Moved from 110-100 stem safety advice please

[Birdster]

Hi All,

I was finding the reach a bit long on my B’Twin. Especially after riding my Trek with a shorter stem and slightly smaller frame.

I purchase a pack of spacers and they have the same diameter but are slightly thinner edge to edge.

I’ve tightened everything back up and left 5mm gap between the top of the tube and the top of the stem. The photos on the beige fabric show the same diameter but width difference. All seems line up nicely on the bike.



Thanks in advance.

P.S just a changed the chain as well and that was interesting using the quick links. Didn’t need the tool in the end but held the back brake and pedalled to get them to click. Bike rides much better now.

[option click]

er, the 5mm should be steerer above the top of the stem, not below it


...and what's that clamp immediately above the top bearing cover?

Edited by option click on Wednesday 19th February 14:32

[Birdster]

This is how it looks from above.


All other spacers were below the stem before so I followed the same but did wonder.

[Birdster]

option click said:

er, the 5mm should be steerer above the top of the stem, not below it


...and what's that clamp immediately above the top bearing cover?

Edited by option click on Wednesday 19th February 14:32

Thanks for the reply.
The third clamp from the top? I never touched it as wasn’t sure but looks like you’d use it when removing the fork/steerer tire

[option click]

The general idea is to have a spacer above the stem in order to give clearance for the preload cap.
I've not seen that clamp before - imagine you could swap it out for a spacer.

[Birdster]

Ah okay, makes sense. I removed a spacer too so that the top clamp is level with the top of the steerer.

[The_Jackal]

option click said:

er, the 5mm should be steerer above the top of the stem, not below it

Edited by option click on Wednesday 19th February 14:32

You sure? That's not what guides say.
The steerer tube should be just below the top edge of the stem.
If the steerer tube is above the stem, it has nothing to preload against.

[anonymous-user]

it is generally better to have the steerer above the stem, so that the stem can clamp up properly onto a decent bit of steerer

then a spacer above the stem is there to provide the preload for the the cap

as it is pictured it will work, but it isn't 'text book'

[Your Dad]

That model comes with the bolted spacer so you can swap stems without worrying about sorting preload.

[waynecyclist]

I would been the clamp, not required really

Stem is a little high above the steerer tube.

[Birdster]

Thanks all. It’s appreciated and want to be sure. This is the photo from the original stem. I was aiming to get as close to this. Assume it wasn’t built text book by the supplier of these bikes?



As I was putting it back together I did wonder if it was correct from looking at the Trek (supplied by LBS)

I’ve now dropped it by removing a spacer and it sits so there is a 2-3mm gap between top of steerer and the top bolt of the stem lines up with the top of the steerer.

Safe to ride tomorrow?

[TCX]

https://www.google.com/url?sa=t&source=web&amp...

[TheTardis]

Snaptastic!

[troc]

It’s perfectly ok to run the preload cap up against the stem. I think the perceived need to a spacer above the stem comes from road racing and carbon steerer tubes but in the mtb world it’s pretty common to only have spacers below the stem.

You do only need 2-3 mm of gap to enable a good preload, 5 m’m is unnecessary imho.

[Dannbodge]

Your last piece of the assembly needs to be around 2mm above the top of the steerer.

It doesn't matter if that is the stem or a spacer, you just need to make sure it's higher than the stem.

If you don't then you cannot preload the headset correctly.

[Your Dad]

Pre-load not an issue in this case as there's the bolted collar at the bottom of the stack of spacers, so removing the top cap/stem/spacers will not affect the pre-load.

[anonymous-user]

I'm not convinced that would hold it for very long on it's own

[GOATever]

It looks like someone has put a seat post clamp on the steerer. The only thing I can imagine is that there was a replacement fork, and the steerer has not been cut down, and is too long, and that clamp is in place of a couple of 3 mm spacers. I like my ‘bodges’ but that’s superb.

[Your Dad]

GOATever said:

It looks like someone has put a seat post clamp on the steerer. The only thing I can imagine is that there was a replacement fork, and the steerer has not been cut down, and is too long, and that clamp is in place of a couple of 3 mm spacers. I like my ‘bodges’ but that’s superb.

It's designed and sold like that, see my previous post.

[JEA1K]

Just a thought but would suggest flipping your stem so you can use less spacers ... you should still be able to achieve a similar position to your other bike.