Topic: Building of a CB500 classic racer

[Howell]

hei rene,

i would make that wheel fixed instead of spring loaded

TG

 

I'll see in practice how it works and if it's robust enough , maybe I have to tighten it , only removing than the spring and fasten the nuts at the frame side
.

[paulages]

Hey René,

Did you consider the 'old' ATK system? Are you familiair with that? It contained a roller above and under the pivot of the swingarm. Kept the chainslack even on shocktravel. Must have a article about it 'somewhere'.

Cheers, Rob

Hey Rob,

I know that system  a little bit complex to make that , but this took only two hours to make it.


gr.René

My race bike has a tensioner mounted above the swingarm pivot, homemade and not too complicated. I'll see if I can find a picture of it. I also have a spare CB750 tensioner that I thought about using in the same way, but was concerned about getting the wheel over the pivot point, and like TG was concerned about the spring being strong enough to overcome heavy loading.

Looks great though.. let us know how well it works.

[turboguzzi]

here you go

i now see that its two nylon blocks, one in front of the bracing triangle, one behind. the bolt goes through the strip. in four seasons chain consumed about 6-8mm of the slider

[mec]

here you go

i now see that its two nylon blocks, one in front of the bracing triangle, one behind. the bolt goes through the strip. in four seasons chain consumed about 6-8mm of the slider

looks good
mec

[turboguzzi]

here you go

i now see that its two nylon blocks, one in front of the bracing triangle, one behind. the bolt goes through the strip. in four seasons chain consumed about 6-8mm of the slider

looks good
mec

hei mec, what are you building these days?

TG

[mec]

hi,
during x-mas holydays i built some toys for the kids. the last days i welded (repaired) a broken ducati crankcase and did some aluminium fuel tank repairs. i gave my (non/bad running) cb1100r a last try, reworked the carbs a fourth time, had a look at the wiring, tested all electric/electronic stuff for proper numbers, changed to cbr600 coils and now...it seems to run. idles great and throttle response is ok. it took me two days and i was more than one time to send it to hell.
i am working on my dry slipper clutch for my sohc 750. i will start a thread in the near future.

mec

[Really?]

What's the wire on the sprocket bolts supposed to hold?  Not the bolts from turning.

[turboguzzi]

What's the wire on the sprocket bolts supposed to hold?  Not the bolts from turning.

exactly that, prevent the bolts from becoming loose. just like the bent tabs you will find in a stock motorcycle in critical areas like rear sprocket and brake discs bolts.

[Really?]

Not done very efficiently then.  It should be redone.  The main idea is that if one bolt starts to loosen it tightens the other.  In the case of the sprocket, those bolts look like they can turn multiple times before the wire would even come into play.

It should look more like this.  Even in this pic it is not quite right but it is far more efficient for its purpose than what is on the sprocket.



This is one of the big reasons airplanes generally do not fall out of the sky or thing fall off of them while they are in the sky.

[turboguzzi]

sharp eye,

been in aeronautical R&D for five years, including working hands on with the mechanics in the hangars, so have a rough idea of what you are talking about

agreed that it's a half assed lockwire job but when you just swapped sprockets and have just a few minutes before putting on your leathers for the race, that's the outcome working the lockwire pliers in that tight spot is a PITA... bear in mind also that it's only for some extra safety, the stock setup doesnt have lock tabs there.

TG

[MRieck]

Not done very efficiently then.  It should be redone.  The main idea is that if one bolt starts to loosen it tightens the other.  In the case of the sprocket, those bolts look like they can turn multiple times before the wire would even come into play.

It should look more like this.  Even in this pic it is not quite right but it is far more efficient for its purpose than what is on the sprocket.



This is one of the big reasons airplanes generally do not fall out of the sky or thing fall off of them while they are in the sky.

You're supposed to bend those pig tails back so you don't stab yourself. Ouch!;)

[Howell]

To adjust the preload of the fork spring I made this thing:

[turboguzzi]

nice, and now you have also a piece of italy on your bike, valter moto make beautiful stuff.

I use the same solution, a threaded 8mm rod attached to the cap, just dont have the external adjuster

TG

[Howell]

nice, and now you have also a piece of italy on your bike, valter moto make beautiful stuff.

I use the same solution, a threaded 8mm rod attached to the cap, just dont have the external adjuster

TG

TG we have some more italian pieces on it , Tarozzi clipons and last year also a rearset.
The valter moto caps were on clearance sale , these ones are made for 17 mm boltheads.
 

[Ricky_Racer]

Howell, about a pic of the Italian rearsets? What brand did you choose? Thanks! RR

[Howell]

Howell, about a pic of the Italian rearsets? What brand did you choose? Thanks! RR

The rearset is also Tarozzi , but for this year we gonna use a homemade rearset , much lighter and with little bearings in the shift and brakepedal .
The Tarozzi's rotate directly on the mounting bolts with the footpegs.
Homemade rearset

[Ricky_Racer]

Thanks, Howell!  Yeah, the only thing I dislike about the Tarozzis (other than the oversized shift pad) is the fact that the linkage and footpeg both move.  Seems to be an Italian design preference.

Good luck in the spring races!  RR

[Howell]

rene, in my bike i also have a teflon chain slider at this point that raises the chain above the triangle bracket and it also helps keeping more constant chain  tension.

since i run quite a strong angle of swingarm, without it the chain becomes too slack when the suspension is fully open.

its a bit like they use in off-road bikes.

After Turboguzzi came with the idea of a chain tensioner , I have made one this afternoon.
Therefore I used the roller and bearing of an old CB750 primary chain tensioner.
On the paddockstand it works , I hope also on the track.

Looking on the internet site of Cycle X I saw that they sell complete rearchaintensioners

[bwaller]

It's obvious you're trying to improve the changing tension issue Howell, did you have problems last year without one?

I was going to make a spring loaded tensioner too, but might just mount a dirt bike chain roller under the swingarm pivot for now if it will help. You never had an issue with yours TG?

[RustyOlive]

Howell, about a pic of the Italian rearsets? What brand did you choose? Thanks! RR

The rearset is also Tarozzi , but for this year we gonna use a homemade rearset , much lighter and with little bearings in the shift and brakepedal .
The Tarozzi's rotate directly on the mounting bolts with the footpegs.
Homemade rearset

hmmm? I really like the looks of this set up. Looks like there is lots of playing around room to finess that sweet spot... Might have to steal this idea for my own build. =)

[Howell]

It's obvious you're trying to improve the changing tension issue Howell, did you have problems last year without one?

I was going to make a spring loaded tensioner too, but might just mount a dirt bike chain roller under the swingarm pivot for now if it will help. You never had an issue with yours TG?

Last years the chain touched often the uppersite of the swingarm, because we use 2 cm longer shocks than the originals ,and by doing that the angle of the swingarm changed.
For this season we gonna use a 2 cm longer swingarm and now the chain touches the swingarm permanent without a tensioner

[turboguzzi]

Brent,

first try was with some black plastic (?) which wore out fast. then switched to white nylon (hope that what it is, so more ?? ) and never touched it again in 3.5 yrs. like i said just a few mm of wear.

cant really explain, but somehow the spring tension doesnt "feel" right, top run of the chain will get slack on over-run?

with a fixed block, the change in arm angle gets compensated by less "break" in the chain bottom run, so tension remains equal.  i would do it fixed.....

then there's the question of sliding vs. roller.... less moving parts sounds better to me

TG

[bwaller]

I have this roller and will weld in a bracket tomorrow as near the swingarm pivot as possible. I checked chain tension within the arm travel and it does slacken the more the shocks compress, so as mentioned this may help.

Thanks.

[Retro Rocket]

I have a GSXR swingarm and it already has the white plastic chain guide on it so thats what i am using...

Mick

[simon#42]

i use PTFE for all mine , its as slippery as a slippery thing and never wears out . you can buy it in blocks or bars its a bit more expensive than plastic but does last better . dont like the idea of rollers , they come standard on the rs 125 hondas i run and we are forever changing them .