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Re: Plunger suspension ride height adjustment

Posted: Tue Mar 19, 2019 6:21 am
by adrian.hannam
The old ones are both wound in the same direction.

Re: Plunger suspension ride height adjustment

Posted: Thu Mar 21, 2019 12:47 pm
by jj.palmer
This may be a bit theoretical but should the selection of the spring strength also be considered in reference to the working mechanism of the Ansty linkage in that of maintaining a constant chain tension throughout the up and down movement of the rear wheel.

In an article some years ago in the Cheval called "Spring Heels" it indicated that the Ansty linkage gave a constant chain tension within .004 inch when the up and down movement of the rear wheel was within 1.500 inch of its mid position, see attachment.

If stronger or weaker springs are fitted that takes the rear wheel movement outside this 1.500 inch parameter would this seriously effect the chain tension. The article did not give any indication whether it would or it would not, perhaps a little bit of a calculaton is called for.

Regards,
John P.

Re: Plunger suspension ride height adjustment

Posted: Wed Mar 27, 2019 3:50 pm
by berniejones
I've just had the following quote in from a local firm to make up some springs. Given the likely length of the wait for Drags I'm planning to order some of these and if anyone else would like to add to the order then hopefully the price might go a bit lower.

0.312" compression spring

2 off @ £75 each

4 off @ £47 each

material BS 5216 HS3

delivery 7-10 days


Please let me know if you would like to add to the order and I'll wait until the end of the week and see where we are. (I assume VAT is to be added but waiting for confirmation). Might have to add cost of postage but that should be it.

I also need to confirm the precise dimensions but haven't taken mine out to measure yet so if anyone has the correct figures could you please let me know?

Thanks,
Bernie

Re: Plunger suspension ride height adjustment

Posted: Wed Mar 27, 2019 6:27 pm
by pauldridge
Bernie
I guess I recently got the very last spring (one only) from Dfly. The dimensions are very close to that stated on their website.. Approx 6.5" long and 2" diameter

Phil

Re: Plunger suspension ride height adjustment

Posted: Mon Apr 01, 2019 2:30 pm
by jj.palmer
Having made my previous comment about the strength of suspension springs I did not realize how amazingly accurate the Ansty suspension is at maintaining a constant chain tension thoughout its total travel, did some calcs. to prove its accuracy, see attached results.

Regarding chain tension it may even be more accurate than the swinging arm suspension as the centre of the swing arm is not on the same centre has the gearbox sprocket, therefore the geometry of the Ansty suspension may have been compensated to overcome this.

Regards,
John P.

Re: Plunger suspension ride height adjustment

Posted: Wed Apr 03, 2019 3:35 pm
by keith wainwright
I had to make up spacers to go under the top hat cover. It was difficult to compress down to start the domed nut. I made up a simple jig using a rack clamp. Cured my problem. Keith

Re: Plunger suspension ride height adjustment

Posted: Wed Apr 03, 2019 6:01 pm
by JohnnyBeckett
try harlow springs ltd 01279 429004 they are very good they made me springs and very quick

Re: Plunger suspension ride height adjustment

Posted: Wed Apr 03, 2019 6:37 pm
by berniejones
Seconded. They make the 0.312 springs as their part number HSNO2555.
Mine arrived next day and have made a huge difference when riding two-up.

Cheers,
Bernie

Re: Plunger suspension ride height adjustment

Posted: Wed Apr 10, 2019 2:59 pm
by pauldridge
Bernie,
I tried placing an order with Harlow Springs, but they quickly informed me that they only ship to addresses in England. Guess I'll just have to wait the 10-12 weeks for Draganfly to get around to placing a replacement order with them!

Re: Plunger suspension ride height adjustment

Posted: Thu Apr 11, 2019 8:25 am
by berniejones
Paul, Have sent you a PM.

Cheers,
Bernie