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View Full Version : String fraying over new Cheetah idler wheel



damo_hart
08-18-2008, 08:49 PM
Hi there,

I received a new 08 Cheetah M-Pro last Friday and after only putting a few dozen shots through it I have noticed that the where the shooting string runs over the idler wheel the edges are becoming frayed against the side of the wheel groove. I was surprised it isn't wrapped with serving but just the "naked" string.

Is this something I should be worried about and if so how should I address it? Rub some wax on it while it is drawn perhaps?

thanks

Damo

jonnyriabov
08-18-2008, 10:48 PM
My bengal broke in the same spot, the same day I had my 300 shot tune. Dealer said faulty string and replaced it, no questions asked

damo_hart
08-18-2008, 11:57 PM
It looks to me like the string is hitting the side of the groove when the shot is released as there are yellow marks (from the string) on the wheel. The wheel looks straight though so maybe it is the cable slide pushing the string off to the side that causes that?

Must be nasty when a string breaks?!

Montalaar
08-19-2008, 02:23 AM
It is. Never happend to me but to other shooters standing beside me.

You could check for small scratches in the wheel, maybe it fell down.

Thrawn30
08-19-2008, 10:36 AM
I'm having the same thing happen to my string on my 08 Cheetah.

damo_hart
08-19-2008, 07:10 PM
so am I right that there is supposed to be no serving on the string over that wheel? Seems like a design issue to me if a few of us are having it.

Anyone spoken to Martin about it yet? I am in Australia and have emailed them but no reply as yet.

Please post any responses you get from them.
ta

Damo

Montalaar
08-20-2008, 01:09 AM
It can take some days until they answer.

The most single cam bows have no serving where the idler wheel is.

Tom Cat
08-20-2008, 01:49 AM
The idler wheel may have a sharp edge on it. I used a chain saw file and sand paper to remove the edge on my 2008 cheetah which did the same thing. No problem now.

sccheetah
08-20-2008, 09:28 AM
I have an 08 Cheetah package bow from Academy - for almost a month now (second one). Had to return the first one the day I got it, as one strand of the string was broke where the peep was factory installed (may pop). Last night the String came off the Idler Wheel while drawing, I had noticed where the string was/had been rubbing the left side (looking from rear) of wheel, it leaves lots of yellow tracks on edge of wheel. After string came off, I took it strait to a local bow shop (local - 25 miles away - open till 9pm) and informed them of what happen. Tech put in bow press and put string back on, and looked things over, he said the wheel is a little skewed - not bad, and that string has been rubbing wheel quite a bit. Tech took wheel apart / off and said the axle is strait and everything looks ok - still skewed though. I told him to go a head and make a new string/cable, as it was noted that this string was damaged when it came off wheel (another 50 bucks to fix brand new bow). The tech also noted the the string was not serv'ed where it goes over the wheel and that is not good, so my new string will be served at upper wheel. After I get it back (2 days), I will check it out some more and update... I do not want to deal with factory yet, hunting season is too close and I need to shoot, takes too long to deal with most manufactures - unless you have too.

but from reading here, looks like Martin may have an issue with new Cheetah's... has Martin replyed / addessed any of these Cheetah issues?

Also, I am very happy with this bow, I wanted a 30" ATA bow for hunting. I have been using a 36" ATA for around 10 years and really needed shorter bow for tree stand hunting (and yes - just wanted a new bow). The Cheetah is very quiet (already got all Silencer stuff installed) , shoots smooth, shoots Accurately, very comfortable, not too heavy (for me), not sure yet how fast - but much faster that my old bow!... all that and almost 1/2 what I was going to spend on other bows that I looked at.

bfisher
08-20-2008, 02:57 PM
Look, I have no real experience with the Cheetah, but you guys all need to check for "cam lean". I don't know how many have done this and corrected it. It's possible the idler wheel is leaning some and with such a short A2A bow it's usually more severe.

Now that being said, I have seen very few bows where the string was not served at the idler wheel, but there have been some. You could always return the bows to your dealers or to Martin, but a simple fix would be to press the bow or loosen the limb bolts enough to remove the string. Then take a cotton ball and rub it around the idler's edge and check for any snags. If ya get some then some rubbing with fine grained sand paper can fix that part.

If you have the means then serve the string while the bow is down. Use very thin serving like for end serving loops.

Not the best solution, but it should fix your particular bow. At least I'm glad to see a few people post in a civilized manner. Sometimes engineers don't get everything just right and the company needs to know what's going on out here in the real world.

I just want to remind you all that you won't get much response from "factory" people here on these forums so you need to call or email Martin Archery. Believe me, they will be concerned. There is too much competition in this industry to NOT take care of the customers.

damo_hart
08-20-2008, 07:32 PM
Hmmm well I just took a good look at my bow from behind and the cam end and the idler wheel does indeed lean slightly to the left at the top. This makes sense looking at the angle that the string comes up to the idler wheel from the cable slide - it would have to be a pretty fearsome bearing to withstand that amount of pull and stay perfectly vertical and if it didn't I imagine it would fray on that side instead.

That does explain why it hits the left side though, because the wheel is slightly leaning to the left so as the string is drawn and released it is forced against that thin side of the whee as it rolls on and off the wheel - which is quite sharp. Does sound like a very common problem amongst us though so lets hope there is a fix for it.

I tried to call them today a few times but couldn't catch either Joel or Scott free and they were reluctant to call me back since I am overseas. I left my number though and hopefully they will call me tomorrow. In the meantime if anyone has a fix please post it. I am a bit reluctant to take a chainsaw grinder to my new bow until I have heard from Martin themselves.

I love the bow - apart from the fraying string which worries me alot.

Damo

Dave308
08-20-2008, 07:34 PM
When I bought my Bengal it had a slight lean in the wheel. The dealer said that it would cause the string to fray. Simple fix, he just added a few twists to the cable and straightened it out. I've been shooting it for almost 2 months now with no string fray.

damo_hart
08-20-2008, 08:29 PM
Hi Dave,

Can you please explain to me how and where they put these twists?

thanks
Damo

bfisher
08-20-2008, 10:45 PM
Hi Dave,

Can you please explain to me how and where they put these twists?

thanks
Damo

You may be in luck. Martin bows have limb bolts long enough that you can back them off enough to release the stress on the limbs. Your idler wheel is tilted toward the left. I assume you mean right to left from bottom to top, right? Very common with almost all single cams bows. Actually we call it cam lean, but it is really the limb tips being twisted by the force applied sideways by the cable guard. Look and you'll see it. Sounds like you're not too much of an idiot and can understand this stuff.

FIRST. Take a Sharpie or black marker and mark your string about 2" down from the idler wheel on the same side as the string leech. Now draw the bow and have someone mark the other side of the string (cable slide side) 2" down from the wheel. This is so you know where to serve it if you desire. Wax the heck out of the string, too, especially where it rides over the idler.

OK, back out the limb bolts or use a bow press to remove the stress on the limbs. Just enough to remove the right (viewed from the back) side cable yoke from the axle. Put about 3 to 5 twists in this side of the yoke and reinstall it.

Check it for lean. You can eyeball it and see it if it's off badly, but a good way to check it is to lay an straight edge or an arrow along the side of the wheel parallel to the string. It should run evenly as far as it goes. A little off is OK, but try to remove as much lean as possible. Might take a few tries.

Once you get this we hope this takes care of your problem with the fraying. I know this sounds like a bunch of crap, but it's not just Martin. Almost all single cam bows have some lean. I've seen some so bad that the string actually rolled off the cam as it was drawn. An added bonus about this is---now you know what to look for and how to fix it".

Hope this works for you. Let us know how you make out. We are truely interested. We aren't factory guys. We're just "Archers helping archers".

Barry

damo_hart
08-21-2008, 12:25 AM
Hi Barry. Thanks for the detailed instructions - and the confidence :-)

I did as you suggested - although I ended up having to put about 12-13 twists in the right side yoke - and while it is not perfect it is much, much better than it was. Perhaps I should give it a few more?

You are quite right, it is much better to understand and fix a problem yourself than just give it to someone else to resolve, so thanks again for the advice!

Also I didn't mean to suggest that this was a problem peculiar to Martin bows. With the forces involved I don't think any bow would be exempt from limb tips twisting. At least now we have a solution. :-)

regards

Damo

Montalaar
08-21-2008, 01:29 AM
Oh, it is by the way not a problem of single cam bows only. Every compound bow with a cable slide can or will have a minimum of cam lean.

You can try to untwist the cable on the other side also if there are enough twists in it.

Dave308
08-21-2008, 09:02 AM
You may be in luck. Martin bows have limb bolts long enough that you can back them off enough to release the stress on the limbs. Your idler wheel is tilted toward the left. I assume you mean right to left from bottom to top, right? Very common with almost all single cams bows. Actually we call it cam lean, but it is really the limb tips being twisted by the force applied sideways by the cable guard. Look and you'll see it. Sounds like you're not too much of an idiot and can understand this stuff.

FIRST. Take a Sharpie or black marker and mark your string about 2" down from the idler wheel on the same side as the string leech. Now draw the bow and have someone mark the other side of the string (cable slide side) 2" down from the wheel. This is so you know where to serve it if you desire. Wax the heck out of the string, too, especially where it rides over the idler.

OK, back out the limb bolts or use a bow press to remove the stress on the limbs. Just enough to remove the right (viewed from the back) side cable yoke from the axle. Put about 3 to 5 twists in this side of the yoke and reinstall it.

Check it for lean. You can eyeball it and see it if it's off badly, but a good way to check it is to lay an straight edge or an arrow along the side of the wheel parallel to the string. It should run evenly as far as it goes. A little off is OK, but try to remove as much lean as possible. Might take a few tries.

Once you get this we hope this takes care of your problem with the fraying. I know this sounds like a bunch of crap, but it's not just Martin. Almost all single cam bows have some lean. I've seen some so bad that the string actually rolled off the cam as it was drawn. An added bonus about this is---now you know what to look for and how to fix it".

Hope this works for you. Let us know how you make out. We are truely interested. We aren't factory guys. We're just "Archers helping archers".

Barry

Thanks bfisher. When I posted this I didn't have time to get deep into it. Your the man:D

bfisher
08-21-2008, 12:10 PM
Hi Barry. Thanks for the detailed instructions - and the confidence :-)

I did as you suggested - although I ended up having to put about 12-13 twists in the right side yoke - and while it is not perfect it is much, much better than it was. Perhaps I should give it a few more?

You are quite right, it is much better to understand and fix a problem yourself than just give it to someone else to resolve, so thanks again for the advice!

Also I didn't mean to suggest that this was a problem peculiar to Martin bows. With the forces involved I don't think any bow would be exempt from limb tips twisting. At least now we have a solution. :-)

regards

Damo

Yes, it's not a perfect solution, but it helps. I would like to see something like a shorter yoke on one side, but the thing is the amount of limb twists can vary from bow to bow so the extra twists is about all we can do now.

Just like you found out. Sometimes it takes a lot of twists to get the lean out. A lot of guys will suggest putting in a half twist or a couple twists. They are living in a dream world. One or two twists is not squat. You do what you have to do. And learn from it.

Look at what Simon said. You can take a few twists out of the left side yoke. I'll give you credit. At least you're willing to try and ultimately learn something about these things. In reality compounds are bery simple machine. The problems you see are very common to most all of them so the fix is usually the same, too. Just some worse than others.

Just like tuning, which you should do. All this preliminary stuff like getting limb twists out and such should be done as a prep for tuning. There are lots of tuning methods and you just need to find which one (or more) work for you. Learn them and then apply that method to just about all bows. Sometimes you have to find other methods, but most bows will work in the same manner.

Montalaar
08-21-2008, 01:05 PM
Yes, it's not a perfect solution, but it helps. I would like to see something like a shorter yoke on one side, but the thing is the amount of limb twists can vary from bow to bow so the extra twists is about all we can do now.


That is exactly the way my custom cablea re made. One side is a half cm shorter than the other side resulting in the kill of any limb twist or cam lean. It works perfect for me. =)

bfisher
08-21-2008, 01:30 PM
Simon, although you have done as I say can be done, it is a hassle. Twisting the yoke is quick and easy and allows the companies to not have to dabbe with such trivialties (spelling).

Of course, being Martin shooters we are well aware of the solution we consider perfect. It's called the "X SYSTEM". Now if they could only adapt it to the Cat Cam the world might be a perfect place.

Montalaar
08-21-2008, 02:43 PM
I just can agree to you...

damo_hart
08-21-2008, 10:11 PM
Hi Guys,

There are no twists in my left side yoke so I'll see how it goes. I gave the frayed part a good waxing too and it seems to run alot nicer on and off the idler now. I like the fix - nice and easy - and with the good design of those long limb bolts I don't need a bow press or anything to work on it. :-)

I have had an old Pro-line Force II bow for many, many years and this Cheetah is my first new and modern bow, so there are a few things for me to learn that's for sure. Thanks again for helping out in that regard!

I hope this info will be useful to others.

Damo

sccheetah
08-25-2008, 07:46 AM
Got bow back from local bow shop... Made new string and he was able to solve the Cam Lean issue, like stated in this thread, just twist string at axle until strait - mine did not take that many twists.

bfisher
08-25-2008, 12:37 PM
Know what I like about these forums? People are getting some help and don't need to do a search and read for a couple days to find the info they need. Well done, gentlmen. You too, Alec.

brushrat
10-16-2008, 02:22 PM
hi, everyone out there...i am a brand new member and this is my 1st post. Hope i am doing it right and wasn't suppose to start a new post(???). Anyways..i too have a "fuzzy" string after less than 1 month shooting. I was absolutley sick over it..especially after doing what i considered a lot of research prior to buying a martin bow. I called the martin company in Washington state and talked to a fella,( i think he said his name was Joe), he said that the bow may or may not have a problem. How can a 1 month old bow, cause that much wear to the string over the top wheel and not have some sort of problem???? He did suggest that i take it to a martin dealer and have them take a look at it to determine if it had a problem. If they said " yes" , then i was to re-contact them. The local Dealer from 30 miles away,(only thing bad about living in the country) determined it had "excessive cam lean" and twisted the cable yoke on the one side aprox. 8 turns and said that should do it. I asked him if that constituted a permanent fix and he implied it did but to watch it and keep it waxed good. Iv'e shot it since and to my amazement i think it actually fixed it (or at least slowed it down)! At any rate, now i have a brand new bow with 1 years string wear on it already and not knowing when it will go "poof"! I can't afford to buy $60-80 string sets every couple months. I pray i didn't make a big mistake by buying this model. Aside from the string issue it is far and away more accurate than my old bow. Does anyone know if martin is willing to address this problem and build their cables slightly shorter on the one side or step up their quality control problem (adjust the cam lean) before it goes out the door. It sounds like there are several other martin bow owners with the same complaint.....and of course there is no warranty on strings.

Montalaar
10-16-2008, 02:50 PM
Hmmmm. I checked the cam lean on a friends new bengal soem weeks ago and i found none. Seems as if only the Cheetah has this massive cam lean problem. Any bow owner should be able to identify cam lean by themself and be able to do something against it. Lets see what the 09 M2-Pro cam will bring us. maybe there is no longer a problem of massive cam lean with those bows. Hopefully...

I am getting kind of sick of reading about that. :P

razorjack
10-16-2008, 06:52 PM
FYI,i just recently purchased a new 08 cheetah also,and the string out of the box has no serving on it where the idler wheel is.my proshop put brand new strings and cables on it from martin and gave me the old ones for spares,they said some of the cheetah's came like that.

Cheeta2950
10-18-2008, 07:07 PM
I bought my '08 Cheetah from Bass-Pro shop here in Orlando few months back, they pulled it right from the box and set it up while I waited. It does not appear to have any cam lean and the string was served from the factory around all cam and idler wheel contact surface. These stories just point out how prodution problems are not the norm but, remember when you use to not buy american made cars built on monday or friday.

brushrat
10-27-2008, 10:11 AM
hey, did you have a chance to talk to anyone to see if all the newer 08strings (or 09) will be served over both cams for all martin bows or just the cheetas? After about 3-4 weeks of shooting, my 08 bengal needs a new string. The only way i would consider buying a new string from martin is if they are served on both ends, otherwise i'll go online to one of the other string builders.

themick313
10-27-2008, 09:19 PM
I would go with the serving over the idler... I am not sure why but the 08s do not have the serving. I had the serving put on the bow before I shot it for the first time and have had no problems with this. I did have a Jaguar that didn't have the serving on the idler wheel and the string starting wearing and coming over the idler wheel. I exchanged it for the bengal and adding serving. If you took this to a bow shop and had them add serving added then you shouldn't have any issues... shouldn't... :confused:

But I have been extremely impressed with my bow and if you get this you will also likely notice a difference in your string noise... it should be quieter as well.

Cheeta2950
10-28-2008, 10:57 AM
I am new to all this so can only go with what I got, but my bow has not given me any problems. No cam lean and alot of serving, so much that just recently when I redid accessories on string, tubepeep removal and going away from metal nock, I reduced serving from center from 10" to 3".
Side benifit to learning yourself was going from 110g accessories(235fps) to 23.5g(260fps).Real quite to boot:D