Mechanics Quick Question Thread [Ask Questions Here]

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Mechanics Quick Question Thread [Ask Questions Here]
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Posted: Jan 16, 2020 at 21:48 Quote
chickenrunz wrote:
Hi, appreciate all your advice. When next changing the chain on my enduro I promise to use a better housing and cable, been researching that a lot now.

I have now started on researching rim spoke tension. Got myself a park tool and am practicing on the oldest bike first. Reason is I don't trust my best LBS i sent it there for spokes tensioning and my park tool says it's not evenly tensioned.

But nothing on the internet tells me the spoke tension ratio for left and right side spokes. Is there an easy ratio?

All my family members' bikes are mtb, 26 27.5 and 29 all disc brakes. All but one are the old QR 100 front 135 rear, one is thru axle 110 front 148 rear. No asym rims. All are round spokes alloy wheels.

Thanks for any pointers. I don't want to stuff up my new bikes but got a few old ones that I'm playing around with. Darn things tweak one spoke and the entire wheel is affected lol. Doesn't stop me trying though I don't know what ratio to aim for.

Some tension is a bit of an art. Aim for 120 kg-force on the drive side for the rear and disc side for the front. Wheel true is more important then perfectly balanced tension.

Posted: Jan 16, 2020 at 22:06 Quote
chickenrunz wrote:
Hi, appreciate all your advice. When next changing the chain on my enduro I promise to use a better housing and cable, been researching that a lot now.

I have now started on researching rim spoke tension. Got myself a park tool and am practicing on the oldest bike first. Reason is I don't trust my best LBS i sent it there for spokes tensioning and my park tool says it's not evenly tensioned.

But nothing on the internet tells me the spoke tension ratio for left and right side spokes. Is there an easy ratio?

All my family members' bikes are mtb, 26 27.5 and 29 all disc brakes. All but one are the old QR 100 front 135 rear, one is thru axle 110 front 148 rear. No asym rims. All are round spokes alloy wheels.

Thanks for any pointers. I don't want to stuff up my new bikes but got a few old ones that I'm playing around with. Darn things tweak one spoke and the entire wheel is affected lol. Doesn't stop me trying though I don't know what ratio to aim for.
I won't claim to be an expert wheelbuilder, so please correct me if im wrong. But you only use the tensio on the short spokes (drive side rear, brake side front). No ratio, just even tension on the short side.

Posted: Jan 16, 2020 at 23:44 Quote
Hmm. Hmm. Ok that's interesting... That means I need to get a trueing stand... I thought you just get the numbers to an end point...

Does it matter where on the site I use the park tool or do I need to be at a specific point on the spoke?

Posted: Jan 17, 2020 at 4:33 Quote
Hey guys, I have a trek slash 9.8 the seat post is 31.6, I want to get another seat clamp, what size do I need ?

TIA !

Posted: Jan 17, 2020 at 4:35 Quote
chickenrunz wrote:
Hmm. Hmm. Ok that's interesting... That means I need to get a trueing stand... I thought you just get the numbers to an end point...

Does it matter where on the site I use the park tool or do I need to be at a specific point on the spoke?
Center point, your guage came with a calibration sheet which is specific to your tool make sure you use that and that you don't lose it.

Posted: Jan 17, 2020 at 5:21 Quote
Hey guys I bought my nephew his first bmx its a 16”. And he is 8

He has trouble reaching the brake lever. Is there anyways to get a longer lever or adjust so its closer to the bar?

On my mtbs and mx bike the levers are all adjustable but this one doesn’t seem to be.

Posted: Jan 17, 2020 at 5:54 Quote
Thepureface wrote:
Hey guys I bought my nephew his first bmx its a 16”. And he is 8

He has trouble reaching the brake lever. Is there anyways to get a longer lever or adjust so its closer to the bar?

On my mtbs and mx bike the levers are all adjustable but this one doesn’t seem to be.

There should be a small grub screw on the inside of the lever body. If not you should be able to get a pair of plastic levers which have this pretty cheap.

You can see the screw pretty clearly in these images https://www.amazon.co.uk/KIDS-BIKE-V-BRAKE-LEVERS-Childrens/dp/B07JH2YS3Z/ref=asc_df_B07JH2YS3Z/?tag=googshopuk-21&linkCode=df0&hvadid=375446013724&hvpos=1o13&hvnetw=g&hvrand=3929571955586841619&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006892&hvtargid=aud-861612201097:pla-816028467093&psc=1&tag=&ref=&adgrpid=77100533696&hvpone=&hvptwo=&hvadid=375446013724&hvpos=1o13&hvnetw=g&hvrand=3929571955586841619&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006892&hvtargid=aud-861612201097:pla-816028467093

Posted: Jan 17, 2020 at 9:34 Quote
chickenrunz wrote:
But nothing on the internet tells me the spoke tension ratio for left and right side spokes. Is there an easy ratio?

Yes, there's an extremely easy ratio: get the rim centered! The flange offsets on either side are almost never equal and this is what dictates the tension ratio. If, for example, one hub has a 20 mm offset on one side and 30 mm on the other, while some other hub has 25 mm and 25 mm, these wheels clearly cannot have the same tension ratios and still have both rims centered. The symmetrical hub can have the same tension on both sides; if you did that to the asymmetrical hub, the rim would be centered between its flanges, which is not centered between the dropouts.

This is the general strategy:

• Spoke length should be sufficient to fully fill the nipple or emerge out the end by a tiny bit.
• Tension on the side with less flange offset will be higher.
• Tension on the high-tension side should be near to the maximum rated tension, which is usually limited by the rim, but occasionally by the nipple or spoke.
• Ideally, tension will be uniform all around each side, albeit different from one side to the other.
• Rims are never perfectly straight or round, so there will probably be small variances, especially if the rim has been bent from riding and is being forced straight by spoke tension.
• The rim joint is never perfectly straight. It's better to allow a little wobble at the joint than to strive for straightness with highly uneven tension.

Posted: Jan 17, 2020 at 9:39 Quote
radatabs wrote:
Thepureface wrote:
Hey guys I bought my nephew his first bmx its a 16”. And he is 8

He has trouble reaching the brake lever. Is there anyways to get a longer lever or adjust so its closer to the bar?

On my mtbs and mx bike the levers are all adjustable but this one doesn’t seem to be.

There should be a small grub screw on the inside of the lever body. If not you should be able to get a pair of plastic levers which have this pretty cheap.

You can see the screw pretty clearly in these images https://www.amazon.co.uk/KIDS-BIKE-V-BRAKE-LEVERS-Childrens/dp/B07JH2YS3Z/ref=asc_df_B07JH2YS3Z/?tag=googshopuk-21&linkCode=df0&hvadid=375446013724&hvpos=1o13&hvnetw=g&hvrand=3929571955586841619&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006892&hvtargid=aud-861612201097:pla-816028467093&psc=1&tag=&ref=&adgrpid=77100533696&hvpone=&hvptwo=&hvadid=375446013724&hvpos=1o13&hvnetw=g&hvrand=3929571955586841619&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006892&hvtargid=aud-861612201097:pla-816028467093


Thanks dude. Something like that is exactly what Im after.

Posted: Jan 17, 2020 at 13:40 Quote
Hey pinkbike,

random question what's the difference between a headset press vs a bb press?? Can one tool do both jobs??

cheers!

Posted: Jan 17, 2020 at 21:10 Quote
Length of the press, a bb press might not be long enough an a HS press while long enough, might not have enough thread for BB. Some presses will do both with adapters

Easy to make your own with a long bolt an some plates but some HS/BB parts dont like being pressed on the external

Saying that though. Theres nothing like the quality of a good specific press. It's down to the thread pitch an the wieght an length of the levers

Posted: Jan 18, 2020 at 0:56 Quote
chickenrunz wrote:
That means I need to get a trueing stand

Ideally yes, but if I had to choose between a truing stand and a tensiometer, I'd choose the latter. You can improvise a truing stand via popsicle sticks taped to your seatstays or fork, but there's no substitute for a tensiometer. Well, a calibrated frequency meter would also work and I think I once saw an app for that, but that's still a tensiometer of sorts.

Posted: Jan 18, 2020 at 5:56 Quote
Looking for a service kit for Marzocchi Roco Lo 2014 - 200*57 Air Damper. Looking online there is only one
retailes that *potentially sells these: https://bicyclesuspension.de/products/marzocchi-8501302-c-roco-air-lo-oil-seal-kit?variant=17715811024955. I have contacted the seller and he suggests this is the correct kit but there is no way of verifying this without service documents, which again can't be found anywhere!Can anyone assist?

Alternatively, does anyone know of a UK suspension service centre that would perform the service? I have tried pPushcycles and a few others but no one wants to touch it.

Posted: Jan 18, 2020 at 5:59 Quote
Same here when I needed my 55's repaired. No body wanted to know. I found 1 place, south coast suss. That said he do the work if I could source the parts Frown
f*cking sucks , sort it out FOX


 
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