Ascot Forum

First Generation Ascots => The Thumper Years: Modified To Full Customs => Topic started by: FT500R on June 16, 2020, 03:04:14 am

Title: FT500 Vintage racer
Post by: FT500R on June 16, 2020, 03:04:14 am
While my other project is not even finished I am going to start a new one.
I stumbled acros a very cheap FT500 donor bike, it's a stranded flattrack project by the previous owner and it is perfect for what I intend to do with it.
I want to build a small racebike to compete in vintage demo races here in the Netherlands.
These races are on street circuits and ranked on consistancy instead of outright speed so it also means I can keep the engine relatively stock (and cheap).
The whole build will be on a small budget to keep it fun.
I already have a set of CBR600f Hurricane forks and wheels for it.

What needs to be done:
- Get the bike running
- Mount CBR600F Forks and wheels
- Make and mount a seat
- Make and mount front fairing
- Brace the rear swingarm (in the class I am running the swingarm itself needs to be stock)
- Fix exhaust or make one out of stainless
- New rear springs
- Rearsets for ground clearance
- The bike will be build as a racebike without lights or anything, there is registration on the frame though so I am contemplating to have removable lights to be able to test the bike on the street.

I've added 2 pictures of the style that I am aiming for.

Any tips and tricks are greatly appreciated.
I know the FT500 was used in AHRMA championships quite a lot so any racing upgrade knowledge would be great
Title: Re: FT500 Vintage racer
Post by: FT500R on June 17, 2020, 06:02:11 am
Had some spare time yesterday evening so started to look at the state of the donor.
Man it is dirrrrty!
There is a thick layer of caked crap everywhere on the bike. Started to tackle that with some old rags and decreaser but I have a long way to go.
While I was at it I thought I would testfit the CBR forks.
One thing lead to another and now the full CBR front end is in.
Length difference is quite significant.
I still have to put the clipons on instead of the handle bars and I do want to lower the forks a bit further on the tripple tree.
Next in line is cleaning the carb, giving the starter mechanism some maintenance and reinstalling the wiring harness, after an oil and filter change I would like to see if I can get some noise out of her.
Title: Re: FT500 Vintage racer
Post by: J6G1Z on June 19, 2020, 12:59:54 am
I had to remove about a 1" section out of the side stand after the CBR swap. Beware of the oil sump now sitting lower when you go over a speed bump, etc. I used Honda CR type motocross handlebars. I retained the OEM FT triple clamps & slid the CBR fork tubes into place.
Title: Re: FT500 Vintage racer
Post by: FT500R on June 25, 2020, 01:57:42 am
Mounted the clipons, brakes and rear wheel of the CBR today.
The rear wheel does rub a bit on the right hand side of the swingarm, might be because the chain is a bit short (it's still the old 530 chain) and the wheel is very forward in the adjusters now.

After that I sprayed some primer on the tank to prevent rust.

Doesn't look half bad.

I also tried to clean the carb which went reasonably well. Biggest problem was that I can't get the jets out. Soaking them in penetrating oil now to hopefully get them out.
Title: Re: FT500 Vintage racer
Post by: FT500R on June 28, 2020, 09:38:20 am
Got the jets out today!
Soaked them in penetrating oil for some days and they actually came out pretty easily.
With the carb cleaned I turned my attention to the electric system to diagnose any problems.
I hooked up the loom that I got with the bike. Connected everything up and first checked if I had power.
Ignition on and yes we have power!
Disconnected the pinion solenoid. Pressed the starter button and the starter motor works.
Disconnected the motor and connected the pinion solenoid, pressed the button again and this also works!
Connected the pinion solenoid again but took the sparkplug out.
Pressed the button and the engine cranks over, even better the sparkplug has a nice and strong spark!
So naturally I couldn't resist.
I reinstalled the sparkplug, got some starting spray and had the bike running for the first time in quite some years. (Without exhaust or air filter... Sorry neighborhood)
Not on gasoline yet (didn't hook up the tank) but great to know most of the engine seems alright.
Next step is to change the oil, hook up the tank and the exhaust and see if I can get her running on gas.
Title: Re: FT500 Vintage racer
Post by: murdo on July 02, 2020, 02:56:10 am
Nice work.
What brand/type of starter spray did you use?
Title: Re: FT500 Vintage racer
Post by: FT500R on July 02, 2020, 05:08:50 am
Brake cleaner....
almost anything flammable will work TBH.
Would even use deodorant spray on my mopeds back in highschool (always nice to have your moped smell like a teenage boy)

Ordered a bunch of parts to start overhauling the bike.
There is a lot of RTV everywhere, someone tried to RTV the leaking cam O-rings so will be taking it apart after I've tested it a bit.
Total list of ordered stuff:
- Upper engine mount (was missing)
- Lefthandside CBR600F rearset with shifter pedal
- Tank rubber mounts
- kickstand spring
- Plug for the rev drive hole (will run electric rev counter)
- TDC check cover
- Exhaust studs (Do not order the ones from CMSNL. they are m6x35 while the FT needs m6x45!)
- Overhaul kit for the CBR front forks (dust seals, oil seals, bushings, everything)
- Full gasket set
- Exhaust gaskets
- Brake lever
- Throttle tube because mine was internally broken.

What I am still looking for:
- Proper jets for the carb (Keihin N424-26 jets are almost unobtainable here. I can get n424-21s but those are too long)
- Airfilter, looking at a foam style filter
- Exhaust muffler (need to clean and repair the original rusted out one that came with the bike
- seat (looking for a classic endurance style seat)
- Half fairing (same as above)
- lights
- rear springs (cb750sc)
- tires (bridgestone s10)
- chain and sprockets
- front brake discs as these are worn
- braided brakelines
- small stuf I will surely find when working further on the bike
Title: Re: FT500 Vintage racer
Post by: FT500R on July 06, 2020, 04:44:35 am
Got all my parts in before the weekend so took some time to install some of them.

Fitted my old rusty exhaust without muffler (muffler coming soon). Also fitted the CBR600 rearsets, some fab work required to the frame but think they will work great.
With the fully cleaned carb I wanted to try to get it running on actual gas instead of starter spray.
Hooked up the tank of my other FT as this has some relatively fresh gas in it.
https://www.youtube.com/embed/HbT5xlXsaJg
She runs really good!
No strange engine sounds whatsoever.
Also ran her through some gears while on the stand and everything works as intended.
Title: Re: FT500 Vintage racer
Post by: patrino on July 08, 2020, 11:00:22 am
Looking good, thanks for the update!
Title: Re: FT500 Vintage racer
Post by: hellblom on July 08, 2020, 04:06:29 pm
Very cool!
Title: Re: FT500 Vintage racer
Post by: FT500R on July 09, 2020, 11:12:10 am
Got a new airfilter and a new second hand exhaust today.
For the airfilter I went with a foam (double layer) filter. This should filter nicely, at least much better than those cheap mesh filters, and because it is foam you can easily fit it in the cramped space.
For the exhaust I was able to get a second hand Megaton exhaust for cheap. They are cheap exhausts anyway so I don't expect too much from it. It did come with multiple DB-killers so hopefully I can make it somewhat quiet.
Will be a bit of an effort to fit as the rearsets limit room for a link pipe.
I am also playing around a bit with possible seats. My original plan was a NSR250 seat but those are from the early 90s while the organization of the demo races I want to participate in want to have a more 70s/80s vibe.
Best option that I could work out in paint looks to be an altered Laverda SFC750 seat.
Title: Re: FT500 Vintage racer
Post by: FT500R on July 28, 2020, 04:18:26 am
Had someone with a bit of photoshop skill make an indication of how the bike could look.

Ordered the seat unit so that should arrive one of these days.
For the front fairing I have one that I am going to look at next week.

Also looking to make a link pipe to mount the exhaust muffler
Title: Re: FT500 Vintage racer
Post by: hellblom on July 28, 2020, 03:10:07 pm
Nice! I also bought a cbr600 front end the other day.

Do you know why the forks sticks out so much above the triple tree? Why is it not in line with the top of it?
Title: Re: FT500 Vintage racer
Post by: FT500R on July 29, 2020, 08:28:20 am
Originally the clipons are mounted on top of the tripple tree.
So there has to be space for that and therefore they portrude a bit further through the tripple tree.

When I first mounted the forks in the FT, I mounted them flush with the top (you can see in one of my earlier posts).
That made the forks look very long and skinny and I also didn't like the stance.
I will stiffen the front forks anyway (found an old instruction how to improve the forks of a CBR600F1).

regards,
Paul
Title: Re: FT500 Vintage racer
Post by: FT500R on July 29, 2020, 10:36:26 am
To properly fit the CBR rear wheel I still had to make rear brake support bracket.

I am using the CBR mounting bracket and CBR brake caliper but I decided to use the FT brake support bracket.

Had to make a new hole to line up with the mounting bracket.
After that the bracket was way to big so I got my angle grinder out again.

Fits up nicely now.
Title: Re: FT500 Vintage racer
Post by: hellblom on July 29, 2020, 01:45:24 pm
Thanks for sharing the info on how you solved the rear brake. I will get there pretty soon myself.

I see what you mean by the front end looking skinny when the forks are flush with the triple tree. The stance is better as you have it now, but I do not like the protruding forks, hmm..

Title: Re: FT500 Vintage racer
Post by: hellblom on July 29, 2020, 02:05:28 pm
Another question: can you send me the link to the overhaul kit for the CBR front forks (dust seals, oil seals, bushings, everything) that you bought? Are you planning on doing the service yourself? If so, please share how it went, I am a bit hesitant on doing service on forks myself. It seems tricky...
Title: Re: FT500 Vintage racer
Post by: J6G1Z on July 29, 2020, 07:07:52 pm
I ended up doing this.
Title: Re: FT500 Vintage racer
Post by: FT500R on July 30, 2020, 03:23:38 am
Another question: can you send me the link to the overhaul kit for the CBR front forks (dust seals, oil seals, bushings, everything) that you bought? Are you planning on doing the service yourself? If so, please share how it went, I am a bit hesitant on doing service on forks myself. It seems tricky...

I got them from a dutch webshop.
http://www.japparts.nl/index.php?main_page=product_info&cPath=79_86_93_183&products_id=16849
http://www.japparts.nl/index.php?main_page=product_info&cPath=79_86_93_183&products_id=17699

I have rebuilt some forks before. It is not that hard just follow a haynes manual and you will be alright. I have a CBR haynes manual I can send you if you like.
The adaptations as stated in the above files will be new for me too so I'll have to find out how that works myself.
When I get to that I'll take some pictures and share them here.

I ended up doing this.
I saw that on your original post on the swap, a lot cleaner than my solution! But mine was very easy with the parts I had lying around. Might change it up eventually but I am happy with how it is right now. Does the job ;)
Title: Re: FT500 Vintage racer
Post by: J6G1Z on July 30, 2020, 10:24:34 pm
Thanks. I didn't even think about using the original one. Your solution is more clever.

EDIT: The bracket/strap that I made, required shocks with smaller diameter springs.
Title: Re: FT500 Vintage racer
Post by: hellblom on July 31, 2020, 01:47:50 pm
It would be awesome if you could send me the manual! I think you can send DMs through this site?

I will have a look at the links you attached, thanks again.
Title: Re: FT500 Vintage racer
Post by: FT500R on August 06, 2020, 03:05:29 am
Got my new seat unit in the mail some days ago.
It was a bit too long for my taste so I shortened the seating area and cut off the 'flap' at the rear to flow a bit more with the curve of the side panels.

First picture is before cutting it up and the other 3 of the current size.

Will have to rework part of the seating area to fit the frame a bit better. I am also contemplating if I should extend the seat unit down to meet up with the framerails. The unit is nicely in line with the fold in the tank at the moment and that line could be visually broken if I do extend it down.
I also have to strengthen the unit so I can actually sit on it and come up with a solid way of mounting it all.

Title: Re: FT500 Vintage racer
Post by: FT500R on August 24, 2020, 02:41:13 am
I strengthened the new glassfiber seat with some aluminium yesterday.
This will be bonded to the seat to provide some rigidety and enough strength to mount it to the bike properly.
I also made the upper mount for the CBR footpegs.
For the lower mount I use the FT footpeg upper mount.
I ground half of a large nut round, drilled a hole in the frame in the correct spot and wedged the nut in the hole.
The footpegs are where I want them and it already is very sturdy.
I will be welding it all the way around later.
A quick bend in the shifting mechanism solved any clearance issues with the frame.
Pretty happy with the result, ground clearance is better then with the original footpegs.
I do have to adjust the brake pedal a bit. It is too low (have to bend my foot very awkward to push it) and it is the first thing to hit the ground when tipping the bike over.
It has some adjustment so that will be an easy fix.
I also got a small entry level MIG/MAG welder so this will help with making the exhaust later.
Title: Re: FT500 Vintage racer
Post by: FT500R on September 07, 2020, 11:34:06 am
Due to the CBR footpegs I have to reroute the exhaust.
I roughly eyeballed the route and bought some mandrel bends.
After some more eyeballing, some measuring and cutting I ended up with a rather nice linkpipe.

By shortening the original exhaust that was very rusty on that end anyway I can slide this linkpipe over and fit the exhaust quite nicely.
It is really close to the swingarm and rear master brake cylinder but it has enough clearance I think.

There is also enough wiggleroom to get it properly aligned when I start welding everything together.
Pretty happy with the result.

Have to get my welder working a bit better and then I can get another step further in the build.
Title: Re: FT500 Vintage racer
Post by: murdo on September 07, 2020, 06:02:19 pm
Nice work!
Title: Re: FT500 Vintage racer
Post by: FT500R on September 17, 2020, 10:06:17 am
Got a new front fairing.
Made the fairing stay on the front already, have to tweak it a bit more but it is already pretty sturdy.
Will add some brackets to the sides to keep them in the correct position and from flapping around.
Also welded my linkpipe. Have to add a bracket to fix the linkpipe to the frame on the spot where the exhaust normally mounts and have to add a muffler hanger.

The windscreen on the pictures is one I had lying around. I will not use this one but it was more to get an idea of the looks.
Title: Re: FT500 Vintage racer
Post by: hellblom on September 21, 2020, 03:05:58 am
What size tires do you have on this mr FT500?
Title: Re: FT500 Vintage racer
Post by: FT500R on September 21, 2020, 07:09:28 am
110/70/17 front
140/70/17 rear
Title: Re: FT500 Vintage racer
Post by: FT500R on September 28, 2020, 04:01:50 am
I've welded supports for the fairing so it is installed.
I made one support from the neck of the frame forward and 2 small tabs on the sides of the frame.

My welding isn't great but it's solid and when I will prepare for final painting of the frame I can grind the ugly bits down a bit.

I am very satisfied with the position and sturdiness of the fairing. It really hugs the bike nice and tight.

Title: Re: FT500 Vintage racer
Post by: murdo on September 28, 2020, 04:08:45 am
Looking good.  :)
Title: Re: FT500 Vintage racer
Post by: hellblom on September 28, 2020, 02:00:07 pm
Well on the way! Looks good.
Title: Re: FT500 Vintage racer
Post by: FT500R on October 13, 2020, 03:11:29 am
Refurbished the front forks this weekend.
Not the first one I did and since this is not a cartridge style fork it was really easy.
Replaced all the seals and slider bushings as the seals were leaking and the bushings completely worn.
I removed the whole anti-dive system as this will lockup the forks when braking on a bumpy road (not something you want when riding on street circuits)

Also drilled some extra holes in the damping rods to prepare for cartridge emulators. I have gone for the YSS PD valves instead of the more well known racetech gold valves. Primarily because the YSS are actually obtainable in Europe and they are a lot cheaper.
I'll be running 15wt fork oil and will have to shorten the spring or the spacer to accomodate for the PD valve. Will post more on that whenever I get them.

The postal company has lost my package with the valves though but at least everything is prepared and they should be a quick drop in.
Title: Re: FT500 Vintage racer
Post by: FT500R on October 16, 2020, 03:07:21 pm
Fully welded the exhaust and slapped some cheap heat resistant paint on it. (I also drilled some holes in the header to weld in the inner tubes that got loose, seems to have worked)
After that I got some new sticky stuff for the FT.
I went with Bridgestone RS10s. Read a lot of good reviews about them, they were pretty affordable and were available as a set in the sizes I wanted. Really happy with them. I got 110/70/17 for the front and 140/70/17 for the rear.

For the front forks I came across these things:
(https://ae01.alicdn.com/kf/HTB1u264XlyWBuNkSmFPq6xguVXaf.jpg)
These fit on the forks instead of the current caps. I would loose the air valves and with that the possibility to pressurize the forks but would gain pre-load adjustment. Anyone any experience with something similar?
Title: Re: FT500 Vintage racer
Post by: murdo on October 16, 2020, 04:15:30 pm
I used the adjustable top caps on one of my CBR250's and found they made a noticable difference.
Title: Re: FT500 Vintage racer
Post by: FT500R on October 26, 2020, 11:25:06 am
Got the PD-valves in the mail this weekend and installed them.
Really clever little things.
You put them in your forks between the damper rod and the spring.
The spring preload of the little valve controlles the amount of oil that can flow when the forks compress, with that it controlles the compression damping.
Rebound is still controlled with the oil viscoscity.
I've set the valves on 3 turns preload (out of 7) for now. The forks still feel a bit soft but this could also be due to the relatively weak standard fork springs.
I had to shorten the fork spacer with 14mm (thickness of the PD-valves) to keep normal pre-load on the fork springs.
I'll keep them like this for now, changing the pre-load on the PD-valves is relatively easy so I can dail them in further when I get to test ride the bike a bit (you do have to 'open up' the forks by removing the top cap, spacer and springs).

Title: Re: FT500 Vintage racer
Post by: patrino on November 04, 2020, 06:55:44 pm
Looking good - thanks for the update!

I reckon you'll like the cartridge emulators.  I'm a big fan - for the last ten years or so I've been running them (RaceTech's version) in all my vintage bikes.

You may already have figured this, but in case you need to adjust the emulators, a tool like this is helpful to grab them from the top of the damping rod:  https://www.homedepot.com/p/GrabEasy-24-in-Flexible-4-Claw-Pick-Up-Tool-Jewelry-Retriever-Clog-Remover-Drain-Snake-in-Chrome-PF0401/202505170
Title: Re: FT500 Vintage racer
Post by: FT500R on November 06, 2020, 04:28:46 am
Thanks.
I indeed used a similar tool. Works like a charm and you don't have to drop the valves in or turn the forks upside down to get them out.

I just ordered new shocks and progressive fork springs so the whole suspension should be sorted.
Title: Re: FT500 Vintage racer
Post by: FT500R on November 12, 2020, 08:05:05 am
Christmas was early this year (or Sinterklaas which we celebrate in the Netherlands).
Just got my Hagon shocks and fork springs.
I went to the importer of Hagon shocks here in the Netherlands to discuss which type would be best for my situation and instead of the more expensive adjustable 2810 series they actually recommended the 'standard' shocks as these have progressive damping.
This progressive damping various according to the sharpness of the shocks and with that would be more optimal than a set damping that will always dampen the same way.
I did get springs specifically for my own weight, the bike and the racing I will be doing with it.
Together with the progressive fork springs and the YSS PD-valves this should give a much improved ride.

Hope to install everything this weekend.
Title: Re: FT500 Vintage racer
Post by: FT500R on November 15, 2020, 05:06:52 am
When racing I have to remove the side and center stand, which means that parking the bike is a bit difficult.
To make it a lot easier to prop the bike up I welded 2 long nuts on the rear swing arm to fit paddock stand bobbins.

The Hagon shocks I bought are a bit longer than the orignals (was recommended this by someone who races FT500s). The bike looks pretty sweet with the shocks installed.
I also made a muffler support from a strip of aluminium. Might add some speedholes in it to add lightness ;)
Title: Re: FT500 Vintage racer
Post by: FT500R on November 17, 2020, 09:46:43 am
Fitted the hagon progressive fork springs today.
These replace the original spring, washer and spacer.
Problem was that I had shortened the spacer to make room for the PD-valves (about 20mm).
I can't just shorten the progressive springs so I fitted them as is, I do have quite a lot of spring pre-load now (about 37mm) but statically the forks feel great and not harsh at all.
Title: Re: FT500 Vintage racer
Post by: hellblom on November 22, 2020, 12:44:02 pm
Nice, which model of the progressive springs was it?