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Sprocket adaptor play
andyd - 26/4/03 at 06:26 PM

Anyone using a Fisher Sportscars sprocket adaptor on a blade engine?

Having just coughed up over £7 at our local Honda dealer for the sprocket bolt and washer that we managed to misplace somewhere in the garage, we find that after fitting it (them?) there is some play in the adaptor. The bolt is done up tight but the splined bit of the adaptor seems to be slightly too short resulting in free play in the forward/backward direction.

Does this matter at all? I'm worried that because of this it'll allow vibration to start as even with the prop bolted in place the UJ at the front still allows the play even though the prop overall doesn't have any play. Incidentally putting the original front sprocket back on and refitting the bolt/washer, the same amount of play is present. However on the bike the chain "wobbles" a small amount anyway so I'm guessing that it not so much of a problem. But what about on the car where it may vibrate the fillings from our teeth?


locodude - 26/4/03 at 07:25 PM

If you mean the sprocket can still slide up and down the spline then yes it's a common thing. You need a washer with a 30mm i/d approx 3mm thick. This will cure it.


andyd - 26/4/03 at 09:47 PM

Chris,

Do you mean a washer to fit "behind" the adaptor i.e. fitted over the splines first before the adaptor then fit the big washer and bolt to keep it in place?

If so that size doesn't sound like something that you can get at B&Q. Any clue as to where I may obtain such a thing. I wish I had a lathe!

[Edited on 26/4/2003 by andyd]


locodude - 27/4/03 at 12:06 AM

If you put the washer behind the adaptor then you have more room for the locknuts, and yes it's nice to have a lathe. Drilled out sierra hub nut washers are just the thing!!!


andyd - 27/4/03 at 10:21 AM

Thanks Chris, I'll have to hunt around to find something like this or maybe get my mate to get one made up via his lathe owning buddies.


ChrisGamlin - 27/4/03 at 11:29 AM

Andy, make sure you get something to stop that adapter moving though, like Chris says a spacer washer of some sort to remove any slack. I know of one Locost BEC racer who unbeknown to him, had the same issue (Stuart Taylor forgot to supply the spacer), and the end result was the adapter and prop breaking the bolt and a lot of damage done by a flailing prop (luckliy no injuries though!)

Chris


andyd - 27/4/03 at 12:34 PM

Ouch... that's what I was afraid of happening. Definately be sorting this one out.


dodgyroger - 27/4/03 at 06:43 PM

Andy,

If you source a supplier for that spacer, let me know. I have the same problem but have not got around to sourcing one yet.

Better still, get two and I'll settle up with you

Roger


andyd - 27/4/03 at 09:12 PM

No worries Roger, I'll let you know as soon as I have two.


carnut - 27/4/03 at 09:13 PM

I seem to have a similar problem. When i did the nut up tight the adapter didnt slide up and down but it did seem to have a bit of wobble in it. I thought that this was normal as it was like that with the sprocket. I am now unsure on wether it is correct or not.

By the way im using a blackbird engine and the adapter is from mk.

Any ideas would be greatly recieved


ChrisGamlin - 27/4/03 at 09:51 PM

There shouldnt be any movement regardless of engine, should be tight, so I'd give it a check carnut

Chris


carnut - 28/4/03 at 04:18 PM

cheers, ill take it out and have a closer look. I think that putting a washer in should do the trick.


dodgyroger - 28/4/03 at 09:29 PM

Better make that 3 spacers Andy


steve faunch - 28/4/03 at 10:09 PM

Im running a blade powerd car & had the same problem. M.K. supplied me with some shimms problem solved