jethro00

I know this is a long shot, but some of you are super knowledgeable. So, I am taking a shot. My stoker rides on a 2016 Thudbuster ST. This past weekend, the rear clamp bolt fell out somewhere during our ride. I emailed Cane Creek last night to see if they can give me the size of the Allen bolt so I can see if Lowes has something that will fit. I have checked the Cane Creek website for specs on the bolt, but the diagram on the website doesn't give the clamp bolt sizes. My LBS is closed in New Orleans due to Covid-19. So, that is not an option for now.

Does anyone happen to know the size of the rear clamp bolt on a 2016 Thudbuster ST? The Cane Creek diagram is attached with a red arrow by the missing bolt. Thanks!

unikid

Based on the picture, the front and rear bolts are the same.

Simply remove front bolt and take it to Home Depot to find a match?

unikid

I assume yours looks like this? https://www.sjscycles.co.uk/seat-pos...-bolt/?geoc=US
If so then you might try a basic M5 bolt from Home Depot in a pinch to see if that works. I bought similar bolts from Home Depot for my old Gravity Dropper post a while back and they worked fine for me.

However if it doesn't work for some reason, you can order the official replacement.
Although it appears you may not be alone in the official bolts stripping and failing: https://www.pinkbike.com/forum/listc...hreadid=191757

jethro00

Unikid, I have had a problem with that bolt getting loose. I have tightened it from time to time. I have wondered why it gets loose. The "nuts" that receive the clamp bolts appear to be like short pieces of aluminum rod that were tapped for threads and fit inside a channel. If I can replace the missing bolt and it continues to get loose, I may need to re-drill the hole and tap for a size larger threads. That sounds like a project

Yes, both clamp bolts appear to be the same size, with different heads. The forward clamp bolt has a knob for a head. The rear lamp bolt is a cap (Allen) type head. Under normal circumstances, I would do as you suggest and go to Home Depot or Lowes with the front bolt and one of the "nuts" and see what I can find. Alas, with a Covid-19 infestation in New Orleans, I am not allowed to go into any stores at present (stoker's orders). So, I am hoping that someone can ID the rear clamp bolt. If so, Home Depot will let you pay online and put the product in a locker outside the store (accessible 24/7) and provide a code for opening the locker.

unikid

Did you see my second post with a link to the actual bolt? It's an M5. Does that bolt match your back bolt?

Here is a link to all the associated parts on the same web site, including the washer and the threaded barrel piece: https://www.sjscycles.co.uk/search/?...20bolt&geoc=US

jethro00

Unikid, thanks so much!. Now I see your link and those are indeed the parts. Now I can see if I can get those at Home Depot or Lowes. Like the person in one of your links, I suspect a weak bolt thread and/or a weak thread in the barrel nut. My rear clamp nut came loose a number of times before it fell out.

unikid

If you can't find a new barrel nut, maybe try some Blue Loctite to hold it better?

Yamato72

We lost one of these bolts on a ride too. Fortunately we "heard it" and were able to backtrack and find it. Threadlocker is a must once you find a replacement.

jethro00

Yamato72, in hindsight, I think I know where we lost it. We went back to look 2 days later, but no luck. We have fenders. So, sometimes I hear something pulled up from the ground ricocheting through the fender and back out. On our Sunday ride, I heard some kind of metal sound I could not place. It stopped, so we kept riding. In hindsight, I suspect to was the rear saddle clamp bolt falling off and ricocheting as it made its way to the ground. Unfortunately, that was on a levee path and it would be very hard to find.

If we find a replacement, Loctite or some type of Threadlocker is a good idea. Alas, I have not had any luck finding a replacement (M5 x 35 mm) in stock at Home Depot or Lowes that looks like it will work. I have looked on the Internet to see if the bolt (odd head) that comes with the Thudbuster can be found, but have not found that either. I have tried to reach Cane Creek by phone, but keep getting busy signals and have not received a reply to my email. Here is a picture of the actual bolt.

unikid

Is the odd head shape critical to the function of the post? Or just another place to grab the bolt to turn it if the hex opening gets stripped.

Something like this isn't in stock near you?

https://www.homedepot.com/p/M5-0-8-x...4798/204283618

This is similar to what I used to fix my dropper post a while back.

unikid

Or you can go here and pick the exact metal and size you want

https://www.boltdepot.com/Metric_socket_cap.aspx

unikid

The site I shared earlier carries this part, along with the barrel nut and washer. Will they not ship to you? https://www.sjscycles.co.uk/search/?...20bolt&geoc=US

unikid

Lastly you might contact Thomson USA to see if either of their 2 seatpost bolt kits are M5 and close enough in length for what you need.

https://www.bikethomson.com/product-...y/small-parts/

jethro00

Thanks for the suggestions and helping me explore and think through the options.
I did consider the Home Depot M5 x 35mm. My concern is that the head and thread configuration are different. I am unsure if that could cause damage when it is tightened. I do not want to damage an expensive device. Of course, I don't want my stoker's seat to fall off either
I also considered what looks like matching parts from SJS Cycles. But, that is across the pond (UK) and might take a while to make its way to New Orleans.
Fortunately, I finally got an email reply from Cane Creek:
"Sorry you lost that bolt. While you might be able to find a generic bolt that will tide you over, the washer (#6 on the instructions) and cylindrical nut (#1) are pretty specific to the Thudbuster. If you have those two items, then you could pull the forwardmost bolt and take it to your local hardware store and try to match it.

We do have complete bolt kits (BAE0041) available on our website and we are back up and running here in the office, albeit in a safe and limited capacity. So it might take a day or two longer to process, but we can get that to you directly.

No matter what solution you go with, be sure to use some blue Loctite on those bolts going forward. That should help prevent those from coming loose."

That bolt kit is not easy to find on their web site and the listing does not say it is for the 2016 Thudbuster ST. So, they could do a better job of that on their web site and could list the bolt specs. I any event, we ordered the bolt kit for $7.50 plus $12 shipping (for the privilege of not having to go to NC to get the parts). I also ordered some blue Loctite. Blue Loctite and other brands say it works for 6mm and larger bolts. Alas, the bolt for the Thudbuster ST is 5mm. Still, it may help.

When there is a worldwide pandemic and over 40,000 people die from it in your country, it can take a little longer to get information about bike parts and then to get the parts once you find them. For now, we are riding every day with just the front bolt installed. My stoker keeps her weight from being just on the front of the seat and I avoid braking hard, which might rotate my stoker's saddle forward and leave me wearing her like a coat. So far so good, but I'll be glad when those parts get here and there are 2 bolts under that seat

unikid

Glad you found the kit. I assume you bought this: https://www.canecreek.com/product/th...t-kit-bae0041/

jethro00

Unikid, that is the kit we bought. I am going to email Cane Creek to suggest that they annotate that bolt replacement kit on their site to indicate it fits the Thudbuster ST and to list the bolt specs somewhere on their web site. Under normal circumstances, I suspect Cane Creek may have been able to respond more quickly by email or be able to answer their phone. But, that info should be readily accessible on their web site.