1974 R90/6 - Fork springs

[cris nitro]

I believe this is a fairly common problem and fix, but here goes. I(we) have 74 R90/6 that I would like to ride more often. However, the fork springs are so soft that I feel like am going to go over the bars all the time. I don't know if they are old and sacked out or wether they are just soft from the factory. No weight jokes, I am under 200#.

 

What is an easy fix, I'd rather not buy new springs. Can I put a spacer on top of the springs for more pre load?

Thanks.

[Paul Mihalka]

The original fork springs were too soft to begin with and after 30+ years they are history. BMW has heavy-duty springs that work very well, pn. 31421232017, that cost less than $40 each. Progressive also had good springs, I don't know if they are still available.

[cris nitro]

Cool, thanks for the quick info. Sometimes I just don't feel like taking out the RT and want something nimbler. What i really want is a newer Triumph Scrambler, but lack of $$$ is getting in the way.

Thanks again.

Cris

[Rinkydink]

I put the Progressive springs in and they were too stiff. I cut 3/4" off of the plastic inserts (spacers)and voila. Do it, you'll love the difference. Just don't cut the spacers until you try them stock.

[cris nitro]

Thanks, Rink. Are there any specifics to the progressive spring?

Such as strength, etc.?

 

BTW, love the bag liners for the RT. Perfect.

Thanks.

[LuckyLeif]

I've had good luck using RaceTech kit to improve the forks on my Triumph Tiger (which stock is almost as undersprung as the R90). They have a neat calculator where you enter your bike model and your typical riding weight and it spits out the appropriate spring rating for your conditions. http://racetech.com/page.aspx?id=56&menuid=62

For kicks, I pulled up the R90 and entered a rider weight of 190lbs. Stock fork springs are rated 0.33 kg/mm whereas desired rating is 0.88 kg/mm. A set of springs is $110 (I think they are sourced from Eibach). You might also want to consider ugrading to RT "cartridge emulator" valving since you'll be tearing the forks apart to replace the springs.

There are probably other sources of fork springs available, but I was really pleased with the RT springs and gold valves on my 09 Tiger. It was a huge change.

[Rinkydink]

According to how much you ride her you might want to go with Luckylief's suggestions. Progressives are good but not really great. I also put Ikons on the back and the difference was very noticable.

[cris nitro]

Thanks, guys.