Mudguard sizes I’m confused

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brychan
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Mudguard sizes I’m confused

Postby brychan » 24 Dec 2017, 3:29am

Now I know what make of mudguards to get I’m confused about getting the right size.

I have a Boardman MX Sport 54cm size frame and I’m thinking of ordering a SKS Bluemels Mudguard Set but what size do I need 26 or 28 and 35mm 40mm 45mm 50mm 55mm 60mm

Am I right in thinking 26 & 28 are in relation to edge of tyre to centre and the other sizes are in relation to tyre width

Thanks

Valbrona
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Re: Mudguard sizes I’m confused

Postby Valbrona » 24 Dec 2017, 5:04am

26" = regular mountain bike wheel size
28" = 700c wheel size, like with hybrid bikes and road bikes

I believe your bike is a hybrid with 700c wheels, so you will need 28" mudguards. Expect to find 700c marked somewhere on the tyres.

The 28mm, 35mm, etc refers to the width of the mudguard. The idea is to get mudguards wide enough to accommodate the width of the tyres, ensuring that there is no chance the tyre will rub on the inside of the mudguards. Much better to have 'too wide' mudguards as opposed to 'too narrow'.

How wide are your tyres? Next to the '700c' marking on your tyres it will have the width of them in mm.

NB After fitting mudguards, everyone wishes they had gone for a different width.
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mattsccm
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Re: Mudguard sizes I’m confused

Postby mattsccm » 24 Dec 2017, 7:34am

Same as trousers. The width is how wide they are. You chose.

PH
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Re: Mudguard sizes I’m confused

Postby PH » 24 Dec 2017, 7:57am

Here you go, Spa cycles give you the info you need, shame more retailers don't
https://www.spacycles.co.uk/m2b0s80p387 ... -Mudguards

35mm for tyres 700c x 20-28mm
42mm for tyres 700c x 25-35mm
45mm for tyres 700c x 28-38mm
65mm for tyres 26" x 1.6-2.1"

I think your bike came with 32mm tyres, which will go under the 42mm or 45, I see no disadvantage from getting the 45 which gives you the option to go up a tyre size if ever you want to.

pwa
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Re: Mudguard sizes I’m confused

Postby pwa » 24 Dec 2017, 8:27am

PH wrote:Here you go, Spa cycles give you the info you need, shame more retailers don't
https://www.spacycles.co.uk/m2b0s80p387 ... -Mudguards

35mm for tyres 700c x 20-28mm
42mm for tyres 700c x 25-35mm
45mm for tyres 700c x 28-38mm
65mm for tyres 26" x 1.6-2.1"

I think your bike came with 32mm tyres, which will go under the 42mm or 45, I see no disadvantage from getting the 45 which gives you the option to go up a tyre size if ever you want to.


You will also need a hacksaw, allen keys and a small spanner (small adjustable will do fine) and set yourself at least a good hour to fit them. The stays (metal rod) are very tough stainless steel and are deliberately made too long so that you fit them, play around with the adjustments, and cut them to the right length. Once cut, you can't uncut, so of course you only cut when you are sure. I'd set the guards so that they are at least 10mm clear of the tyres, and a bit more would be good.

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robgul
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Re: Mudguard sizes I’m confused

Postby robgul » 24 Dec 2017, 9:08am

A few non-exhaustive tips for the process of fitting SKS/Bluemels* mudguards:

1 Make sure you have eyelets on the forks for the stays
2 Make sure you have clearance through the fork crown and rear brake bridge
3 Check again that you have clearance through the fork crown and rear brake bridge
4 Cut the black plastic end caps so that you just have the cap, not the "banjo" part - see below
5 Fit the stays (at their longest point) to the mudguards on the bench - BEFORE ATTEMPTING TO FIT THE MUDGUARDS TO THE BIKE - just about tightening the nuts (remember that the breakaway stays are on the front mudguard)
6a Fit the front mudguard clip to the brake caliper bolt (or through bolt on the crown for disc brakes) [You may need to find a longer bolt for thick fork crowns - or make one from a piece of stuffing and 2 aeronuts)
6b Bolt the stays to the eyelets on the dropouts [If you need clearance for a disc caliper create a "stud" as extension to keep the stay clear of the caliper]
6c Adjust the length of the stays to clear the tyres and cut off the surplus metal if necessary [a hacksaw is awkward - bolt croppers or an angle grinder make it easier] - leave approx 1 cm extra on the stay length.
6d Superglue the end caps onto the stays (see 4 above)
6e If the clip fouls the lower part of the headset fix the clip as high as you can on the bolt and then bend the upper part of the clip back over the nut until it clears the headset cup)
7 Follow a similar procedure for the rear mudguard - it's easier if you remove the wheel first especially if the bolt behind the bottom bracket is through the bridge rather than being a clip over the bridge.

From experience of fitting about 30 pairs of mudguards in the shop so far this winter points 3 (4) + 5 are the really useful points.

Rob

* arguably SKS and Bluemels (made by the same firm) are pretty much the same, just that SKS cost more!
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pwa
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Re: Mudguard sizes I’m confused

Postby pwa » 24 Dec 2017, 9:34am

robgul wrote:A few non-exhaustive tips for the process of fitting SKS/Bluemels* mudguards:

1 Make sure you have eyelets on the forks for the stays
2 Make sure you have clearance through the fork crown and rear brake bridge
3 Check again that you have clearance through the fork crown and rear brake bridge
4 Cut the black plastic end caps so that you just have the cap, not the "banjo" part - see below
5 Fit the stays (at their longest point) to the mudguards on the bench - BEFORE ATTEMPTING TO FIT THE MUDGUARDS TO THE BIKE - just about tightening the nuts (remember that the breakaway stays are on the front mudguard)
6a Fit the front mudguard clip to the brake caliper bolt (or through bolt on the crown for disc brakes) [You may need to find a longer bolt for thick fork crowns - or make one from a piece of stuffing and 2 aeronuts)
6b Bolt the stays to the eyelets on the dropouts [If you need clearance for a disc caliper create a "stud" as extension to keep the stay clear of the caliper]
6c Adjust the length of the stays to clear the tyres and cut off the surplus metal if necessary [a hacksaw is awkward - bolt croppers or an angle grinder make it easier] - leave approx 1 cm extra on the stay length.
6d Superglue the end caps onto the stays (see 4 above)
6e If the clip fouls the lower part of the headset fix the clip as high as you can on the bolt and then bend the upper part of the clip back over the nut until it clears the headset cup)
7 Follow a similar procedure for the rear mudguard - it's easier if you remove the wheel first especially if the bolt behind the bottom bracket is through the bridge rather than being a clip over the bridge.

From experience of fitting about 30 pairs of mudguards in the shop so far this winter points 3 (4) + 5 are the really useful points.

Rob

* arguably SKS and Bluemels (made by the same firm) are pretty much the same, just that SKS cost more!


It can be a fiddly job, and for someone who is not good with their hands it might be one to leave to the bike shop. But for those who like having a go it can work out quite satisfying.

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Heltor Chasca
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Re: Mudguard sizes I’m confused

Postby Heltor Chasca » 24 Dec 2017, 10:37am

All good advice upthread. It isn’t easy, but you will probably do a better job than your LBS because you have time. Their time is a loss leader on mudguard fits so they do it ASAP.

Measure thrice and cut once. I prefer bolt cutters. Some a dremmel. Some a hacksaw.

Enjoy. It’s weirdly satisfying.

brychan
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Re: Mudguard sizes I’m confused

Postby brychan » 24 Dec 2017, 1:09pm

Thanks Guys for your time & advice

These are mudguards I’ve ordered from Amazon
Image Attachments
AAFDD64E-3251-4346-8920-F901F01B885D.png
Mudguards

brychan
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Re: Mudguard sizes I’m confused

Postby brychan » 24 Dec 2017, 3:55pm

brychan wrote:Thanks Guys for your time & advice

These are mudguards I’ve ordered from Amazon


I’ve now cancelled this order I don’t think they will fit on the front fork

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robgul
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Re: Mudguard sizes I’m confused

Postby robgul » 24 Dec 2017, 4:04pm

brychan wrote:
brychan wrote:Thanks Guys for your time & advice

These are mudguards I’ve ordered from Amazon


I’ve now cancelled this order I don’t think they will fit on the front fork


Yep - I had one of these bikes in (not for mudguards) and it's probably only realistic to fit a guard on the downtube and a tail guard clamped to the seatpost - that said IMHO you're wasting your time and money as both would be pretty useless to stop mud and spray.

Rob
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Cyril Haearn
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Re: Mudguard sizes I’m confused

Postby Cyril Haearn » 24 Dec 2017, 4:22pm

It seems awfully complicated just to fit them :wink:
Remember the safety releases on the front, I have them on the back too to make more space
Go to your LBS or H**f***s and just look at mudguards, stays, fittings, or look at the bikes parked at the station, best to invest a bit of time doing that before ordering
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pwa
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Re: Mudguard sizes I’m confused

Postby pwa » 24 Dec 2017, 4:31pm

The problem seems to be around the disc brakes getting in the way on the front, which makes it awkward to get around the lack of mudguard eyes at the base of the fork legs. And the rear has no bridge between the seat stays. It's like the manufacturers have bent over backwards to make sure you get a muddy stripe up your back.

I'm sure I could bodge them on one way or another, but it would involve a bit of head scratching and a lot of rummaging though a box of nuts and bolts. It might have very little to do with the instructions on the packet.

Debs
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Re: Mudguard sizes I’m confused

Postby Debs » 24 Dec 2017, 5:26pm

I recently fitted SKS Bluemels [matt black edition] 35mm to my Trek Domane SL8

Fortunately for a sporty CF bike the Domane has neatly hidden screw holes for optional adapters mudguard eyes which i've utilised into service, after fitting the 35mm Bluemels i wasn't entirely happy with the close clearance; especially where the aluminium stay brackets are riveted under the guards which come close to the sides of the 700x28mm tyres, however the guards do present a nice slim streamlined appearance and i think would work in practise.

But being the fusspot i took them off, ordered up the same again Bluemels matt black edition again but this time in 45mm size, and this time bags of clearance, they present a functional practical look that i think will suit the job better.

The difference between 35mm and 45mm:
Image

Trek provide a small 90 degree bent metal bracket to locate under one of the disc brake mount screws and to give just enough clearance to get around the disc calliper. The position in the picture below is provisional, just needs a bit more fettling will get it neater :D

Image
Last edited by Debs on 26 Dec 2017, 7:52pm, edited 1 time in total.

Brucey
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Re: Mudguard sizes I’m confused

Postby Brucey » 24 Dec 2017, 6:35pm

brychan wrote:
brychan wrote:Thanks Guys for your time & advice

These are mudguards I’ve ordered from Amazon


I’ve now cancelled this order I don’t think they will fit on the front fork


IIRC on current suntour forks there are mountings about 1/3rd of the way up the fork leg for mudguards. You need an angle bracket to fit them

Image

https://www.sjscycles.co.uk/mudguards/sks-front-wheel-stay-kit-suntour-forks/

or

https://www.sjscycles.co.uk/mudguards/sks-suntour-angle-bracket/

At the rear some 'p' clips and a little adaptation will allow a mount onto the seat stays even if there is no bridge.

I did an image search for 'Boardman MX sport' and only a few images had any mudguards in them and they were nearly all various miserable clip-on affairs.

Boardman should feel a bit ashamed of themselves IMHO; a UK bike brand designing bikes that are so awkward to fit mudguards to, is ridiculous.

BTW I would probably buy 35mm mudguards for your bike.

cheers
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