Tried to reduce an XT 9speed chainset down to a single and bash set up last night but the heads of the chainring bolts go stright through the holes in the shimano bash ring. Do i need special bolts or washers or what else am i missing?

Ive bodged some spacers for now but want get this sorted properly.

Thanks

Charlie the bike monger sells special short ones. I use the stainless ones. Other retailers available.

Sorry maybe wasn’t very clear the heads of the bolts are too small in diameter for the holes in the bash ring so i can’t get the bash ring to stay on…. The bolts basically fall through the bolt holes. The bolt length is fine i think assuming that it is just supposed to bolt on in place of the outer.

You can buy a bolt set designed to fit the bashguard but washers will work.

There are metal inserts that fit into the bash guard before you fit the bolts.

The bolts are fine. The bash ring holes should have cylindrical metal inserts in them that reduce the diameter of the hole.

Where did you get the bash from – should ask whoever sold it to you to give you these bolt hole inserts otherwise its not really useable…

Edit: iBaa, beat me to it…

By the way, assuming this is the Shimano bash from an SLX double? the next thing you’ll find is that it doesn’t quite fit the crank arm spiders of an XT crankset. You’ll need to file a teeny bit off the bash or the crank spider at each of the four arms to make it fit. Save yourself the trouble and buy an E-13 Turbocharger bash – looks much nicer too…

The metal inserts might work loose on the SLX bash too, if it is one, and it might try to get off your bike while you are riding along.

The metal inserts might work loose on the SLX bash too, if it is one, and it might try to get off your bike while you are riding along.

The SLX bash has metal inserts (prob what the OP is missing) and should also only be used with SLX or Saint chainring bolts, the heads on those are bigger to ensure they hold the metal inserts AND the plastic bash in place. If you use normal bolts then the Bash will eventually fall off as above.

should also only be used with SLX or Saint chainring bolts, the heads on those are bigger

Ok, just to clarify, by the “heads are bigger”, you actually mean the bolts are longer, right? Can’t speak for the Saint, but the SLX chainring bolts (M665 and M660 – just measured both) have the same diameter head as normal – 7mm, which if you think about it makes sense or they wouldn’t fit in the standard recess in a chainring. But, they are longer (12mm vs 8mm) so that full thread is engaged despite the extra thickness of the bash over a standard chainring (or thin alu bash).

Just as an aside, my E-13 Turbocharger came with a set of longer chainring nuts, so you can still use the standard Shimano chainring bolts, and have enough thread engaged. Just another way around the problem…

is that one of those black plastic shimano bash rings

throw it in the bin, they look god awful, just take a look at all the ruined bike pics on here

sian tones have metal inserts so the bolts engage no idea with others

Thanks all its the slx one and i bought it a year ago but didnt get round to fitting it. Call to the friendly LBS tomorrow to see if they can help if not then i will order something less fugly instead!

Well, if its the LBS you bought it from they certainly should have included the metal inserts – and they should also have told you you’d need longer chainring bolts, and it wouldn’t fit XT cranks without a bit of filing (assuming you told them how you were gonna use it?)

Does seem like it might be easier to just get an E-13 Turbocharger (or similar) which will fit without any modification, comes with all the bits you need, and looks much better anyway! 🙂

Ok, just to clarify, by the “heads are bigger”, you actually mean the bolts are longer, right? Can’t speak for the Saint, but the SLX chainring bolts (M665 and M660 – just measured both) have the same diameter head as normal – 7mm

apologies, the one i had in my head was the older saint bash, which had bigger lip on the outer bolts (not designed to recess into chainring) to hold the bash and metal insert. Not applicable to new SLX bash.

the one i had in my head was the older saint bash

Ah, likewise, I’ve only had experience with the SLX ones, not Saint, so could only comment from that perspective…

It sounds like you have a M800 (Saint) bash guard. In this case it needs special Shimano bolts and washers to fit. What you need is “item 8” (which you will notice includes a washer) from this link:

http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-M800-2277C_v1_m56577569830608895.pdf

i bought one cheap on here and had all the same issues… sold it on Ebay…

I have an old XT one, suspect the issue is similar.

They sell the bash guard for an incredibly reasonable £8 odd

The bolt kit is a separate item and costs about £16.

I filed some washers down to fit. It has not fallen off after two years of regular riding.

I have an old XT one, suspect the issue is similar

Really – Shimano do an XT one? Be interested to see that, as I’ve only been aware of SLX and Saint bash guards made by the big S.

Interestingly, the new 10 speed XT M785 doubles can’t even fit a bash, let alone come with one – so Shimano must be moving away from the idea of bashguards… tho’ I don’t understand why?