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-   -   Shim rear with or without Steering Damper (https://www.superhawkforum.com/forums/modifications-performance-29/shim-rear-without-steering-damper-24861/)

dbog44 03-05-2011 03:50 PM

Shim rear with or without Steering Damper
 
I am thinking of shimming the rear....But 1st question that comes to mind , will this increase chances of tank slapper???? I do not plan on lowering the front. This question make have been asked before, but was unable to find in the my searches..

Thanks

8541Hawk 03-05-2011 04:15 PM

I've run both the rear raised 6mm & the forks pulled up 10mm and the front at stock height with the rear up 10mm and neither set up required a damper.

Of course YMMV but IMHO no damper is needed.

dbog44 03-05-2011 04:21 PM


Originally Posted by 8541Hawk (Post 294809)
I've run both the rear raised 6mm & the forks pulled up 10mm and the front at stock height with the rear up 10mm and neither set up required a damper.

Of course YMMV but IMHO no damper is needed.

Thanks appreciate the feedback.

smokinjoe73 03-05-2011 05:26 PM

I have the shim and front tubes protruding about 4cm above triples and no damper. If you need a damper on this bike its just covering other problems (or maybe for the racetrack).

NooB 03-05-2011 07:50 PM

^^ Mine's the same way (except 4mm above top triple.. lol) and it's rock solid stable at speed. Forget the damper, it's just dead weight.

smokinjoe73 03-06-2011 09:36 AM

Hey noob, that was 4 CM not MM above the triple.

JamieDaugherty 03-07-2011 03:12 PM

Agreed - I'm running about +50mm rear ride height and slightly lower than stock front height with no problems at all. I get some funny looks at the track when I tell them I'm not running a steering damper. Actually, since most people like to see run one, I try to keep that quiet if possible. Luckily it's one of those things that the techs tend to miss with their "inspections".

smokinjoe73 03-07-2011 04:08 PM

Jamie you would know this. What is the stock fork tube's protuberance above the triples? Oh yeah, if that's you in your avitar is Tony Elias your favorite pro?

nothing 03-07-2011 07:09 PM

what are the benefits of raising the rear?

D VTR RIDER 03-07-2011 07:54 PM


Originally Posted by JamieDaugherty (Post 294968)
Agreed - I'm running about +50mm rear ride height and slightly lower than stock front height with no problems at all. I get some funny looks at the track when I tell them I'm not running a steering damper. Actually, since most people like to see run one, I try to keep that quiet if possible. Luckily it's one of those things that the techs tend to miss with their "inspections".

Jamie,
I didn't want to hijack the thread but my questions are still relevant. 50mm is a lot. Are you using a shim under the shock to achieve this or do you have ride height adjustment on your shock? Regardless, how many mm is the shock lengthened to achieve this? I assume approximately a ration of 5:18. Can you confirm the exact ratio?
I'm using approximately +28mm differential after re-springing the front end i.e. +18 rear and -10 up front and was under the impression that any more would cause stability problems.The fact that you are using 50+ mm is very interesting. The rear swing arm angle has increased substantially. Have you noticed a change in rear traction, squat under power or tire wear issues?

Tweety 03-08-2011 01:43 AM

D _VTR_RIDER, I can't remeber the stock ratio in my head, but the thing is, lowering the front without raising the rear is a bad idea, not because it causes instability, but because you tend to bottom out hard parts... That's why most of us here advice the new guys not to drop the forks on an otherwise fairly stock bike...

The thing is, you can raise the rear a pretty good amount without any problems at all, and in combination with the front, you still keep the hard parts away from danger... But yeah, going too far is most definetly possible, and would be a very bad idea... Basically, the sweet spot seems to be "Loose, on the edge of control"... ;) Yeah, easy to say, hard to do, and if you over do it, it hurts... ;)

The change in swingarm angle you mention is interesting, I have read up on that a lot, apparently you can cure a lot of handling problems with a steeper swingarm, (and most definetly produce even more) basically it puts more control on the valving of the rear shock...

Ie, raising to much with a crappy stock shock might not make things better, but if you have a shock that's setup the right way, or like Jamie, have the know-how to fiddle with it, it can be a very good idea, besides the geometry changes...

I have in my own small way done the same with the longer SP2 swing, a bit steeper angle to keep the wheelbase down, and give me more traction, and so far it seems to have worked...

I think in terms of ride height, I'm about the same as Jamie, around 45-50 mm give or take a few, and around 10-15 mm down in the front... But with completely different dynamics on the swingarm though...

JamieDaugherty 03-08-2011 08:54 AM


Originally Posted by smokinjoe73 (Post 294974)
Jamie you would know this. What is the stock fork tube's protuberance above the triples? Oh yeah, if that's you in your avitar is Tony Elias your favorite pro?


I don't remember exactly. I think I ran mine right at the top of the clip-ons.

Nah, not a big fan of Elias. Why?



Originally Posted by nothing (Post 294987)
what are the benefits of raising the rear?

I've found that it better balances the bike during turning, pretty much all over actually.



Originally Posted by D VTR RIDER (Post 294994)
Jamie,
I didn't want to hijack the thread but my questions are still relevant. 50mm is a lot. Are you using a shim under the shock to achieve this or do you have ride height adjustment on your shock? Regardless, how many mm is the shock lengthened to achieve this? I assume approximately a ration of 5:18. Can you confirm the exact ratio?
I'm using approximately +28mm differential after re-springing the front end i.e. +18 rear and -10 up front and was under the impression that any more would cause stability problems.The fact that you are using 50+ mm is very interesting. The rear swing arm angle has increased substantially. Have you noticed a change in rear traction, squat under power or tire wear issues?

The actual ratio is 3.88:1. I am using a completely different shock on my bike, something that I custom made myself. It started out it's life as a WP for and R6 but it's been changed significantly since then.

The swingarm angle is not changed enough to cause any problems (+50mm isn't as much as you might think). Rear traction is fine, no problems at all with spinning. In fact it's better than stock but there are other things that I've done to help there too (spring and valving). These have also considerably reduced squat and tire wear - again, these are not related to the rear ride height but are a result of the overall setup.

JamieDaugherty 03-08-2011 09:12 AM

What happened to dbog44, I wonder if we scared him away!

dbog44 03-08-2011 10:01 AM


Originally Posted by JamieDaugherty (Post 295042)
What happened to dbog44, I wonder if we scared him away!

No Jamie...I'm still here....Just soaking up the info between working my A@# off. I'm still not sure if should lower the front or not....may just shim the rear and see where it takes me. I do still plan on sending my rear f4i shock....will I have to shim that or can I adjust that to the desired ride height.

Thanks to all for the input....Thats why I love this forum

dbog44 03-08-2011 10:26 AM


Originally Posted by Tweety (Post 295012)
D _VTR_RIDER, I can't remeber the stock ratio in my head, but the thing is, lowering the front without raising the rear is a bad idea, not because it causes instability, but because you tend to bottom out hard parts... That's why most of us here advice the new guys not to drop the forks on an otherwise fairly stock bike...

The thing is, you can raise the rear a pretty good amount without any problems at all, and in combination with the front, you still keep the hard parts away from danger... But yeah, going too far is most definetly possible, and would be a very bad idea... Basically, the sweet spot seems to be "Loose, on the edge of control"... ;) Yeah, easy to say, hard to do, and if you over do it, it hurts... ;)

The change in swingarm angle you mention is interesting, I have read up on that a lot, apparently you can cure a lot of handling problems with a steeper swingarm, (and most definetly produce even more) basically it puts more control on the valving of the rear shock...

Ie, raising to much with a crappy stock shock might not make things better, but if you have a shock that's setup the right way, or like Jamie, have the know-how to fiddle with it, it can be a very good idea, besides the geometry changes...

I have in my own small way done the same with the longer SP2 swing, a bit steeper angle to keep the wheelbase down, and give me more traction, and so far it seems to have worked...

I think in terms of ride height, I'm about the same as Jamie, around 45-50 mm give or take a few, and around 10-15 mm down in the front... But with completely different dynamics on the swingarm though...

Tweety....I'm running a stock rear.....do you think I will notice much with the rear shimmed ?...Theory is the tail raised will help dive into turn quicker... but I realize that if you have a piece of lumber as a rear shock(stock set up) there are limitations. So would I be hurting my handling or possibly helping????

Thanks again for all input....you guys are great..

smokinjoe73 03-08-2011 11:43 AM

Jamie. the elias reference is the riding style in the avitar. Waaay off the bike.

Dbdogg44; yes you will notice a huge & great improvement putting in the shim. Besides you can always remove it. It made my bike feel 50lbs lighter and steer more intuitively.

JamieDaugherty 03-08-2011 01:17 PM


Originally Posted by dbog44 (Post 295059)
I'm still not sure if should lower the front or not....may just shim the rear and see where it takes me.

I wouldn't bother with lowering the front, right away. Raise the rear first and adjust the front later if you want 'more'.


Originally Posted by smokinjoe73 (Post 295074)
Jamie. the elias reference is the riding style in the avitar. Waaay off the bike.

Ha ha, it just looks like that. That's an off-camber turn at Grattan so it's deceiving.

smokinjoe73 03-08-2011 02:30 PM

No way man, you are in another zip code than the bike. If that was the finish line you would win by half a bike length over your own bike. Don't get me wrong, it looks good but watch toy elias; same style. Like they say if he were any more committed he would have to be committed....

dbog44 03-08-2011 02:57 PM

Thanks guys

D VTR RIDER 03-08-2011 04:32 PM


Originally Posted by Tweety (Post 295012)
D _VTR_RIDER, I can't remeber the stock ratio in my head, but the thing is, lowering the front without raising the rear is a bad idea, not because it causes instability, but because you tend to bottom out hard parts... That's why most of us here advice the new guys not to drop the forks on an otherwise fairly stock bike...

The thing is, you can raise the rear a pretty good amount without any problems at all, and in combination with the front, you still keep the hard parts away from danger... But yeah, going too far is most definetly possible, and would be a very bad idea... Basically, the sweet spot seems to be "Loose, on the edge of control"... ;) Yeah, easy to say, hard to do, and if you over do it, it hurts... ;)

The change in swingarm angle you mention is interesting, I have read up on that a lot, apparently you can cure a lot of handling problems with a steeper swingarm, (and most definetly produce even more) basically it puts more control on the valving of the rear shock...

Ie, raising to much with a crappy stock shock might not make things better, but if you have a shock that's setup the right way, or like Jamie, have the know-how to fiddle with it, it can be a very good idea, besides the geometry changes...

I have in my own small way done the same with the longer SP2 swing, a bit steeper angle to keep the wheelbase down, and give me more traction, and so far it seems to have worked...

I think in terms of ride height, I'm about the same as Jamie, around 45-50 mm give or take a few, and around 10mm down in the front... But with completely different dynamics on the swingarm though...

I changed out the springs to .95 kg nearly 11 years ago when it nearly bucked me off the bike when I hit a bump healed over. No fun when all that is attached to the bike is the heal of your boot on the edge of the seat. My arse was puckered up real good after that. At the time I raised the front forks by 10mm. I didn't take an initial measurement and therefore didn't have a reference point. I'm dragging parts still with the rear raised with a 5mm shim. I've acquired rear sets so dragging parts won't be an issue this year.


The actual ratio is 3.88:1. I am using a completely different shock on my bike, something that I custom made myself. It started out it's life as a WP for and R6 but it's been changed significantly since then.

The swingarm angle is not changed enough to cause any problems (+50mm isn't as much as you might think). Rear traction is fine, no problems at all with spinning. In fact it's better than stock but there are other things that I've done to help there too (spring and valving). These have also considerably reduced squat and tire wear - again, these are not related to the rear ride height but are a result of the overall setup.
Thanks for the ratio Jamie. I will increasing the rear in increments now that I know that others have gone so far. I've experienced severe tire wear the last time at the track. 2 days and the tire was pooched. It would be interesting to see if increase rear ride height would improve on this assuming with no other changes. I've had 2 so called suspension experts adjust sag, rebound and compression dampening.
As lap times go down, you start to feel a lot of the VTR's nuances or limitations.

Tweety 03-09-2011 02:24 AM


Originally Posted by JamieDaugherty (Post 295083)
I wouldn't bother with lowering the front, right away. Raise the rear first and adjust the front later if you want 'more'.

Ha ha, it just looks like that. That's an off-camber turn at Grattan so it's deceiving.

Agreed, start with the rear... It will give you more than the front to start with...

Tweety 03-09-2011 02:54 AM


Originally Posted by D VTR RIDER (Post 295108)
I changed out the springs to .95 kg nearly 11 years ago when it nearly bucked me off the bike when I hit a bump healed over. No fun when all that is attached to the bike is the heal of your boot on the edge of the seat. My arse was puckered up real good after that. At the time I raised the front forks by 10mm. I didn't take an initial measurement and therefore didn't have a reference point. I'm dragging parts still with the rear raised with a 5mm shim. I've acquired rear sets so dragging parts won't be an issue this year.

Thanks for the ratio Jamie. I will increasing the rear in increments now that I know that others have gone so far. I've experienced severe tire wear the last time at the track. 2 days and the tire was pooched. It would be interesting to see if increase rear ride height would improve on this assuming with no other changes. I've had 2 so called suspension experts adjust sag, rebound and compression dampening.
As lap times go down, you start to feel a lot of the VTR's nuances or limitations.

I can imagine that pucker moment... ;) I had a similar one when I bottomed out my forks first week of owning my bike... Stock forks, the oil hadn't been changed in forever and smelled like rotten eggs and came out in three distinct consistancies... The thinnest one was like water, so it really didn't affect the damping noticably...


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