SJS Wheels - Says they won't take a SS freehub - but why ?

I have these wheels on a fixie I've just purchased, but would like the option to also run single speed

https://www.sjscycles.co.uk/wheelswheelsets/700c-622-wheelset-36h-mavic-open-sport-rims-with-sjsc-fixed-hubs-in-silver/

According to the questions/answers on the website, it won't allow for the installation of a SS freewheel..

But why?
I (wrongly) assumed that I'd just be able to screw one on :(

It is a fixed thread so much less thread than a single speed hub would have so not recommended (although I have done it before)

Yeh it’s do-able.

I assume they don't like that only about half the threading on the freewheel will engage on with that on the wheel (probably rightly so, strictly speaking). I have run freewheels of various denominations (Hope, Shimano, ACS, etc.) on double-fixed and not died... and I continue to do it on a couple of bikes. Take that how you will.

hi!

ryan from sjs...

text book, there is not enough thread to safety secure a freewheel on

you will find many people who have done it and not had an issue but I personally sjs wouldnt recommend it!

Also depending on the freewheel, you might not be able to get it off again.

Grrrr... ok thanks all..
Looks like I'm going to have to get a new wheel :(

Or a flip-flop hub and lace it yourself? Plenty of good value flip flop rear wheels about - keep an eye on the classifieds on here also.

https://www.sjscycles.co.uk/hubs-other/novatec-eco-fixed-free-rear-hub-silver-32-hole/

A freewheel will work completely fine on the fixed threads. It will come off without any problems if you grease the threads before installation.

Ignore the man who works at a bike shop trying to sell you more things.

You'll be fine running it on a fixed thread. The only problem you might encounter on certain freewheel/hub combos is the freewheel body fouling on the hub body itself. That's pretty rare, and you'll likely not know until it happens, but it has happened to me.

Do it on a Novatec double fixed hub, have done for years. At times i have run double SS freewheels.

Safety element is correct, a shop staffer would not be able to say do it or it can be done for liability issues. So i wouldn't slate mechanics for saying no.
The risk is less thread engagement over using the correct full thread for a SS freewheel.

It's well covered already on this thread.
many do it with no issue, you do it at your own risk and risk of damage to hub.

The amount of thread engagement will be the same as a fixed cog, it’s a non-issue.

The Sturmy Archer and Shimano freewheel i have are 10mm thread depth, and 16-18mm overall thickness.
The Fixed sprockets i have are 6mm thread depth, and around 6.9mm overall thickness.
Your ruler is out if thats the same :)

Even 7 speed cassettes where only threaded on less than half of their width no?

7 speed cassettes are slid on no?

So the 6mm of thread on your fixed sprocket will engage with x cm of thread on your hub. x must be <6mm and the full length of thread on your hub to facilitate it working correctly.

Screw on your 10mm thread depth freewheel on to the same hub, thread engagement will still be x cm.

No ruler required.

Your logic is out.

The female thread could be 2 metres long, it’ll still engage the same amount of the male thread.

6 then? Multi speed freewheel anyway. Before freehubs

Correct from my learnings!

ok - so I'm confused.. lol
The general consensus is that its fine ??

I have a freewheel ordered so I guess I'll wait and see

It's fine

It’s fine.

....

YOU'LL DIE AN INCREDIBLY PAINFUL GORY DEATH!!!?!

Factor in the possible cost of a new brake?