Pre 1980 Moto Guzzi Forks - shorten?

[Rusnak_322]

is it possible to shorten the forks of a 850T or T3? I just want to have them about 1" shorter so that they don't stick up so far about the triple clamp.

Other bikes without the enclosed damper are easy to shorten by cutting spacers.

I am pulling the forks apart this weekend to replace the internal dampers that have lost their dampening. (#22 in the attached pic) Any tips? First time pulling apart these forks.





And the bike handles fine with the lowered forks, I have been riding it for a few years that way. Once i get some dampening back into the front end and not have it feel like it is all springs, it should ride even better.

[acogoff]

     What tires are you running that required the tubes raised? I have found the T3 has very quick (turn in) steering with the stock 100/90-18 on the front and 110/90-18 on the rear. There are differences between tire carcasses ratios, front to back between manufacturers also. If it bothered me that much, I would put the "stock" tubes back flush and buy a set of pirelli MT route of the stock size of 100/90 front and 110/90 rear and give them a go. In 40 years of riding my T3, I found those tires to give the quickest turn in. This is all considering you still have the stock fork tubes on your guzzi. Let me add this note that the shinko 712 of the stock sizes front and rear give a pretty good turn in rate also, but not as quick as the pirelli routes.

[Rusnak_322]

     What tires are you running that required the tubes raised? I have found the T3 has very quick (turn in) steering with the stock 100/90-18 on the front and 110/90-18 on the rear. There are differences between tire carcasses ratios, front to back between manufacturers also. If it bothered me that much, I would put the "stock" tubes back flush and buy a set of pirelli MT route of the stock size of 100/90 front and 110/90 rear and give them a go. In 40 years of riding my T3, I found those tires to give the quickest turn in. This is all considering you still have the stock fork tubes on your guzzi.

Front is a Continental 90/90-18 and the rear is a 4.00 x 18.

The issue is not that the bike isn't turning in fast enough, it is 100% to balance out the looks with the 13" Marzocchi shocks. The bike would look like something out of EZ Rider if the forks were flush with the top triple clamp. 

I want the lower frame rails to have a slight forward rake and the exhaust to be parallel to the ground.

Like I said, it handles fine now, maybe once I get some dampening into the forks and fix the wooden feeling front brakes I may start riding faster. But this isn't my go to corner carver. And the long wheelbase and weigh is never going to be what I would call "flickable".

[fotoguzzi]

pretty cool looking bike.. no comment on the raised forks other than I wouldn't do it that way.

[Frenchfrog]

I can't say I've evr seen someone raise hem up that much either but then I am myopic

[jbell]

Good looking bike.  No opinion on the forks.

[Rusnak_322]

The bike is a Frankenstein bike. Made up of spare parts someone had accumulated after racing AHRMA for years. Who knows if those fork tubes are stock. I will measure them when I pull the forks apart this weekend.

The bike handles fine, the square profile rear tire probably has more effect on the handling than the fork drop. Plus these bikes have a very slack geometry compared to modern bikes. I was reading on other forums about fitting modern forks and custom triple clamps (which I do not want to do) onto racing Tonti bikes and they talk about clearance with the alternator cover. I have plenty of room between my wheel and the cover.




 

[Luke]

I believe that Forking by Frank sells custom length fork tubes, back in the day they were mostly longer tubes.

[Tom H]

Just curious, do the lower legs hit the lower triple?

I read the specs on my EVT and raised the forks up about an inch, this was all I can go before they would hit per the specs. I did put a zip tie on the chrome leg to see how far the lower travels. So far there is still about an inch of clearance. I have not tried going over the mother of all pot holes yet. Also I think that if I go any farther, the fender will hit my front exhaust crossover.

Good luck,
Tom

[Rusnak_322]

Just curious, do the lower legs hit the lower triple?

I read the specs on my EVT and raised the forks up about an inch, this was all I can go before they would hit per the specs. I did put a zip tie on the chrome leg to see how far the lower travels. So far there is still about an inch of clearance. I have not tried going over the mother of all pot holes yet. Also I think that if I go any farther, the fender will hit my front exhaust crossover.

Good luck,
Tom

No, not even with the crap dampening in the forks. I expect it to be better when I put the new cartridges in it.

[acguzzi]

If you get shorter tubes from frank you'll have to make sure you dont bottom out the dampers, you may need to shorten the rod or there may be some meat in the top plug you could take off to correct the travel

[Diploman]

If I were you, I would keep the fork tubes just as they are, delete the high handlebar (very incongruous on a cafe-styled bike) and fit a set of Tarozzi high-rise clip-ons to the protruding fork tube tops.  If you go for the high-rise clip-ons, the bars could be set at nearly the same level as currently, but would look much better, more coherent with the bike, and would have the advantage of being adjustable in both angle and sweep.  If you fit the clip-ons to the top of your fork tubes, they will be above the triple clamp which you would not need to disassemble.

http://www.fastfromthepast.com/clip-ons

Re the fork cartridges:  The OEM dampers on Guzzis of this era are quite useless, with damping hardly even fit for a screen-door opener.  Recommend you fit a set of FAC dampers (MG Cycle), which, even though not adjustable, offer vastly improved and consistent damping in both compression and rebound.

Good-looking bike, BTW.

[Roebling3]

Am I confused? It looks to me that you have a forward rake. The upper and lower parallel frame tubes appear ~1"+ lower at the steering stem, (as does the exhaust header tube); relative to the level of the vertically set brick background. As I see it you already have, and may be adding extra pressure on your wrists.
     Lower rear tire profile?
Terrific looking bike. Excellent pictures.  R3~   

[Rusnak_322]

Am I confused? It looks to me that you have a forward rake. The upper and lower parallel frame tubes appear ~1"+ lower at the steering stem, (as does the exhaust header tube); relative to the level of the vertically set brick background. As I see it you already have, and may be adding extra pressure on your wrists.
     Lower rear tire profile?
Terrific looking bike. Excellent pictures.  R3~

I have the rake exactly how I want it, I was just hoping to reduce the amount of fork showing above the triple clamps.

I think that if I went with clip-ons, i would probably want to go with the swan neck style as I think it would look more appropriate on this bike. 

[Diploman]

Either the swan necks or the Tarozzis would be an improvement over the one-piece high bar which looks very out of place on an otherwise nicely-styled cafe-esque bike.  The swan necks are nice, adjustable in height and sweep (but not angle) and would look good on your bike.  The Tarozzis also would look good, adjustable in angle and sweep (and height if you put them below the triple clamp), but they would have the advantage of hiding the protruding fork legs above the triple clamp, which seems to be your objection to the current setup.  With the Tarozzis you could hide the protruding fork legs and not have to modify the length of your forks.  With the standard fork lengths, replacement damper cartridges are readily available (eg, FAC's), but if you shorten the fork legs you may have to source custom dampers and/or springs.

[Antietam Classic Cycle]

Theoretically, you could shorten the rods #27 (or have a shorter one made) and cut the same amount off of the springs #29.

First though, since you describe the bike as a "Frankenstein", measure what you have to try and determine what the dampers and springs are from. The original V7 Sport, 750S, S3, LeMans 850, 850-T, 850-T3 (up to '78) damper is 395 mm long. If yours happen to be the 1979 and later T3, SP1000, Convert, G5, CX100, LeMans II dampers which are 410mm overall length, then "backdating" to the earlier shorter dampers and springs could get the results you want.

[antmanbee]

You could put riser clipons mounted above the top triple and it should give you a riding position close to what you have now and it would not look so strange having all that fork sticking up so far.
The clipons need about 1 to 1 1/4" to mount to.
I have used this on my Jackal mounted as I describe.
I got Chinese riser clipons in 45mm but you need 35mm I think.
https://www.ebay.com/itm/For-35mm-Fork-Clip-ons-Handle-Bar-CNC-Pair-Riser-Regular-Handlebar-Higher-Raised/281971672344?hash=item41a6d24518:m:mkQjZ74yd1yxJFT398S 7hWg

Then get the FAC dampers inserts and leave the forks as they are.

[chuck peterson]

I think your fighting the 13” shocks in the back... stock I believe is shorter....12” or 12 1/4?...lower the rear instead?

I understand the square tire look but traditionally that skinny rear tire size oem does some magic on the guzzi geometry and handling...T-T3-Convert-SP

I notice the gas tank is off kilter a bit giving the perception the frame is leaning down on the nose but it’s just the tank positioning

It’s a cool bike...some flat track some bobber some cafe...I notice I’m trying to make it one or the other. It’s almost perfectly in between them all

 

[Antietam Classic Cycle]

I think your fighting the 13” shocks in the back... stock I believe is shorter....12” or 12 1/4?...lower the rear instead?

Stock shocks were 12 3/4" eye-to-eye, the extra 1/4" isn't going to make a difference.

[Rusnak_322]

Stock shocks were 12 3/4" eye-to-eye, the extra 1/4" isn't going to make a difference.

Plus shorter shocks are going to go against the rake look I am going for.

[Rough Edge racing]

 I understand and like the slight front down attitude on a cafe racer... I don't like a bunch of fork sticking up through the top yoke than is an afterthought...You ship then the Frank's and it's 70 bucks total  for shortening and shipping them back. Obviously you have to deal with springs and shock length details...The big issue is Frank's...They are not too good with customer service but they are not dishonest.They just don't seem to hear the phone or always answer emails...They shortened 41mm Showa tubes for me a few months ago.. about 3 weeks total time...But shortening forks isn't difficult for a guy with a lathe than can cut metric threads, maybe a local machine shop is interested...

[Rusnak_322]

UPDATE:

Pulled the forks apart over the weekend to install the new fork dampers and the ones I bought are shorter then what I have. I also have 2 piece fork springs.

Quick email to MG Cycle and it turns out that someone in the past changed the internals. I have the longer dampers and springs. I am ordering the new springs and that should reduce the overall height of the forks by a good chunk.

As soon as I get the new, shorter springs, I will update the overall height reduction.

[Frenchfrog]

I'm thinking your tubes are longer than standard too

[Antietam Classic Cycle]

UPDATE:

Pulled the forks apart over the weekend to install the new fork dampers and the ones I bought are shorter then what I have. I also have 2 piece fork springs.

Quick email to MG Cycle and it turns out that someone in the past changed the internals. I have the longer dampers and springs. I am ordering the new springs and that should reduce the overall height of the forks by a good chunk.

As soon as I get the new, shorter springs, I will update the overall height reduction.

Just what I wrote...

First though, since you describe the bike as a "Frankenstein", measure what you have to try and determine what the dampers and springs are from. The original V7 Sport, 750S, S3, LeMans 850, 850-T, 850-T3 (up to '78) damper is 395 mm long. If yours happen to be the 1979 and later T3, SP1000, Convert, G5, CX100, LeMans II dampers which are 410mm overall length, then "backdating" to the earlier shorter dampers and springs could get the results you want.

[Rusnak_322]

Thank you for your help Charlie.
I was confused when I tried to put the thing back together. I had thought that the longer/shorter dampers would have been the damper body, not just a longer rod. I put them side by side (with the rods retracted) and they looked the same.

Only after struggling to get the c-clip on did I look at them with the rods extended.

[Rusnak_322]

I'm thinking your tubes are longer than standard too

I have been searching, but I cannot find any length measurements for the tubes, only 35mm dia.

[Frenchfrog]

Forking by Frank might have the data ...nothing in Guzziology as I remember.If I were to do the same to my bike (T 3 ) the fender would hit the alternator after 1/2 " I guess.... These could be off a later bike with the longer headstock ?