Stem Raiser or High Rise Stem - safe on carbon forks?

[autolycus]

There's a very similar and recent thread here but i didn't want to hijack it and there are a few differences which may be important so i've started another. What i have to report might be relevant to the other so if a mod feels it is appropriate to merge them, please do.

I recently bought a Boardman Team hybrid with carbon steerer and Halfords built it with an adjustable high rise stem that i supplied. I then swapped it for a similar one which is a gloss black finish to match the bars, but i get a clicking noise if i press up/ push down hard on the grips on one side or the other, which unnerves me a bit. (I didn't notice it on the earlier one, but it wasn't on for long.) I think it is coming from the angle adjuster.

So, i thought about using the original stem on a riser, but the consensus on the other thread seems that a high rise stem is a safer option.

Other than dimensions, there doesn't seem too much detail in advertised products, but I found some comprehensive information on the Humpert website specifically on their 'Comfi' stem which looks a seriously strong bit of kit.

http://humpert.com/en/bikeparts/mar...tec&produktart=2&einsatzbereich=4&produkt=426

However, on downloading the assembly instructions there are (several) dire warnings about not fitting this stem to a carbon steer tube for safety reasons... "risk of breakage!" Similar warnings apply on the 'High Charisma' instructions.

I notice the torque settings on the steerer clamp bolts are unusually high - perhaps this is the reason for the warning. But i am seriously confused about what device IF ANY is going to give me safely the considerable front elevation i need to ride this bike comfortably.

Thanks for any considered advice.

 

[youngoldbloke]

Just looked at the Boardman Team on the Halfords website and it says Carbon Fork with Aluminium steerer? What is the steerer tube made from? Can't see why the stresses on the steerer tube should be any greater with the High Charisma stem than with a more usual design - but then I'm no engineer.

 

[autolycus]

Thanks for that. But i've just rechecked the Boardman Website and under the Hybrid Team description it says "Full Carbon, tapered steerer".
And under Specification: "Fork Full Uni-directional Carbon Fibre, Tapered Steerer".

And the 'High Charisma' is a 'usual design', it's the 'Comfi' that is more unusual, but both carry the warnings about carbon steerers.

I'm not fixated on Humpert, it's just that it's the only manufacturer i've found that actually produces assembly instructions.

Can no-one point me towards a stem with a decent rise that would be safe with a carbon steerer?

Please?

 

[autolycus]

Well this thread did not spark too much interest, but i think this coda is noteworthy, if not astonishing.

Very long story (fairly) short.

I contacted Halfords Customer Services and asked which adjustable/high rise stem (if any) is safe for use with this bike. They replied that the steerer is aluminium so any stem is suitable. I wrote back saying i was pretty certain they were wrong and could they please send a more diligent answer on an important point of safety. They again replied asserting that the steerer is not carbon and that any stem is safe.

I took the bike for its 6-week check and mentioned the issue. After more exhaustive research and inspection of the fork and steerer the store staff assured me yet again that the steerer is aluminium and that the adjustable stem i was using was quite safe.

Twenty minutes later as i was about to leave, i was told that that the fork is in fact full carbon and that i should not use any adjustable or high rise stem with this bike. Apparently a technician from Evans who happened to be in the shop at the time had inspected the steerer and pronounced it carbon.

I swear i am not making this up.

A week later i got a third letter from customer services, this time confirming the fork to be full carbon - 'not recommended for use with an adjustable stem' - and offering a full refund.

I accepted the refund, but not before writing to Mr Dennis Millard, the chairman of Halfords, to make him aware of the shameful and potentially lethal ignorance in his marketing and customer service departments. I also informed him that the website and POS literature still boasted an aluminium steerer. And i invited him to compensate me for the masses of research and no little time and money i had spent adapting the bike to my own preferences, based on the false information that the bike was safe for its intended purpose. I also informed Trading Standards of the misrepresentation.

That was two weeks ago. I have had not so much as an acknowledgement from Mr. Millard - a self-professed Boardman bike fan - or indeed Trading Standards.

And as of today, the Halfords website still describes the Boardman Team Hybrid as "Carbon fibre blades with aluminium steerer for comfort and performance". I hope this exposition may at least warn any Boardman Team Hybrid owners - or prospective owners - of the dangers of modifying the stem. Or of taking at face value any information however often repeated by Halfords Customer Services.

 

[Globalti]

You trusted the goons at Halfrauds? Blimey.

 

[autolycus]

Well, not exactly. You can see i remained sceptical despite all their false assurances.

Incidentally, I don't think Boardman come out of this too well either - i attempted to contact them directly, but was referred back to Halfords.

I do have to report that i heard from Trading Standards a few mintutes ago, so maybe something will get done after all.

Not holding my breath for any goodwill compensation from Halfords though but ;-)

 

[vickster]

Did you look at the steerer, it's quite easy to see / hear whether it's alu or carbon from my experience. Not hard to remove a stem

 

[autolycus]

Of course you're right. And the guy from Evans knew at a glance - from the type of fixing bolt that is used apparently. But it's not my expertise that's at issue here, nor the essential point I'm making. It's the ignorance of Halfords marketing, customer services and technical staff. And their apparent indifference towards rectifying a potential lethal error on their part.

Going back to my original post, there is also the wider issue of adjustable/riser stems on full carbon forks. Apart from the example i gave, i found practically no unequivocal advice not to fit such a modification - on discussion forums or on myriad websites selling the items. Certainly no-one here responded in that vein. As you say, it's not hard to remove/swap a stem and i bet there are a lot of cyclists out there who have done this mod in blissful ignorance of the potential danger they may have put themselves in.