Question on Pro Twin front forks

[HDTboy]

I am going to buy and race a Penske in the back

Why not talk directly with your Penske supplier for the best option to compliment his shock? Rather than treating your motorcycle like it's a parts catalog special, perhaps you could build it as a package.

[Ivan]

Allready have talked to him
This is an old thread now lol.

[Shaun]

Why not talk directly with your Penske supplier for the best option to compliment his shock? Rather than treating your motorcycle like it's a parts catalog special, perhaps you could build it as a package.

Thanks for that mate. As of NOW THOUGH, Robert Taylor ( And who i really hope) from CKT will be doing all my fork work! I have done a sub contractor deal with Robert, where any fork work I have said I will do for a customer, WILL BE DONE @ CKT ( Robert T)

I will be a sales rep and set up person for riders with either Penske, (Ohlins and other CKT Product) and Traxxion fork kits, GAS CHARGED or AK20.

This means, that any rider using either product, can use me or CKT at the race track or on here, to help them make there bikes handle better/safer!

Working together with Robert again closely like this, is a win win for all involved, riders and us as well.

[svr]

This is a relatively low cost mod but its also easy to do it badly. Enlarging and adding extra holes in the bottom of the damper rods ( as per Race Tech suggested method ) MUST NOT be done in this way as you actually end up with a dead area of high speed rebound damping. Dirt bikes with 300mm of travel can get away with it, but not road race bikes with 120mm of travel. I have had this conversation directly with Paul Thede and he agrees with what I have stated.

As a brazen pitch for my business doing the job we supply Ohlins superbike springs as part of the package, the advantage here being is that we stock all the rates. If you find that you end up needing a slightly different rate to those supplied we exchange at no cost excepting courier recovery costs. Further advantages of these springs is that they are highly polished so there is less internal wall rubbing friction and they are very short but still with adequate stroke integrity. Short springs means less coils to rub and create friction and rapid oil contamination, also weight reduction.
Another thing to bear in mind is that damper rod forks are very viscosity and ambient temperature sensitive. Because there is so much badly controlled bleed they must neccessarily run around 15 weight oil in winter and 20 weight in summer, although personally I prefer to see only what centistroke rating the oils are as the only true indicator of flow rate. Such relatively thick oils can vary in characteristic enormously over the course of a day. First thing in the morning the rebound speed can be very lethargic, and yet in the middle of the day when the suns out the rebound speed is appreciably faster. For that reason dont fill it with a cheap oil that has widely varying flow chracteristics according to temperature. I dare not say it in print but there is also one high profile brand of oil that a lot of people have been duped into using in their forks that has very poor corrosion resistance properties.
The set up we provide is very well dialed and we are always available for set up advice.

Exactly! I rode my SV with a GSXR1000k2 front end for 4 years and swapped back to standard with springs and emulators for some summer protwin races - the big thing is that the oil viscosity varies HEAPS with temperature changes (thanks Robert), adjustment is a pain in the arse, and having the fork set up with enough overall compression damping means harsh high speed compression damping. Is that from crude damping or high stiction?

[Robert Taylor]

Exactly! I rode my SV with a GSXR1000k2 front end for 4 years and swapped back to standard with springs and emulators for some summer protwin races - the big thing is that the oil viscosity varies HEAPS with temperature changes (thanks Robert), adjustment is a pain in the arse, and having the fork set up with enough overall compression damping means harsh high speed compression damping. Is that from crude damping or high stiction?

A bit of both but given time ( and there is never enough of that ) I would like to experiment with a set of emulators with smaller size low speed bleed bypass holes in the poppett, combined with less preload on the stock 64lb springs or slightly more preloaded 40lb poppett springs. Essentially more low speed damping combined with less high speed. So many ways to skin the cat!

One day I am going to dyno an emulated fork.

[Ivan]

Quick question.

I rode my SV yesterday it was great.
Only problem is it has racetech emulators in it and 9 KG springs which I dont think the springs are suited for me, It was Geoff Booths old K1.
The problem I was having was under braking at Taupo especially off the long back straight I was having quite a big Dive in the suspension and I want a firmer front end, to make myself more confident of harder braking.

Could I resolve this issue by putting 10KG springs?

Any Help Appreciated

[HDTboy]

Why not talk directly with your Penske supplier for the best option to compliment his shock? Rather than treating your motorcycle like it's a parts catalog special, perhaps you could build it as a package.

This guy'd be good to listen to

[Ivan]

This guy'd be good to listen to

Im not running a Penske in it at the mo I will be tho when Finances allow.
its just a GSXR750 shock in it at momment.
I asked on here incase Robert or Shaun replyed.

I dont like PMing people its annoying for them and I dont want to waste anyones time on a question like this when Joe Average may know of a reason etc.

[Robert Taylor]

Quick question.

I rode my SV yesterday it was great.
Only problem is it has racetech emulators in it and 9 KG springs which I dont think the springs are suited for me, It was Geoff Booths old K1.
The problem I was having was under braking at Taupo especially off the long back straight I was having quite a big Dive in the suspension and I want a firmer front end, to make myself more confident of harder braking.

Could I resolve this issue by putting 10KG springs?

Any Help Appreciated

The 9s will indeed be too light but 10s may be too heavy. What is your personal height and weight in your everyday clothes?

[GSVR]

Im not running a Penske in it at the mo I will be tho when Finances allow.
its just a GSXR750 shock in it at momment.
I asked on here incase Robert or Shaun replyed.

I dont like PMing people its annoying for them and I dont want to waste anyones time on a question like this when Joe Average may know of a reason etc.

As well as the springs you could check to make sure you have the right oil level in each fork leg. And also check that the emulator relieve port springs are wound up to the sportier recommendation.

Another thing you could do it put some spacers in to put more preload on the springs. Just 5 or 10mm can make a big difference to how the bike feels.

I'd like to know what year GSXR shock you have fitted and if the spring is standard. These are generally to soft. That and the fact you have the fork legs up through the triples may make your pegs bottom out early. Aftermarket rearsets are around 25mm up and back. Was Geoff running standard rearsets when he raced it?

Congrats on the bike Ivan you will have a blast.

[Ivan]

The 9s will indeed be too light but 10s may be too heavy. What is your personal height and weight in your everyday clothes?

Ok I will find some scales and weigh myself but my height is 6 foot 1
and my rough guess to weight is 67kgs

[Ivan]

As well as the springs you could check to make sure you have the right oil level in each fork leg. And also check that the emulator relieve port springs are wound up to the sportier recommendation.

Another thing you could do it put some spacers in to put more preload on the springs. Just 5 or 10mm can make a big difference to how the bike feels.

I'd like to know what year GSXR shock you have fitted and if the spring is standard. These are generally to soft. That and the fact you have the fork legs up through the triples may make your pegs bottom out early. Aftermarket rearsets are around 25mm up and back. Was Geoff running standard rearsets when he raced it?

Congrats on the bike Ivan you will have a blast.

Geoff said he put heavier oil in the rear shock. The spring has a sticker on it with a number its yellow I can get you that number if you like I do not know what year 750 it is but it has compression and rebound as well as preload for the spring.
I was actually thinking of spacers but didnt know if this was the right way to skin the cat.
I think I might get omeone who knows a thing or 2 about these to check the emulators out asI dont want to muck around and make a pile of junk.
I dont know if Geoff was because there are no peg scrape marks on the peg from him and I guessed he would have pegged it.
I was going to get a aluminum bracket machined up that raises them I dont really wanna put them back as they fell fine were they are.


What are these spacers you talk of can I buy them through a bike shop?

[GSVR]

Geoff said he put heavier oil in the rear shock. The spring has a sticker on it with a number its yellow I can get you that number if you like I do not know what year 750 it is but it has compression and rebound as well as preload for the spring.
I was actually thinking of spacers but didnt know if this was the right way to skin the cat.
I think I might get omeone who knows a thing or 2 about these to check the emulators out asI dont want to muck around and make a pile of junk.
I dont know if Geoff was because there are no peg scrape marks on the peg from him and I guessed he would have pegged it.
I was going to get a aluminum bracket machined up that raises them I dont really wanna put them back as they fell fine were they are.


What are these spacers you talk of can I buy them through a bike shop?

Geoff was quick on it when he was racing and would have it set up ok.

The rearset risers are an easy way to go but you should also carry some spares for these parts as one minor off can ruin your day if you happen to snap a rearset and don't have a spare.

The spacers are nothing special and even washers the right size would do. If you know someone with a lathe they could machine up a couple of sizes in a short time.

Probably the best preparation you can do at the moment is just riding the bike. Your've identified a couple of things you want to change ie the forks diving and the footpegs. After your've done that then decide what you next thing will be. Good new sticky tyres are always a plus but it comes down to budget how often you put new ones on.

Didn't Terry Fitzgerald borrow this bike for a race down south this year when he binned his bike?

[Ivan]

Geoff was quick on it when he was racing and would have it set up ok.

The rearset risers are an easy way to go but you should also carry some spares for these parts as one minor off can ruin your day if you happen to snap a rearset and don't have a spare.

The spacers are nothing special and even washers the right size would do. If you know someone with a lathe they could machine up a couple of sizes in a short time.

Probably the best preparation you can do at the moment is just riding the bike. Your've identified a couple of things you want to change ie the forks diving and the footpegs. After your've done that then decide what you next thing will be. Good new sticky tyres are always a plus but it comes down to budget how often you put new ones on.

Didn't Terry Fitzgerald borrow this bike for a race down south this year when he binned his bike?

He Might have.

Yeah i am not one for liking to muck around but I want ti so I feel comfortable pushing into corners without huge front end dive.
The tires are probably a meeting old and are Conti Race Attacks I cant say anything about them they were just brilliant once they got heat in them and surprisingly low tire pressures in the rear 23PSI!!!!!
I have done a quick fix and removed the peg Bobbons as that gives me an extra 10 mm clearence. Currently the budgetis low and am planning onjust riding the thing. Just want to sort mainly the suspension issue and itl be perfect

[Robert Taylor]

Ok I will find some scales and weigh myself but my height is 6 foot 1
and my rough guess to weight is 67kgs

You need .95 SPRINGS with preload set so that static sag is between 20 -25mm depending on available grip. PM me for the rest of the info.