FXR top speed?

[RDjase]

What is a FXR's top speed with standard 14/49 gearing?

My son Tyler rode his at Manfeild in the weekend (on the back track, on Saturday) and had a ride at lunchtime on sunday. He said it wouldnt rev anymore and I assume it was on the rev limiter.
It was windy and had a tail wind on the back straight, wasn't missing/rev limited on the front straight

What is the rev limit ?

What are the gearbox ratio's ?

What is the primary ratio ?

I will do some maths and work out the speed

[Yow Ling]

a real good one will do about 140
rev limiter is 12900 or 13000

go to fxr150.co.nz most tech info is there

[EJK]

14 Front, 47 rear + 88kgs rider.

148kph on dashboard wtih about 3-400rpms left to the limiter.

[RDjase]

a real good one will do about 140
rev limiter is 12900 or 13000

go to fxr150.co.nz most tech info is there



He is a light weight, 45kg ish with his gear on, Bike has clipons, RS125 tail piece, no road gear, stock carb , pod filter, raised the needle one groove , and a short pipeand muffler. I made a wiring harness so I didnt cut up the original. It could be a road bike again if I weld on the rear subframe....................doubt that will ever happen tho

I will check out the fxr forum,

Cheers

[RDjase]

Transmission:
Clutch: Wet multi-plate type
Transmission: 6-speed constant mesh
Gearshift pattern: 1 down 5 up
Primary reduction ratio: 3.500 (70/20)
Final reduction ratio: 3.428 (48/14)
Gear ratios, Low: 3.000 (33/11)
2nd : 1.857 (26/14)
3nd : 1.368 (26/19)
4th : 1.095 (23/21)
5th : 0.923 (24/26)
Top : 0.800 (20/25)
Drive chain: RK 428HO, 132

Is that 1st gear ratio correct?

Seems a big jump into 2nd, havnt riden my sons bike enough to take any notice, just a few laps at Roys Hill

[koba]

Best speed at the sprints for a standard road one was 127.5.
Thats real speed, his speedo was reading somthing silly high.

[Kickaha]

Best speed at the sprints for a standard road one was 127.5.
Thats real speed, his speedo was reading somthing silly high.

When I ran my one through a flying km it was reading 140 and doing 121, that was a stocker

[koba]

When I ran my one through a flying km it was reading 140 and doing 121, that was a stocker

True, So was this.
Maybe he had the mirrors off and the like but he rode it to the event.
It was a perfect day on a flying 1/4. Think the runup is 2.2km. the course is ever so slightly down hill.

Gotta love the cheapo speedos!

[Str8 Jacket]

I may, or may not have seen 144 on my speedo this morning. Must've been going damn near 120 cause I was overtaking people! :eek:

[Buddha#81]

I may, or may not have seen 144 on my speedo this morning. Must've been going damn near 120 cause I was overtaking people! :eek:

Reckless fool :woohoo:

[Shorty_925]

What is a FXR's top speed with standard 14/49 gearing?

My son Tyler rode his at Manfeild in the weekend (on the back track, on Saturday) and had a ride at lunchtime on sunday. He said it wouldnt rev anymore and I assume it was on the rev limiter.
It was windy and had a tail wind on the back straight, wasn't missing/rev limited on the front straight

What is the rev limit ?

What are the gearbox ratio's ?

What is the primary ratio ?

I will do some maths and work out the speed

Yea I heard him over the back on the limiter, thought it was on the CBR though?

[Str8 Jacket]

Reckless fool :woohoo:

Im training so that I can ride the Weds night rides here in Welly.

[Number One]

Im training so that I can ride the Weds night rides here in Welly.

You trying to have to try talkin your way out of another ticket hun? :shutup:

Perhaps we'll be seeing an almost identical thread but with a slightly different outcome - take it easy racer girl ;)

[avgas]

They get to 140 fine, its getting them to 152 (on speedo) which is difficult......take the distance it took you to get from 0-140.....and triple it to get to 152.

FYI
152 on speedo works out as 135kph on the radar.
Which was a $330 fine.....many moons ago.

[woodyracer]

At hampton i was hitting 160km/h or so down the back straight and i passsed modified ones with ease.. so i would say a good stock one would be doing around 130km/h...

[RDjase]

Yea I heard him over the back on the limiter, thought it was on the CBR though?

He had fun on the CBR but it wasnt on the limiter, the FXR was:shit: Bloody hoon :yes:

Transmission:
Clutch: Wet multi-plate type
Transmission: 6-speed constant mesh
Gearshift pattern: 1 down 5 up
Primary reduction ratio: 3.500 (70/20)
Final reduction ratio: 3.428 (48/14)
Gear ratios, Low: 3.000 (33/11)
2nd : 1.857 (26/14)
3nd : 1.368 (26/19)
4th : 1.095 (23/21)
5th : 0.923 (24/26)
Top : 0.800 (20/25)
Drive chain: RK 428HO, 132


13000rpm divided by 3.5 (primary ratio) = 3714rpm (clutch hub rpm)

3714rpm diveded by 0.800(top gear) = 4642rpm (front sprocket rpm)

4642rpm diveded by 3.5 (final drive, 49/14) = 1326rpm (wheel rpm)

1326 x 0.001795 ( wheel circumfrance in Km, 1.795 mtr) = 2.38 kpm (kilometres per minute)

2.38 x 60 = 142.8 kmh


If you work out the wheel circumfrance by the 100/80 17 sizing (aspect ratio over width the wheel diameter ) = 1.855 mtrs. I measured the wheel cicumfrance from the valve down, marked the concrete and measure the length after one turn back to the valve down
Dont know if there would be any tyre swell at those speeds to change the amount?

When we were working out ratios and speeds with my mates drag bike they had 2 height/circumfrace changes from tyre swell. It was doing 145mph tho

[RDjase]

I may, or may not have seen 144 on my speedo this morning. Must've been going damn near 120 cause I was overtaking people! :eek:

you must have been doing about 12500rpm in top when that cop pulled you over for a chat Hels:gob:

[grantnz]

Gearshift pattern: 1 down 5 up

What you talkin' 'bout Willis???

Everyone knows FXR gears go 1 up, 3 down, 1 up and then down for the last 2 to hit 2nd.
A little confusing ,I know, but anyone with half a brain can do it.

[Henk]

Huh? .

[RDjase]

Gearshift pattern: 1 down 5 up

What you talkin' 'bout Willis???

Everyone knows FXR gears go 1 up, 3 down, 1 up and then down for the last 2 to hit 2nd.
A little confusing ,I know, but anyone with half a brain can do it.

It was pretty spectacular and painfull all at once too aye mate:shit:

[Damien_Toman]

With 14/49, the standard gearing which I am using now (using std. wheels and GP125 slicks - important), I have clocked 142kph at Pukekohe on the standard speedo, on the straight, which I think is slightly down-hill towards the hairpin. That is with a modified engine, XR250 carb and custom exhaust.

On my drive to Auckland from Kaiapoi (nr. ChCh :)) on the FXR (picking up my TradeMe purchase), I recorded a maximum of 138kph on the speedo with standard road tyres and an unmodified engine that was using 12/49 gearing, downhill with the wind on my back and on the limiter :). The GPS said 118kph. The standard 14/49 would have been more appropriate for that journey (covered in a thread about 1 year ago).

[avgas]

With 14/49, the standard gearing which I am using now (using std. wheels and GP125 slicks - important), I have clocked 142kph at Pukekohe on the standard speedo, on the straight, which I think is slightly down-hill towards the hairpin. That is with a modified engine, XR250 carb and custom exhaust.

On my drive to Auckland from Kaiapoi (nr. ChCh :)) on the FXR (picking up my TradeMe purchase), I recorded a maximum of 138kph on the speedo with standard road tyres and an unmodified engine that was using 12/49 gearing, downhill with the wind on my back and on the limiter :). The GPS said 118kph. The standard 14/49 would have been more appropriate for that journey (covered in a thread about 1 year ago).
You need to find a longer straight. :innocent:
Like I said earlier. You can get it to around the 140 mark (speedo speed) in about 1km of straight. If you have about another 2-3km you can get another 10ish kmh before the valves start bouncing.

The RG was way more fun doing it however........

Ah I miss my old 2am work runs........too broken to do them now.

Note: my recommendations WILL fuck engines. May my ol' RG rest in peace.

[phoenixgtr]

I had my old road going FXR say 155 on the speedo a few years ago. That was a good engine that one. Far better than my bucket...maybe not now it's not standard anymore

[gav]

The only time my FXR ever sees a speed anything like that, its strapped down in the back of my van! :innocent:

[woodyracer]

The only time my FXR ever sees a speed anything like that, its strapped down in the back of my van! :innocent:

and the only time i ever sees a speed anything like that in a van is when the boys from top-gear are dropping it from a great height :innocent:

[EJK]

Question:
If rear was raised by two teeth, how will it affect the bike's riding?
Less top speed but incrased acceleration?

[RDjase]

Question:
If rear was raised by two teeth, how will it affect the bike's riding?
Less top speed but incrased acceleration?

Yep, thats what it will do. It works more if you change the front sprocket. Divide the rear teeth by the front to get your final drive ratio




Transmission:
Clutch: Wet multi-plate type
Transmission: 6-speed constant mesh
Gearshift pattern: 1 down 5 up
Primary reduction ratio: 3.500 (70/20)
Final reduction ratio: 3.428 (48/14)
Gear ratios, Low: 3.000 (33/11)
2nd : 1.857 (26/14)
3nd : 1.368 (26/19)
4th : 1.095 (23/21)
5th : 0.923 (24/26)
Top : 0.800 (20/25)
Drive chain: RK 428HO, 132


13000rpm divided by 3.5 (primary ratio) = 3714rpm (clutch hub rpm)

3714rpm diveded by 0.800(top gear) = 4642rpm (front sprocket rpm)

4642rpm diveded by 3.5 (final drive, 49/14) = 1326rpm (wheel rpm)

1326 x 0.001795 ( wheel circumfrance in Km, 1.795 mtr) = 2.38 kpm (kilometres per minute)

2.38 x 60 = 142.8 kmh


If you work out the wheel circumfrance by the 100/80 17 sizing (aspect ratio over width the wheel diameter ) = 1.855 mtrs. I measured the wheel cicumfrance from the valve down, marked the concrete and measure the length after one turn back to the valve down
Dont know if there would be any tyre swell at those speeds to change the amount?

When we were working out ratios and speeds with my mates drag bike they had 2 height/circumfrace changes from tyre swell. It was doing 145mph tho

Just put your sprocket sizes/ final drive ratio into this equation to work it out

[koba]

Question:
If rear was raised by two teeth, how will it affect the bike's riding?
Less top speed but incrased acceleration?

That's the theory.

Although in practice for some bikes a change like that may also show a HIGHER top speed because the engine is able to pull better in top gear.

[richban]

At Taupo this year I hit the limiter in top with the standard gearing. 14/49. Now that works out to be about 137kph based on the numbers given in this post. Limiter 12500rpm. So I thought I would use this equation to work out what gearing would get you to the magic 100mph. 16/47 will do it. 165kph on the limiter. I have run a 16 49 at Manfield but the bike was going shit so I went to a 15 front. Still it was no where near the limiter then. It has more power now but me thinks it would take some serous ponies to get 95kgs of me 165.

[all4A50s]

At Taupo this year I hit the limiter in top with the standard gearing. 14/49. Now that works out to be about 137kph based on the numbers given in this post. Limiter 12500rpm. So I thought I would use this equation to work out what gearing would get you to the magic 100mph. 16/47 will do it. 165kph on the limiter. I have run a 16 49 at Manfield but the bike was going shit so I went to a 15 front. Still it was no where near the limiter then. It has more power now but me thinks it would take some serous ponies to get 95kgs of me 165.

Is that with the bike strapped into the back of the van used in Top Gear?:innocent:

[Bert]

Is that with the bike strapped into the back of the van used in Top Gear?:innocent:

heeehhee. I suspect he will now completely shame the GTR250 riders....

Try this excel file, sorts out the gearing / speed for all gears, might be of some use.

[koba]

At Taupo this year I hit the limiter in top with the standard gearing. 14/49. Now that works out to be about 137kph based on the numbers given in this post. Limiter 12500rpm. So I thought I would use this equation to work out what gearing would get you to the magic 100mph. 16/47 will do it. 165kph on the limiter. I have run a 16 49 at Manfield but the bike was going shit so I went to a 15 front. Still it was no where near the limiter then. It has more power now but me thinks it would take some serous ponies to get 95kgs of me 165.

Keen to try it in the sprints sometime?

Chuck Kyle on it or somthing...

[richban]

Keen to try it in the sprints sometime?

Chuck Kyle on it or somthing...

True when does that happen? We could have a weigh off to find the skinniest pilot we have.

[koba]

True when does that happen? We could have a weigh off to find the skinniest pilot we have.

Do we need to weigh to work out Kyle is tiny?

Caleb would be the only one close...

I'm not sure when the next sprint event is going to be but we should have a bit of notice before it. The website is: http://www.cliffhanger.org.nz

[Kendog]

Damon is another little fella.

[koba]

Damon is another little fella.

Yea, growing rapidly tho!
It makes me feel old how much he as grown since we all first met him!

[RDjase]

Do we need to weigh to work out Kyle is tiny?

Caleb would be the only one close...

I'm not sure when the next sprint event is going to be but we should have a bit of notice before it. The website is: http://www.cliffhanger.org.nz

Ran a 15/49 at Track 1 Taupo with a TZ125 fairing on Tylers FXR, he said it was screaming but didn't hit the limiter on the loooong straight, must have been close

He weighs maybe 50KG with his gear on, still running stock engine, carb. Just got a different pipe.

About 150kmh? after doing the maths

Bigger carb and a 16, Want to get the Ton out of a FXR:scooter::woohoo:

[avgas]

Now that works out to be about 137kph based on the numbers given in this post.
I must have done that here
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Speedo read 153kph at the time (1999)

Out of intrest also my RG read 210kph on the speed, same year.

Good bit of road for speed testing.

[koba]

Ran a 15/49 at Track 1 Taupo with a TZ125 fairing on Tylers FXR, he said it was screaming but didn't hit the limiter on the loooong straight, must have been close

He weighs maybe 50KG with his gear on, still running stock engine, carb. Just got a different pipe.

About 150kmh? after doing the maths

Bigger carb and a 16, Want to get the Ton out of a FXR:scooter::woohoo:

Do it quick before he grows too much more!!



Speedo read 153kph at the time (1999)

Out of intrest also my RG read 210kph on the speed, same year.

Good bit of road for speed testing.

I've also had my RG150 reading around 210, real speed was measured at 160!

[RDjase]

Do it quick before he grows too much more!!





Tyler is a diet of bread and water, FXR on a diet of Cams, Compression and Carbs

100MPH has got to be done on a FXR !

[grantnz]

Tyler is a diet of bread and water, FXR on a diet of Cams, Compression and Carbs

100MPH has got to be done on a FXR !

Has to be with photos. There is a new speed camera set up in Bulls which takes pics both ways, gets you comming and going. Can be confirmed with the most profitable revenue camea in NZ just 5kms down the road at Sanson. So 3 pics for the ton up FXR and job done. Let me know if you need accomodation in Bulls, got a couple of mates there.

[RDjase]

Has to be with photos. There is a new speed camera set up in Bulls which takes pics both ways, gets you comming and going. Can be confirmed with the most profitable revenue camea in NZ just 5kms down the road at Sanson. So 3 pics for the ton up FXR and job done. Let me know if you need accomodation in Bulls, got a couple of mates there.

Need a flying 1/4 mile, better not let a 13 year old loose on the road on a race bike at the Ton !

Not sure about the rules for a flying 1/4 at a closed road event if you havnt got a road licence, he has a MNZ one

[koba]

Need a flying 1/4 mile, better not let a 13 year old loose on the road on a race bike at the Ton !

Not sure about the rules for a flying 1/4 at a closed road event if you havnt got a road licence, he has a MNZ one

He need your signature and consent, otherwise I think he is right.

[Hiflyer]

Need a flying 1/4 mile, better not let a 13 year old loose on the road on a race bike at the Ton !

Not sure about the rules for a flying 1/4 at a closed road event if you havnt got a road licence, he has a MNZ one

IIRC if the road is closed you don't need a road licence... although at Meremere you need a road licence and wof etc etc.

It might vary from event to event

[RDjase]

IIRC if the road is closed you don't need a road licence... although at Meremere you need a road licence and wof etc etc.

It might vary from event to event

I have seen some events say a road licecne or a race lincence but only if you are over 16. Tyler has Junior Road race licence, Can get a Senior when he is 16

There are 2 differnt type of road closures too, Cant remember what the diff is but it in the MNZ rules of local council regulations

Did you get to the track last weekend?

[Hiflyer]

I have seen some events say a road licecne or a race lincence but only if you are over 16. Tyler has Junior Road race licence, Can get a Senior when he is 16

There are 2 differnt type of road closures too, Cant remember what the diff is but it in the MNZ rules of local council regulations

Did you get to the track last weekend?

Sure did! Got burnt to shit but had so much fun... going to try find some leather pants that zip to my jacket before the nest one so I can have a wobble on the track by myself.

[Dutchee]

Sure did! Got burnt to shit but had so much fun... going to try find some leather pants that zip to my jacket before the nest one so I can have a wobble on the track by myself.
Did you and Henk establish what size you are?

It was great to meet you and when I was in lap scoring I did spot you heading out to flag quite a few times (thanks for that).

As for the burnt bit, went to speedway to spectate the week before, left sunscreen at home, got burnt, peeled, buckets Saturday same scenario, same result. Can't believe we both forgot that stuff.

[Hiflyer]

Did you and Henk establish what size you are?

It was great to meet you and when I was in lap scoring I did spot you heading out to flag quite a few times (thanks for that).

As for the burnt bit, went to speedway to spectate the week before, left sunscreen at home, got burnt, peeled, buckets Saturday same scenario, same result. Can't believe we both forgot that stuff.

Na we established we're "About the same size" and that's the closest we got :facepalm:

I thougth the view from the first straight was good, then I went to the flag post atthe infield (number 3 I think) and THAT was cool!

[avgas]

I've also had my RG150 reading around 210, real speed was measured at 160!
Really? Should really put the front wheel down then ;)

Nah I found the Speedo was about 10-20% out (depending on where you are on it). When I was doing 180, the 955i was doing 175. Had it radar'd once at 174 (long walk home).
The guy that worked the engine reckoned it was good for 200, but I reckon 180-190 is more realistic. Was a bummer they stopped the route pkj sprints - would have been keen to know.

I miss that bike........but not the lack of torque below 10,500.