Author Topic: RD350 Track Bike build  (Read 16584 times)

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Online 5port

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Re: RD350 Track Bike build
« Reply #300 on: March 17, 2021, 04:39:05 PM »
Well, I have a rolling and stopping chassis!   :)





It might look similar but, it is now a working chassis, just short of an engine!  :D
Since the previous pics of the bike, there is a long list of jobs done.  The Tank, seat and muddy are fitted, the front brake and rear brake function, the rearset footrests are fitted and, the throttle awaits its engine!  :)
The front brake caliper is an original 250/400C part.  It came from Dave James.  I cleaned it and fully overhauled it with new stainless steel pistons and a genuine Yam seal kit.  I put all new bolts in it.  One of the big bridge bolts, the lower mount bolt and all the nuts are Ti.  I kept the original paint and decal. 
The master cylinder is a pattern 1/2" 250LC one from Norbo.  Seems good quality and, I have chosen the size for single disc.  The black steel braided brake line is Hel, custom made.  It is a great piece of brake line, just £33 delivered.  I really love the quality, Hel certainly came well above the standard for the price-great!  The top banjo bolt is Ti.  Brake fluid is Motul factory line racing DOT4 that seems to have the best spec/price.  Brake pads are the SBS Double Carbon Racing HH spec and, they are supposed to be good!  ;D
So, with the front brake working, I have been able to judge the fork springs.  Yep, it is firm.  But, that is what I expect, the spring rate is 1.75 times the OE first stage.  Very roughly, putting about 100kg on the forks is giving about 50mm of travel so, we are in the ballpark.  Of course, the proof of the puddin' is how it handles!   





So, towards the rear. ;D  The rearsets are fitted.  I really like the cable brake, although it is a bit of a snaky routeing. However, it works nice and is adjustable.  The rear brake torque arm has been modified.  As supplied, the thick alloy arm thinned down alot to fit into the bracket on the swinger.  I thought that looked weak so, I have made an extra arm out of 5mm thick alloy plate that is held on by two 8mm Ti setscrews that are locktite'd in place.  That makes the mount into a fork that has twice the ammount of alloy in the upper joint than it had.  10mm Ti bolts and nuts secure each end with alloy bushes.  The footrests are nice and feel solid, all held with Ti setscrews. I have tested them by standing on the pegs!  :D 
 As a point, most fasteners are loctited and, the Ti stuff with holes will be wirelocked, so somethings get both, some things rely on torque/Nylock.  The method I apply is that I use at least the Yamaha original locking and, an extra level where possible.
You might spot the "ventilated" rear drum. I am pleased with that and I think it will be satis.  ;D
The sprocket is fitted in the same way as RD250/400E or 250LC, with bolts in rubber, central giant C-clip and the four plastic collars that limit sprocket twist on the rubbers.
Then, there is the seat..  ???

       


Just like the early TZ, my Meadspeed "Maxton" seat doubles as a tank mount and as a minimal perch for my bum!
You can see the rubber strap that runs up from a TZ style bracket held under the seat and retains the tank on its rubbers.  8)
Now, the fglass seat is not hugely strong, maybe strong for a 65kg rider but, not STRONG!   :D  So, you have to look at the design and decide where the weight has to go.  In this case, your weight needs to go straight down from the seat pad, into the frame tubes below.  You do not want the seat to carry your weight through the 6mm mounting bolts.. the fglass is not reinforced for that.  ???
So, let's look underneath..



So, under the seat you can see that the base is moulded with areas, directly under the leatherette seat pad, where the rider weight should transfer directly onto the frame tubes.  On an early TZ250/350, those tubes are also the ones that continue rearwards into a loop under the back of the seat.  The RD frame has a slightly different arrangement but, you should see how I have some "T" shaped steel brackets welded on to the top area of this RD frame.  Overall, I wanted this seat slightly higher than an early TZ one, so that is why those T shaped brackets stick up about 15mm.  You can see at the front of the seat, here there is about 17mm of poly spacer block to secure the nose of the seat and, at the rear there is a shaped poly block, nut, bolt and conical washer on each side.  The spacers and reinforcing alloy/poly blocks are Araldited onto the fglass to strengthen the securing points.  Also, note the rear nuts are just plain in the pic, Nyloc's going on to finish.  :)

   

 :) :) :) :) :)
 

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« Last Edit: March 19, 2021, 08:11:13 AM by 5port »
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Offline german

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Re: RD350 Track Bike build
« Reply #301 on: March 17, 2021, 10:27:53 PM »
Hi Chris,
looking very good so far. You know, only with one thing I can't live..... ;) :D
Regards Uwe
« Last Edit: March 17, 2021, 10:38:02 PM by german »
Classic Racers do not hide the ashes, they keep the fire burning
Yamaha DS7, RD250, RD400, Yapol TZ250B, Daspa TZ350, FZ750/1000, Honda RS125, Jackson Special 250, Höpfner-TD3, Hejira PE250, Broadstock F350 Sidecar, Honda RS250/1990

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Re: RD350 Track Bike build
« Reply #302 on: March 18, 2021, 07:10:16 AM »
Hi Chris,
looking very good so far. You know, only with one thing I can't live..... ;) :D
Regards Uwe

Thanks Uwe!
You know that the LC wheels were designed for British taste!  :D :D
Actually, they have grown on me and, in U.K. those wheels are very popular because the 250/350LC is a very popular cult bike.  So, I think those wheels are now more valuable!  ;D.
Overall though, I am aiming to fit the spoke wheels next year, the main reason is the 2.15 rear rim size that I can use on the rear.  The rear LC 1.85 size seems very strange, should have been 2.15!  ::)
Wheels are tricky, you can fit all sorts of types but many will need a lot of engineering to fit and many are surprisingly heavy.  The Astralites would be great but they are just rare and expensive.  I don't understand why they had so much trouble making them.
Anyway, thanks for your support Uwe!

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Offline G Jones

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Re: RD350 Track Bike build
« Reply #303 on: March 18, 2021, 03:57:17 PM »
Never mind the bike - time you got them slabs grouted....

Online D Peacock

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Re: RD350 Track Bike build
« Reply #304 on: March 18, 2021, 04:02:11 PM »
Looking well  8)

I quite like the LC wheels, they are probably comparable in weight to wires and also fulfil one of my major requirements - being cheap!
For speed add lightness!

GSXR1100 - Big boy’s bike
GSXR400RKSP - Track / Race bike
YR5 - 52bhp - Ported RD barrels, 28mm carbs, Mick Abbey pipes, Powerdynamo with Zeeltronic DC controller, premix, Euro CR 6 speed box.
GT200X5 - Bog standard.

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Re: RD350 Track Bike build
« Reply #305 on: March 18, 2021, 04:08:23 PM »
Never mind the bike - time you got them slabs grouted....

That is a very good point!  ;D  However, the gaps let the rain drain away better.  ???

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Offline german

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Re: RD350 Track Bike build
« Reply #306 on: March 18, 2021, 06:49:47 PM »
Hi Chris,
you know, Wheel wise it's only a personal taste of myself. You have to be lucky with them, not I.
About the Astralite's I can give first hand information.
At our race in Schleiz(Germany) in 2019 I got the last Astralie wheel in a small width from Paul Allender, the owner of Astralite. We spoke about the situation. There are more than one factor why he stopped to produce them. It was only a side business of him anyway. Both his wife and he did that mostly after normal work. Raw material dried up. The company he got the aluminium from had doubled the minimum purchase of raw material. So a huge investment would had to be done. On top the company where he got pressed the wheel halves before had folded. So he would had to find another company first. The last batch he made needed around 4 years to sell. So when he count on his own age he decided to stop further production and choose a bit more free time.
Astralite wheels are my favourite ones. I have 17 of them collected over the last 10 years. Mostly bought in the UK, 15 in 18" and a set of small width 17" in my Honda RS125 NF4.
But have a few PVM, Kuma, Tecnomagnesio 18" aftermarket wheels for RD/TZ also. I like casted wheels more than spoked ones. But Daniel is right. Most cast wheels are not much lighter as spoked ones if at all.
Regards Uwe
Classic Racers do not hide the ashes, they keep the fire burning
Yamaha DS7, RD250, RD400, Yapol TZ250B, Daspa TZ350, FZ750/1000, Honda RS125, Jackson Special 250, Höpfner-TD3, Hejira PE250, Broadstock F350 Sidecar, Honda RS250/1990

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Re: RD350 Track Bike build
« Reply #307 on: March 18, 2021, 07:15:53 PM »
Hi Uwe,
Yes, I read that they had material availability problems.  Still, I guess the sales possibilities for vintage parts are not as good as I imagine?  For instance, the SBS Double Carbon race pads (and any other race pad for the Yamaha steel caliper) are marginal on sales. 
I guess that we are actually lucky for RD/TZ '70's parts?  There are problems with some items but, you can still buy parts, and do what I am with my track bike. :)  Mind you, I still have spent quite a bit of money to get it all together.   ::)

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Offline german

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Re: RD350 Track Bike build
« Reply #308 on: March 18, 2021, 07:49:24 PM »
Chris,
the sales possibilities are good for classic bike parts. But wheels are a huge investment. The Astralite cost much less as any other still available wheels. Astralites did cost between 1000-1200 Pounds depending on the size. PVM, Champagnolo or Morris wheels are more in the range of 2000 Pounds now. Not counted in the copies which are knocked out in the eastern states like Tschechien. Even the west german Kuma wheels which were used on the last works MZ's in 1975/76 are available as reproduction done now in East Germany privately at a price of around 1000 Pounds. They are blanks and can be bored to RD/TZ axle, disc and sprocket dimensions.
On the other side nearly every part for a TZ250/350 is available. In fact you can build a whole TZ out of replica parts. On many parts you can choose from various sources.
About the brake pads, the answer is simple. Only a few people know that these pads are available. I can speak for mainland europe. Near no one uses the genuine RD/TZ caliper. Most are on aftermarket ones like Lockheed, Grimeca, Brembo or even the blue spot late Yamaha 4-pod calipers due to the fact that no good brake pads were available for a long time and the lack of different compounds.
And yes, a ground up build of a race bike always cost a bit of money.
Regards Uwe
Classic Racers do not hide the ashes, they keep the fire burning
Yamaha DS7, RD250, RD400, Yapol TZ250B, Daspa TZ350, FZ750/1000, Honda RS125, Jackson Special 250, Höpfner-TD3, Hejira PE250, Broadstock F350 Sidecar, Honda RS250/1990

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Re: RD350 Track Bike build
« Reply #309 on: March 18, 2021, 09:49:40 PM »
You would think that there would be a great Mass production cast wheel for easy conversion to the RD but, I don't see them, other than the LC.  :D 
The Lockheed caliper has confused me.  I think it must have a qualification as an old part?  I am sure it is still produced.  Always looks a bit clunky to me and, usually needs a bracket to adapt to a fork.  I think it has only a tiny bit larger pistons than the RD steel caliper.
Yes, agree that any "new build" track bike is not cheap.  However, maybe the RD is still great value for anyone wanting a fun classic 2T track bike.  Price-wise, I think that there is a lot of bike for your money with a fairly modern sports bike, but that is going to be 4T and not from the times I am interested in.  ???
Cheers

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Re: RD350 Track Bike build
« Reply #310 on: March 18, 2021, 10:57:36 PM »
Hi Chris,
the Lockheed caliper and his copies like Grimeca, Fontana, Spondon, PVM, WiWa, Brembo use a 41mm piston so smaller than a RD/TZ caliper piston which has 48mm and all are lighter than a RD/TZ caliper even with the additional bracket. All of these calipers are period correct. But for example a brake caliper has not to be period correct anyway. As long as it has not more than 4 pistons and axial mounted it is okay for us.
I know of a cheap mass production cast wheel which could be converted for use in a RD. 8) And they have the benefit to look a bit like Champagnolo mag wheels. Though a bit of machining is required but nothing serious. To see on this bike a friend of mine build 10 years ago and I sourced the wheels for him. They are Kawasaki GPZ305 wheels in the dimensions 1,85"x18 front and 2,15"x18 rear. And yes, the GPZ normaly has belt drive no chain. And they are light.


Regards Uwe
« Last Edit: March 18, 2021, 11:00:12 PM by german »
Classic Racers do not hide the ashes, they keep the fire burning
Yamaha DS7, RD250, RD400, Yapol TZ250B, Daspa TZ350, FZ750/1000, Honda RS125, Jackson Special 250, Höpfner-TD3, Hejira PE250, Broadstock F350 Sidecar, Honda RS250/1990

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Re: RD350 Track Bike build
« Reply #311 on: March 18, 2021, 11:07:42 PM »
That's NICE!!!!!!!!!!!!!!!

I think those wheels would look great on an LC too

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Re: RD350 Track Bike build
« Reply #312 on: March 18, 2021, 11:11:46 PM »
Tony,
the above is a LC.  ;)
Regards Uwe
Classic Racers do not hide the ashes, they keep the fire burning
Yamaha DS7, RD250, RD400, Yapol TZ250B, Daspa TZ350, FZ750/1000, Honda RS125, Jackson Special 250, Höpfner-TD3, Hejira PE250, Broadstock F350 Sidecar, Honda RS250/1990

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Re: RD350 Track Bike build
« Reply #313 on: March 19, 2021, 07:17:21 AM »
Yes, you remind me about those  Gpz305 wheels now.  They do look like Campags but, I discounted them as needing a bit of engineering to make a decent rear sprocket adaptation. Typical! A good looking wheel comes along, with Belt Drive!  >:(
I thought that would also be tight in an RD or TZ swing arm with the sprocket adaptation.  The LC has a wider swinger at the rear, including the aftermarket one on that bike.
Thanks for the details on the brakes.  I still find the look and real race history of the RD steel calliper is far stronger than the Lockheed.  "Period" rules would make me mad if trying to race competitive. There are so many expensive ways of getting around the regs.  For instance, you can use almost any modern fork tech, as long as the forks don't have visible adjusters.  No, I find all that too silly and I am happy building my fun track bike that has a lot of real original parts. :)
Cheers

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Re: RD350 Track Bike build
« Reply #314 on: April 08, 2021, 10:59:28 AM »
Steady progress on the RD350 Track bike.  I almost thought Spring was here but, it has snowed since!  ???
"Small" but time-consuming jobs are coming along.  The fitting of the exhausts is one and getting the swing-arm play shimmed is another.  The needle bearing swing arm modification gives a very nice and accurate swinger mounting.  However, when tightened-up there is about 1.2mm side to side movement.  The RD250/400 manuals state 1mm movement.  ???  But, that "1mm movement" really relates to wear in the standard plastic bushes. The manuals only state that you should "refit the original shims" and do not  mention the amount of side-to-side on the bearings.  My free-play is zero but the side-to-side is 1.2mm.   ::)
So, I decided to dig deeper..   There is little extra info in the LC manuals but, the YPVS manual has more info!  :)
The 350YPVS info says the same 1.0mm max play or wear in the bearings but, it also states the side-to-side movement should be 0.1 to 0.3mm or, 4 to 12thou inch. Furthermore, it says the shims should be equally set on each side.  This all makes sense.  :)
So, I am just waiting for a suitable selection of shims to arrive, I reckon I will fit a 0.5mm one each side and get just 0.2mm side-to-side left.   :)
The exhausts that I am trying are used 350LC/YPVS, possibly Swarbrick.  Now, as far as I can discover, these are not the best I can get, but I can't afford any others this year so it is Hobsons' choice!  :D
I expect that they will run fine and it is better to use the bike this year than just wait till next year!  ;)    My plan is to get a set made to match by Mick Abbey in the Autumn.  Mick has had great success with his pipes and so, that is the way to go.  In the meantime, I am trying to sort out the mountings.   ;D
Getting there- slowly!

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