Quill / A-Head Conversion - Testing Times / Advice Required!

Ok...
Flick the kettle on this is a long one & I'll do my best to describe the issues im having.

My 1st build and ive decided to use a quill conversion to a-head.
The adaptor came with a horrible plastic removable top cap and beneath that sits an M7 bolt, which as im sure your aware screws into the mouse.

Now...i wanted to use a decent top cap, so ive purchased a Ritchey one - but this now means that the original bolts too short as the head of the bolt sits in the new (higher placed) top cap.

So my question are as follows:
1) Can i obtain an M7 bolt the length i need with an allen key head? And if so where please - as ive struggled to date!

2) Get an M8 which are more widely available - drill the top cap accordingly and get the mouse drilled and re-threaded to suit?

3) Another fix that one of you guru's can suggest!

Thank you in advance for your help......in advance!

[Makes a tea, pulls up chair.]

I've been thinking through this problem too as I also want to avoid the rubbish top cap.

You could get a longer M7 bolt, but I really struggled to find one recently for a stem clamp. Resorted scouting through LBS drawers for one. Not much online. But I'd be cautious about using this method. Top caps are designed to allow you to preload the headset, actually once stem clamp is tight the top cap doesn't do too much. If you use it to tighten the quill against you're putting a lot more load on it, then you've got to worry about the interface between the cap and the adaptor being sufficiently strong.. Could all go wrong.

Drilling the top cap and rethreading the wedge would be interesting! I think you'd get the same problem as above..

I was thinking about using a top cap that didn't need a start nut. xLite for example did one that allows the top cap to just bolt into an expanding bung. Cane creek also do one, I run it on my road bike with carbon steerer. This does depend on the depth of the recess in the top of adpator and the location of the expander wedge bolt though. If the bolt is close to the top you've not got much room. If it's like those old Zoom stems though and it's 25mm down there then you're good for this option. Or you could simply use a nicer push in top cap, USE Rin-Go-Star for example. Although these only come in 1" 1/8th if i remember right. Any CNC people on here interesting in milling one (£££?)? or a MOET cork?

Dave - thanks for the great reply....

This morning I have ordered the Hope Hed Doctor - in the hope that it doesnt foul the recessed M7 bolt !

I will keep you posted and may even take pictures when done if im feeling really sad -

Glad im not alone in this pickle Dave - Thanks again mate

Moet cork = last resort!!!!!!!

EDIT: Type quicker, eat slower....


The problem you are going to have is that the quill converter needs to be very tight into the steerer in order to stay in place. Now if you use a top cap it will be tensioning down on the stem in order to get really tight meaning that you need the big diameter bolt as a stardard M6 that sits in a top cap may not be strong enough (a top cap is not a structural part of an aheadset set up, just there to load the bearings, where as a quill bolt is a structural part) so you will need the thicker bolt so you will need to drill the top cap, or find another way of inserting it. May be thing about retaining the standard bolt and set up in the quill converter and then using a drilled rubber bung to hold the top cap in place.

Also remember that if you do decide to use the big bolt and drill out the top cap that you should fit the stem to the quill converter before you install it in the bike and tighten the stem bolts alot as the top cap will be trying to pull the quill converter through the stem otherwise and it will be a bugger to get tight.

Does any of that make sense, it did in my head.....

Basically though the top cap isn't designed to be a structural part but you are trying to make it into one so you need to adjust the design accordingly!

do you have any pictures as I've not used a convertor.... and what have mice got to do with it :?

Ah, too late to the party. Good to see that we are all thinking alike though!

btw, top of headdoctor expander site 12mm below top of stem...
not sure how long the expander is.

Have you not thought about using a standard Quill stem top cap ?


or contact
http://www.tastynuts.com
or http://www.tibolts.co.uk/
too see if they have or can make one.
etc..

https://www.btowstore.com/epages/BT2519 ... ts/0000105

any use ?

https://www.btowstore.com/epages/BT2519 ... ts/0000105

any use ?

the bolt supplied with converters are identical with standard quill stem bolts. They are usually very heavy steel.
I replaced my steel bolt with an alloy bolt from one of my old Cinelli quills
Never thought about fitting a standard A head cap in place of the orrible plastic thingy . Good idea.
You just need to be sure that the cap will take the stress of the converter bolt loading without deflection The converters have a steel cap integral with the tube