Another tele fork question (sorry)
Posted: Tue Mar 28, 2023 10:34 pm
Hi folks, while I have the forks off my 1950 VB to replace the seals, I thought I'd investigate another puzzle:
When I got the bike, 2 1/2 years ago, I was surprised at the softness of the forks. Also, they seemed to sit a bit low. This was confirmed when I was able to compare my bike to others on a recent N.Z. Ariel rally - you can see about 1" less of the seal carrier than other similar singles. i also get a definite clonk if I hit a decent bump or pothole (of which there are many around here). The steering head is not loose and i had the specified amount of oil in the forks (although it was SAE 30, which may not be appropriate ?).
The obvious reason is weakened springs, but after some basic measurements and tests I'm not so sure.
They look in good condition, have an orangish paint blob on the top, 20 1/2 turns and a free length of slightly over 10 inches and 0.21" wire thickness. Looking at Waller and the Draganfly site it seems that they are probably their part number H55-54 (Single and KH 11-20 stone rider), so their free length is perhaps a 1/4" shorter than quoted. I did a (rather crude) compression test with a 5L pack of oil and it seemed to be close to Drags quoted spring rate, so I'm a bit puzzled as to why they sit so much lower than other bikes.
Given that new springs are pretty costly by the time I get them over here, I was wondering about fitting a 1" pre-load spacer on top of the springs, but not sure if that would be a sensible or safe idea. Or do I just evict the moths from my wallet and buy replacement springs ?
As always, any guidance is welcomed.
Cheers, Bevan
When I got the bike, 2 1/2 years ago, I was surprised at the softness of the forks. Also, they seemed to sit a bit low. This was confirmed when I was able to compare my bike to others on a recent N.Z. Ariel rally - you can see about 1" less of the seal carrier than other similar singles. i also get a definite clonk if I hit a decent bump or pothole (of which there are many around here). The steering head is not loose and i had the specified amount of oil in the forks (although it was SAE 30, which may not be appropriate ?).
The obvious reason is weakened springs, but after some basic measurements and tests I'm not so sure.
They look in good condition, have an orangish paint blob on the top, 20 1/2 turns and a free length of slightly over 10 inches and 0.21" wire thickness. Looking at Waller and the Draganfly site it seems that they are probably their part number H55-54 (Single and KH 11-20 stone rider), so their free length is perhaps a 1/4" shorter than quoted. I did a (rather crude) compression test with a 5L pack of oil and it seemed to be close to Drags quoted spring rate, so I'm a bit puzzled as to why they sit so much lower than other bikes.
Given that new springs are pretty costly by the time I get them over here, I was wondering about fitting a 1" pre-load spacer on top of the springs, but not sure if that would be a sensible or safe idea. Or do I just evict the moths from my wallet and buy replacement springs ?
As always, any guidance is welcomed.
Cheers, Bevan