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Rear hight adjustment

7 posts Started 5 Mar 2017 Last recovered post 9 Mar 2017 Wayback Machine snapshot 10 Jul 2017

#1

After a long winter - almost ready to fly again - I've wondered why my sidestand is to short app. 20 mm, bike is like laying down.just renovated front suspension  with new seals ect. - Found the rear spring is a hyperpro purple spring and std. shock.

With a std shock the hight is none adjustable on a RC36-1.

All the links below is original -when the bike is on its center stand, the rear wheel is just 20mm above the ground, does anyone know if there is a trick to raise the length of a shock on RC36-1 ? I don't know who mounted the hyperpro on the rear, but it looks like the shock is a few mm to long - any good ideas

cheers

#2

On the later RC36 (93-97), there is a top clevis mount that bolts vertically through the frame that can be shimmed to change the ride height (same as my VTR1000 and 5G VFR800), but I don't think that applies to your 1990, the top shock mount looks to bolt horizontally through the main frame in a fixed location. So I would doubt that you can have a modified rear ride height with a standard shock and linkages. Are you sure that the shock is not also changed for some other Honda part? 

#3

Changing to a harder spring should not affect the length of the stock shock with the bike unloaded. The shock will top out at the OEM length unless it's been internally modified. The rear tire sitting 20mm shy of the ground on the centerstand, within the variances of tire height, seems close to stock. I'll check my 91 later tonight.  It sounds like the sidestand may have been shortened or check if the front end spring spacers are too short. long. (Derp)

My 91 rear tire is around 1.5 inches ( ≈ 38mm) above the ground on the c/stand. It's a Metzeler Z6 170/60-17 with a 636mm diameter. I doubt you have a tire that's 40mm taller so it's likely the shock or linkage has been modified. Just for comparison, the sidestand is ten inches from the middle of the pivot bolt to the round tip.

#4

I had time to do some more investigations today

side stand is 10 inch long

tried to lower the front 15 mm to se how muck that'll give. - side stand is still 1,5 -  2 cm to short

[image: 58bdbb9e685c5_2017-03-0616_23_17.thumb.jpg.c75d0f244c539d9f9314a50c3a57a386.jpg]

rear shock is std but with a hyperpro spring

took it down from the lift again - with wife holding the bike I measured the fork leg from top to buttom

[image: 58bdbba2de0fe_2017-03-0617_41_45.thumb.jpg.e146d112c7c64e082f0ab1eb22d28b9b.jpg]

[image: 58bdbba0acecd_2017-03-0617_41_10.thumb.jpg.e9bce76943c6ff4cfb3104f32d15c6d7.jpg]

82,2 cm - the same as with the front lifted - I guess it's called "SAG" or something,

When I sit on the bike i lowers 2,5cm in front

I think the previus owner has been a heavy guy - putting in some heawy springs

took a measure at my NR 750 replica, build over the same bike, fork length "SAG" is 78,2cm = 4 cm shorter

I have a feeling that the solution is new springs fitting my weight

can't se any stamps on the springs just the purple at the rear and a printed logo on it - frontsprings is no name or signs

is there a way to determin the strength of the springs

#5

I think there may only be one Hyperpro progressive spring (one size fits all!), but I'm not certain. 

Did someone "flip the eccentric", by any chance?  That would result in an instant 30-40mm extra rear ride height.  If the rear caliper bracket carrier bolts have been countersunk, that will be it.

Ciao,

#6
8 hours ago, Helweg

is there a way to determin the strength of the springs

Check to see if the rate is engraved on the end surface.

#7

good news

I contacted hyperpro with my issue

A guy from Hyperpro Holland "John Troost" took time to guide me - together we found out that springs in front is Hyperpro, but they were mounted upside down " not that this matters in my case " but the worst was, who ever installed them back before 2007  did use the original spacers 50mm

According to John,  with my weight ect..ect., a 15mm spacer should do the trick - the rear is mounted correct

did the mod yesterday, what a difference sag is just correct now. And the side stand is long enough now.

 can't wait to come home and test ride it today. I only had two or three turns on it last year, and it felt bad,

anyway thanks for your input.

cheers !

End of thread · 7 posts recovered Wayback Machine snapshot 10 Jul 2017