Topic: Lower front fork by sliding tube in triple tree

[dgilling]

I was looking to get some Hagon shocks and have been emailing back and forth with Dave Quinn.  I noted to him that I lowered my front end by sliding the fork tubes up in the triple tree.  he responded with the following advice.  I don't think I even understand what he's saying.  does this sound possible? 

"One note, please be VERY careful sliding your tubes up through the triple
trees. I have seen many modified motorcycles owners have a panic stop and
trap the front end with a frame tube or exhaust and down you will go. If you
do take this route remove the springs and collapse the front forks to ENSURE
you will not have any contact."

I just eyeballed installing my fork tubes, I'm not sure where they should even sit.  Below is a picture of the fork tubes as they sit now.   

[frodef2]

I made a similar discovery on my marzocchi fork conversion. The available space between the top of the tire and the bottom triple is less than the total fork travel. So if i where to make an emergency stop, the tire would hit the bottom triple before the forks bottom out.     The stock forks are a lot weaker than these forks, so i guess fork flex is also a factor. For tire to frame/exhaust clearance.

Frode j


Sent from my iPhone using Tapatalk

[Flyin900]

Normally the top of the upper fork tube is flush with the top triple tree clamp not including the top spring retaining cap. Yours is obviously a few inches above that mark.
Others may be able to comment on the interaction of your changes. I figure the Honda engineers had lots of time to determine the best setting for each bike. So myself I don't personally try to reinvent the wheel.

[dgilling]

I guess you can test this by just taking the springs out and letting everything compress to bottom out.  then you can see where that point is.  My fork tubes are off an F and about 1/4 inch longer than my original K models. 

[Steve_K]

Sliding the tubes up will quicken the steering, if there are no other frame changes.  I have done the same on a HawkGT. I had no clearance problems with the exhaust or the frame.  But, after sliding up 10 mm at a time(as I remember, could have been 20 mm),  I had a bike that I could not ride in a straight line.  Mind you, it cornered very well,  but riding fast in a straight line was scary.
I would suggest slide the stock tubes slowly(say 5 to 10 mm at a time), so you will not be surprised.  I had a lot fun doing it and I may try it again in the future.
Steve

[evanphi]

When I bought my bike the tubes were raised about 1" in the trees. Held up just fine. I put them back to stock.

[bwaller]

What are you trying to achieve by lowering the front?

Besides the danger of the fender whacking the lower triple or exhaust or both, the effect on the chassis can't be ignored. Lowering the front (looks like 2") will indeed quicken the steering by reducing the rake, but on the negative side also reduces trail enough to affect straight line stability. The real issue though with too little trail is the possibility of a tank slapper if something upsets the chassis, like a bump or pothole in a corner when it's already under some stress.

It may feel fine....until it doesn't! Just be aware.

[NobleHops]

What Brent said. That's lowered a LOT, I'd say too much. That bike will be prone to instability. Ever get a good tankslapper going?

I had one HORRENDOUS one a long time ago, totally self-inflicted due to some very stupid behavior on my part, still can't believe I saved it. You don't want to flirt with that. IMO an inch is the outer limits I'd flirt with for stability reasons, and I'd sneak up on it too.

The other issue you were cautioned about is the clearance from the fender to the triple clamp. In a hard braking scenario if you hit that hard you will probably go down hard and fast. Do as was suggested, remove the fork caps (with the front of the bike supported or suspended) and carefully lower it to ensure you have clearance. But for sure, 10mm increments provide a LOT of change in chassis geometry. What you've got is radical.

[NobleHops]

P.S. You have lost a LOT of cornering clearance like that, and if you try to compensate by raising the rear, the bike will be unrideable.

[jaguar]

Its not a Honda Civic.
"lowering" a bike is never a performance improvement.

That picture is silly low.
Mr Quinn is correct to warn people about doing stuff like that.

[NobleHops]

Its not a Honda Civic.
"lowering" a bike is never a performance improvement.

That picture is silly low.
Mr Quinn is correct to warn people about doing stuff like that.

Yeah and everytime I see some n00b bike builder hacking at his bike in search of the proper "stance" for the kewl look they want I throw up in my mouth.

[jaguar]

We should have a memorial for all the good bikes lost to hipsters building "café racers" that were little more then chopper art projects


Me thinks that the bandwagon is full and they are moving onto other hobbies.

[dgilling]

Okay.... this would be why I asked, and what a forum is for.  I'm not looking for a performance improvement by lowering the bike.  I just think they look better slightly lower.  Like most people do.  All the manuals I have including the honda manual don't show exactly how or where the tubes go in the triple during re-installation.  Overall, I'm not to worried about it though because I'm going to get hondaman do a completely safety check and checkout on the bike. 

We should have a memorial for all the good bikes lost to hipsters building "café racers" that were little more then chopper art projects


Me thinks that the bandwagon is full and they are moving onto other hobbies.

 

I'm a little offended if you're calling me a hipster as I'm nothing of the sort.    This bike rebuild is in no way a cafe and pretty much all stock with nothing but performance enhancements and some things that just look slightly better to myself. 

Yeah and everytime I see some n00b bike builder hacking at his bike in search of the proper "stance" for the kewl look they want I throw up in my mouth.

Haven't hacked anything. 

I already raised things back up after Flyin900 gave me a ball park of where they should be. 

[bwaller]

You're ok dgilling. Every once in a while the troops will get wound up & tear a piece off someone for taking a chance at something.

These older bikes aren't able to ride too low anyway because the engine width will cause the asphalt will grind through all sorts of hard bits in the corners. Get that thing back up where it belongs and we'll leave you be. 

Just kidding man.

[Tim2005]

Agree all of above, even 5mm change makes a noticeable difference.

Anyway, onto the shocks -  question- just curious as  to what length the 400f Hagons are available in now, is it still 310mm?

[NobleHops]

You're ok dgilling. Every once in a while the troops will get wound up & tear a piece off someone for taking a chance at something.

These older bikes aren't able to ride too low anyway because the engine width will cause the asphalt will grind through all sorts of hard bits in the corners. Get that thing back up where it belongs and we'll leave you be. 

Just kidding man.

Yes, this. Sorry for my snide remark, it was more generally focused than at you, but it was in your thread. I don't know what you're up to, but when it comes to things like frame and chassis geometry and, you know, stability, I do kinda lose it when the "form over function" crew (present company excepted) starts dreaming up 'upgrades' that include dubious ideas like raising the fork tubes 2 inches. These bikes have plenty of areas for personalization without compromising function, safety or performance and while customs are not my thing personally, that's all good.

Have a ball, carry on!

N.

[SOHC4 Cafe Racer Fan]

What are you trying to achieve by lowering the front?

Besides the danger of the fender whacking the lower triple or exhaust or both, the effect on the chassis can't be ignored. Lowering the front (looks like 2") will indeed quicken the steering by reducing the rake, but on the negative side also reduces trail enough to affect straight line stability. The real issue though with too little trail is the possibility of a tank slapper if something upsets the chassis, like a bump or pothole in a corner when it's already under some stress.

It may feel fine....until it doesn't! Just be aware.

The collective consideration is for your safety.  Too many people modify their motorcycles for a "look" and utterly ignore the affects on performance; like the guys who want Firestone (no sidewall grip) tires.  I would take the precautions advised of, in checking the clearance of the fork under full collapse.  If there are no interference issues, I would not lower your forks more than an inch.  The only instance where I could see this as an option is where people are using a GL fork with forks over 2" longer than their stock forks.

[dgilling]

I'm all for "my safety".  Which is precisely why I posted it and I truly appreciate the knowledge and responses of this forum.  My ignorance is shown in the fact that I didn't really think about all those other things.  What should the travel be for a stock CB750k7?  The previous owner had a fork brace installed on my bike and I rode it like that for 10 years.  it's about 1" thick and bolted right under the bottom of the triple tree.  I never thought twice about it, but it would effectively shorten your travel.  the tubes I got are from a F bike too and were about 1/4" longer than my stock tubes.  I'll have to take that into consideration. 

Here is the link to my build.  You'll see that i'm not doing anything crazy and my overall goal for the rebuild is "Just Better".  Better shocks, Hondman bushings, Hondman top end rebuild,  new bearings all around, brighter headlight, better brakes, and cosmetic upgrades.  All while staying basically stock.

Thanks for the inputs.   

http://forums.sohc4.net/index.php?topic=137018.0

Agree all of above, even 5mm change makes a noticeable difference.

Anyway, onto the shocks -  question- just curious as  to what length the 400f Hagons are available in now, is it still 310mm?

This is what Dave Quinn gave me for the Type A Hagon shocks.

"Hagons make clevis bottomed shocks for Ks in 335mm/13.2². Besides the stock
spec we can also offer 360mm/14.2². Hagons do not make their shortest fork
bottom shocks (310mm/12.2") in a heavy enough damper for the CB750K."

Extended Length     Compressed Length     Travel
360 mm  14.2"         11.0"               3.2"
335 mm  13.2"         10.0"               3.2"

I read on another website that Dave suggest that the 2810's aren't really worth it.  You buy the Type A's because they're pretty much the same thing with out some minor adjustments.  If you want the adjustments you should upgrade to the Nitros because you can rebuild them.  I was thinking if I want the adjustments I'll just buy the IKONS at that point.  Not really sure which shock to get at this point.  Buy the Type A's and save $200 or by the IKONs and have a rebuild-able shock with full adjustments. 

[NobleHops]

I'm all for "my safety".  Which is precisely why I posted it and I truly appreciate the knowledge and responses of this forum.  My ignorance is shown in the fact that I didn't really think about all those other things.  What should the travel be for a stock CB750k7?  The previous owner had a fork brace installed on my bike and I rode it like that for 10 years.  it's about 1" thick and bolted right under the bottom of the triple tree.  I never thought twice about it, but it would effectively shorten your travel.  the tubes I got are from a F bike too and were about 1/4" longer than my stock tubes.  I'll have to take that into consideration. 

Here is the link to my build.  You'll see that i'm not doing anything crazy and my overall goal for the rebuild is "Just Better".  Better shocks, Hondman bushings, Hondman top end rebuild,  new bearings all around, brighter headlight, better brakes, and cosmetic upgrades.  All while staying basically stock.

Thanks for the inputs.   

http://forums.sohc4.net/index.php?topic=137018.0

Agree all of above, even 5mm change makes a noticeable difference.

Anyway, onto the shocks -  question- just curious as  to what length the 400f Hagons are available in now, is it still 310mm?

This is what Dave Quinn gave me for the Type A Hagon shocks.

"Hagons make clevis bottomed shocks for Ks in 335mm/13.2². Besides the stock
spec we can also offer 360mm/14.2². Hagons do not make their shortest fork
bottom shocks (310mm/12.2") in a heavy enough damper for the CB750K."

Extended Length     Compressed Length     Travel
360 mm  14.2"         11.0"               3.2"
335 mm  13.2"         10.0"               3.2"

I read on another website that Dave suggest that the 2810's aren't really worth it.  You buy the Type A's because they're pretty much the same thing with out some minor adjustments.  If you want the adjustments you should upgrade to the Nitros because you can rebuild them.  I was thinking if I want the adjustments I'll just buy the IKONS at that point.  Not really sure which shock to get at this point.  Buy the Type A's and save $200 or by the IKONs and have a rebuild-able shock with full adjustments.

Having a rebuildable shock is frankly awesome if you're going to ride it a lot. For very short money you get new suspension every few years. But if this is a 'now and then' rider like my old bikes are, I'd have a hard time spending the extra dosh.

[dgilling]

Having a rebuildable shock is frankly awesome if you're going to ride it a lot. For very short money you get new suspension every few years. But if this is a 'now and then' rider like my old bikes are, I'd have a hard time spending the extra dosh.

I like the idea of having the option for the rebuild.  Plus i feel like I'll buy the best now and not every second guess that I want to upgrade in the future.    I won't ride it a ton.  Probably 2-3 times per week and only when weather permits being i'm in Denver.  maybe a road trip or two in the summer. 

[SOHC4 Cafe Racer Fan]

I agree with Nils, but I am an advocate of spending mod money on brakes and suspension before "go fast" parts.  Having a rebuildable shock is a nice perk if you find yourself needing to rebuild the shock down the road.  The Hagon is great for a "ride right now" shock and it's definitely better than the Chinese junky shocks on ebay.

[NobleHops]

I agree with Nils, but I am an advocate of spending mod money on brakes and suspension before "go fast" parts.  Having a rebuildable shock is a nice perk if you find yourself needing to rebuild the shock down the road.  The Hagon is great for a "ride right now" shock and it's definitely better than the Chinese junky shocks on ebay.

Agreed, and if you're going to ride it 2-3 times a week, that's the right idea. Rebuildable. They can be adjusted to tune during that process too, which is awesome.

[dgilling]

Is the IKON $200 better?  I feel like it would be, and I like the looks better. 

All my money will go to suspensions and brakes first.  I don't care if the bike is fast.  In fact I prefer it to be slow to keep me out of trouble. 

[Retro Rocket]

Is the IKON $200 better?  I feel like it would be, and I like the looks better. 

All my money will go to suspensions and brakes first.  I don't care if the bike is fast.  In fact I prefer it to be slow to keep me out of trouble.

Ikons are better than Hagon, more compliant, even though Hagon seems to have great customer service, most reports here say they are a bit stiff. Personally, I've used quite a few Koni's {now Ikon} and continue to use them, one of the best shocks made for our bikes...

[Tim2005]

I like the Hagons, have got them on the Seeley and the 400, and I have never actually had Hagons needing a rebuild so have kinda saved myself twice $200 over the years. They do seem to last well. My 460 has rebuildable Marzocchis and you can't get the parts now...