 04 r1. It has the proper springs rates for track use. The forks have ktech valves in them and theres a Ohlins shock on the rear.

I took it to a suspension tuner there for a final setup. The only thing he did was make a adjustment to the shock dampening. 

There is one turn that requires any hard braking. You go from bout 110 to 45…….in the shortest distance possible. The front end always dived alot in that turn but after his adjustment to the shock, the front end dive was way less and the motorcycle felt flatter.

Asked him what he adjusted. He slowed down the shock rebound. His explanation was this…..being hard on the gas caused the rear to compress…squat. When the throttle was closed, the rear uncompressed and because the rebound speed was to fast , it was allowing to rear of the motorcycle to raise too fast. So it really wasnt the forks diving too much but the rear coming up too fast.

Squat isnt something discussed much in street riding which is why I mentioned it.

Also how you ride plays a significant role in properly setting up a motorcycle. I could not ride my R1 on the street because its setup for fast speeds and hard braking. 

Which leads me to this…..how do you explain the difference in street speeds and track speeds?

Well, with pictures…..here are two pictures of same type tire, Pirelli Diablo Supercorsa, both SC3 compound….street legal track tire.

One is a 180/55 on my GT, the other a 200/55 on my R1. I ride pretty damn hard in the twistes on my GT.

Notice the difference in wear between the GT and the R1.

Thats the difference in speed from street riding and track riding. The first is the R1, second the Gt

[kilo3]

1 hour ago, duckie said:

His explanation was this…..being hard on the gas caused the rear to compress…squat. When the throttle was closed, the rear uncompressed and because the rebound speed was to fast

It's that the opposite? Since the chain front sprocket is higher than the pivot point of the rear swingarm, it's going to expand the suspension under acceleration.  Don't super fancy race bikes have cams on their swingarms to adjust the height in relation to the frame?

I also might be full of crap but I do like physics.

Edited December 7, 2022 by kilo3