klhada

Upping this tread with a question: how much can my frame flex? Bike is a Langster street, size 58, with Sram Omniuns. Sorry for the bad picture, but it shows that I can put a pencil between the frame and chainring, and it's almost one finger of clearance in the part where the chainring would contact the frame.

BUT, cleaning the bike today, I found some weird scratches on the paint in that part (right now covered by tape). I can post pictures of the scratches lately, but it REALLY looks like the chainring touched the frame. The scratches were a bit deep. Can the frame flex that much, moving more than 1cm in the chainring area? Right now I weight 90kg, and use the bike on some good climbs. I used some black tape to cover the scratches, just as a guide. I will try to go to the hard climb tomorrow, and see if it touchs the frame. If so, I'm actually scared to use the bike

mouse

klhada

yeah, everything works fine. Today I rode 94km with the bike, and nothing out of ordinary.

BUT, then it hits me. If the frame flexed that much, it would be impossible to ride, since I use a rear brake as well. It would touch the rim far before the chainring hit the stays (and THAT I know how it feels).

So, maybe it was just some gravel/whatever which got stuck in that exactly place.

mouse

hardboiled718

An aluminum frame should never flex that much. It's possible you picked up something that got stick in your chainring, and when it scratched the chainstay it knocked itself off.

wphamilton

Maybe, everyone says that you will. I ride mine that way though without issue, just use my brakes when my cadence gets to about 130.

mouse

wphamilton

Never heard that you'll suffer a calamity and die if you don't use foot retention, or never heard of someone riding FG without foot retention?

Leukybear 

It's a good idea for fixed gear drivetrains where there's no freewheel letting you coast.
Constantly driven by the rear wheel's inertia via the drivetrain, a fixed gear's pedals won't stop rotating until the wheels do.
It's not fun to have the skin on the back of your legs skinned by your pedals when your feet slip in a higher cadence.

klhada

well, since I'm the original poster of the actual responses, I might say that I still use double brakes, but now use SPDs Less pratical, but easir on the mind, and specially helpful on the climbs

IAmSam

It doesn't get much interest nowadays, but wayyy back when, there were more than a few discussions here about very light wheelsets, and what parts to use to build your own...

Some of the hubs that got a lot of love for this purpose were low spoke hole, low flange Novatec & Gran Compe SF. Maybe it's the times, but I've been checking around the interwebz lately and I couldn't find low hole versions of these hubs. Retrogression carried the Gran Compes but was out of stock the latter part of last year, and who knows what they will be doing after their move. I've also asked several LBS around me about ordering them and been told that none of their distributors have them. I've run into a brick wall.

So my question for the group is - does anybody know anywhere that one can currently buy low spoke count, low flange Novatec or Gran Compe SF hubs in Silver?

TIA...

TimothyH

^^ Maybe try Alex's Cycles.

bonsai171

Are carbon bars ok on a fixie? Was thinking about putting some Easton carbon bars on my kilo TT mostly for comfort (got 37cm wide bars now, will go to a 40cm) but also for vibration damping. Are they safe to use since there is more stress on a fixie? If I am climbing a really steep hill, my tendency is to pull up on the bars (which is probably bad form , but....) will I break the bars doing that? Not totally comfortable with carbon bars yet (never had them on any bike!), but maybe someone can convince me lol.

Dave

veganbikes

If they need to be fixied, then probably not but a good well known carbon bar from a company with a solid reputation with carbon fiber is fine on really any bike. However I will note that if you are worried about carbon bars buying them and using them probably won't help much. Anything that needs to be fixied should not be ridden whether a frame or fork or stem or bars or seatpost whatever if it is broken don't ride it at all. If you want good vibration dampening go for a eeSilk seatpost and some thicker more cushioned tape and maybe also look at a ShockStop stem.

If you are worried about stress maybe go see a therapist. If you think you are putting to much stress on a bike like a fixed gear, unless your name is Robert Förstemann or Sir Chris Hoy or someone like that you probably don't have to worry much. Certainly cheap components don't hold up well especially to heavy use and abuse but if you get decent stuff and treat it will you will be fine.

bonsai171

Whaaaat? Assuming you are joking here :-) Nothing is broken on the bike, just looking at some wider bars that happen to be carbon.

I'll have to look around at different bar tape, maybe even double layer.

For seat posts, haven't found a lot of nice options in 26.8mm. There is a Nitto Crystal Fellow and a Thomson elite. That's about it unless you count cheap ones like Uno :-p

Dave

TimothyH

Carbon bars will be fine. You aren't going to have a problem with the Easton bars. They won't break or twist.

It isn't going to be a night and day difference in terms of vibration dampening. Maybe a little but you are not going to ride it and say, "Wow! Amazing! I can't believe its not butter!!!"

The only problem is going to be leaving them out in the sunlight. No, I just made that up. Only kidding. They will be fine.


This is pretty funny.

And Dave is like, "Whaaaa?"




-Tim-

Leukybear 

As previously mentioned, perfectly fine. Just be sure to pay attention to the torque spec on the bar itself and not the stem.
If it is tightened to spec and slips, use carbon assembly paste for extra grit-grippage.

TMonk

I used to be scared of carbon bars and parts but I'm not any more. Big thing as previously mentioned is using a torque wrench.

TimothyH

Nothing to be scared of.

JohnDThompson 

"Nothing to be scared of?"

Then why is he wearing a diaper?

bonsai171

lol. Will Tektro RL340 brake levers work with Carbon handlebars?

Dave

veganbikes

Joking? Me? No? I am serious 100% of the time all the time without fail. You said things needed to be fixied so I would be careful and get them fixed before you run into trouble.

Thomson Elite or Nitto Crystal fellow are both fine seatposts I have used the Thomson ones for many years and have had a Nitto in 26.8 for a while and both have been excellent quality wise. 26.8 sadly is not really a common size and is designed to piss you off. You can sometimes find old Dura Ace or Ultegra/600 seatposts in that size but not often and not for cheap. Basically a good bike would would use a 1 1/8" threadless headset and fork and a 27.2 seatpost and everyone is happy because parts are easily available but to save money Bikes Direct buys the cheap stuff because most folks buying that stuff don't know or care what any of that means so it leads to issues like this for people who do know what it means.


Yeah I like it when people miss the joke sometimes. Gotta have some fun.

Leukybear 

LOL

bonsai171

It is frustrating at times on the forums when you post a legitimate question, and get a response like your first post. Feels like the question wasn't really answered.

In addition, no one has said whether my brake levers will work or not. Back at ground zero.

Dave

phobus

There's nothing specific to carbon bars that would prevent them from working with any levers. Road bars all have the same diameter in the area where you attach the levers. Mountain bars use a different standard bar diameter. But as a rule, all road levers should fit on all road bars, and all mountain levers on mountain bars.

The only thing you might need to be careful of is to not over-tighten the lever's clamp bolt.