Thread: technical silly questions

So now that my old blue hard-tail has street tires on it, it's really fast. This led me to make it a 1X8. I took off the inner and middle chainring and put the 44t in the middle. No, of course it doesn't fit right, but close, and now I can use the full gear range with the big ring. Only problem is that now the chain can slip off in high gear. Is there some kinda product I can add on to this fucker to prevent that? Do I need a 104mm 42t or 44t single-speed non-ramped chainring? If so, who wants to sell me one for cheap?

Second unrelated question: would going from a 6" front rotor to an 8" make a significant difference in my stopping power? And why according to Jenson, would hayes not recommend an 8" rotor with a standard QR fork that says it can accept a 210mm rotor? They won't sell the caliper adapter, yet other sites will. Also there is a torque spec on the rotor, yet a rotor just comes with a little torx wrench and some bolts. What gives?

Third: I have trouble keeping straight while climbing on narrow single track. Am I just a stupid beater or would something like a 28" handle bar (which I think would be more comfortable, too) help a lanky individual like me?

Thank you for dealing with my jonginess in Sprockets, again.

Originally Posted by stuckathuntermtn

So now that my old blue hard-tail has street tires on it, it's really fast. This led me to make it a 1X8. I took off the inner and middle chainring and put the 44t in the middle. No, of course it doesn't fit right, but close, and now I can use the full gear range with the big ring. Only problem is that now the chain can slip off in high gear. Is there some kinda product I can add on to this fucker to prevent that? Do I need a 104mm 42t or 44t single-speed non-ramped chainring? If so, who wants to sell me one for cheap?

a non ramped chainring would help, but you'll probably be alright if you just setup the front derailleur as a guide. You don't need a shifter or cables, just set the FD up in its normal position, and use the limit screws to adjust it so that its centered over the chainring.

Second unrelated question: would going from a 6" front rotor to an 8" make a significant difference in my stopping power? And why according to Jenson, would hayes not recommend an 8" rotor with a standard QR fork that says it can accept a 210mm rotor? They won't sell the caliper adapter, yet other sites will. Also there is a torque spec on the rotor, yet a rotor just comes with a little torx wrench and some bolts. What gives?

a bigger rotor will definitely help your stopping power, but should be entirely unnecessary (and maybe even undesireable) on a bike w/ street tires. Unless you're looking to be able to lock up the front wheel really easily, an 8" rotor is overkill.

Jensen / hayes doesn't recomend an 8" rotor w/ a quick release because the rotational force that gets placed on the QR / dropout w/ an 8" rotor is higher and more exaggerated with the larger rotor, and it can potentially cause the wheel to rip out of the dropout. From what I've heard, its rare that this would actually happen and mostly its just hayes' lawyers covering their asses, but I think there is at least some truth to it (especially if the QR is not closed quite right). engineering mags could probably give you a better answer

Third: I have trouble keeping straight while climbing on narrow single track. Am I just a stupid beater or would something like a 28" handle bar (which I think would be more comfortable, too) help a lanky individual like me?

wider bars might help that a bit, but generally I think the advantage to wider bars is for cornering (more leverage on the bars makes it easier to lay the bike over into a turn). Try just looking farther up the trial while you're climbing.

THanks, I think we just chucked the old parts, and I should have mentioned the second and third questions were for my full suspension trail bike.
Also, the tabs on the 44t ring (hard tail, now) don't quite match up with the space available on crank (do you need a pic?) so it's a little left of where it should be. Would that single speed ring fit in the crank's middle spot flush? I think just that would help a lot. Should I maybe take a link out of the chain?

Originally Posted by stuckathuntermtn

THanks, I think we just chucked the old parts, and I should have mentioned the second and third questions were for my full suspension trail bike.
Also, the tabs on the 44t ring (hard tail, now) don't quite match up with the space available on crank (do you need a pic?) so it's a little left of where it should be. Would that single speed ring fit in the crank's middle spot flush? I think just that would help a lot. Should I maybe take a link out of the chain?

you could probably rustle up a FD that'd work as a guide at freecycles.
not quite sure what tabs you're talking about. a single speed ring probably wouldn't fit any differently on the crank, the ring just won't have any ramps and the teeth will all be uniform in height. Taking a link out of the chain won't make much difference; the chain will be marginally tighter, but still prone to falling off.
It'd also be a good idea to check your chainline - shift to the middle of the cassette and eyeball the chain to see if its lining up straight with the ring. If its way off, that could be a big reason why the chain is falling off so easily.

Here's a silly question:

Are Shimano chains compatible with SRAM cassettes?

Originally Posted by knumbskull

Here's a silly question:

Are Shimano chains compatible with SRAM cassettes?

Sram chains are compatible with Shitmano cassettes so I would think so.

Stuck- shortening your chain on the HT will help as well.

Originally Posted by Beaver

Sram chains are compatible with Shitmano cassettes so I would think so.

freudian slip?

Originally Posted by knumbskull

freudian slip?

No slip, just the way I see it.

Originally Posted by stuckathuntermtn

Also there is a torque spec on the rotor, yet a rotor just comes with a little torx wrench and some bolts. What gives?

Im confused, what were you expecting? Them to include every tool youre going to need along with the product??? If you want to set it to the proper torque youll probably need to buy a torque wrench as well.... You dont buy a bottom bracket expecting them to just include the tools to install it as well do you?

You bought a rotor... not a torque wrench would be the short answer.

It's not a bit, or anything, it's a little wrench. Why would they put a torque spec on it if I can just use a little wrench? I don't expect a BB to come with the wrench, but I don't usually expect something that seems to call for a specialized tool to come with something like a little key.
I also want to know if the bigger rotor will slow me down THAT much faster without locking the wheel (it's the front wheel!), I've definitely felt myself hitting the limit of my stopping power a few times and getting close to skidding, but still going to fast into a corner(beater).
I'm gonna have to post a pic of what my crank looks like as soon as a recover from this heat exhaustion. I'm sure the chainline is off. Of course, with an 8 speed cassette, there's no middle gear to put it in to test that, but I'm sure it's off.
Sram chains and Shimano cassettes work together pretty much all the time. Just make sure it says Shimano compatible freehub, and an appropriate speed chain. It's just an 8/9 speed standard I think.

if you read the directions for pretty much any part for your bike, there will be a torque spec for everything. The only reason rotors actually say the torque spec on the rotor is A. because its easy to put their because they are already laser engraving it anyway and B. because the lawyers make them.

the wrench is little because you barley need any torque. My Hayes Stroker Trails (which are ok, but I wouldn't buy them again) need 5.65 Nm of torque, which is 4.1 pound-feet. That is like nothing. My torque wrench only goes as low as 20 lb-ft. So basically, if you reef on those little guys with that tiny little wrench, they are plenty tight, maybe even over tight if you reef with a normal length allen wrench.

Of course, lawyers, how silly of me not to realize.
Here's what my crank looks like. Big ring is moved to the middle and you can't really see in that pic that it doesn't sit flush as its tabs are longer than the space for them. So it's a little left. My question is will a 42t or 44t 104mm SS chainring fit right AND keep the chain from slipping off if I'm pumping hard in high gear? Don't make me get out the dremmel.

in my experience, as long as you are running a rear cassette (and not a single speed) the only real good way to keep that chain on is with a chain guide. Sorry, but that's how it is.

Originally Posted by DirkaDirkaJack

if you read the directions for pretty much any part for your bike, there will be a torque spec for everything. The only reason rotors actually say the torque spec on the rotor is A. because its easy to put their because they are already laser engraving it anyway and B. because the lawyers make them.

the wrench is little because you barley need any torque. My Hayes Stroker Trails (which are ok, but I wouldn't buy them again) need 5.65 Nm of torque, which is 4.1 pound-feet. That is like nothing. My torque wrench only goes as low as 20 lb-ft. So basically, if you reef on those little guys with that tiny little wrench, they are plenty tight, maybe even over tight if you reef with a normal length allen wrench.

Torque values are spec'd based on the "construction" of the fastener in use. Overtightening can cause fatigue and eventually lead to failure of the fastener. It can also degrade performance. For example, in the case of automotive brake rotors, fastening each bolt to a different torque value (ie, not using a torque wrench) can cause warped rotors and give you that wonderful wobble when you step on the brakes. Not sure that could happen on brake rotors, but the point is the same. As a general rule, I'd say when you're working on bikes, you're far more likely to overtighten than undertighten.

FYI - you can get torque wrenches that go down to ridiculously small values (Snap On makes one w/ a full-scale reading of 8 in-oz!). If you're working on cars and bikes, you'll end up with at least 3 torque wrenches.