For anyone with a passion of 2 stroke bikes

phil G

04/05/2006 at 14:56

EddieJ wrote

Thinking about it further, with the set up running above, there is an degree of free movement at the swingarm slotted end to allow for adjustment of the chain tension and wheel travel. I pressume that with this set up there must be a very very slight amount of time delay before the brake is 100% effective. With the underslung torque arm position, there is no slack and it is a direct pull.
If this was the reason, then I doubt that anyone but a top level GP rider of the day would ever notice the change.
Interesting that it made such a big difference on the MX bikes that had drum brakes.

After having a think, i remember it a bit more detail on this.The important point is that drum rear brakes were rod operated , not hydraulic.

Because having the torque arm attached to the frame kept the backing plate in the same place realative to the brake pivot (rotationally , not heightwise) , the feel of the pedal would vary dependant on how much travel was being used . This meant that when you braked hard and the front dived , the rear would be lighter and the swingarm would be 'below centre' relative to the straight line between the swingarm pivot and the front sprocket, which is the point at which the the wheel is furthest away from the front sprocket, straight line wise. Braking with the rear like this meant that the suppleness at the beginning of the stroke was being acted on by the braking force , which meant the rear end would hop all over the place going into corners .
By allowing the backing plate to move relative to the swingarm , the brake force didn't act through the suspension in the same way .

The only thing i can honestly say that demonstrates this well is that bastion of motorcycle design, the C90. If you ever rode one , and pulled on the front brake , the front would actually rise. The effect there is more severe because the length of the front swingarm is very short , but the mechanical principles are the same.

www.aliceracing.com

ickle pob

06/05/2006 at 16:01

just picked this up.

Needs de-stickering and repainting in my own colours like the ZXR was

Another ZXR400 racebike
2007 ZX6R Racebike
2004 SV650s K4 Roadbike
EX-Gilera 180 Runner 2T Wheelie Monster
Ex-CBR600rr racer
Ex-Honda RS125 racer
EX-Polini GP3 proddy racer
EX-Polini XP4 Motard racer
EX-Polini 910 Carena racer
Moped mayhem endurance racer - no more
EX-POLINI SCOOTERINO RACER
EX-ZXR400 National Racer
EX-Steel Frame CBR600 Racer
EX-CBR600 KRC Endurance racer
EX-1/5th scale RC bike racer
And Ex-R1 Formula1 sidecar passenger/crash test dummy

EddieJ

06/05/2006 at 17:54

Edited: 16/03/2008 at 20:50

ickle pob

06/05/2006 at 19:32

EddieJ wrote

Good lad!!

They are fantatic bikes, unless you are racing against them Then it is a case of counting the laps or even corners and waiting to get in the middle of 125 sandwich..

With ref your weather station and base settings question in relation to carrying it out on a dyno, I seem to remember a debate a while on another forum about this. I think that it may have been on two-strokes.com If I can find the thread I will post it up for you.

I now have a weather station, so can hopefull get a back to back base setting with the sellers one at the weekend. I don't think i will get to aintree next saturday, as there is a time and money issue. Bought the bike, warmers, transponder, leather alterations and name, and the bike is getting a piston and ring just to be safe before i use it, and with the entry and juice as well it's just too much for one wage packet. Also it would be the first time riding it, so i think i am going to get a trackday at Oulton ( only 20 miles away ) or a wednesday afternoon at Mallory just to get a feel for the bike in a less stressful environment.

VR46

07/05/2006 at 10:10

Kev_YZF wrote

All with the cagivas for me....

Sex weeeeeeee

Wanna buy one ?

www.classic-motorbikes.com/stock.asp?StockID=102717

If I was rich ....................

but I'm not

Tayto.King

07/05/2006 at 19:12

Anyone on here ever built a Cagiva Mito 125 with a 350ypvs lump fitted,as i've seen a couple in the past on German websites

Can't afford the 500's so i'd like to build one.

priller

08/05/2006 at 16:11

ask on 125ccsportsbikes.com, there's 3 on there & a rs125 with a 350 ypvs engine.

Bevans MC Cardiff | VD Chat |

jap4performance |

PJ Motorcycle Engineers |

SuperBike

FB74

08/05/2006 at 17:36

Hi, I love 2 strokes...this is mine. Ciao and I hope you like it!

EddieJ

08/05/2006 at 18:33

Edited: 16/03/2008 at 20:51

demographic

08/05/2006 at 18:43

FB74 wrote

Hi, I love 2 strokes...this is mine. Ciao and I hope you like it!

Very nice indeed, what radiator are you using for it? that looks different?

What did you change on the frame to fit the engine in? Must have done the front frame members round the Y piece and how did you make the head steady?Any detailed pics of the frame mods?

What tank fits it as one problem I have spotted with 250/500 hybrids is that you can only fit a 250 tank on there which limits capacity.

I could eat my dinner of that bike its sooo clean.

FB74

08/05/2006 at 21:30

Thank you guys.
I'm sorry but my english is very rusty and I'm not able to understand all that you write in particular tech words...In any case I hope you can understand what I'm writing:

1) 1999 cr250 Frame: you have to modify engine front connections, the X on exhaust ring(to lift up in order to give space to exhaust), the head support, swingarm/engine spacers..

2) radiator: handmade with cr500 volume
3) Tank: Alu-handmade tank in order to give more space to the increased head of 500 cc. You can use also the standard tank but you have to lift up plastics.

The bike is nicer than rider

I'd like to be better

brownie

08/05/2006 at 22:07

Beautiful FB, thank you for posting your pictures.

Free secure file hosting and transfer service

demographic

09/05/2006 at 09:45

FB74 wrote

Thank you guys.
I'm sorry but my english is very rusty and I'm not able to understand all that you write in particular tech words...In any case I hope you can understand what I'm writing:

1) 1999 cr250 Frame: you have to modify engine front connections, the X on exhaust ring(to lift up in order to give space to exhaust), the head support, swingarm/engine spacers..

2) radiator: handmade with cr500 volume
3) Tank: Alu-handmade tank in order to give more space to the increased head of 500 cc. You can use also the standard tank but you have to lift up plastics.

The bike is nicer than rider I'd like to be better

Yes, very good thank you.

Your English is far better than my Italian so don't worry

nuttynick

09/05/2006 at 18:11

A few pics of my bike as this is a Two-Stroke thread:smoke: Likes Rich's, an LC hybrid with a YPVS motor, but mine had a Banshee quad racer top end and KR1S carbs

EddieJ

09/05/2006 at 19:01

Edited: 16/03/2008 at 20:51

nuttynick

09/05/2006 at 20:06

It's had a nut and bolt rebuild and is still an on going project(do you ever finish them???) All the work is by myself, with a few parts made by people like Nigel Kimber (NK Racing) The banshee top end is a bolt on fit once you block off the lower water passages as the YPVS crankcases are slightly different around the front of the cylinder. It gets well thrashed, including a good run from Chelsea Bridge to the Ace Cafe for Yamaha day the other week.

y2blade

09/05/2006 at 20:52

nuttynick wrote

A few pics of my bike as this is a Two-Stroke thread:smoke: Likes Rich's, an LC hybrid with a YPVS motor, but mine had a Banshee quad racer top end and KR1S carbs

ive just CUM

very nice bike you got there nick

http://tickers.tickerfactory.com/ezt/d/4;10752;417/st/20100529/e/isle+of+man+TT/dt/6/k/b8a2/event.png

number8

09/05/2006 at 22:18

i need another 2t ....

ile always regret selling my RG250 , espically as i saw what happned to it after i sold it

looking at getting another but cant find the space or cash to do so ...

and the guy i sold it to sprayed it silver , badly and covered it in blue anodised shit!!! i spotted it on the lc forums a while back and it had been at least sprayed a decent gloss black , but why o why did the guy i sold it to destroy it so much!!!!

This is madder than the day Mr mad went ot madville on national mad day while tied to another mad thing.
You sir are mad as a baloon!
Keep it up ---- KFZ
TIT#148E/A TWO#/A/1150 (gs) 1100 (bmw s) 850(trx fighter) 750 (zx7r) 650 (sv commuter hack)
Brought to you by
--<>-- Olly Logic [TM] --<>--

Ric

09/05/2006 at 22:25

Nick, what's the top end you got on there? Is it a T-Rex?

Did you spot this one earlier on?

Team RNR

Valves are things to hold air in tyres!

Ric

10/05/2006 at 12:36

Here's a couple of for H2Simon...

Jerry Collier's ex Brian Shultz Prostock H2

Andy Haley's H2

Team RNR

Valves are things to hold air in tyres!

Bike reviews

Classifieds