Cycling UK Forum

My Bombardier motorcycle has a very odd headset set up.

It has four bearings: a needle roller bearing (which may or may not be tapered, I dont know) near both top and bottom, with a radial roller thrust bearing at either end.
To make it even more complex they go into a pair of cones that themselves fit eccentrically into the cups pressed into the headset.

I thought m/c's normally had ball bearing headsets like that Commando
and it was only the higher quality German BMWs with tapered rollers.

I've ended up changing the cheap ball bearings in several motorbikes for lovely taper rollers.... it can make quite a difference to the bike.

The Bombardier setup sounds a bit like the one suggested by MickF, earlier.

cheers

Brucey wrote: That is pretty unusual, I wonder how many other bikes are like that?

Every two stroke MZ uses plain roller bearings in the headstock, as does the bigger MZ Skorpion (660cc tourer).

I've never seen one that's rattled itself to death or died from overloading. Plenty die from lack of maintenance as the originals are unshielded and accumulate muck over the years. They're a bit awkward to get to so don't see as much love as they should.

Well unusual or not, they are the originals and are as good as new so I wont be changing them any time soon. Not that I ride it these days the front wheels been behind the wardrobe for ages waiting for me to send it of for a stainless rim.

Good days are for cycling and bad days are for not going motorcycling

I have only had threaded headsets on all my bikes. Very pleased with them. The only maintainence problem was when one was indexing, Brucey advised me to put loose ball bearings in, it has never needed adjusting since that day.
One time I had an alloy quill stem snap but the long bolt held the pieces in place and I carefully rode the 10 miles home with a broken stem. Glad it wasn't an ahead stem that snapped!

Maybe you should put long bolts through your fork legs incase they snap
You can't put double redundancy into everything.

Brucey wrote:The Bombardier setup sounds a bit like the one suggested by MickF, earlier.

Yep.
Ball bearings top and bottom for load-bearing, and a roller system internally for lateral strength.

No doubt too heavy and tolerance intolerant, but it would be maintenance free and idiot proof.

Mick F wrote:

Brucey wrote:The Bombardier setup sounds a bit like the one suggested by MickF, earlier.

Yep.
Ball bearings top and bottom for load-bearing, and a roller system internally for lateral strength.

No doubt too heavy and tolerance intolerant, but it would be maintenance free and idiot proof.

well you could always take the engine out of a motorbike, fit pedals, and say the same thing.....

I honestly think that if you made it even only double the weight of a standard headset it would still be a nightmare to build; e.g. you can't even measure the diameter of these thin-walled bearings accurately, because they distort so easily. Just putting the calipers/mic on them pushes them out of round.

cheers

WrightsW5 wrote:I have only had threaded headsets on all my bikes. Very pleased with them. The only maintainence problem was when one was indexing, Brucey advised me to put loose ball bearings in, it has never needed adjusting since that day.
One time I had an alloy quill stem snap but the long bolt held the pieces in place and I carefully rode the 10 miles home with a broken stem. Glad it wasn't an ahead stem that snapped!

I once had the steerer snap on a Galaxy 10 miles into a CTC century ride (1995, somewhere near Gloucester if I remember correctly). By lowering the bars as far as they could go, I was able to get the stem to grip the lower, unbroken part of the steerer, and rode the remaining 90 miles like that, in a very racy position.

jb wrote:Maybe you should put long bolts through your fork legs incase they snap
You can't put double redundancy into everything.

It's just that I have never felt the need not to have threaded, especially as it's more pleasing to look at than ahead, the safety was an unexpected bonus.

sjs wrote: ...I once had the steerer snap on a Galaxy 10 miles into a CTC century ride (1995, somewhere near Gloucester if I remember correctly). By lowering the bars as far as they could go, I was able to get the stem to grip the lower, unbroken part of the steerer, and rode the remaining 90 miles like that, in a very racy position.

I presume that the stem had originally been fitted such that the expander bolt was level with the threaded section of the steerer, rather than the plain section? IMHO esp. if you are a strong rider and/or put a lot of force through the handlebars, having a steerer with threads that long (or insufficient quill insertion) makes such breakages quite likely.

Years ago it was commonplace to be able to buy replacement forks with a long threaded section on them so that you could just cut them to length. I never fancied that arrangement much, since the quill would never extend below the threaded section.

cheers

Brucey wrote:

sjs wrote: ...I once had the steerer snap on a Galaxy 10 miles into a CTC century ride (1995, somewhere near Gloucester if I remember correctly). By lowering the bars as far as they could go, I was able to get the stem to grip the lower, unbroken part of the steerer, and rode the remaining 90 miles like that, in a very racy position.

I presume that the stem had originally been fitted such that the expander bolt was level with the threaded section of the steerer, rather than the plain section? IMHO esp. if you are a strong rider and/or put a lot of force through the handlebars, having a steerer with threads that long (or insufficient quill insertion) makes such breakages quite likely.

Years ago it was commonplace to be able to buy replacement forks with a long threaded section on them so that you could just cut them to length. I never fancied that arrangement much, since the quill would never extend below the threaded section.

cheers

I don't know. It was a standard Galaxy from 1992 or thenabouts, with the stem inserted a reasonable distance, or so I thought. The LBS claimed that Dawes claimed such a thing was more or less unheard of, and replaced the forks FOC.

what would cause an aheadset to seemingly have no 'vertical' play (the forks don't 'drop' at all when lifting the front wheel) but at the same time display horizontal movement of 3mm side to side above the top bearing race? damaged upper bearings?

in an A-Head type, a failed or missing wedge would do that.

But it could be anything in the top race; investigation required, I'd say..

cheers

Possibly a tight fitting seal in the bottom cup. Does the fork drop if the steerer is given a tap downwards?