jpe's Bumble bee - The collected mods

[Racer-unk]

My stops are 10 mm Cap screws inserted into bottom bracket of Suzuki triple clamp. My levers touched way to much for comfort.

[jpe70]

Somewhat short and collected experiences from first track day on rebuilt TRX:

Old rear shock, still wears rear tire very good. I interpret that as an overall good setup. Initially it felt a bit nervous off throttle but that was cured with more rebound damping in the forks, it really was too springy, and less preload in the rear to lower it a bit. That last part may need undoing once I get front springs fitting my weight, bike is a little soft and low with stock fork springs. ThunderAce swing arm and dog bones now leaves the stock shock on #2 preload setting.

Front tire a used Bridgestone W02 Soft slick and rear Pirelli SuperCorsa SC2. Think I prefer the Pirellis on the TRX actually, always wanted the Bridgestone on the R1. Was a nice day ran with standard 2,3 bar front and 1,8 bar rear all day (hot off the warmers).

Acceleration is a bit poor from 5500-6000 rpm, probably due to bike running rich and that affects top speed slightly. Need to go down a gear instead and keep it over 6500, pulls nicely then. Much less engine brake than I had anticipated, idle is set somewhere 1500-2000 rpm and I had to brake in the beginning because I was expecting a lot more torque braking. It's a good thing, easier to change down and keep the speed into turn without upsetting the rear.

Removed the fan on the diet, didn't have the slightest temp problem all day. Hardly ever reached 80 deg C. Ambient temp somewhere 18-23 degrees all day.

Brakes, hardly used them for real, but the Galfer track day pads that used to fade for me in racing works just fine with this lower top speed and the bite is almost a bit too quick, a little difficult to modulate in a "situation" but there is no doubt what so ever they will put me on my face if I'm too heavy handed. Better than the opposite.

Anything else...? No need for a db-killer even on this restricted track. Modest oil consumtion for some reason, likely I don't have complete check on it. More than make sure there is enough. My personal best on the track is a very modest time, but still made with a aprilia Tuono V4R. First day on the rebuilt TRX matched that time, that's something to the geometry and driveability of this old bike. Compared to really fast laptimes we are 2-3 seconds slow. Last time on the stock TRX I think we only managed 5-7 seconds slower than this day. Difference being bike weight, wheels & suspension and my experience.

Anything else is posted on that blue place.

[coxylaad]

good write up.

Looking forward to see how you develop the bike.

Have you measured your steering head angle ?

[jpe70]

good write up.

Looking forward to see how you develop the bike.

Have you measured your steering head angle ?

Thanks! I'll ride it a bit and see what the wallet says at the end of summer. Got plans already but someone needs to pay for it too...

No, haven't done any measuring of angles. Front should sit as a stock bike with 30-ish mm fork above, compared to stock 18 mm. That's 12-15 mm down and we measured rear to about 30 mm raise. Nothing extreme but still very agile.

[jpe70]

Some small changes that needs to be documented then...

Rear sets
Adapter plates from ProJection Racing and billet unfolding race footpegs from UK-based eBayer trevsvintagemachineshop. Most pegs seem to have M8 fitting and I bought a pair on chance which now lives with a friends Suzuki. M10 is correct stock replacement.



Rejetting
Yet again. Returned to old pilot and main after a VERY fat dyno run. Pilot should be stock size then and main I can't remember but 145 is flying around somewhere. Adjusted float height so both at least are the same. Really need to get myself a pair of properly set up TDMR/FCR....




Front
Finally got the springs, so a set of Wilbers linear 0.95 springs for the R6 fork is now in place. Front and rear adjusted to 25 mm rider sag, after the track day it seems rear shock returned somewhat to life and started moving so I had to return on the preload setting on it too. Backed it down from 5 to 2 when changing dog bones, now back on 4.
With previous springs fully turned in preload gave me 30 mm rider sag without riding gear, now I have notches to go. Unfortunately rebound damping in the fork is at it's limit, but since I don't have to brake the bike all that much I hope it won't be a dealbreaker even with the harder springs.



Design
The white vinyl had to go, it's too crappy and won't stick. Wasn't even difficult to remove so clearly wrong type for small wrappings. Plan was to respray the bike same Performance Blue as the van and put the same stripes on. No time for that though, so will just put the stripes on for now and save the repaint for later.

[jpe70]

No more modifications for now, riding the bike as is over summer. Spent three days at Autodromo Brno with it, behaved adequately if not brilliantly. But we had a bit too hot weather for the bike's setup. What I missed on those days was a bit crisper throttle response, a quick shifter and a better rear damper. But we managed.

Setup for these days was as noted previously:
25 mm rider sag front and rear.
Fairly much rebound damping, in fact it was bottomed in the front.
SuperCorsa SC1/SC2 with 2,3/1,8 warm pressure. Turned out SC1 in the rear probably would have been better with nearly 50 degree C in the track day 2.

Stable as anything with a hint of lacking some rebound damping (a tad springy when flicking bike over from side to side fast). Getting back home, I've changed oil and filter, air filter back to K&N and waiting for another set of tires. Will do some brake cleaning and change the rubbers before next track day on a smaller track.

Plans for the next step this winter is to do something about power, and the oil consumption. So there's a set of flatslides, Ignitech, a small engine/top end rebuild and suspension restoration on the to-do-list. Had plans for big bore and porting, but money is an issue. I'll settle for a modified top end gasket for increasing compression and some further weight reduction...

[jpe70]

So, a bit suddenly and in the end a bit more taxed then I expected there will be TDMR's!

Just got them out looks clean, trying to get them in place any day. Just have to remember flipping connectors on TPS.

[jpe70]

Carbs

TDMR's installed, TPS connector outer cables shifted and sensor calibrated (turn until RPM shows 4000). Stock throttle cables used, cut down lenght to fit (took off about 60 mm) and added an adjuster on the bottom of return cable (M6). Cables rerouted on the outside past the ignition coil, fits straight in on the carbs without extra bends. Choke cable is also shortened by 35 mm according to instruction from Topham to fit the shorter stay on the carbs.

Don't know jetting as of yet, probably std from Topham, but will put the bike on the dyno shortly for a first shakedown and get some A/F ratios. Carbs are without bellmouths, have airbox connectors on with K&N pod filters mounted.

UTube: https://youtu.be/79qzq5STA_U

[coxylaad]

Nice one. Bet you cant wait to get out and see the difference in them

[jpe70]

Been very little posted here, have had trouble posting getting an error message actually.

A few things have been done, I'll get back to that if this post works.

[jpe70]

Nice one. Bet you cant wait to get out and see the difference in them

Did that. It's properly angry now for stock engine, with the TDMR's and the TCIP4.

[jpe70]

OK, so a small update then. We already covered the carbs. Turns out they are not standard jetting but rejetted on a dyno for the TDM they were used on. With the pod filters even. Got hold of the Ignitech TCIP4 from the same bike too, and it had a modified curve which I assume is adapted to the jetting. So the whole package should work fairly well as is, however I don't know if it's performance or economy optimized.



We'll see once I get it on a dyno and have some A/F-values.

Currently working on replacing ignition lock and connection shift light and map switch button to the TCIP4. Saved almost half a kilo with a race button setup for the power and rain light.

[jpe70]

.... oh, yes almost forgot. It's now officially a real project bike. Almost like coxy's work.... I started cutting the frame.

[coxylaad]

keep up the progress reports

[jpe70]

Putting a placeholder here then.

Not much going on, the weather and other obligations are keeping me out of the garage at the moment. Did one try at getting the rear light in there, but screwed it up so had to start over.

There are a few things in the pipeline before next season, but doesn't look like I can do as much as I wanted or planned by a longshot. Engine will come out and get some paint, but not sure if I'll be able to do the much needed rebuild. Wet weight will come down to 180 kg finally and there will be some general freshing up with a little paint. Planning on using new buttons for map switch and start rev/pit lane limiter once I get the rear light in place again.

Currently though there are 4 bikes and all the equipment crammed in on 14 square meters...