[funkdoobiest]

Hello,
I have a quick question for those who have a Chumba F5 with the newer upgraded linkage piece with the bearings. I have been told that the shock bolt that mounts the shock to the linkage piece is an M7 bolt. I've been told that I need to buy an M6 reducer and drill it out to 7mm, and that these reducers are readily available from other sources than Chumba. My question is, has anyone found this bolt from another source besides Chumba? Is it a proprietary piece, or can it be found at a hardware store or Fastenal or something? I think mine is bent and I'm getting some annoying play.

Thanks

 

[Eastern States Cup]

McMaster-Carr

 

[rollertoaster]

When I had mine, I had bent a couple linkage bolts. I called chumba and they sent me a few spares for free. But if you are bending bolts in the linkage chances are your shock is undersprung.

 

[funkdoobiest]

Thanks for the responses. That link has a ton of stuff, but I can't seem to find anything in M7.

Maybe I should bump the spring rate up 50lbs or so.

Unfortunately, dealing with Chumba can be a hassle for even the smallest things, and their online "store" has bolts for the XCL and that's about it. I know I need a shock reducer and can just drill one out, but I have had trouble finding any bolt that resembles the smaller shock eyelet bolt.

 

[rollertoaster]

what shock and spring weight are you using also what is your riding weight?

I was about 200-210lbs when I had mine and was running a vivid b tune. 400lb spring ( I think), and medium bottom out bumper. Your results may vary, I was using a custom made lowering link and had removed the floating brake. Not sure how different my link was but it was a tad lower than the chumba link. My HA was about 62.5-63, and BB height was 13.7"

 

[funkdoobiest]

I'm probably about 175 running a 300lb spring on a DHX.

I'm not sure the bolt is "bent" as in noticeably bent or curved after multiple big hits or something, but worn out after about 2 or 3 solid years of riding and in need of replacement. My F4 and F5 were notorious for destroying the M6 bolts in the bell crank linkage until I upgraded the F5 w/ the bearing linkage. Now, the play seems to be coming from the shock bolt and isn't major, but it's noticeable and makes a sound when riding. So, the play might just be the wear and tear that reducers and bolts go through. I still need the bolt, however, and Chumba's customer service that people used to rave about hasn't really been all that great recently, at least in my experience.

 

[gonefirefightin]

private message jimmydean, he has one

 

[SprungShoulders]

Chumba's customer service that people used to rave about hasn't really been all that great recently, at least in my experience.

That's the understatement of the decade...

I really do love my F5, but Chumba's CS blows. When the time comes I think I'll be moving on, if for no other reason than that. I don't really mind twisting in the wind if I own a frame from a defunct builder; that comes with the territory. Not being able to get the time of day from a supposedly active company is...disappointing at best.

That being said, have you waded through the handful of F5-related posts on the MTBR Chumba forum? I thought I recall seeing something there about the M7 bolt... I'm still running the stock link. I tried to upgrade, but the piece I (after months of waiting) received from Chumba wasn't usable. Repeated calls and emails after that were ignored.

Good luck.

 

[funkdoobiest]

Sorry to hear about your misfortune as well. My problems range from not receiving stuff on time from them or being unable to actually reach Chumba, to (the most common for me) the employees not knowing enough about their own product to send you the right parts. I've dealt with them for both my F4 and F5 and never had a smooth transaction other than the time I order grips and decals. I tried to order the MAIN pivot for the F4 once and they sent me various M6 bolts for the linkage. The best time, though, was dealing with two or three different employees in the same phone call, not one of which knew what a shock eyelet reducer was. I think it was a great brand when Ted ran things, but my next DH bike won't be a Chumba.

I'll have to look over on MTBR. Most of the Chumba threads right now seem to be focused on the Chumba drama.

 

[rollertoaster]

I'd try a 350 on a dhx. But that's a personal preference, basically if you ever feel the rear bottom on that bike you are undersprung. However if it takes you 2 years to bend a bolt you might be alright.

The best setup I found on my f5 was to run a somewhat stiff spring with medium compression dampening (vivid, I absolutely hated a dhx on mine), a lowering link, and a pushed boxxer wc on 3 clicks of compression. It was fast, active, but was by no means a plow bike. It skipped across the rocks without getting hung up.