Steerer too short - BBB extender

[stewlewis]

I couldn't find a replacement steerer, my forks were OK so I didn't want to replace them so I looked up extenders.
The BBB - BHP 21. These have been mentioned a few times so I thought I'd give one a try.

Some pics:

Steerer too short, It only caught the first bolt of the stem.
I rode it like this around Cannock but it was always in the back of my mind, not good.
Also I do like to have a spacer below the stem onto the headset, I have no idea why.

The BBB BHP-21.
Advertised as 25.4/28.6. This is the 1 1/8 size. 25.4mm internal dia of the steerer tube (the diameter of the BBB quill stem extender), 28.6 external diameter of steerer (the ext diameter of the BBB spacer/shims).

Weight 0.28kg

Whack out the star nut, with a cloth on the front tyre so it doesn't fly across the garage.

The bottom nut of the BBB is keyed? into the wedge to stop rotation? or make a lighter wedge?

The BBB spacer/shims have a key to stop rotation and are split to tighten to the extender. They fit quite tight to the BBB, flip'n'slide 'em off with a screwdriver.

A bit of grease on the wedge, fits nicely into the fork steerer.

The through bolt to the wedge is tightened, then the stem cap bolt tightens into that.

Judging the height with the stem. I kept the quill/wedge tightish to stop it dropping into the steerer.

With the BBB spacer/shims in place. A finger up the fork steerer to hold the BBB at the right height helped.

This bit was as fiddly as Jimmy Saville. Getting the height right to pre-load the headset was a pain in the ass. The supplied stem cap bolt just wasn't long enough, no matter how I tried to rearrange spacers and the BBB. I ended up finding a longer bolt.

All done, I popped a spacer on top of the stem when getting the height right, I didn't feel the need to change it.

I did wonder about sitting the stem on top of the h-set and bolting as much stem as possible to the fork steerer. The BBB is well made though and with the wedge/quill bit tightened nicely it seems solid enough.

I do wonder if the steerer was way short and the whole stem clamped to the BBB would it be solid enough. The instructions show it as fine to do so.

I guess it would even be OK if the fork steerer didn't make it through the headset top, but you'd be relying on the quill/wedge tightness to hold it. But then that'd bee the same as the olden days. Well aparty from your forks falling out too.

 

[AMPrider]

I made something exactly like that for myself a few years ago. I always wondered(until now) why there wasn't a similar product on the market.

 

[We_are_Stevo]

Nice one Stew...

 

[MADJEZ]

I had the Halfords one which is similar.

The only worry I had is that the top cap is not holding the forks on as it would in a normal aheadset. Can anyone see this would be a major problem ?

I rode around quite happily for about 18months on mine without mishap (does need tightening every couple of weeks).

 

[highlandsflyer]

How short were you?

A shorter stack headset/stem could have sorted it, with a rise on the stem if needed.

Just more options.

 

[We_are_Stevo]

I had the Halfords one which is similar.

The only worry I had is that the top cap is not holding the forks on as it would in a normal aheadset. Can anyone see this would be a major problem ?

I rode around quite happily for about 18months on mine without mishap (does need tightening every couple of weeks).

The top cap doesn't 'hold the fork on' to the bike, it just tensions the headset bearings prior to tightening the stem bolts...

...take the top cap off after you've set everything up and your fork isn't going to just drop out!

 

[drystonepaul]

If the lower stem bolt is clamped to the original section of steerer then you shouldn't have any problems with this set up.

I do wonder if the steerer was way short and the whole stem clamped to the BBB would it be solid enough. The instructions show it as fine to do so.

From experience I have found that those extenders tend to be problematic when both bolts are clamped onto the extender part. The quill just cannot be tightened enough to prevent unwanted rotation.

 

[velomaniac]

Hold on, this is Retrobike, the system is effectively a threaded headset idea which we all should be familiar with and there's nowt wrong with checking and retightening your headset, thats just good maintenance.I have a couple of bikes with the BBB extender, I think its a great system. If you want a system as good as the original then get some forks with a long enough steerer

 

[Logic.Al]

Hold on, this is Retrobike, the system is effectively a threaded headset idea which we all should be familiar with and there's nowt wrong with checking and retightening your headset, thats just good maintenance.I have a couple of bikes with the BBB extender, I think its a great system. If you want a system as good as the original then get some forks with a long enough steerer

Easier said than done if you ride gates like my huge M-Trax

 

[stewlewis]

The top cap doesn't 'hold the fork on' to the bike, it just tensions the headset bearings prior to tightening the stem bolts...

...take the top cap off after you've set everything up and your fork isn't going to just drop out!

With this extender should the quill part loosen off the top cap will stop the forks dropping out but only slightly. As it's bolted to the wedge should the forks drop the wedge should pull tight against the quill, it wouldn't stop a fail but may stop a disaster.

Hold on, this is Retrobike, the system is effectively a threaded headset idea which we all should be familiar with and there's nowt wrong with checking and retightening your headset, thats just good maintenance.

The quill part is familiar but with this system there's just no threading to stop the forks dropping out.

As Paul has had some experience and says they may loosen and rotate I have no reason to disbelieve that, as for my setup with some stem still on the original steerer I'm happy.

This was the cheapest and easiest option for me, no fork swaps or lower stack headset swaps, this bike wasn't worth additional expense.