Author Topic: YZ 490 TLS backing plate (Read 8436 times)

bishboy · « **on:** January 16, 2014, 06:12:24 PM »

I have a couple of YZ 490 twin leading shoe backing plates.

The first one looks to be in very good condition and looks to be powder coated $200 shipped

The second one is in good condition and looks like its been painted, but is missing a couple of things. It's missing the cotter pin on one of the arms (it's just got a bit of race wire on there at the moment) and doesn't have the spring on the outside. $175 shipped

Bump......

Just the thing needed to upgrade your pre 85 brakes

KTM47 · « **Reply #1 on:** January 16, 2014, 06:33:44 PM »

Please note!!!! Only YZ465 twin leading shoe brakes are legal for the Evolution class. Parts of non EVO legal bikes can not be used in EVO bikes. So YZ 490 brakes and forks are not legal.

Ted · « **Reply #2 on:** January 16, 2014, 07:11:09 PM »

It's OK Kev, Andrew is not trying to mislead anyone. He plainly says they are for a 490. He is also selling a pair of 490 forks in which he states he fu..ked up himself thinking they were for a 81 465. It's all good if you have a Pre 85 and need some forks and brakes.

bishboy · « **Reply #3 on:** January 16, 2014, 08:15:12 PM »

Yeah, wasn't trying to mislead anyone, that's why I'm selling them as I bought the forks and one TLS in a blonde moment and the other TLS, the seller told me it was a 465 one

Also, a good upgrade for those single leading shoe brakes, pre 85 or pre 90 only though

tony27 · « **Reply #4 on:** January 17, 2014, 07:33:04 AM »

Will fit the 465 hub but not the forks, locating lug is 45deg out

KTM47 · « **Reply #5 on:** January 17, 2014, 11:04:13 AM »

I wasn't implying Andrew was trying to mislead anyone, but I did want to make it clear that this could become an issue, particularly at the Post Classic MX Champs. I may be in a position to make some billet TLS backing plates to suit the 1981 forks. Would anyone be interested.

Kevin

Sorelegs11 · « **Reply #6 on:** January 17, 2014, 12:37:24 PM »

They came out standard on 81 IT465s so why could you not fit one to a yz?

Davey Crocket · « **Reply #7 on:** January 17, 2014, 01:06:12 PM »

This is where everybody gets confused........they are different parts....the lug is in a different position.....J models have it at 3 O'clock...H is at 1.30....forks are totally different....J has adjustable rebound on the bottom.

holeshot buddy · « **Reply #8 on:** January 17, 2014, 11:02:23 PM »

yz 490 j forks dont have adj comp on bottom they are the same as 465 forks just diff lug for brake
big advantage apparantly
but everyone runs pd valves

KTM47 · « **Reply #9 on:** January 18, 2014, 11:24:31 AM »

Quote from: holeshot buddy on January 17, 2014, 11:02:23 PM

yz 490 j forks dont have adj comp on bottom they are the same as 465 forks just diff lug for brake
big advantage apparantly
but everyone runs pd valves

You are making a good point, but the forum doesn't decide what is legal or not. Why not email the Classic MX & DT Commission through MA and ask them to consider them as carry over parts.

Ted · « **Reply #10 on:** January 18, 2014, 12:31:39 PM »

And you may have an answer by the time you reach 150 years of age

Paul552 · « **Reply #11 on:** January 18, 2014, 04:24:15 PM »

Quote from: KTM47 on January 17, 2014, 11:04:13 AM

I wasn't implying Andrew was trying to mislead anyone, but I did want to make it clear that this could become an issue, particularly at the Post Classic MX Champs. I may be in a position to make some billet TLS backing plates to suit the 1981 forks. Would anyone be interested.

Kevin

So would they be legal? (not a piss take a serious question)
If you copied a period braking part and made it from solid would it qualify?

Ted · « **Reply #12 on:** January 18, 2014, 05:36:06 PM »

Is a Karl Landraus swingarm legal? If you can answer that there's your answer.

The rules are vague Paul. Simple but open to conjecture.

I'm just waiting for the day a guy fits a supercharger inside his motor housing ( thus not altering its external appearance ) and turns up

holeshot buddy · « **Reply #13 on:** January 18, 2014, 08:26:38 PM »

nitrous would be better

strange how everyone goes on about certain model bikes rm swingarms etc
eg yz forks when there is stuff all differance the tests back in the day said the J forks
were worse than the h go figure that main reason people use them is availiability of h forks
scarce as seems funny how most maico riders run billet backing plates and torque arms and pd valves
none of which were avaliable back in the day

KTM47 · « **Reply #14 on:** January 19, 2014, 11:08:11 AM »

Quote from: Paul552 on January 18, 2014, 04:24:15 PM

Quote from: KTM47 on January 17, 2014, 11:04:13 AM
I wasn't implying Andrew was trying to mislead anyone, but I did want to make it clear that this could become an issue, particularly at the Post Classic MX Champs. I may be in a position to make some billet TLS backing plates to suit the 1981 forks. Would anyone be interested.

Kevin

So would they be legal? (not a piss take a serious question)
If you copied a period braking part and made it from solid would it qualify?

The various billet alloy Maico backing plates that are around to my knowledge have never been challenged, including the twin bolt ones, which appeared to be considered a saftey issue. So why wouldn't a billet alloy reproduction of the 1981 YZ TLS brake also be OK.

As for the Karl Landraus swingarms etc, if they were an exact replication of swingarms that were used in the day (eg Thor etc) in my opinion they would be legal, but Karl adds modern features which makes them illegal.

Also another point. The old YZ (and other brands) hubs and backing plates are magnesium and these can fail with age. So it can be considered a safety issue. This is the main reason the Maico backing plate is replaced the bolt hole that holds the brake stay arm on can break.

oldfart · « **Reply #15 on:** January 19, 2014, 11:21:51 AM »

The mere mention of the word "Safety issue" can open up a complete can of worms. Most of these old jiggers are way past there use by date and would be riddled with stress fractures in thier frame members - swing arms and brake components.

KTM47 · « **Reply #16 on:** January 19, 2014, 11:33:08 AM »

Quote from: oldfart on January 19, 2014, 11:21:51 AM

The mere mention of the word "Safety issue" can open up a complete can of worms. Most of these old jiggers are way past there use by date and would be riddled with stress fractures in thier frame members - swing arms and brake components.

Yes you could be right. However you can buy most parts for Maicos as reproduction items. (frames, swingarms, wheels, forks etc). So for safety reasons everyone should be racing Maicos. But what would be the fun in that. Just another side note. You can build a Manx Norton from brand new parts and most of the cars in the Touring Car Masters are complete rebuilds with new parts.

Also most riders aren't riding/racing their bikes at the speeds they did when they were new.

sa63 · « **Reply #17 on:** January 20, 2014, 06:01:10 PM »

Also some irony in the fact that because nearly all original rear shocks are rooted or not rebuildable , we use repro and external rebound and comp clickers are allowable (for safety!!)

So Applying that logic repro. forks with external & adjustable clickers should fine!!!

Yet non adjustable forks ie it250k/490) that came off a bike that wasn't non linkage are not legal .....!!! Hmmm!!

Makes those fox forx and yz465H a pretty valuable commodity, maybe we need repro. fox forx with clickers too!(for extra safety!!)

anyway good luck selling the TLS backing plate!!

bishboy · « **Reply #18 on:** February 17, 2014, 04:31:38 PM »

Bump......

Just the thing needed to upgrade your pre 85 brakes

evo550 · « **Reply #19 on:** February 17, 2014, 07:16:42 PM »

Quote from: holeshot buddy on January 17, 2014, 11:02:23 PM

yz 490 j forks dont have adj comp on bottom they are the same as 465 forks just diff lug for brake
big advantage apparantly
but everyone runs pd valves

I had a set of "J" forks that adjustment on bottom of fork legs...

bishboy · « **Reply #20 on:** February 18, 2014, 11:30:29 AM »

Walter, yes they do fit those forks.

tony27 · « **Reply #21 on:** February 18, 2014, 12:17:37 PM »

The plates will fit the 465 wheel but not the forks, I bought a 490 backplate to raid some parts off for my 465h & everything is a straight swap apart from the hole for connecting the brake cable is smaller on the aluminum arm

head · « **Reply #22 on:** February 18, 2014, 01:30:56 PM »