Author Topic: B17 tension bolt - is there a better solution  (Read 676 times)

B17 tension bolt - is there a better solution
« on: April 19, 2020, 10:23:27 am »
Morning all, with immaculate timing the tension bolt on my B17 has sheared off. I believe this is a common occurrence, and, having checked and discovered that Brooks are currently closed (no surprise) there is no prospect of a warranty fix anytime soon. So I’m wondering has any one come up with a fix that improves the durability of this troublesome component?

Edit, I just found this

https://www.youtube.com/watch?v=2QjlEsD-O9o

Anyone else tried this?

Thanks in advance.

A

Re: B17 tension bolt - is there a better solution
« Reply #1 on: April 19, 2020, 12:13:25 pm »
there are various ways of installing a M8 bolt or length of studding (which is what the video is about, which knowledge might spare someone seventeen otherwise wasted minutes of their life), and this will get you out of the poop either temporarily or permanently. 

However if you break nosebolts then a piece of standard studding is unlikely to be an improvement; you need something which is made in material which is as good or better.

cheers

Re: B17 tension bolt - is there a better solution
« Reply #2 on: April 19, 2020, 12:29:13 pm »
I have a very successful alternative which involves a round file, a machined
stainless steel replacement cap head bolt and the nut from the nosebolt of a B17 ti.

There are a number of my modified solutions out on test and have been for 18 months now so I am happy that it works.

The quicker solution if you can get them imo is to buy the standard B17 ti nosebolt and nut and use the round file on both the nose cradle and the nut retainer to enlarge the holes to make them fit.

The benefits include simple Allen key tensioning going forward and easier replacement of future failures.

Re: B17 tension bolt - is there a better solution
« Reply #3 on: April 19, 2020, 01:34:54 pm »
[quote author=Brucey link=topic=115419.msg2489061#msg2489061 date=1587294805

However if you break nosebolts then a piece of standard studding is unlikely to be an improvement; you need something which is made in material which is as good or better.

cheers
[/quote]

Out of interest what would be a better material to use in this application?

Re: B17 tension bolt - is there a better solution
« Reply #4 on: April 19, 2020, 01:56:12 pm »
it needs to be stronger, tougher and/or more corrosion resistant, depending on the service loading and the conditions.

I've used modified allen bolts for some years, and have suggested their use on several previous occasions.  An A2 stainless bolt is appreciably  stronger than an A4 grade one. However even an A2 is not much stronger than an 8.8 non stainless bolt, but it is more corrosion resistant. For strength (but not good corrosion resistance) a 12.9 grade bolt would be a good choice.  Corrosion resistance is likely to be important if you sweat much.

If you want an easy solution  (some drilling and filing required) this is £3

https://www.spacycles.co.uk/m2b0s204p4042/SPA-CYCLES-Spa-Saddle-Tension-Bolt-Steel

and allows allen key adjustment etc

cheers

Re: B17 tension bolt - is there a better solution
« Reply #5 on: April 19, 2020, 03:30:29 pm »
That's similar to the Brooks B17 ti setup.

The reason Iwent to  proper stainless steel bolt was because the B17 ti variant is still made of cheese though probably cheddar rather than brie.  The Spa bonus steel ated but I suspect not nearly as strong as the stainless bolts that I eventually used.

Re: B17 tension bolt - is there a better solution
« Reply #6 on: April 19, 2020, 04:04:19 pm »
Thanks folks, some really good options in there

A

Re: B17 tension bolt - is there a better solution
« Reply #7 on: April 19, 2020, 10:22:46 pm »
That's similar to the Brooks B17 ti setup.

The reason Iwent to  proper stainless steel bolt was because the B17 ti variant is still made of cheese though probably cheddar rather than brie.  The Spa bonus steel ated but I suspect not nearly as strong as the stainless bolts that I eventually used.

what grade bolts did you use?

cheers


Re: B17 tension bolt - is there a better solution
« Reply #9 on: May 04, 2020, 07:37:50 am »
That's similar to the Brooks B17 ti setup.

The reason Iwent to  proper stainless steel bolt was because the B17 ti variant is still made of cheese though probably cheddar rather than brie.  The Spa bonus steel ated but I suspect not nearly as strong as the stainless bolts that I eventually used.

what grade bolts did you use?

cheers

Oops, sorry Brucey - didn't see this.

I will dig out the detail sometime soon.