zzyzx_xyzzy

The lockring held. The HUB broke.

4352264851_df73d867d0.jpg

I am now mentally filing track thread and lockrings under the category for "worst mechanical interfaces."

Does it work out well to get a tommicog and respace a front disc hub out to rear width?

xB_Nutt

https://www.wiggle.co.uk/p/cycle/7/Ch...ub/5360044293/

https://www.wiggle.co.uk/p/cycle/7/Ch...et/5360044294/

leed

Ouch. As for the front disc hub, I've only heard good things about that method.

Steev

I'm running a front disc hub with a home drilled cog. Chain-line came out at 46mm for a 130mm spaced hub and no dish, which suits me as I'm using the outer ring of a road double. My biggest concern is that a front hub uses smaller bearings than a rear, but I haven't put enough time on the bike to see how the bearings are going hold up.

Tomo_Ishi

Have you seen Velosolo? 50-60 UKP so it's more affordable than Philwood bolt-on cog/hub setup. I would eventually have to lace one for myself, but people use this cog-lockring setup fine, you know?

TejanoTrackie 

Another option is the Miche system, which uses splined cogs that slide onto a carrier that is permanently screwed onto the hub. A lockring is used to keep the cogs from sliding off, but it takes no load and is tightened lightly. Another advantage of this system is that cog changes are quick and easy.

https://www.worldclasscycles.com/mich...ier_on_hub.htm

mihlbach

What hub is that so I can avoid it?

The chances of this happening again are remote even with a cheap formula or novatec hub. I would just replace it with another track hub.
The tomicog/disc front hub interface is indestructible and great for offroading, but excessive for road riding. I built a tomicog wheel with a Surly front disc hub. The Surly front hubs use the same bearings as the rear, so converting the hub involves changing only the axle and nuts. WIth any disc hub conversion, getting the chainline right is a bit more challenging than a normal track hub and you may end up with a slightly dished wheel. The excessive amount of axle spacers and inboard position of the NDS bearing could compromise bearing life. Also keep in mind that front hubs were not designed to be rear hubs so in the event of failure you are **** out of luck in terms of warrantee replacement.

mihlbach

I also use the Miche system for a track bike that mostly sees road use. I have been quite pleased with it, both in terms of ease of cog change and cost effectiveness.

zzyzx_xyzzy

I know that this kind of failure is unlikely and stripping the threads is also unlikely with proper installation and tons of people use threaded hubs with no problem. It's more the principle of the thing. The threaded cog/reverse threaded lockring interface would have never existed if there were competent mechanical engineers involved. I feel the same about cottered cranksets, threaded headsets that rely on keyed washers, etc.

I can get a perfectly ok front disc hub out of the bin at recycled cycles for $8 and a velosolo or tomicog, and borrow the axle and spacers from this hub, so it actually works out to be of the cheapest options. Hilly around here so I don't anticipate wanting less than 16t anyway.

JohnDThompson 

Skidz?

Doesn't look like a JRA event in any case.

WoundedKnee

That looks awesome.

RooNYC

I stripped a novatec hub in about 1.5 months of riding. Flipped to the other side and stripped that in 3 weeks. now I have an origina8 stamped forumla style hub. What can I expect in the durabilty department from my new hub?

Im not getting the miche splined cog thing. I could see it being great if the hub had splined and the cog mounted onto the hub directly but it uses a "cog carrier" that screws onto the hub the same way that a threaded cog would screw on. Would this unscrew when skid stopping the same as aregular cog and put pressure on the lock ring? Im thinking since its more parts it would actually be weaker that a solid cog threaded onto the hub. Im probably missing something. Can someone please explain how this system is an improvement on the standard threaded cog/hub?

mihlbach

Yes, you are missing how to properly install a cog and lockring.

WoundedKnee

I don't know how, but I installed my first cog wrong. Now I always use rotafix and oodles of grease. No problems on my Formula.

AEO

just goes to show how you don't want Italian or French engineers designing your mechanical bits

Tomo_Ishi

mihlbach is right. Awww ... I was actually looking forward to the Velosolo stuff. I can service that hub 100% with my eyes closed and all.

Wow wait, the carrier is screw-on right? That's same as any cog ain't it? I wouldn't do it if you are stripping the thread with normal cogs. ... a better hub is probably a better solution. ... But that doesn't mean it ain't cool. I would love one, but it's an import here.

TejanoTrackie 

Unlike a screw-on cog that you may want to remove in the future to either change gearing or replace a worn cog, the Miche carrier is meant to remain permanently attached to the hub. Therefore, I installed mine with Loctite red threadlocker, tightened it with a cog tool in a large bench vise and let it cure overnight before riding. The carrier has now become an integral part of the hub and will never come off. The only disadvantage is that the hub will now only work with the Miche cogs, but they are relatively inexpensive and readily available. The nice thing about this system is that the lockring only needs to be tightened lightly, so it is easily removed and there is no chance of stripping its threads or the hub lockring threads. Oh, and one more advantage is that the Miche cogs are symmetric, so you can reverse them when they get worn on one side, thus doubling their normal life.

WoundedKnee

What if you don't use Loctite? Then the only advantage is easy cog changing right?

TejanoTrackie 

I'm not sure that the Loctite is really necessary if you do a good job of tightening the carrier, I just wanted to be 100% sure. The lockring would still do its job if the carrier happened get loose and start to unscrew, but that is not good for either the hub or lockring threads. In any event, every time you install and remove a normal screw-on cog you are wearing out the hub threads, whereas with this system there is no wear no matter how often you change a cog.

bionnaki

ive never considered the miche system. is there any play? does play ever develop?

what tool would one use to initially tighten the carrier -- or do you simply tighten by hand? would you say this is a system that one would never have to use a chainwhip? I hate chainwhips.

how are the cogs? on par with eai, surly, da, etc?

Sixty Fiver

People have been using the threaded cog and reverse locking since the very earliest days... old coaster hubs also use the same system and are constantly subjected to back pedaling to engage the brake.

99% of the failures are due to improper installation.

In this case the hub was probably a POS and bet it falls under the category of people trying to make a part as light as possible to save a few grams of weight.

operator

The system sucks ass. Play eventually develops between the carrier and the cog, producing noise. Which means replacing the carrier and cog when that happens. Seen it enough times to tell you that it's only useful under specific situations where cog changes need to be very quick.

TwoShort

I'm not sure how old a coaster hub you're referencing, but the ones I've taken apart cover a reasonably broad time range, and have all had some sort of splined cog.
I basically agree that most failures of the reverse-thread lockring system are due to improper installation, but I'd call that a weakness of the design: it is too easy to install it improperly.

cnnrmccloskey

Being to easy to mess up is not a flaw of the design, its a flaw of the user. I installed my first cog/lockring on improperly because I thought it was simple and that I didn't need instructions, I was wrong that was my error, I stripped the threads, took the two seconds it takes to learn to do it right and have never had another problem

TejanoTrackie 

I have not experienced problems with play developing, however, I use this system on the track where I am not constantly back pedalling and reversing the loading on the splines. As you said, the main advantage for someone like myself is that on the track I can make quick gear changes during workouts or races.