Front Sprocket Retainer Plate -

[leerichards]

I have just returned from a short tour of Spain & France and suffered a breakdown on the first day. Whilst moving off in first gear i heard a metal on plastic scraping noise which got faster as i accelerated. I removed the front sprocket cover and then the front sprocket retainer plate and noticed that the front sprocket retainer plate inner teeth had been completely worn down, to form a smooth inner ring. This allowed the front sprocket to move freely up and down the remaining length of the drive shaft, in turn grinding against the inside of the front sprocket cover. A logistical nightmare then followed and a replacement part was sourced in Santander, which my mate went and collected. (cheers rich)

I own a 2005 TA, which i purchased with only 5000 miles on the clock and i am truly shocked that this fault has occurred.

My question's are these:

a) What can cause this amount of ware on a critical part in such a short space of time?

b) Should there be any minor lateral movement of the sprocket on the drive shaft? or should it fit perfectly with no movement at all?

Im concerned as even with the new retainer fitted, the sprocket has slight movement.

I have noticed a similar thread on the forum, which seems like the same problem. Although, i am unable to confirm whether both the front and rear sprockets on my bike are original. I would guess that when i purchased the bike with such low mileage, i would expect them to be the original ones.

Any advice much welcomed.

Thanks

Lee

[@lf]

I belive there should be some play in the sprocket when cold.
When driving the metal heats up and need some space to expand.

All my bikes have had some play in the front sprocket.

Did you see this thread?

http://www.xrv.org.uk/forums/transalp/36515-transalp-front-sprocket-problem.html

[leerichards]

Thank you

Any ideas about the ware on the retaining plate?

Cheers

lee

[BobA]

Lee


I'm usually on the AT forum, but here are my suggestions.


Check the chain isn't too tight. If you were on a trip I'm guessing the bike would have been more loaded than usual, possibly making the chain too tight and putting strain on the front sprocket. Slightly slacker than Honda recommendations is OK, and DO NOT rely on so-called bike mechanics to get it right!!

Check whether you have an OE or aftermarket front sprocket (AT ones have rubber sides to them) and if you have an aftermarket one, MAKE SURE it is fitted the corrct way round. If it's back to front (with the boss towards the engine) to front and rear sprockets will not be in line, making the chain put a sideways force on the front sprocket.



Good Luck



Bob

[leerichards]

Hi Bob,

Thank you for your advice. I have read a few threads on the forum and can see that there are a few cases of the same issue out there.

I bought the bike with only 5K on the clock, and have only done the daily commute in the summer months, so i have only clocked up about another 2k in the year that i have had the bike.

I beleive that the sprokets currently fitted to the bike are the original ones, but i will check them over the weekend.

Any ideas regarding the retainer plate?

Thanks

Lee

[default]

Hi Lee,
Mystery to me, I have 70,000 miles on this part after about five sprocket changes. It should not have any reason to wear out. Was it fitted in to correct way give us pictures maybe that might show the problem.

Was the chain alignment correct.

Strange

Steve

[leerichards]

Hi

Thanks for your reply. As far as i'm aware, both sprockets are the original parts.

Will try to upload some pictures, although tried earlier without success.

Thanks

Lee

[leerichards]

Here's some pics of the sprockets front and rear and the old retaining plate that has the teeth stripped. Click here.

Thanks,
Lee

[Lutin]

Was the retainer plate actually screwed to the sprocket, as it looks like it has been moving about all over the place to wear that much.

[Cabby]

Hello Lee...I recently replaced the front sprocket on my old Alp.

I seem to remember that the retaining bolts should be treated with thread lock.......you don't think it was just loose enough to move around a bit, do you...that could explain it.

loctite on the new one asap, if not already there.