Triumphrat

spumoni · 11-18-2009, 01:23 AM

Hello all:

I decided to go with the 13.5 inch progressive 418's for my new 2008 Scrambler, mainly to lower the rear one inch. Even though they're not here yet, I got anxious and lowered the front forks exactly one inch by simply loosening the fork clamps as mentioned in the forum (it took me a while to figure out that I had to loosen the gator clips before the forks would slide up!). I made sure that both were lowered by exactly one inch, and tightened the fork clamps back to 27 nm like the Haynes manual said, even though it didn't feel tight enough.

Does this look right?

Thanks in advance!

kenneth_k · 11-18-2009, 05:27 AM

that looks ok..

did a search on progressive lowering fork springs but didnt find any for the Scrambler...
I use 10-1550 on my Bonneville 2001... -1,5" works really good...
but i dont know the diffrence in length between scram/bonnie.

both the scram and bonnie uses the same 11-1126 springs for standard length and i dont se why you cant use 10-1550 lowering springs?!?!

am i totally wrong here guys?

Forchetto · 11-18-2009, 05:45 AM

I'm no expert, you've probably noticed...

, but it seems that you'll be fitting rear shocks that are something like 20 mm shorter than stock.
Due to the angle of the shock, it means that the back end won't be lowered by the same amount. Don't know how to do the geometry, but the back end will probably go down by only 16 mm or so.

I would only drop the forks by that amount. In any case 25 mm seems excessive and may lead to a quick and lively steering feel which could result in wobbles or at worse tank slappers.

fatass · 11-18-2009, 07:47 AM

I got the Progressive 1" Bonneville lowering kit for the front end of my Scram, and 12.5 rear shocks, which equaled a 1" lowered Bonnie or about a 2" lowered Scrambler, allegedly.

roadscum · 11-18-2009, 02:50 PM

Quote:

Originally Posted by Forchetto

I'm no expert, you've probably noticed...

,

Maybe, maybe not...... but I like the way you think and alway listen when you speak!

CommandoRdster · 11-19-2009, 06:04 AM

Quote:

Originally Posted by Forchetto

I'm no expert, you've probably noticed...

, but it seems that you'll be fitting rear shocks that are something like 20 mm shorter than stock.
Due to the angle of the shock, it means that the back end won't be lowered by the same amount. Don't know how to do the geometry, but the back end will probably go down by only 16 mm or so.

I would only drop the forks by that amount. In any case 25 mm seems excessive and may lead to a quick and lively steering feel which could result in wobbles or at worse tank slappers.

I was just about to say the same thing.You've steepened the fork angle A LOT.I'd be very careful riding that thing until I was sure how it handled.Even then,it might surprise you under certain circumstances,such as a high speed sweeper,or a bumpy corner under braking.

Find a spot on the sprung part on the rear of the bike,say,the upper shock bolt.With your stock shocks in place,measure to the ground.Install your new shocks,then measure again.The difference is how much you want to lower the front(Not necessarily how high you should raise the stanchions).That should very closely approximate stock rake & trail.

kenneth_k · 11-19-2009, 08:03 AM

Correct trail is somewhere between 5-13 cm, depending on if you have a rigid frame or a swing arm frame. You can never know exactly, Correct trail is essential for optimum ride!!

# 1) Hold the measure tape from the front wheel axle and vertical down to the floor. Mark the spot.

# 2) Place the tape parallel to the steering axle, following the angle of the steeringhead all the way down to the floor. Mark also this spot.

Measure the distance between the two spots – this is your trail!

A suitable measure for rigid frames and choppers is between 5-10 cm. If you have a standard bike with rear suspension, the trail should be between 8-13 cm.

Scrambler: Rake 27.8º
: Trail 105 mm

Every change you do on the geometry of the bike will have effect!
but i think with small changes and doing both the front and back you will be good....

My Bonneville 2001 have 11.5" rear shocks (292 mm)
and I lowerd it 2" front... (Big change!!)

12000 Km this summer without any bad experience.. It handles like a dream!!!

Ps. the photos and text is from... http://tolle.se/index.html?lang=eng

Our Swedish fork and trippeltree GURU! .ds

good luck with you bike

kenneth_k · 11-19-2009, 09:44 AM

Here you have some good reading........
i find this very interesting..

From this site.... http://www.sportrider.com/tech/146_0310_art/index.html

"""""Raising or lowering the front end of your bike changes much more than just rake and trail, however. It also changes the angle of the swingarm, which can play a big part in handling, especially on more powerful bikes. We will cover more rear-end geometry in a later issue, but you should know that adjustments in trail are by far the most apparent change a rider will feel when raising/lowering the bike's front end."""""

I learned ALOT...

hope this helpes...

Fred Hornberger · 11-25-2009, 02:20 PM

I would really like to raise my Bonnevile up to the same height as my Scrambler. I know longer shocks in back, but how about the front. The fork tubes do have different part numbers on microfische so the Scrambler tubes are probably longer. Any other solution beside buying new tubes ($$$$). Both of my bikes are 2007