Comstar wheel problem CB750
graham hanson
My 1981 UK spec CB750FA which I've only had for a month has Comstar
wheels and I've noticed a strange noise. I checked the alloy "spokes"
and found one of them was loose but only on one side of the wheel.
The rivets are tight on one side of the wheel but not on the other and
there is about 1mm of movement (1/25th inch) if I pull the "spoke"
sideways.
My questions are:
- Is this dangerous ?
- How can I fix it (could I maybe tighten the rivet by hitting it one
side with a 1 lb hammer but with a 2 lb hammer the other side, being
careful not to hit the rim). There are no cracks around the spoke or
the rim.
Hope someone out there can help as another wheel is pricey - even a
used one.
TIA
Graham Hanson
Tilman Göttke
> My questions are:
> - Is this dangerous ?
> - How can I fix it (could I maybe tighten the rivet by hitting it one
> side with a 1 lb hammer but with a 2 lb hammer the other side, being
> careful not to hit the rim). There are no cracks around the spoke or
> the rim.
>
> Hope someone out there can help as another wheel is pricey - even a
> used one.
>
with a hammer will most likely not work and you risk to damage the wheel.
Why don't you simply ask the Honda dealer of your least distrust whether he
can replace the rivet. The rivet shouldn't be a pricey item (um, I think).
For 20 dollars including work should give you peace of mind here.
Just my .02
Tilman
Landau, Germany
2000 Ducati ST4 (sold)
2001 Ducati ST4s (will arrive in 3 weeks)
Graham Hanson
Older Gentleman) wrote:
>graham hanson <graham.han...@cwcom.net> wrote:
>
>> New to posting here...
>>
>> My 1981 UK spec CB750FA which I've only had for a month has Comstar
>> wheels and I've noticed a strange noise. I checked the alloy "spokes"
>> and found one of them was loose but only on one side of the wheel.
>> The rivets are tight on one side of the wheel but not on the other and
>> there is about 1mm of movement (1/25th inch) if I pull the "spoke"
>> sideways.
>>
>> My questions are:
>> - Is this dangerous ?
>> - How can I fix it (could I maybe tighten the rivet by hitting it one
>> side with a 1 lb hammer but with a 2 lb hammer the other side, being
>> careful not to hit the rim). There are no cracks around the spoke or
>> the rim.
>>
>In Britain firms used to re-rivet Comstars, so it can be done. But I'd
>say it has to be done properly.....
>
>--
>The Older Gentleman
>XJ900S 750SS CB400F CD175
>BOF#30 GAGARPHOF#30 GHPOTHUF#1 WUSS#5 YTC#3 IHABWTJ#1 OETKBC BOTAFOT#60
>http://www.btinternet.com/~Chateau.Murray/homepage2.html
Thanks all for the replies.
I spoke (no pun intended ! ) to a guy at a breakers shop today and
mentioned the problem to him. He first asked me the age of the bike
(1981) and when I told him, he said "oh it's rivet fretting. it was a
well known problem with early Comstar wheels. It was especially bad
in Australia in the early eighties. People found that there could be
only a few rivets holding the wheel together".
He offered me a selection of wheels at 20.00 GBP each and suggested
mine was scrap. I'm going over later in the week to get another wheel
and I'll fit it before I ride the bike again.
Has anyone else heard of this problem (especially in Australia) ?
All I noticed while riding the bike was a (road speed) fairly quiet
squeak and only noticed the loose spoke by chance. I would reccommend
anyone with early 1980's Comstar wheels to go out and check their
spoke rivets - sooner rather than later.
Graham Hanson
Jim Chesnutt
JimiC
'81 CB750F
Mike Fleming
graham.han...@cwcom.net (Graham Hanson) writes:
> I spoke (no pun intended ! ) to a guy at a breakers shop today and
> mentioned the problem to him. He first asked me the age of the bike
> (1981) and when I told him, he said "oh it's rivet fretting. it was a
> well known problem with early Comstar wheels. It was especially bad
> in Australia in the early eighties. People found that there could be
> only a few rivets holding the wheel together".
>
> He offered me a selection of wheels at 20.00 GBP each and suggested
> mine was scrap. I'm going over later in the week to get another wheel
> and I'll fit it before I ride the bike again.
I had a rear wheel on a Superdream fail for this reason, but it was
rather worse than you describe - there was actually a little play all
through the wheel.
Might be worth talking to someone like Central Wheels (depending on
where you are in the country) and see if they could repair it.
--
Headshake? Check the following: tyre pressures, tyre wear and general
condition, balance weights not missing, wheel spokes (where applicable),
wheel plates (Comstars), shock absorbers and forks not leaking, wheel
bearings, steering head bearings, swinging arm bearings.
Graham Hanson
I had a closer look at the "spoke" and I think what has happened is
that the rivet must have been slightly loose from when it was built.
This has allowed the "spoke" to move and wear away the on the rivet
to the extent that it is now loose (and getting looser). I guess the
rivet is steel and the "spoke" is alloy (which is softer).
Graham Hanson