Motorcycle mirror screw size: M8/M10, standard vs reverse, and generic mirrors that fit

When you try to replace a motorcycle mirror, the screw spec is what usually trips people up.

Parts that look the same can be 8mm or 10mm, and they also split into standard thread and reverse thread.

Once you know the spec on the bike, you can also choose a generic mirror, not only an OEM part.

This article lists matching mirrors by screw spec, and conversion adapters you can use when the spec is different.

Screw spec quick table

If you already know the diameter and direction on the bike, start with the table and confirm a product that fits.

Item	KEMIMOTO KM065	DGYACHOR generic mirrors	SUKIRACING round mirrors	Tinotenda! M8 mirrors
M8 standard	○	○	×	○
M8 reverse	○	○	×	○
M10 standard	○	○	○	×
M10 reverse	○	○	○	×
P1.25 stated	○	Unknown	Unknown	Unknown
Left and right set	○	○	○	○

KEMIMOTO lists P1.25. For the other three, also check pitch on the product page before you buy.

Picks by situation

Even with the same screw spec, price, shape, and included parts differ.

• If you need both M8 and M10, KEMIMOTO is the pick
• If you want a cheap left-and-right set, DGYACHOR is the pick
• If you want round M10, SUKIRACING is the pick
• If you want M8 for a small bike, Tinotenda! is the pick
• If you want TANAX, NA-010 is the pick
• If you want aluminum, DAYTONA HIGHSIDER is the pick
• If the screw spec is different, use a conversion adapter

If you still do not know the spec, confirm size and thread direction on the bike first.

M10 mirrors

For M10, some products include parts for both standard and reverse thread.

• If you will also use M8, KEMIMOTO KM065
• If you want a lower price, DGYACHOR
• If you want round, SUKIRACING
• If you want TANAX, NA-010
• If you want aluminum, DAYTONA HIGHSIDER

KEMIMOTO includes M10 standard and reverse parts plus M8 parts, and it also states P1.25.

DGYACHOR is a left-and-right set with M8 and M10 adapters. It is the pick if you want to swap both sides for less money.

SUKIRACING is a round mirror that works with M10 standard and reverse. You cannot mount it on an M8 bike as-is.

TANAX NA-010 and DAYTONA HIGHSIDER are sold as one piece. You need two pieces to replace both sides.

M8 mirrors

For M8, choose an M8-only product or a product that includes M8 parts.

• If you need both M8 and M10, KEMIMOTO KM065
• If you want a cheap M8-only set, Tinotenda!
• If it includes M8 adapters, DGYACHOR

KEMIMOTO also includes two M8 standard bolts and one reverse bolt. Pitch is P1.25.

Tinotenda! is M8 only. You can choose a spec with matching standard threads, or a spec where left and right thread directions differ.

Maker tendencies

You cannot decide the screw spec from the maker name alone.

On Yamaha, some models use standard thread on the left and reverse thread on the right.

Even in the same maker, the spec changes by model and year. Confirm diameter, direction, and pitch on the actual bike.

Conversion adapters

Even if the mirror you want and the bike spec differ, some combinations can still mount with a conversion adapter.

Item	DAYTONA 99585	DAYTONA 99591	DAYTONA 99583	DAYTONA 99581
M8 standard → M10 standard	○	×	×	×
M8 reverse → M8 standard	×	○	×	×
M10 reverse → M10 standard	×	×	○	×
M10 standard → M10 reverse	×	×	×	○
Use side	Left and right	Right	Right	Left and right

If you put an M10 standard-thread mirror on an M8 standard-thread bike, DAYTONA 99585 is the pick.

If you put an M10 standard-thread mirror on an M10 reverse-thread bike, use 99583.

Checks before you buy

For a generic mirror, you do not need an OEM part-number match.

• Confirm whether the diameter is M8 or M10
• Confirm thread direction on left and right
• Confirm thread pitch
• Confirm it will not hit the cowl or other parts
• Confirm whether it is a left-and-right set or sold as one piece
• Confirm the size of the mirror surface
• Confirm the conditions needed for vehicle inspection

A part with a different diameter, direction, or pitch will not mount as-is.

If the spec is different, choose an adapter that matches the conversion you need.

Q&A

If it covers both, will it fit every bike?

It will not fit every motorcycle.

Even an M8 and M10 product may change diameter with the included adapters.

You also need standard vs reverse and pitch to match, not only diameter.

If it is 10mm, can I swap it?

Even 10mm to 10mm will not mount as-is if thread direction or pitch differs.

Some models are reverse thread on the right only, so confirm the spec on each side.

If it is inspection-ready, will it pass?

Even if the product alone meets a standard, that does not mean the bike will pass after it is installed.

Mirror size, how it is fixed, and mount position also have to meet the standard.

Same screw on left and right?

It depends on the product and the bike.

The mirror body can be the same on both sides, while the bike is reverse thread on the right only.

In that case you use a reverse-thread adapter on the right only.

Can I replace one side only?

If the product is sold as one piece, you can replace one side only.

Height, shape, and rearward view can change between left and right.

If you want the look and rearward view to match, a left-and-right set is the pick.

If you are stuck, use this

In the end, choose from the spec on the bike and the shape you want.

• If you need both M8 and M10, KEMIMOTO KM065
• If you want a cheap left-and-right set, DGYACHOR generic mirrors
• If you want round M10, SUKIRACING round mirrors
• If you want M8 for a small bike, Tinotenda! M8 mirrors
• If you want TANAX, TANAX Baren T.T. Mirror NA-010
• If you want aluminum M10, DAYTONA HIGHSIDER Victory X

If you want to cover both M8 and M10, KEMIMOTO KM065 is the pick.

If price comes first, choose DGYACHOR. If you need M8 only, choose Tinotenda!.

If the spec is different, use a DAYTONA adapter that matches the conversion.

• M8 standard → M10 standard: DAYTONA 99585
• M8 reverse → M8 standard: DAYTONA 99591
• M10 reverse → M10 standard: DAYTONA 99583
• M10 standard → M10 reverse: DAYTONA 99581

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