Tips for lowering front forks

[TontoAssistento]

Hi. 

 

Just installed the oem lowering links. Now next thing for me is to lower tge forks a littlebit. 

I am not a mechanic, so I would like to have some step by step tips to do it. 

 

How much shoud it be lowered since I have the oem lowering links? 

 

How did you do it?

 

 

 

[Engineer]

15mm seems to be the generally accepted maximum that the forks can be lowered. The height is set by measuring from the top of the lower triple clamp to the top of the fork outer tube and as standard should be 215mm. Therefor the fork legs can be moved up in the triple clamps until this dimension is 230mm.

 

Take the weight off the forks by supporting the bike under the forward part of the engine guard, preferably with a scissor jack, then loosen the clamp bolts on the triple clamps one leg at a time and adjust the height of the leg in the triple clamps to the new dimension (230mm). You may have to lower the front of the bike a little. Re-torque the clamp bolts to the specified torque.  23 N•m (2.3 kgf•m, 17 lb•ft) for the top bolts and 20 N•m (2.0 kgf•m, 15 lb•ft). Then do the same to the other fork leg.

[TimmyTheHog]

6 hours ago, Engineer said:

15mm seems to be the generally accepted maximum that the forks can be lowered. The height is set by measuring from the top of the lower triple clamp to the top of the fork outer tube and as standard should be 215mm. Therefor the fork legs can be moved up in the triple clamps until this dimension is 230mm.

 

Take the weight off the forks by supporting the bike under the forward part of the engine guard, preferably with a scissor jack, then loosen the clamp bolts on the triple clamps one leg at a time and adjust the height of the leg in the triple clamps to the new dimension (230mm). You may have to lower the front of the bike a little. Re-torque the clamp bolts to the specified torque.  23 N•m (2.3 kgf•m, 17 lb•ft) for the top bolts and 20 N•m (2.0 kgf•m, 15 lb•ft). Then do the same to the other fork leg.

@Engineer QUESTION WITHIN A QUESTION *SHOCK*...okay joke is now out of the way.

 

When you say lifting one fork at a time, won't that cause bind to the wheel down low?

or does the fork flex enough to allow the twist?

 

sorry for the noob question...

 

[TontoAssistento]

Thank you engineer! This is why I wanted to join tge group, because there are helping People around! 

[Engineer]

@TimmyTheHog As long as the forks are not fully extended it is possible to adjust the fork legs independently as all you are doing is slightly compressing (or de-compressiing) the spring in one fork leg with respect to the other leg.

It sounds complicated but trust me it works ok.

[TimmyTheHog]

20 minutes ago, Engineer said:

@TimmyTheHog As long as the forks are not fully extended it is possible to adjust the fork legs independently as all you are doing is slightly compressing (or de-compressiing) the spring in one fork leg with respect to the other leg.

It sounds complicated but trust me it works ok.

ah so one leg would effectively compressed while the other leg moves and because it is only moving 10~15mm which isn't much, it shouldn't twist.

 

okay, that makes sense...

[TontoAssistento]

8 hours ago, Engineer said:

15mm seems to be the generally accepted maximum that the forks can be lowered. The height is set by measuring from the top of the lower triple clamp to the top of the fork outer tube and as standard should be 215mm. Therefor the fork legs can be moved up in the triple clamps until this dimension is 230mm.

 

Take the weight off the forks by supporting the bike under the forward part of the engine guard, preferably with a scissor jack, then loosen the clamp bolts on the triple clamps one leg at a time and adjust the height of the leg in the triple clamps to the new dimension (230mm). You may have to lower the front of the bike a little. Re-torque the clamp bolts to the specified torque.  23 N•m (2.3 kgf•m, 17 lb•ft) for the top bolts and 20 N•m (2.0 kgf•m, 15 lb•ft). Then do the same to the other fork leg.

No loctite? 

[Matth]

No locktite!

[Engineer]

23 minutes ago, Matth said:

No locktite!

Correct No Locktite. (Service manual does not call for Locktite).

[Cruizin]

Moving this to tech tips , thank you to @Engineer ! 

[TimG]

12 hours ago, Engineer said:

15mm seems to be the generally accepted maximum that the forks can be lowered. The height is set by measuring from the top of the lower triple clamp to the top of the fork outer tube and as standard should be 215mm. Therefor the fork legs can be moved up in the triple clamps until this dimension is 230mm.

 

I have the Rally-Raid 20 mm lowering links fitted. I raised my forks by 20mm to compensate. They seem to be fine after 1000+ km travelled. The gold portion of the fork leg protrudes 7mm above the top clamp as standard/delivered. I moved it up to protrude 27mm. It still clears the tank shroud on full lock by a few mm with the (taller) Rally-Raid pre-load caps fitted. To maintain the front/rear geometry/balance both ends should be lowered a similar amount where possible. Lowering the back more than the front will 'slow' the steering response a little. Cheers.

[Louis]

7 hours ago, TimmyTheHog said:

ah so one leg would effectively compressed while the other leg moves and because it is only moving 10~15mm which isn't much, it shouldn't twist.

 

okay, that makes sense...

My understanding is that it's possible for it to twist, creating a bit of binding! 

I usually just tighten up the top clamp bolts just a bit, just enough so that the legs will not slide through any more. Then bounce the front while holding the front brake a few times, Now tighten up all the bolts progressively till correct torque is achieved. 

Just takes a little bit longer. 

Edited June 27, 2020 by Louis

[TimmyTheHog]

41 minutes ago, Louis said:

My understanding is that it's possible for it to twist, creating a bit of binding! 

I usually just tighten up the top clamp bolts just a bit, just enough so that the legs will not slide through any more. Then bounce the front while holding the front brake a few times, Now tighten up all the bolts progressively till correctly torque is achieved. 

Just takes a little bit longer. 

I guess better safe than sorry to do the bounce align trick anyway...

 

well, sounds simple enough (famous last words along with Hold by beer)

[Matth]

Yep they should have done the front otherwise  it will alter the geometry of the beast!

[jas340]

On 8/9/2020 at 8:31 AM, Matth said:

Yep they should have done the front otherwise  it will alter the geometry of the beast!

And that's why I never take my bike back to the stealership after I buy it except to mount a new tire. No 600 mi service check.  If you ain't Japaneses keep your hands off my bike.

[Ktmmitch]

2 hours ago, Mudchute said:

I've just had the OEM lowering kit fitted but the dealer hasn't dropped the forks at all. I notice that RPP recommend a 10mm drop with their 20mm lowering kit, so wondered if this is a standard ratio i.e. 50% of the rear drop transferred to the forks?

 

Not a std ratio, but generally lower the front 50-75% of the rear lowered amount.

[Mudchute]

16 minutes ago, Ktmmitch said:

 

Not a std ratio, but generally lower the front 50-75% of the rear lowered amount.

Thanks, I think most folk assume the ratio is 1:1, but it would seem that's not automatically the case. I think I'll start with 50% i.e. 9mm and see how that feels

[dirt5track]

Thanks all for this info, I just made the adjustment and found that my forks were uneven from the factory. 

[Alvin]

Hello Everyone,

 

What is the right amount to lower my T700 2020 model Front Fork if i lowered the rear shocks with OEM lowering link from Yamaha (18mm)?  

 

 

Stay Safe Everyone

[Stevey3737]

I would lower the front 10-12mm and try it out to see how it feels

[TenereTraveler]

I've raised my forks a total of 18 mm up through the triple tree clamps after lowering the rear end and threw on some knobby tires; I've noticed lately above 60 mph when wind gusts contact the front hand guards I get a slight constant handlebar wobble side to side similar to tank slap but not as severe, just enough to make the front end of the bike wiggle on the highway. If I purposefully stiffen up my arms it'll stop until the wind hits it just right again. I've noticed the bike is more prone to it around long sweeping high-speed turns.

I've found this fairly annoying and my brother has noticed my bike doing it while riding next to me. It has never turned into a full-on tank slap or gotten out of control at all but it does get worse as speed increases.

I've put 3,000 mi on the bike before making those changes and it's never happened before that so I know it was one of those 3 changes.

I think I am going to start with lowering the forks back through the triple tree clamp back to stock and see if that changes anything.

[JohnnieBoy]

7 hours ago, TenereTraveler said:

I've raised my forks a total of 18 mm up through the triple tree clamps after lowering the rear end and threw on some knobby tires; I've noticed lately above 60 mph when wind gusts contact the front hand guards I get a slight constant handlebar wobble side to side similar to tank slap but not as severe, just enough to make the front end of the bike wiggle on the highway. If I purposefully stiffen up my arms it'll stop until the wind hits it just right again. I've noticed the bike is more prone to it around long sweeping high-speed turns.

I've found this fairly annoying and my brother has noticed my bike doing it while riding next to me. It has never turned into a full-on tank slap or gotten out of control at all but it does get worse as speed increases.

I've put 3,000 mi on the bike before making those changes and it's never happened before that so I know it was one of those 3 changes.

I think I am going to start with lowering the forks back through the triple tree clamp back to stock and see if that changes anything.

Hmmm... I don't know if I'd attribute what you're experiencing to lowering the forks/links? I would look at tire choice/wear/pressure more than lowering as a cause. As long as the front end is straight I can't see how lowering it would be the issue.

 

I put the RR 20mm links on and raised the fork tubes right up to the lower taper line - 15mm? I've run it about 1000 miles like this hwy/dirt and zero issues. I do 65/75+ regularly on the hwy (and even upto 100+), smooth as silk. I've even removed the bar end weights to install HDB handguards & mirrors.

 

Love this bike!

[TenereTraveler]

On 5/21/2021 at 8:00 PM, JohnnieBoy said:

Hmmm... I don't know if I'd attribute what you're experiencing to lowering the forks/links? I would look at tire choice/wear/pressure more than lowering as a cause. As long as the front end is straight I can't see how lowering it would be the issue.

 

I put the RR 20mm links on and raised the fork tubes right up to the lower taper line - 15mm? I've run it about 1000 miles like this hwy/dirt and zero issues. I do 65/75+ regularly on the hwy (and even upto 100+), smooth as silk. I've even removed the bar end weights to install HDB handguards & mirrors.

 

Love this bike!

Thanks for the advice! I read through other forums on here recently and found a few people with the same issue as myself after going to a knobby front tire. I guess its a characteristic of the way the outer knobs grip that I wasn't aware of.

[dmottv]

Changing the height of the rear and the front could change the weight % focused on each, right? Could this have some impact on the handlebar wobble some are experiencing?  
 

I’ll be installing the RR 20mm lowering links soon and be looking at these adjustments. 

Edited May 31, 2021 by dmottv

[AZJW]

I'm with @JohnnieBoy on this one. My gut feeling is the wobble is the result of installing knobbies, not the lowering of the front end. 

[Rocky_Mtn_T7]

The previous owner installed the Yamaha lowering links and from what everyone has said it looks like the forks weren't moved at all. Did anyone get install instructions with the Yamaha lowering kit? As I am curious to see what Yamaha recommends?