[Closed] Bossnut rear linkage play

Try tightening the rear QR up first. Really tight. It can make a big difference. Check rear hub bearings as well ?

@timizere:

my bike is the Bossnut V2. There is no play at my bike

Possible in your case: something seized up and the "wrong" part of the shock mount started turning and this started to "open" the hole in the seatstay?

There shouldn't be "play". This will end up cracking?

If possible try to contact the engineer of the Bossnut Mr. Mike Sanderson (Calibre Bikes/ GoOutdoors) directly.
You might need a new seatstay?

If you are able to contact Mike:
would be nice to ask him if it's possible to add a page "Spares" on their web page http://calibrebicycles.com/
Like: suspension bearings / bushings and seatstay / chainstay parts and similar?

Guess there are other Bossnut bikers out there which might need these parts...

@timizere: please check if you got an message from singletrackworld

If the mount point has been welded together a bit wide then you might find it doesn't close down on the top hat properly. Find out the torque for the bolt and undo it. If it wobbles side to side when loose, and this doesn't disappear when correctly torqued, then you could shim the sides of the top hat, or maybe push for a warranty.

Thanks for the responses! I agree that a spares page would be very handy. Dealing with the stores for replacement parts is tiresome, as despite the employees being very friendly most tend to not know a lot about bikes haha.

Just to clarify, the play is where the shock joins the frame, not on the seat stay.

I have asked to speak to Mike through G O customer services, but they seem hesitant to let me speak to him directly. I assume he's a busy guy!

@timizere, message: please check if you got an message from singletrackworld. Single track page top right: LogIn. Then Profile. Then "Messages". This will solve:

I have asked to speak to Mike through G O customer services, but they seem hesitant to let me speak to him directly. I assume he's a busy guy!

Just to clarify, the play is where the shock joins the frame, not on the seat stay.

O.k.. Understand. The "replacement" would be new frame then...
Or-if somebody has the tools and skills: open the mounting holes in the frame (reaming) and then put a special made bushing in / take the play out?

There is definitely no play at my Bossnut. Checked a minute ago again.
Play is bad. Needs to get fixed.

If no warranty: Need to know a hobby guy who is in precision mechanics and has some nice machine tools...? It's not complicated - but easy to ruin the frame when done in a wrong way.

also possible maybe: others had this problem before and there is a fix available. Searched in google for this? Not Bossnut related.

I agree that a spares page would be very handy. Dealing with the stores for replacement parts is tiresome

Guess this is an very important issue. Without that and without a direct service contact to Calibre Bikes the Calibre bikers won't be too happy in the long run...
If you get hold of Mike Sanderson please point that out if possible.
Thanks!

post above from bikewhisperer:

If the mount point has been welded together a bit wide then you might find it doesn't close down on the top hat properly. Find out the torque for the bolt and undo it. If it wobbles side to side when loose, and this doesn't disappear when correctly torqued, then you could shim the sides of the top hat,

Tried that? Maybe even an easy fix!

Is it worth trying to contact him on twitter?

@MAD_EYE_MIKE

Checked last night, play where the linkages attach to the frame, no - none.

Play where the shock attaches to the linkage, yep - couple of mm each way where the eye of the shock slides on the pivot.

baldiebenty

Checked last night, play where the linkages attach to the frame, no - none.

Play where the shock attaches to the linkage, yep - couple of mm each way where the eye of the shock slides on the pivot.

That's not good. I fear: this will soon cause some bigger problems.

baldiebenty - Member
Checked last night, play where the linkages attach to the frame, no - none.

Play where the shock attaches to the linkage, yep - couple of mm each way where the eye of the shock slides on the pivot.

But is the play between the bolt and the chainstays or in the bushing in the shock? A couple of millimetres (.080”)? Seems a hell of a lot.

There's no play in the bushing itself, the play is where the pivot bolt and bush (whatever it's techy name is) goes through the rear end of the shock.

Looking at it from above if you grab that back end of the shock right where the pivot goes through it'll shift left and right by probably a mm in each direction within the confines of the mounting.
Given that it's at 90 degrees to the linkage movement, it's my "spare" bike and the backend on the Bossnut is a bit flexy anyway, it doesn't bother me. I've thought about shimming it somehow but the bike doesn't get enough use to be worth the time/effort as it's mainly used by my son and it's not turned a wheel outside the garage since maybe October. I'll stick to cleaning and maintaining the one getting used 🙂

goes through it'll shift left and right by probably a mm

guess that won't be so critical. Bit side to side play.
Might be easy to fix by using washers / shims?

Irrespective of the shock, is the pivot shaft a tight fit within the slot when bolted up to the correct torque?

Help me to understand how it mounts on the Bossnut. Is it a single DU Bush on the shock with 2 aluminium pressfit spacers to make up the gap?

DU Bush but as I recall no spacers on mine, which now you mention it strikes me as weird/wrong. Could be my fault as I have stripped it down a couple of times.

Can anyone else take a look at their V1 Bossnut?

hahah
Can't look right now (V2 Bossnut) - but I'am pretty sure (99%) that there are black spacers both sides.

@timizere:
With your Bossnut we talk about play in the axis of the damper- right?

baldiebenty has play side to side...

@stu1972 :The shock uses this mounting hardware; https://www.amazon.co.uk/gp/product/B0062N5ELE/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

with a du bush.

I don't have the bike at the mo as it is in the shop, however there was both lateral and vertical play where the shock joined the frame before I took it in. Basically the whole thing was loose.

As a separate issue- my shock has been sent off to Fisher for warranty service, so I won't have the bike back for 2 weeks or so to investigate any fixes.

From the posts so far the play issue isn't as normal as I have been told. The bike is under warranty so I will push them to get it fixed.

I thought I'd keep this updated, to document and perhaps help someone else with the same issue-

I got the bike back with a tiny amount of play still in the joint- 2 proper rides later there is at least 1mm play- very noticeable when riding. I had a new set of shock bolts put on last time they were in the shop as they were rounded off from people cranking them tight trying to stop the play. Had a look at the 'new' ones again after the last ride to double check nothing had come loose, and they were rounded off too! I haven't touched them, so clearly someone in store has been attempting to fix the problem by cranking it as tight as possible again...

To summarise, everything (including a brand new shock, as that failed separately) has been replaced apart from the frame. I'm going back in on Monday to talk to the store manager and try to make some headway.

As an aside, I suggested that GO have an online shop for replacement calibre specific parts, and was told something is in the works for that. We'll see!

Update/question; I got the bike back, the shop had put a washer between the bolt and the frame, which appeared to have solved the issue. 2 rides later and the play is back as before. I took the shock off and observed this;

Can anyone say if this is normal? I suspect not seeing as the mounting hardware on the other end of the shock sits nice and snug, with only a tiny amount of sideways movement.

Incidentally, when I reinstalled the shock there seemed to be no play, until i put a little pressure on the bike by leaning it over and standing lightly on one of the pedals. The play immediately returned, so thats how I'll be testing in future.

Have right now a brand new Fox shock (different from the RockShock you have) on my desk.

New thru bolts, both sides: this is not really a tight fit. The play is very small - but there is indeed some minor play.

Additional to the video you say "two rides later the play is back". For me this means you feel the play when biking? This would be bad.

When you do what you show in the video: when you grab the thru bolt - in the way that you cover part of the thru bolt and part of the frame and move the shock: is there any "relativ" movement between the thru bolt and the frame?(this would be very bad)

If not: possible to put a new Monarch thru bolt bushing into the Monarch? The washer they put in (on the side) might be an o.k. idea. But if there is too much play in the Monarch bushing you need a new bushing?

If you can be asked I would buy a cheap micrometer (sp?) and do some measuring then get the exact right size bushes from TFT....

I bought some bespoke ones from them and they were spot on. Just measure accurately. 🙂

Do this, keep receipt and ask GO to compensate you?

They likely will as it's a cheap way to get you out of the store. It costs them far more with you returning time after time. Demo the new bushes have cured the issue, to them... Can't see how they can then argue the point?

Thanks for the reply 🙂

I can indeed feel the movement when riding, however I can't detect any movement between the bolt and frame. It seems that there is a bigger gap between the shock mount hardware and the frame at the end with play than at the other end of the shock.

I should have mentioned that the shock is brand new, 3 rides old with new mount hardware and bushing. I've also changed the bolt attempting to fix the problem.

T

Thanks poopscoop, good shout, I'll bare that in mind. I actually emailed Mike Sanderson directly at the same time as posting this, and he has replied already, so that's encouraging.

Yes - sad to fight these issues.

But to contact Mike Sanderson / Calibre Bikes is a very good idea. What I hear from Calibre bike owners that he is really a guy who loves his bike and who likes to keep his customers happy.

I wonder a bit how he is able to design bikes, fix daily production issues and things like this at the same time...

GO people are nice and (try to be) helpful - but with these issues pretty helpless.

Would be best to have some contact information on the calibre-bikes.com webpage directly. Would be much, much better than bugging GO all the time without really getting this issues sorted out.

Good luck! But if Mike took over now this "play issue" will be solved soon I hope.

I love my Bossnut V2 - but there must be a more efficient path to get issues like this solved.

Should should not be moving like that in the video. It looks like the hole assembly is floating on the mounting bolt?

Is the pin tight in the bush?

The pin should be a slip fit in the frame and the bolt clamps the frame onto the ends of the pin. If the threaded hole is blind and the bolt is too long the bolt will bottom out and not clamp the frame onto the pin. Same result if the bolt shank is too long. If the pin is too narrow there will be play as the frame cannot clamp down on it.

I got a call yesterday from a very nice and knowledgable fella, who is Mike's 'warranty and tech guy.' We discussed the problem in detail and he's sending me out some shock bolts to try. he quite rightly pointed out that even the thickness of paint wearing off the frame could cause the amount of play I was getting. As a result of the conversation I had a look at the inside of the frame where the shock hardware sits, and there is a .5mm?! indentation where the hardware has worn into the frame.

I had a go at making some shims from hi-tek aluminium plating (stella can) today to fit in between the shock mount hardware and the frame, and after much fiddling and faffing the play seems to have gone. when I tensioned the bolts things were nice and snug without binding, and there was no lateral or vertical movement in the linkage. I'll have to give it a good thrashing to test it properly, but I gave it some fair abuse around the carpark and no play returned.

I know this fix was suggested above, but tbh I'm still not sure how I feel about it as I've had to botch a fix for a bike less than a year old and still in warranty. It would seem that getting custom mount hardware to fit the slightly wider gap would also work, so thanks for the suggestion, I might go down that route as a more permanent solution. either way I'll be dead happy if the play goes for good.

Thanks for everyones suggestions, and I'll report back in a few weeks as to whether the botch has lasted.

Hopefully this will be the final update on this issue, as I believe it has been fully resolved.

Shortly after my last post I received another email saying that alongside the bolts I would receive a new seatstay in the post. I didn't request this, it was done from GO's own initiative. I asked for torque specs for the rebuild and was immediately answered with the relevant info. The package arrived the next working day.

Fitting the new seatstay has been a night and day difference, it was clear immediately that there was something wrong with the old one- there is now no play at all.

I feel far more confident in the calibre brand knowing that the guys behind the bikes are so helpful, willing and swift to act to problems. The only negative is that I wasn't referred to those guys sooner by the GO store, and had to seek them out myself.

It's also worth noting there are now spares on the GO website, so you can get new shock bolts etc.

+1 for Calibre/GO

Glad you got it sorted. I've been 95% sure of getting one but this thread was at the back of my mind. Now my dilemma is:

get a V2 that has dropped in price to £900* ready for the Evo to appear

or

wait a few weeks & get an Evo

or

wait for the TripleB mid summer

* As mrs FB is a cub leader we can get a further 15% off so it makes the price £765 -bugger just checked and it doesn't apply to this deal. With the discount I can get the Evo for less than the V2 so it'll be a decision on Evo vs Triple B

@timizere is there any chance you could send me Mike's email address please?